Ultrasound Elastography and MicroPure Imaging in the Differentiation of Benign and Malignant Thyroid Nodules

The Utility of Ultrasound Elastography and MicroPure Imaging in the Differentiation of Benign and Malignant Thyroid Nodules,  Nazan çiledag, Kemal Arda, Bilgin Kadri Arıbas, Elif Aktas and Serdal Kenan Köse, AJR: 198, March 2012


Abstract

OBJECTIVE. The aim of this study was to evaluate the utility of ultrasound elastography and MicroPure imaging in the differential diagnosis of benign and malignant thyroid nodules.

SUBJECTS AND METHODS. A total of 74 consecutive patients (65 women and nine men; age range, 21–80 years; mean [± SD] age, 51 ± 12.7 years) with thyroid nodules, who were referred for fine-needle aspiration biopsy by endocrinology or general surgery clinics, were prospectively examined using B-mode ultrasound, ultrasound elastography, and MicroPure imaging. The strain value ratio (strain index) of thyroid nodules was calculated. Patients with malignant or intermediate fine-needle aspiration biopsy results underwent thyroid surgery.

RESULTS. Using MicroPure imaging, 17 of 65 benign thyroid nodules (26.6%) and three of nine malignant thyroid nodules (33.3%) were found to contain microcalcifications. The sensitivity, specificity, negative predictive value, positive predictive value, and the accuracy rate of MicroPure imaging were 42.9%, 80.6%, 93.1%, 18.8%, and 77%, respectively. By using receiver operating characteristic analysis, the best cutoff point (2.31) was computed (area under the curve, 0.87; p < 0.001). The sensitivity, specificity, negative predictive value, positive predictive value and accuracy rate of the strain index values were 85.7%, 82.1%, 98.2%, 33.3%, and 82.4%, respectively, when the best cutoff point of 2.31 was used (p = 0.001). The p value (x = malign) was 0.96 for a strain index value higher than 2.31.

CONCLUSION. This preliminary study indicated that ultrasound elastography and MicroPure imaging can be used for the differentiation of benign and malignant thyroid nodules.

Thyroid nodules are a common finding in the general population, especially in geographic areas of iodine deficiency. Over 95% of thyroid nodules are benign and less than 5% are malignant [1]. Ultrasound is a noninvasive and easily available imaging technique for the evaluation of thyroid nodules. Many studies have reported the utility of ultrasound for the differentiation of benign and malignant thyroid nodules [1–5]. The presence of calcification, hypoechogenicity, irregular margins, absence of a halo, and predominant solid composition in the sonographic image are the key features associated with an increased risk of malignancy. However, the sensitivity, specificity, and negative and positive predictive values for these features are highly variable across patients and across different machines, and no single sonographic feature can diagnose thyroid cancer with high sensitivity and high positive predictive value [1–5].

Fine-needle aspiration biopsy of thyroid lesion is the preoperative screening method of choice worldwide, because it distinguishes benign and malignant lesions with high accuracy [6–8]. Because of its simplicity, low cost, and absence of major complications, it is the initial investigative technique in the management of thyroid diseases [6–8].

Real-time sonographic elastography is a newly developed dynamic imaging technique that displays tissue elasticity by measuring the degree of distortion under the application of an external force. Like palpation, sonographic elastography uses tissue deformation or strain that is caused by external compression and is based on the precompression and compression. Ultrasonographic elastography has been used to examine such organs as the breast [9, 10], thyroid [11], prostate [12], cervix [13], and liver [14]. This technique is a promising imaging technique that can be used for the differentiation of benign and malignant thyroid nodules. However, to our knowledge, only a limited number of studies have described the application of real-time sonographic elastography on benign and malignant thyroid nodules [15].

The MicroPure imaging algorithm (Toshiba) is an adapted filter that is used to enhance bright echoes to visualize and show calcifications, particularly microcalcifications. The purpose of this study was to evaluate the utility of ultrasound elastography and MicroPure imaging in differentiating benign and malignant thyroid nodules.

Subjects and Methods

This prospective study was approved by the Ankara Oncology Research and Education Hospital review board. Written informed consent was obtained from all patients undergoing both real-time ultrasound elastography and MicroPure imaging.

From February 2010 to April 2010, 74 consecutive patients (65 women and nine men; age range, 21–80 years; mean [± SD] age, 51 ± 12.7 years) with incompletely diagnosed thyroid nodules referred for fine-needle aspiration biopsy by endocrinology or general surgery clinics were examined prospectively. Patients with nodules larger than 40 mm, purely cystic or anechoic nodules without solid components, and shell-calcified nodules that could cause color-coding problems were excluded from the study.

All patients were examined by using gray-scale ultrasound, MicroPure imaging, and real-time sonographic elastography with a 10-MHz linear transducer (Aplio, Toshiba) during the same examination by the same operator. In sonographic elastography, the deflections occurring before and after tissue compression were calculated semiquantitatively via the shear modulus (Young modulus) and were displayed graphically in the elastogram.

The gray-scale sonography and elastography in all patients was performed by the same radiologist to prevent differences among operators and to standardize the degree of nodule pressure. All interpretations were performed before biopsy by the same operator, and the radiologist was blinded to the final diagnosis of the patients.

The sonographic examinations were performed in two steps. Gray-scale sonography and MicroPure imaging were performed for all patients in the first step, and real-time sonographic elastography was performed in the second step using the same probe during the same examination. B-mode ultrasound was performed first, then in the second step MicroPure imaging was performed, and the third step was real-time sonographic elastography.

For real-time sonographic elastography, compression was performed repeatedly in a vertical direction with light pressure and was followed by decompression. The strain value ratio (strain index) of thyroid nodule to muscle was calculated. Acquiring measurements at the same depth of the nodule and adjacent muscle was a critical issue for strain ratio calculations. Color coding of elastographic images was classified into five groups according to the Ueno classification [9]. A score of 1 indicated strain for the entire lesion (i.e., the entire lesion was evenly shaded in green) (Fig. 1); a score of 2 indicated strain in most of the lesion with some areas of no strain (i.e., a mosaic pattern of green and blue) (Fig. 2); a score of 3 indicated strain at the periphery of the lesion, with sparing of the center of the lesion (i.e., the peripheral part of the lesion was green, and the central part was blue) (Fig. 3); a score of 4 indicated no strain in the entire lesion (i.e., the entire lesion was blue, but its surrounding area was not included) (Fig. 4); and a score of 5 indicated no strain in the entire lesion or in the surrounding area (i.e., both the entire lesion and its surrounding area were blue) (Fig. 5).

Fig. 1: 56-year-old woman. Elastogram of benign thyroid nodule revealed elastographic color score of 1.

All of the patients underwent fine-needle aspiration biopsy under ultrasound guidance within 5 days of the real-time sonographic elastographic evaluation. A 21-gauge needle was used with an attached 20-mL syringe for fine-needle aspiration biopsies. The procedure was repeated one or two times. The collected material was placed onto glass slides, smeared, and equally fixed in air and 95% ethyl alcohol. Air-dried slides were stained with May-Grünwald-Giemsa stain; alcohol-fixed slides were stained using Papanicolaou method and H and E stain. The cytologic diagnoses of the thyroid nodules were compared with real-time sonographic elastography and the MicroPure imaging features. Nine patients with malignant nodules and eight patients with benign nodules in whom the diagnosis was achieved by cytologic examination underwent surgery, and the pathologic diagnoses were confirmed. Cytologically, 57 benign nodules were monitored by ultrasound for 12 months, and repeated biopsies were performed.

For the statistical analysis, quantitative variables were compared using Student t test for independent samples test, and qualitative variables were compared using the chi-square test. To determine the best of cutoff point for strain index, the receiver operating characteristic analysis was used. The quantitative data are presented as mean (± SD). A p value less than 0.05 indicated statistical significance with a 95% confidence level. All statistical analyses were performed using the SPSS packet program (version 11.5, SPSS).

Results

Seventy-four patients (age range, 21–80 years; mean age, 51 ± 12.7 years), including 65 women (age range, 21–80 years; mean age, 49.9 ± 12.3 years) and nine men (age range, 37–78 years; mean age, 58.2 ± 13.2 years), were enrolled in the study (Table 1). The maximum diameters of the evaluated thyroid nodules were 7–36 mm (mean, 17.2 ± 7.2 mm) (Table 1). Table 1 and Table 2 show the features of the patients and the benign and malignant nodules, respectively.

At ultrasound examination, 74 nodules were identified. Among 74 nodules, 56 nodules (75.7%) were solid, and 18 nodules (24.3%) were heterogeneous with cystic degeneration. Thirty-two nodules (43.2%) were hypoechoic, eight nodules (10.8%) were isoechoic, six nodules (8.1%) were hyperechoic, and 10 nodules (13.5%) were hypoechoic. Regular margins were observed in 60 nodules (81.08%), and irregular margins were seen in 14 nodules (18.9%). Calcifications were found in 17 of 65 benign nodules (26.6%) and in three of nine (33.3%) malignant nodules (Table 2). There was no statistically significant difference (p > 0.05).

Fig. 2: 32-year-old man. Elastogram of benign thyroid nodule showed elastographic color score of 2.

Fig. 3 : 48-year-old man. Elastogram of benign thyroid nodule showed elastographic color score of 3.

Fig. 4 : 56-year-old woman. Elastogram of thyroid nodule revealed elastographic color score of 4. Final diagnosis was papillary carcinoma.

Fig. 5 :
65-year-old woman. Elastogram of thyroid nodule with elastographic color score of 5. Final diagnosis was papillary carcinoma.

Fig. 6: 58-year-old woman. MicroPure (Toshiba) image of thyroid nodule showing microcalcifications. After fine-needle aspiration biopsy, diagnosis in this case was papillary carcinoma.

Fig. 7: 45-year-old woman. Elastogram showed thyroid nodule in right isthmic portion with elasticity index of 5.44, with color score of 4. After fine-needle aspiration biopsy, final diagnosis was papillary carcinoma.

Using MicroPure imaging, 17 of 65 (26.6%) benign thyroid nodules and three of nine (33.3%) malignant thyroid nodules revealed microcalcifications (Fig. 6). The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy rate of MicroPure imaging was 42.9%, 80.6%, 93.1%, 18.8%, and 77%, respectively.

TABLE 1: Demographic Features of Patients Included in This Study

TABLE 2 : Characteristics of Benign and Malignant Nodules

Color coding of elastographic images was classified into five groups according to the Ueno classification [9]; of the 65 benign nodules, 41 nodules (63%) had a score of 1 or 2 (15 nodules had a score of 1, and 26 nodules had a score of 2). Of the nine malignant nodules, eight (88.8%) had a score of 4 or 5 (four nodules had a score of 4, and four nodules had a score of 5). Of the 65 benign nodules, 21 (32.3%) nodules had a score of 3. Only one of the malignant lesions (11.1%) had a color score of 3, and none of the malignant nodules had a color score of 1 or 2. Of the 65 benign nodules, two (3.0%) had a color score of 4 and one (1.5%) had a color score of 5. The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy rate of strain index values were 85.7%, 82.1%, 98.2%, 33.3%, and 82.4%, respectively, when the best cutoff point of 2.31 was used (area under the curve, 0.87; p < 0.001) (Figs. 7 and 8). The p value (x = malign) was 0.96 for strain index values higher than 2.31.

Fig. 8: Results of receiver operating characteristic analysis for strain index. Diagonal segments are produced by ties. With cutoff value of 2.31, area under the curve is 0.87 ± 0.05, asymptotic 95% CI is 0.774– 0.970, and asymptotic significance level is 0.001.

Discussion

Palpation, which is one of the oldest clinical skills, provides information about the stiffness of soft tissues using external compression for physical deformation of the tissue. However, palpation is a subjective examination technique. Elasticity measurements and stiffness evaluations of soft tissues are useful in the differential diagnosis of tumor, inflammation, and normal tissue. It is generally accepted that benign soft-tissue lesions are firmer than normal tissue but softer than cancers [16–19].

Until now, the stiffness of thyroid nodules has not been an objective indicator of malignancy, although it is an important factor in the differential diagnosis of malignant nodules [16]. Although fine-needle aspiration biopsy is the best method for this purpose, it suffers the limitations of being invasive, and sampling errors are inevitable [19]. A recently developed promising imaging technique called real-time sonographic elastography reveals the physical properties of soft tissue by characterizing the difference in elasticity between the region of interest and the surrounding normal soft tissue using manual compression and deformation of the tissue. Essentially, sonographic elastography is based on the combined visualization of tissue elasticity (strain) and the velocity at which the tissue deformation occurs [20]. The degree of deformation of the soft tissue is calculated and combined with a gray-scale ultrasound image as an elastography map for the evaluation of tissue stiffness after ultrasound examination. Therefore, no extra time is needed to perform sonographic elastography.

Some of the major advantages of realtime sonographic elastography are its ease of performance, its noninvasiveness, and its suitability of use during routine ultrasound examinations. In addition, this imaging technique facilitates the dynamic visualization of lesions during compression.

Lyshchik et al. [11] prospectively evaluated the sensitivity and specificity of sonographic elastography for differentiating benign and malignant tumors of the thyroid gland. They reported that thyroid lesions, such as cysts and benign and malignant nodules, exhibit different elastographic characteristics. Cysts appear as dark lesions on elastograms, whereas solid nodular lesions are stiffer than thyroid gland tissue, and malignant lesions are significantly stiffer than benign thyroid nodules. Lyshchik et al. [11] have suggested that a strain index value greater than four is the strongest independent predictor of thyroid gland malignancy (p < 0.001) and exhibits 96% specificity and 82% sensitivity.

Kagoya et al. [19] set a strain ratio or strain index value greater than 1.5 as a predictor of thyroid malignancy. This criterion exhibits 90% sensitivity and 50% specificity. In our study, the sensitivity, specificity, and accuracy rates of the strain index values were 85.7%, 82.1%, and 82.4%, respectively, when the best cutoff point of 2.31 was used.

Dighe et al. [21] studied the differential diagnoses of thyroid nodules with ultrasound elastography using carotid artery pulsation as a compression source combined with limited external compression. They found no correlation between blood pressure and the final diagnoses. In another study, Dighe et al. [22] reported that the utility of sonographic elastography performed using carotid artery pulsation as a compression source to measure the systolic thyroid stiffness index has the potential to substantially reduce the number of fine-needle aspiration biopsies by detecting benign nodules. Although carotid artery pulsation has been used in those studies as the compression source for thyroid elastography, it has also been reported that arterial pulsations may generate compressiondecompression movements that may create interfering elastographic images with unnecessary thyroid movement and it is difficult to restrict thyroid movement [15]. Hence, in the present study, carotid artery pulsation was not used as a compression source.

Microcalcifications are also characteristic findings of malignant nodules [15]. Mixed calcifications are defined by the presence of microand macrocalcifications, and some recent studies have reported that the presence of mixed calcifications suggests an increased potential for malignancy [15]. In addition, calcification is a highly concordant finding in the evaluation by radiologists [15]. The MicroPure imaging algorithm (Toshiba) is a recently developed imaging technique that aids in the detection of the calcifications by enhancing the superficial structures.

Kurita et al. [23] evaluated the usefulness of MicroPure imaging in measuring the microcalcifications in breast lesions. They reported that MicroPure imaging improved the visualization of microcalcifications and suggested that this imaging algorithm is a clinically useful easy imaging technique in the diagnoses of microcalcifications.

Sankaye et al. [24] examined 25 women through breast sonography, and 11 breast malignancies were diagnosed. Four (16%) (three malignant and one benign) calcifications were visualized through ultrasound. All calcifications were detectable using both B-mode and MicroPure imaging. The authors suggested that all four calcifications appeared more subjectively conspicuous using MicroPure imaging than in the B-mode imaging. In our study, 17 (26.6%) of 65 benign thyroid nodules and three (33.3%) of nine malignant thyroid nodules showed microcalcifications by MicroPure imaging.

Fine-needle aspiration biopsy of thyroid nodule is widely accepted as the most accurate, sensitive, specific, and cost-effective diagnostic procedure in the preoperative assessment of thyroid nodules, with low rates of false-positive (2.3%), false-negative (0.2%), and inadequate results [6, 7]. The accuracy of the fine-needle aspiration biopsy analysis approaches 95% in the differentiation of the benign nodules from the malignant nodules of the thyroid gland [6–8]. The use of ultrasound guidance improves the diagnostic yield [8]. Organizations such as the American Thyroid Association and the American Association of Clinical Endocrinologists suggest that the original cytologic diagnosis can be accepted until the nodule grows or changes in appearance [8]. Instead of routine repeated fine-needle aspiration biopsy, several researchers recommended the use of both repeated fine-needle aspiration biopsy and clinical follow-up together [8]. Because fine-needle aspiration biopsy is used as the reference standard in the present study, limitations of fine-needle aspiration biopsy of thyroid nodule also become limitations of this study. In this study, to eliminate false-positive results, nine patients with cytologic malignancies underwent surgery, and their pathologic diagnoses were confirmed. Also, eight cytologically benign nodules were surgically removed and their pathologic diagnoses were confirmed. To reduce the false-negative results, 57 cytologic benign nodules were monitored clinically and by ultrasound for 12 months, and repeat biopsies were performed.

There are some limitations to this study. First, nodules larger than 40 mm are difficult to evaluate accurately because of the difficulties in measuring thyroid nodule elasticity. Practically, a large size can be a limitation in the nodule-to-gland or nodule-to-muscle strain index described in literature [19]. However, in our study, no single nodule was larger than 40 mm. Pure cystic anechoic nodules without solid components and shell-calcified nodules may cause some measurement problems as well, because of posterior shadow or posterior enhancement artifacts of ultrasound imaging. However, we avoided pure cystic, anechoic, and shell-calcified nodules. During sonographic elastography of the thyroid, it is important to maintain a light pressure on the probe because strong pressure may lead to a misdiagnosis [15]. In addition, carotid pulsation is another restriction in the strain index that may have a negative effect on our study; however, the radiologists were experienced in this specific area. MicroPure imaging is a novel and useful method for the detection of especially suspicious microcalcifications, but more experience is needed to evaluate the utility of MicroPure imaging in the diagnoses of microcalcifications.

In conclusion, elastography is a promising imaging technique that can assist in the differential diagnosis of malignant and benign thyroid nodules. The combination of real-time sonographic elastography, MicroPure imaging techniques, and B-mode sonography may be helpful for the improvement of the differential diagnosis of thyroid malignancies.

Received February 26, 2011.

Revision received July 20, 2011.

© American Roentgen Ray Society

Papillary Carcinoma từ mô giáp lạc chỗ trong tủy sống

Xin giới thiệu một tạp chí nội tiết mới của Asean. Đó là tạp chí JAFES (Journal of the ASEAN Federation of Endocrine Societies). Website là http://asean-endocrinejournal.org/. Tạp chí này mới được thành lập và tuyên bố từ hôm Hội nghị AFES 16 ở TP Hồ Chí Minh tháng 11-2011 vừa qua.

Bài về mô tuyến giáp lạc chỗ ung thư hoá sau được trích từ tạp chí nội tiết học trên: JAFES, Vol 26 n0 2, November, 2011.

Introduction

Thyroid tissue in an ectopic location is rare, occurring in 1 out of 100,000 to 300,000 persons; and is usually found in the lateral neck. Ectopic thyroid tissue developing axially is even more rare, with up to 90% of cases being lingual thyroid tissue arising embryologically from a median anlage from the pharyngeal floor. Very rarely, ectopic thyroid tissue may give rise to a carcinoma.

Carcinogenesis of ectopic thyroid tissue located in midline structures such as lingual thyroid and thyroglossal duct cysts, have a reported incidence of approximately 1%, and usually occurs during the third decade of life. Almost all cases are diagnosed post-surgically on histopathologic examination. Management of these cases is individualized.


Presentation

A 12-year old girl developed progressive bilateral lower extremity weakness and sensory deficit, difficulty in ambulation, and bowel and bladder incontinence in 2004.

She had no known exposure to ionizing radiation. Maternal and early pediatric histories were unremarkable. She had no family history of malignancy and thyroid disease. Physical examination revealed a lean build; with vital signs, height and weight appropriate for age. The thyroid gland was not enlarged. Chest and abdominal examination were unremarkable. She had full and equal pulses without peripheral edema. Neuromuscular examination revealed decreased manual muscle strength on the lower extremities, hypoesthesia from T4 dermatomal level and hyperreflexia on both lower extremities. Magnetic resonance imaging (MRI) of the thoracolumbar spine revealed a well-defined enhancing nodule in the spinal cord at the level of T3-T4. The nodule measured 1.16 cm x 1.26 cm x 1.58 cm, with intermediate signal intensity in both T1- and T2-weighted studies, with associated edema above and below the lesion from level T2 down to T8-T9 (Figure 1).

She underwent a T3-T4 laminectomy with tumor excision 3 months after initial consult (January 2005). Histopathologic exam revealed a 3.0 cm x 1.5 cm x 0.8 cm mass, microscopically composed of bland cuboidal cells with uniform ovoid nuclei and adequate amphophilic cytoplasm arranged in pseudorosettes, with some cells exhibiting pale-staining to grayish cytoplasm and rare mitotic figures (Figure 2).

Immunohistochemical staining for cytokeratin and neuron-specific enolase were positive. Ependymoma was considered in the histopathologic report of the excised mass. Two months postoperatively, the patient had gradual improvement of lower extremity weakness and was able to ambulate by herself. She was then lost to follow up.

However, in March 2009, the patient developed gradual progressive weakness of both lower extremities, leading to paralysis. A repeat MRI of the thoracic spine showed an avidly enhancing intramedullary nodule at T3-T4 level, appearing bilobed with irregular margins, measuring 1.13 cm x 1.65 cm x 1.63 cm. The nodule was slightly hyperintense in T1-weighted study (Figure 3) and hypointense on T2-weighted imaging, with some extension to the neural canal at the level of T3-T4.

A second laminectomy with tumor excision was done in May 2009. Histopathologic examination of the excised 2 cm x 1.5 cm x 0.5 cm mass revealed colloid material within the lumen of follicles or ducts (Figure 4) with papillary architecture and nuclear features consistent with papillary carcinoma. These findings were not seen in the histopathologic examination of the first surgical specimen.

Microscopic sections from the second surgical specimen stained positively for thyroglobulin, thyroid transcription factor-1 (TTF-1) and epithelial membrane antigen (EMA) (Figures 5 to 7). The pathologic diagnosis of papillary carcinoma, suggestive of a thyroid primary, supersedes the previous histopathologic diagnosis. Thyroid ultrasound was normal. Thyroid function testing was also normal: thyroid stimulating hormone (TSH) was 1.03 µIU/mL (normal value 0.35 to 4.94), total thyroxine was 9 µg/dL (normal value 4.9 to 11.7), and total triiodothyronine was 1.24 ng/mL (normal value 0.58 to 1.59). Metastatic workup including CT scans of the neck, chest and abdomen did not reveal any metastatic foci.

Papillary carcinoma of the thyroid with spinal cord metastasis was the foremost consideration. A total thyroidectomy was performed in July 2009, to confirm occult primary thyroid cancer and to facilitate ablation of residual thyroid tissue for subsequent surveillance for recurrence using radioactive iodine. Histopathologic examination of the thyroid gland revealed nodular hyperplasia after thorough sampling of the entire specimen. Two months after total thyroidectomy, whole body scan using 2 mCi Iodine-131 revealed functioning thyroid remnants in the anterior neck without undue tracer deposition seen elsewhere. Her postoperative stimulated thyroglobulin level was less than 2 ng/mL. She was placed on daily levothyroxine suppressive doses with regular monitoring of thyroid function tests and thyroglobulin level. Radioactive iodine ablation was not indicated since there was no evidence of remaining iodine-avid lesions in the spinal cord. She was placed on physical therapy and rehabilitation program after spinal surgery and thyroidectomy. The patient, now 19 years of age, remains paraplegic, with no evidence of active malignancy both clinically and on imaging studies, two years since her last surgery. Thyrotropin levels are adequately suppressed and serial results of thyroglobulin levels are undetectable.

Discussion
Thyroid tissue that is located elsewhere from its expected location anterior to the second to fourth tracheal cartilages is ectopic. Embryologically, the thyroid gland develops from a median anlage and a pair of lateral anlages. The embryologic pharyngeal floor gives rise to the median anlage, whereas the fourth and fifth branchial pouches give rise to the lateral anlage. Its descent follows the heart and great vessels and moves caudally from its origin to its location in the neck in front of the trachea. Aberrant caudal descent of the median anlage during development may give rise to an intrathoracic location of ectopic thyroid tissue. There have been reports of ectopic thyroid tissue occurring in the right ventricle of the heart, aberrant right carotid thyroid tissue, carotid bifurcation, lingual ectopic thyroid, intrathoracic ectopic thyroid, substernal goiter, intralaryngotracheal thyroid and spinal cord. Carcinomas arising from ectopic thyroid tissue are uncommon. They have been reported to arise from thyroid tissue in thyroglossal duct cysts, lateral aberrant thyroid tissue, lingual thyroid and mediastinal and struma ovarii. Most tumors in the ectopic locations have been papillary carcinomas, mixed follicular and papillary carcinomas or Hürthle cell tumors. However, a carcinoma arising from spinal ectopic thyroid tissue has never been reported in literature.


Differentiating between a metastatic thyroid carcinoma and malignant transformation of an ectopic thyroid tissue is difficult and can only be done after surgery, as in this case. There are no clinical, biochemical, or imaging parameters that may assist in determining the nature of the lesion; and histological examination is always required for definitive diagnosis. True ectopic thyroid tissue has an arterial supply independent of the cervical arteries that supply the thyroid; the cervical thyroid gland is normal or absent with no history of surgery; the cervical thyroid gland does not have a similar pathologic process as the ectopic tumor, and there is no history or evidence of thyroid malignancy. Although a metastatic papillary thyroid cancer was initially considered, the migration of papillary carcinoma from a primary thyroid to distant sites bypassing cervical lymph nodes is unusual. Also, a review of the post-thyroidectomy histopathology did not reveal malignancy in the thyroid, leading us to conclude that the tumor excised from the patient’s spinal cord was ectopic thyroid tissue that transformed into papillary carcinoma. The postoperative whole body scan that was negative for iodine avid lesions outside the thyroid bed may reflect either complete resection of tumor in the spinal cord or poor iodine avidity. She did not receive high dose radioiodine ablation, and was given a suppressive levothyroxine dose at 100 mcg daily to prevent recurrence.

Conclusion

Metastasis from a primary thyroid carcinoma must first be ruled out before considering malignant transformation of an ectopic thyroid tissue, which is a rare occurrence. There are no clinical, biochemical, or imaging parameters that may assist in determining the nature of these lesions, and histological exam is required for definitive diagnosis.

Surgical excision is the treatment of choice. Post-surgical management includes thyrotropin suppression to prevent recurrence. Radioiodine ablation was not thought to be necessary in this case, as there was no evidence of remaining iodine-avid lesions in the spinal cord.
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ECTOPIC THYROID in MEDIC CENTER, HCMC, Vietnam

CASE 1
Ectopic Lingual Thyroid, Le van Tai, Nguyen Thien Hung, Medic Medical Center, HCMC, Vietnam

We report the case of a 36 year-old female patient who presents with symptoms of dysphonia (hot potato speech) due to abnormal mass at the base of the tongue. Ultrasound detects no thyroid gland at the normal site. At the base of the tongue, there is an hypoechoic mass without hypervascularity on color Doppler, which is suspected for ectopic thyroid tissue. Then Tc99m sodium pertechnetate scanning shows thyroid tissue at the base of tongue and there is no thyroid tissue in the normal location.


CASE 2:

2 Focal Ectopic Thyroid, Jasmine Thanh Xuan, Ng Thien Hung, Phan Thanh Son, Medic Medical Center

A 50 yo female patient was detected randomly with a small nodule at the base of her tongue per ENT endoscopy. This nodule does not appear on neck ultrasound but an another mass was found at hyoid region by ultrasound: solid, echo poor, well vascularization, and no thyroid gland detected at the normal site. At last, on MDCT 64, the 2 ectopic thyroid focals were revealed, one at the base of the tongue and the other, at thyrohyoid membrane.

SIÊU ÂM ĐIỀU TRỊ RUN / nucleus ventralis intermedius of thalamus

Nhân bụng trung gian của đồi thị=nhận nhiều phần các bó chiếu để phân biệt từ bán cầu tiểu não đối bên (qua cuống tiểu não trên) và cầu nhạt cùng bên; hầu như toàn bộ các nhân chiếu của vỏ não vận động.
Nhân bụng trung gian của đồi thị là mục tiêu của thủ thuật xác định trong không gian chuyên biệt để điều trị chứng run, ngoài cách dùng thuốc, như deep brain stimulation, conventional thalamotomy, và gamma knife thalamotomy.

MRI hướng dẫn siêu âm tập trung điều trị (dùng cho u não trước đây) chứng run là cách điều trị mới hơn hẵn gamma knife thalamotomy vì an toàn hơn (không tia xạ).

Siêu âm được tập trung vào nhân bụng trung gian của đồi thị. Để xác định mục tiêu đích, bệnh nhân phải vẽ những vòng xoắn. Bệnh nhân nam đầu tiên 74 tuổi bị run tay P 10 năm, không thể viết được tên mình. Khi bác sĩ chạm đúng target, tay bệnh nhân giảm run, và những vòng xoắn  được vẽ đẹp hơn. Lúc bấy giờ cường độ được tăng lên với hàng ngàn chùm siêu âm hội tụ lại để đốt huỷ mô bệnh là những tế bào gây run, gọi là tạo tổn thương. Tổn thương của bệnh nhân này chỉ có 4mm đường kính.

Máy sử dụng có tên ExAblate Neuro của InSightec Ltd, cung cấp năng lượng siêu âm tập trung để huỷ mô đích, và quá trình huỷ bằng nhiệt này được theo dõi bằng MRI.

Còn trong phòng hồi sức, bệnh nhân đã có thể cầm ly nước bằng tay P mà không đổ vãi. Sau 1 tháng tay bệnh nhân không bị tái phát run.

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nucleus ventralis intermedius of thalamus= the composite middle third of the ventral nucleus receiving in its various parts distinctive projections from the contralateral half of the cerebellum (by way of the superior cerebellar peduncle) and the ipsilateral globus pallidus; nearly all parts of the nucleus project to the motor cortex.

Nucleus ventralis intermedius thalami, the relay of cerebellar afferences, is the target of stereotactians particularly for the improvement of tremor.

Focused Deep Brain Ultrasonography Promising for Essential Tremor (ET)

Megan Brooks, March 30, 2011

Magnetic resonance (MR)–guided focused ultrasonography has been successfully used to relieve a 74-year-old man's debilitating essential tremor (ET) affecting his dominant right hand.

Uncontrollable shaking left the patient unable to use his right hand for more than a decade. After MR-guided focused ultrasonography, "the tremor was gone," W. Jeffrey Elias, MD, a neurosurgeon at the University of Virginia (UVA) in Charlottesville, noted in an interview with Medscape Medical News. "In the recovery room, he used his right hand to drink from a cup without spilling," Dr. Elias added in a UVA-issued statement. The patient has now been followed up for 1 month and he "continues to do well," Dr. Elias said. His tremor has not returned.

The ultrasonography is focused on the ventralis intermedius nucleus of the thalamus. "This is a standard trimmer target; whether we use radiofrequency thalamotomy or thalamic deep brain stimulation, we target a similar place," Dr. Elias explained.

To find their target, the team had the patient draw spirals during the procedure. At first, his hand shook violently, but as the researchers honed in on their target, the shaking subsided and his spirals became smooth. At that point, they increased the sound waves to heat and destroy the tissue, a process called "lesioning," Dr. Elias said. This particular patient's lesion was 4 mm in diameter.

This therapy is delivered with the ExAblate Neuro system from InSightec Ltd. The device delivers focused ultrasound energy to the targeted site, and the thermal destruction is monitored in real time with MR imaging (MRI).

Currently available treatments for ET outside drug therapy include deep brain stimulation, conventional thalamotomy, and gamma knife thalamotomy.
An "advantage of this new procedure [previously used to treat brain tumors] compared to gamma knife is that there is no radiation involved and thus it seems to be a safer procedure," Dr. Moro said.
"It might be superior to gamma knife thalamotomy and thus be a good treatment for tremor patients who cannot have deep brain stimulation or do not want to have an invasive treatment," she added. Only time will tell. 

"By demonstrating that MR-guided focused ultrasound can safely and effectively treat tissue deep in the brain with great precision and accuracy, we will open the door for treating a variety of conditions, such as Parkinson's disease, brain tumors, and epilepsy.

SIÊU ÂM CHẨN ĐOÁN LOẠN SẢN KHỚP HÔNG CHẮC CHẮN LÚC 6 THÁNG TUỔI

Tại Việt nam, siêu âm tham gia khám khớp hông cho trẻ sơ sinh từ 1-2 ngày tuổi từ sau kết quả một tầm soát ở 811 trẻ tại thành phố Hồ Chí Minh của Trung tâm Y khoa Medic (1998) được công bố. Tuy nhiên số bệnh nhi sau 6 tháng tuổi được khám siêu âm không nhiều, có thể bác sĩ lâm sàng quen với hình ảnh X-quang khung chậu, vì điểm cốt hóa đã cản quang rõ trên phim.

Bài trên có ý nói siêu âm khớp hông ở trẻ 6 tháng tuổi có giá trị không thua kém X-quang, lại có lợi thế là không có tia xạ gây hại cho trẻ. Nên dùng siêu âm khớp hông thay thế cho X-quang ở trẻ trên 6 tháng tuổi.

Xem SIÊU ÂM PHÁT HIỆN TRẬT KHỚP HÔNG

Download  DEVELOPMENTAL DYSPLASIA of the HIP and ULTRASOUND



A”Twinkling Artifact” Targets Kidney Stones for Lithotrypsy Treatment

http://www.apl.washington.edu/projects/twinkling_artifact/experiments_modeling.html

Trong bài sau, các tác giả, Dr. Lawrence Crum và Dr. Michael Bailey ở Applied Physics Laboratory tại  University of Washington (APL-UW; Seattle, USA), với kết quả mô hình hoá tác động siêu âm Doppler trên sỏi thận, cho rằng  lực bức xạ âm (acoustic radiation force, ARF) là một trong những yếu tố của cơ chế tạo ra xảo ảnh lấp lánh (twinkling artifact). Cơ chế này hiện còn chưa rõ, dù đã có vài giả thuyết đã công bố trước đây.


Yêu cầu của nghiên cứu xuất phát từ nhu cầu điều trị sỏi thận cho phi hành gia trong không gian: không thể uống nhiều nước và ảnh hưởng của tình trạng phi trọng lực.
Các tác giả cho biết là sỏi khoảng 1/2 milimet sẽ bị dời chỗ dưới tác động của lực bức xạ âm tới chỗ thoát của thận, với tốc độ 1 cm mỗi giây; ứng dụng này như vậy còn có thể được áp dụng cho việc làm sạch các mảnh vỡ sau tán sỏi trong trường hợp điều trị trên mặt đất. 

 Đây là một ý tưởng mới về cơ chế tạo ra xảo ảnh lấp lánh.

Xem twinkling artifact
http://nguyenthienhung.blogspot.com/2010/04/twinkling-artifacts-useful-sonographic.html

http://nguyenthienhung.blogspot.com/2008/12/mt-s-xo-nh-siu-m-mu-v-mu-nng-lng-bng-v.html

Twinkling-Artifact Ultrasound Detects, Treats Kidney Stones, by Medimaging International staff writers. Posted on 14 Feb 2012

Space scientists are developing an ultrasound technology that could resolve various healthcare challenges associated with kidney stone treatment. The new technology detects stones with sophisticated ultrasound imaging based on a process called twinkling artifact, and provides treatment by pushing the stone with focused ultrasound. This technology could not only be beneficial for healthcare in space, but could also transform the treatment of kidney stones on Earth.


Kidney stones are frequently painful and sometimes difficult to remove, and 10% of the population will suffer from them. In space, the risk of developing kidney stones is exacerbated due to environmental conditions. The health risk is magnified by the fact that resource limitations and distance from Earth could restrict treatment options.
The project is led by US National Space Biomedical Research Institute (NSBRI; Houston, TX, USA) smart medical systems and technology team lead investigator Dr. Lawrence Crum and coinvestigator Dr. Michael Bailey; both are researchers at the Applied Physics Laboratory at the University of Washington (APL-UW; Seattle, USA).

Dr. Bailey stated that their technology is based on equipment currently available. “We have a diagnostic ultrasound machine that has enhanced capability to image kidney stones in the body,” said Dr. Bailey, a lead engineer at APL-UW. “We also have a capability that uses ultrasound waves coming right through the skin to push small stones or pieces of stones toward the exit of the kidney, so they will naturally pass, avoiding surgery.”

On Earth, the current preferred removal method is for patients to drink water to force the stones to pass naturally, but this does not always work, and surgery is frequently the only option. In space, the threat from kidney stones is greater due to the difficulty of keeping astronauts fully hydrated. Another factor is that bones demineralize in the reduced-gravity environment of space, dumping salts into the blood and eventually into the urine. The increased concentration of salts in the urine is a risk factor for stones.

Dr. Crum, who is a lead physicist at APL-UW, reported that kidney stones could be a serious difficulty on a long-duration mission. “It is possible that if a human were in a space exploration environment and could not easily return to Earth, such as a mission to an asteroid or Mars, kidney stones could be a dangerous situation,” Dr. Crum said. “We want to prepare for this risk by having a readily available treatment, such as pushing the stone via ultrasound.”

Before a stone can be pushed, it needs to be located. Conventional ultrasound units have a black and white imaging mode called B-mode that creates an image of the anatomy. They also have a Doppler mode that specifically displays blood flow and the motion of the blood within tissue in color. In Doppler mode, a kidney stone can appear brightly colored and twinkling. The reason for this is not known; however, the scientists are working to understand what causes the twinkling artifact image.

“At the same time, we have gone beyond twinkling artifact and utilized what we know with some other knowledge about kidney stones to create specific modes for kidney stones,” Dr. Bailey said. “We present the stone in a way that looks like it is twinkling in an image in which the anatomy is black and white, with one brightly colored stone or multiple colored stones.”

Once the stones are located, the ultrasound machine operator can select a stone to target, and then, with a simple push of a button, send a focused ultrasound wave, approximately half a millimeter in width, to move the stone toward the kidney’s exit. The stone moves about 1 cm per second. In addition to being an option to surgery, the technology can be used to “clean up” after surgery. “There are always residual fragments left behind after surgery,” Dr. Bailey said. “Fifty percent of those patients will be back within five years for treatment. We can help those fragments pass.”

The ultrasound technology being developed for NSBRI by Drs. Crum and Bailey is not restricted to kidney stone detection and removal. The technology can also be used to stop internal bleeding and ablate tumors. Dr. Crum reported that the research group has novel plans for the technology. “We envision a platform technology that has open architecture, is software-based and can use ultrasound for a variety of applications,” he said. “Not just for diagnosis, but also for therapy.”

NSBRI’s research range includes other projects seeking to develop smart medical systems and technologies, such as new uses for ultrasound that provide healthcare to astronauts in space. Dr. Crum, who served eight years as an NSBRI team leader, noted that the innovative approaches to overcome the restrictive environment of space could make an impact on Earth.

“Space has demanded medical care technology that is versatile, low-cost, and has restricted size. All of these required specifications for use in a space environment are now almost demanded by the general public,” Dr. Crum said. “One of the reasons that translation from one site to another is possible is because of NSBRI’s investment.”

Related Links:

US National Space Biomedical Research Institute

Applied Physics Laboratory at the University of Washington

____________________________________________________

A Doppler mode in clinical diagnostic ultrasound detects motion, particularly blood flow, and displays the moving blood as red or blue on the imager's screen. For some unknown reason, when a stationary kidney stone is imaged in Doppler mode, the stone is displayed as a rainblow of colors, which makes the stone readily apparent. Something about the presence of the stone tricks the machine into displaying the color, which is an artifact because the color does not represent true motion.

Because twinkling is an artifact, its appearance can be intermittent and unreliable. The unreliability is exacerbated because of the variability of ultrasound imager proprietary technologies. We are focused on how to understand the artifact and make it into a useful tool to detect and treat kidney stones with lithotripsy.

APPLICATIONS

We see at least three applications of the "twinkling artifact" to kidney stone treatment.

First, stones are usually diagnosed with spiral CT imaging, which cannot be done in a doctor's office and exposes the patient to ionizing radiation. Our ultrasound technique would allow an immediate localization in the doctor's office and spare the patient the radiation exposure.

Second, most stone are treated by lithotripsy, where shock waves are sent into the patient's body to break stones. Most often X-ray fluoroscopy, which is generally not as good as spiral CT, is used to find the stone to target the treatement. These images are not always clear and sometimes the lithotripsy is done based on a best guess as to the stone's location. Twinkling could provide better targeting without the X-ray radiation.

Third, the stone moves as the patient breathes during lithotripsy treatment, which mean that about half the shock waves miss the stone and impact only kidney tissue. Lithotripsy has known side effects (i.e., tissue injury) and the fewer shock waves used the fewer side effects. Twinkling is a sensitive and real-time stone detector that could be used to ensure shock waves are only triggered when the stone is in the lithotripter's focus.

Although the applications are clear, the mechanism that causes twinkling is a complex mixture of factors. The ultrasound imager produces tiny motions in the stone and receives from the stone an echo that is generally stronger than that from tissue and contains reverberations from within the stone. These extra signals appear as if structures within the volume of the stone are moving in and out of the image. The confusion is further compounded by processing within the machine, which essentially amplifies the extra signals and variation in the collection of sequences of images.

Our approach is to use numerical modeling of the echoes and reverberations, and compare these to the raw data collected by ultrasound images for stones in water, tissue, and patients. We then create our own images using specific algorithms that mimic the proprietary processing in the imaging systems. We can generally recreate what is shown on the imagers and detect patterns that are used to specifically image just stones and not motion.

In our experience, the artifact reveals the stone in 100% of the animal studies and has performed reliably in an initial handful of human studies.

HistoScanning™

HistoScanning™ là một ứng dụng siêu âm mới, bằng cách sử dụng thuật toán phân biệt mô tiên tiến, để thể hiện vị trí và lan rộng của mô biệt hoá, nghi là ác tính. Ban đầu dùng cho tuyến tiền liệt, giúp bác sĩ điều trị chọn phương thức xử l‎‎í, lên kế hoạch điều trị và chọn lọc bệnh nhân ung thư để theo dõi tích cực, sau được phát triển cho ung thư vú, buồng trứng và tuyến giáp.



Thuật toán HistoScanning


A. Thuật toán chọn lọc dựa vào đặc điểm biệt hoá mô.


Trình bày hình tượng hoá dấu ấn âm học (acoustic signature) điển hình của 3 thuật toán biệt hoá mô của vùng ác tính và không ác tính. Hình (a-c) thể hiện tổn thương ác tính và hình (d-f) là vùng không ác tính. Chú ý khác biệt giá trị của trục y giữa (a) và (d), (b) và (e), (c) và (f).



B. Thuật toán phân biệt cá thể và kết hợp được tạo nên từ dữ liệu của bệnh nhân (scan + mô học) để đạt được phân cách thống kê tối đa.


Đối chiếu các vùng ác tính và lành tính của tuyến tiền liệt cho kết quả các kiểu phân bố khác nhau về số hoá, phân bố của vùng ung thư (màu cam) lệch sang P (giá trị cao) trong khi vùng không bệnh có màu xanh.


C. Thuật toán được cài vào trong máy siêu âm để tối ưu hoá việc phân biệt mô.


Tích hợp các phân bố về toán học của 3 thuật toán phân biệt giúp xác định kiểu số hoá có khả năng giúp xác định rõ mô tuyến tiền liệt ác tính và không ác tính.


Nguyên lý hoạt động


Ung thư được phân biệt bởi tăng sản bất thường các tế bào ác tính làm thay đổi cấu trúc và đặc điểm mô. Biến đổi hình thái này ảnh hưởng đến kiểu tán xạ của sóng âm truyền qua mô. Thuật toán mới và độc quyền này ghi nhận được các thay đổi của tán xạ âm. Cách tiếp cận này giúp phân biệt đặc điểm cấu trúc mô xa hơn các kỹ thuật tạo hình siêu âm hiện tại. Thuật toán của HistoScanning có thể ứng dụng và xác định cấu trúc mô khu trú trong các cơ quan đặc biệt như tuyến tiền liệt, buồng trứng, tuyến giáp và tuyến vú.

Xem video  HistoScanning

________________________



What is HistoScanning™?


HistoScanning™ is a novel ultrasound-based application that utilises advanced tissue characterisation algorithms to visualise the position and extent of differentiated tissue, suspected of being malignant. Prostate HistoScanning™ is a commercially available specific application that can support physicians managing prostate cancer patients with treatment selection, treatment planning, and selecting patients for active surveillance. HistoScanning™ applications are being developed for Breast, Ovary and Thyroid.

HistoScanning™ algorithms

A

Several algorithms are selected based on their basic tissue differentiation characteristics.

Graphical representation of the typical acoustic signature of the three tissue characterisation algorithms for malignant and non-malignant areas. Graphs (a-c) represent a malignant lesion and graphs (d-f) represent a non-malignant area. Note the difference in the y axis value between (a) and (d), (b) and (e), (c) and (f).

B

Individual and composite differentiation algorithms are trained on patient data sets (scan + histology) to achieve maximum statistical separation.

Comparing normal and malignant areas in the prostate resulted in different distributions of numerical patterns, with distributions related to cancerous areas (in orange) systematically shifted to the right (higher values) when compared to distributions related to the normal area (in blue).

C

Trained algorithms are implemented into the system to provide optimized differentiation.

Mathematical integration of the distributions provided by the three characterization algorithms allowed the definition of numerical patterns likely to be specific of non-malignant or of malignant prostatic tissues.

Principle of Operation

Cancer is characterized by an abnormal proliferation of malignant cells resulting in altered tissue structures and characteristics. The resulting morphological variability affects the scatter patterns of ultrasound waves traveling through the tissue. Changes in the ultrasound scatter footprint are picked‐up by innovative and proprietary algorithms. This approach allows for differentiation of tissue morphology characteristics beyond what is possible with currently available ultrasound imaging techniques. The algorithms used by HistoScanning can be adapted and trained to identify inute localized tissue structures in specific organs (eg. prostate, ovary, thyroid, breast, etc).

The Value of HistoScanning

New insights provided by HistoScanning may help physicians:


• Shorten time to treatment

• Improve the diagnostic accuracy hence reducing uncertainties and patient anxiety

• When cancer is suspected, direct diagnostic modalities (such as biopsies) to lesions most likely to be malignant

• Make more informed treatment decisions

• Implement effective active surveillance programs so as to avoid or postpone radical treatment

• Actively monitor treatment effectiveness

• Achieve cost savings in patient management by ensuring the most efficient use of resources



HistoScanning Applications

HistoScanning technology can be adapted and trained to differentiate tissues in organs accessible by ultrasound. Applications are being developed to address various organs specific clinical challenges. Current developments are focused in the fields of prostate, ovarian, thyroid and breast cancer:


• Prostate HistoScanning is primarily aimed at improving the clinical management of men presenting with elevated levels of Prostate Specific Antigen (PSA) and therefore scheduled to undergo ultrasound guided biopsy. Prostate HistoScanning may help rule out clinically relevant prostate cancer in men with elevated serum PSA due to non malignant conditions and guide biopsies towards the suspicious lesions in men with positive HistoScanning results. Furthermore, it has the potential to provide guidance in treatment selection based on the stage of cancer. HistoScanning for the prostate is currently under clinical evaluation.


• Ovarian HistoScanning is for the clinical management of patients presenting with abnormal pelvic symptoms or a suspicious mass on a routine ultrasound scan. Ovarian HistoScanning has been shown in a multicentre clinical study to have sensitivity in the identification of cancerous tissue of 98% compared with 75% for the radiologist relying on the standard ultrasound scan alone. HistoScanning for the ovaries based on grey level data is currently under limited release.


• Thyroid HistoScanning aims to address the clinical challenges associated with the differentiation and localization of thyroid cancer and may provide a non‐invasive alternative to actively monitor disease recurrence. HistoScanning for the thyroid is currently in the clinical evaluation phase.


• Breast HistoScanning is aimed at supporting ultrasound‐based detection of malignancies in the breast and in particular improving the sensitivity and specificity of breast imaging. Furthermore, Breast HistoScanning is expected to facilitate screening in women with mammographically dense breasts.

Detection, localisation and characterisation of prostate cancer by Prostate HistoScanning™

Lucy A.M. Simmons, Philippe Autier Frantiŝek Zát'ura, Johan Braeckman, Alexandre Peltier, Ire Romic, Arnulf Stenzl, Karien Treurnicht, Tara Walker, Dror Nir, Caroline M. Moore, Mark Emberton

Article first published online: 17 NOV 2011

What's known on the subject? and What does the study add?

Prostate cancer is one of the few solid-organ cancers in which imaging is not used in the diagnostic process. Novel functional magnetic resonance imaging techniques offer promise but may not be cost-effective.

Prostate HistoScanning™ (PHS) is an ultrasound-based tissue characterisation technique that has previously shown encouraging results in the detection of clinically significant prostate cancer. The present study reports on the open ‘unblinded’ phase of a European multicentre study. The prospective ‘blind’ phase is currently in progress and will determine the value of PHS in a robust fashion overcoming many of the biases inherent in evaluating prostate imaging.

OBJECTIVE

To evaluate the ability of prostate HistoScanning™ (PHS) an ultrasound (US)-based tissue characterization application, to detect cancer foci by correlating results with detailed radical prostatectomy (RP) histology.

PATIENT AND METHODS


In all, 31 patients with organ-confined prostate cancer, diagnosed on transrectal biopsies taken using US guidance, and scheduled for RP were recruited from six European centres.


Before RP three-dimensional (3D) US raw data for PHS analysis was obtained. Histology by Bostwick Laboratories (London) examined sections obtained from whole mounted glands cut every 3–4 mm.


Location and volume estimation of cancer foci by PHS were undertaken using two methods; a manual method and an embedded software tool.


In this report we evaluate data obtained from a planned open study phase. The second phase of the study is ‘blinded’, and currently in progress.

RESULTS

31 patients were eligible for this phase. Three patients were excluded from analysis due to inadequate scan acquisition and pathology violations of the standard operating procedure. One patient withdrew from the study after 3D TRUS examination.

PHS detected cancer ≥0.20 mL in 25/27 prostates (sensitivity 93%).

In all, 23 patients had an index focus ≥0.5 mL at pathology, of which 21 were identified as ≥0.5 mL by PHS using the manual method (sensitivity 91%) and 19 were correctly identified as ≥0.5 mL by the embedded tool (sensitivity 83%).

In 27 patients, histological analysis found 32 cancerous foci ≥0.2 mL, located in 97 of 162 sextants. After sextant analysis, PHS showed a 90% sensitivity and 72% specificity for the localisation of lesions ≥0.2 mL within a sextant.

CONCLUSIONS

PHS has the ability to identify and locate prostate cancer and consequently may aid in pre-treatment and pre-surgical planning.

In men with a lesion identified, it has potential to enable improved targeting, allowing better risk stratification by obtaining more representative cores.

However further verification from the results of the blinded phase of this study are awaited.






Differential diagnosis of adnexal masses: sequential use of the risk of malignancy index and HistoScanning, a novel computer-aided diagnostic tool

E. VAES*†, R. MANCHANDA‡, P. AUTIER§, R. NIR¶, D. NIR¶, H. BLEIBERG**, A. ROBERT* and U. MENON‡, Ultrasound Obstet Gynecol 2012; 39:91–98


Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/uog.9079



ABSTRACT

Objective

To assess the value of ovarian HistoScanning TM, a novel computerized technique for interpreting ultrasound data, in combination with the risk of malignancy index (RMI) in improving triage for women with adnexal masses.

Methods

RMI indices were assessed in 199 women enrolled in a prospective study to investigate the use of HistoScanning. Ultrasound scores were obtained by blinded analysis of archived images. The following sequential test was developed: HistoScanning was modeled as a second-line test for RMI between a lower cut-off and an upper cut-off. The optimal combination of these cut-offs that together maximized the Youden index (Sensitivity + Specificity − 1) was determined.

Results

Using RMI at the standard cut-off value of 250 resulted in a sensitivity of 74% and a specificity of 86%. When RMI was combined with HistoScanning, the highest accuracy was achieved by using HistoScanning as a sequential second-line test for patients with R  values between 105 and 2100. At these cut-off values, sequential use of RMI and HistoScanning resulted in mean sensitivity and specificity estimates of 88% and 95%, respectively.

Conclusions

Our data suggest that HistoScanning may have the potential to improve the diagnostic accuracy of RMI, which could result in better triage for women with adnexal masses. Further prospective validation is warranted.

Copyright  2011 ISUOG. Published by John Wiley & Sons, Ltd.



NHÂN CA U TUYẾN HUNG DẠNG NANG TẠI MEDIC

See case 108 A MEDIASTINAL CYSTIC THYMOMA

Discussion

Pankaj Kaul, Kalyana Javangula and Shahme A Farook, Massive benign pericardial cyst presenting with simultaneous superior vena cava and middle lobe syndromes
Journal of Cardiothoracic Surgery 2008

Primary mediastinal cysts constitute approximately one fifth of all mediastinal masses. The cysts may originate from pleura or pericardium, tracheobronchial tree, gastrointestinal tract, neurogenic tissue, thymus gland or lymphoid tissue. Benign teratomas may present as epidermoid cysts, dermoid cysts or cystic teratomas [1]. Mediastinal cystic masses may also result from specific or non-specific infections or parasitic infestations like Echinococcus [2].


Anterior mediastinal cysts most commonly are pleuropericardial, thymic, teratomatous or cystic hygromas.



Pleuropericardial cysts are benign mesothelial cysts that arise as a result of persistence of one of the mesenchymal lacunae that normally fuse to form the pericardial sac [3], or, as suggested by Lillie [4], due to the failure of an embryological ventral diverticulum to fuse. Alternatively, they may be believed to arise from the infolding of the advancing edge of the pleura during its embryological development. These cysts are unilocular, contain clear watery fluid, present typically in anterior cardiophrenic angle, more often on right side than left. Microscopically, the wall has a single layer of mesothelial cells resting on a loose stroma of connective tissue.



True thymic cysts are thin walled, unilocular and contain normal thymic tissue within their walls and arise from third branchial pouch. Microscopically, the wall is lined by low cuboidal epithelium. However, malignant degeneration within a thymoma may result in a cystic thymoma, with a residual mass projecting into the cavity of the cyst from the wall.



Typically, lymphangiomas arise from neck and extend into mediastinum. They contain chyle and are classified according to the size of the spaces into cystic hygromas or cavernous lymphangiomas. Cystic hygromas are multiloculated, and a mediastinal hygroma is almost always an extension of a cervical hygroma. However, rarely, a uniloculated primary anterior mediastinal lymphogenous cyst containing yellow or brown fluid may be found [5].



Teratodermoids are classified generically as benign germ cell tumours. They are further divided into three categories: epidermoid cysts which are lined by simple squamous cell epithelium, dermoid cysts which have squamous epithelial lining containing elements of skin appendages like hair and sebaceous glands and teratomas which may be solid or cystic and contain identifiable cellular elements of two or three germinal layers [1].

Parasternal Sonography

Parasternal sonography is a sensitive technique for the detection of tumors in the anterior mediastinal and subcarinal mediastinal spaces. From AJR 150:1021-1026, May 1988,  American Roentgen Ray Society.

Results


Twenty-seven patients with anterior mediastinal (n = 16) and subcarinal (n = 17) tumors greater than 1 cm in diameter on CT were included in the study. Some patients had tumors in more than one region. Only anterior mediastinal tumors not in contact with the chest wall on the CT scan were selected. Ten patients with large anterior mediastinal tumors broadly attached to the thoracic wall were excluded.

37 patients (11 women, 16 men) were 20-58 years old (average age, 35). In patients with Hodgkin (n = 8) and non-Hodgkin (n = 8) lymphoma, only histologic proof from peripheral lymph nodes was available. In 4 patients, biopsies were consistent with sarcoidosis; 2 were confirmed by mediastinoscopy and 2 by bronchoscopy. Diagnoses were surgically proved in 2 patients with thymomas, one patient with bronchogenic carcinoma, one patient with a malignant fibrous histiocytoma, and one patient with an unclassified sarcoma. One patient each had mediastinal metastases of melanoma and testicular carcinoma.
During the same period, 30 patients with normal mediastinal CT scans were investigated with sonography. Twenty-two were referred for evaluation of lymphoma, nine for initial staging and 13 for restaging. In the latter 13 patients, there had been neither previous mediastinal lymph-node involvement nor mediastinal radiotherapy. Eight patients were healthy volunteers. All patients in the control group (12 women, 18 men) had a normal chest radiograph. They were 21-73 years old (average age, 42).