Elastographic Strain Index in the Evaluation of Focal Lesions Detected With Transrectal Sonography of the Prostate GlandJournal of Ultrasound in Medicine May 2016 35:899-904; Published Online First March 28, 2016, doi:10.7863/ultra.15.01071
Virtual Touch Tissue Imaging for Differential Diagnosis of Thyroid Nodules: Additional Value of the Area RatioJournal of Ultrasound in Medicine May 2016 35:917-926; Published Online First March 28, 2016, doi:10.7863/ultra.15.06002
Assessment of Measurement Repeatability and Reliability With Virtual Touch Tissue Quantification Imaging in Cervical LymphadenopathyJournal of Ultrasound in Medicine May 2016 35:927-932; Published Online First March 28, 2016, doi:10.7863/ultra.15.06067
B-Mode Sonographic Assessment of the Posterior Circumflex Humeral Artery: The SPI-US Protocol—A Technical Procedure in 4 StepsJournal of Ultrasound in Medicine May 2016 35:1015-1020; Published Online First April 12, 2016, doi:10.7863/ultra.15.05037
Elastographic Strain Index in the Evaluation of Focal Lesions Detected With Transrectal Sonography of the Prostate Gland
Objectives—The purpose of this study was to evaluate the value of elastography in evaluating focal lesions detected by transrectal sonography and to suggest a reference strain index.
Methods—Sixty-nine patients with focal lesions on transrectal sonography were referred to our department for prostate biopsy. Focal lesions were classified as either highly or less suspicious lesions by our criteria. A strain index from elastography was calculated for the focal lesions. Systematic 12-core randomized biopsies plus 2 targeted biopsies were performed. The mean strain indices for malignant and benign focal lesions were compared, and a cutoff strain index was attained to maximize the sensitivity and specificity for prostate cancer. Strain indices were correlated with Gleason scores.
Results—The mean strain index ± SD for malignant focal lesions (3.26 ± 1.77) was significantly higher than that for benign focal lesions (2.16 ± 1.52; P = .008). The sensitivity, specificity, and area under the receiver operating characteristic curve for diagnosing cancer were 66.7%, 71.1%, and 0.701, respectively, at a strain index cutoff value of greater than 2.4. The strain index showed a moderate linear correlation with the Gleason score (r = 0.441; P = .013).
Conclusions—Any focal lesion on transrectal sonography with a strain index of greater than 2.4 is at risk for prostate cancer.
Virtual Touch Tissue Imaging for Differential Diagnosis of Thyroid Nodules
Additional Value of the Area Ratio
Objectives—To evaluate the additional value of the area ratio on Virtual Touch tissue imaging (VTI; Siemens Medical Solutions, Mountain View, CA) for diagnosis of thyroid nodules referred to surgery.
Methods—From April 2013 to February 2014, 205 consecutive patients with 225 histologically proven thyroid nodules were enrolled in this retrospective study. Virtual Touch tissue imaging and area ratio measurements were performed for each nodule. The area ratio was defined as the area of the nodule on VTI divided by the area on B-mode sonography. Nodule stiffness on VTI was graded from I (soft) to VI (hard). Receiver operating characteristic curve analyses of VTI, area ratio, and the combination of VTI and area ratio were performed. The sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and Youden index were also evaluated.
Results—By receiver operating characteristic curve analyses, the cutoff values were VTI grade IV and area ratio of 1.09, respectively. Nodules with VTI grade IV or higher or area ratio of 1.09 or higher were more likely to be malignant. The sensitivity, specificity, accuracy, PPV, NPV, and Youden index were 78.6%, 92.3%, 88.0%, 82.1%, 90.5%, and 0.709 for VTI and 81.4%, 87.1%, 85.3%, 74.0%, 91.2%, and 0.685 for area ratio (all P under .05). However, when using the criterion of VTI grade IV or higher and area ratio of 1.09 or higher as a combination, the sensitivity, specificity, accuracy, PPV, NPV, and Youden index increased to 94.3%, 97.4%, 96.4%, 94.3%, 97.4%, and 0.917 (all under .05 compared to VTI or area ratio alone, except for specificity between VTI and the combination).
Conclusions—The diagnostic performance of VTI grading and the area ratio for differentiation between benign and malignant thyroid nodules is equivalent. The performance is further improved with a combination of VTI grading and area ratio analysis.
Assessment of Measurement Repeatability and Reliability With Virtual Touch Tissue Quantification Imaging in Cervical Lymphadenopathy
Objectives—The purpose of this study was to prospectively assess the repeatability and reliability of 2 measurements of cervical lymphadenopathy using Virtual Touch tissue quantification (VTQ) imaging (Siemens Medical Solutions, Mountain View, CA) and to analyze the factors affecting the reliability of the measurements, including pathologic findings, lesion size and location, and shear wave velocities (SWVs).
Methods—In this Institutional Review Board–approved prospective study, 92 patients underwent conventional sonography and 2 VTQ measurements by acoustic radiation force impulse imaging in a single session. The repeatability and reliability of the SWV measurement was determined by using an average coefficient of variation (standard deviation/mean) and intraclass correlation coefficient (ICC), respectively. By comparing ICCs with a 95% confidence interval, the effects of pathologic findings, depth, size, SWV, and distance from the carotid artery on reliability were assessed.
Results—The mean age of the 92 patients included in the study was 51 years (range, 14–77 years). The average coefficient of variation was 19.4%. The overall reliability of the 2 measurements was excellent (ICC, 0.837), but ICCs were significantly decreased<1>1>
Conclusions—For SWV measurement by VTQ imaging, the repeatability was 19.4%, and reliability was excellent. However, caution is warranted in the use of VTQ imaging for superficial soft cervical lymph nodes, as both a superficial location and a soft composition tend to be characterized by low reliability of SWV findings.
B-Mode Sonographic Assessment of the Posterior Circumflex Humeral Artery
The SPI-US Protocol—A Technical Procedure in 4 Steps
Elite overhead athletes are at risk of vascular injury due to repetitive abduction and external rotation of the dominant arm. The posterior circumflex humeral artery (PCHA) is prone to degeneration, aneurysm formation, and thrombosis in elite volleyball players and baseball pitchers. The prevalence of PCHA-related thromboembolic complications is unknown in this population. However, the prevalence of symptoms associated with digital ischemia is 31% in elite volleyball players. A standardized noninvasive imaging tool will aid in early detection of PCHA injury, prevention of thromboembolic complications, and measurement reproducibility. A standardized vascular sonographic protocol for assessment of the proximal PCHA (SPI-US protocol [Shoulder PCHA Pathology and Digital Ischemia–Ultrasound protocol]) is presented.