SIÊU ÂM LÒNG HẬU MÔN và QUA NGẢ TRỰC TRÀNG

Anal (EcoA) and rectal endosonography (EcoEAR) is a useful test in the evaluation of patients with anorectal pathology. However, there is no clear consensus on its indications.

The aim of this study was to determine the opinion of clinicians regarding the current indications and usefulness of this diagnostic test in daily clinical practice. A cross-sectional observational study was conducted using a survey sent to the services of General surgery in a specific area of Spain. The clinical usefulness of the test was evaluated using an analog scale from 0 (lowest value) to 10 (maximum utility) for each pathology. Of the 47 hospitals, 23 responded to the questionnaire (48.9%). The average number of ultrasounds performed in these centers was 217 per year (standard deviation: 140.1, range 73–450) during the last 3 years. The most common indications for this test were: rectal tumor (85%), anal fistula (80%), and fecal incontinence (70%). This test was suggested more, depending on availability in the hospital itself.

In conclusion, anal and rectal endosonography remains a very useful diagnostic clinical test in the opinion of clinicians in general and digestive surgery, especially in the evaluation of patients with anal fistula, fecal incontinence, or rectal tumors.

Fig. 2: Anal endosonography imaging in a patient with fecal incontinence showing internal anal sphincter injury (arrows).

Fig. 3:  3D rectal endosonography imaging showing the presence of a rectal tumor (arrows).

Ultrasound equivalent to CT in detecting appendicitis in kids

Ultrasound equivalent to CT in detecting appendicitis in kids

December 11, 2013

by Lauren Dubinsky, Freelance reporter

There has been a lingering fear about the radiation CT emits — especially for children. But the Children's Hospital at Montefiore in New York City is pretty confident they have found a safe alternative. Investigators at the hospital conducted a study that proves that using ultrasound, which emits no radiation, instead of CT to detect appendicitis in children produces comparable results to CT and does not increase hospital length of stay.

"We've shown that even the additional time and the additional step, putting the ultrasound into the pathway of treatment, does not cause any effects of worsening the course of the appendicitis," Dr. Meir Scheinfeld, director of the Division of Emergency Radiology in the Department of Radiology at Montefiore Medical Center, told DOTmed News.


CT has been the most frequently used imaging technique to detect appendicitis because of how sensitive it is. However, the advanced imaging technique exposes patients to upward of 25 millisieverts a scan — about eight times the average annual dose from naturally occurring background radiation. As a result, some doctors are interested in radiation-free alternatives for children, such as ultrasound, as kids are at higher risk for radiation-induced cancers than adults.

From 2005 to 2011, the Children's Hospital at Montefiore gathered up and looked at the medical records of 804 pediatric patients. The radiologists and clinicians in the divisions of pediatric surgery and emergency medicine started out by increasing the use of ultrasound as the first imaging technique from 33 percent at the start of the study to 90 percent at the end of it. During the same time, they decreased the use of CT as the first and only diagnostic test from 43 percent to less than 10 percent.

"The conclusion of the paper is that despite us making this change, doing ultrasound before CT in patients, still there was no detrimental effect on patient length of stay or complicated appendicitis during the study," said Scheinfeld.

Appendicitis, or inflammation of the appendix, is the most common childhood surgical emergency in the United States and its rate is continuing to increase.

"Although I truly believe that we should use radiation as little as possible and use ultrasound MRI whenever possible, CT is used because it is so amazing," said Scheinfeld. "You can evaluate the entire abdomen and pelvis with a CT scanner within a few seconds."

Although CT scanners are so efficient, Scheinfeld said he still encourages using ultrasound first.

"We should try to reduce medical radiation regardless of whether it causes cancer or not, there's a risk and if the amount of risk is uncertain we should reduce it," he said.

Clinicians in the Division of Pediatric Radiology at the hospital have made it their mission to raise awareness of radiation protection and lower CT scan radiation dose when imaging children. Scheinfeld said their primary level of education and collaboration is with clinicians who are working to diagnose their patients.

"In the past, where the question was appendicitis or not we would encourage them to get the ultrasound first and they have gone along with it," said Scheinfeld.

NHÂN CA CƯỜNG CẬN GIÁP Ở BỆNH NHÂN SUY THẬN MẠN @ MEDIC

Primary or tertiary hyperparathyroidism in CKD 

http://ckj.oxfordjournals.org/

Discussion

In this report, we described a case of a middle-aged Filipino man with severe hypercalcaemia—refractory to volume expansion, loop diuretics, bisphosphonates, calcimimetics and haemodialysis—with PTH concentrations in excess of 2400 pg/mL. Diagnostic evaluation confirmed the presence of an extremely large (2 g) parathyroid adenoma.

HPT and hypercalcaemia resolved rapidly following adenoma resection. We believe that our patient’ s findings reflect the most severe clinical manifestations of primary (in contrast to tertiary) HPT ever described in a patient with CKD.

While HPT caused by parathyroid adenoma is common, this case is novel for several reasons. First, severe hypercalcaemia is rare in primary HPT. This degree of hypercalcaemia results only when primary HPT is exceptionally severe (this case) or when tertiary HPT (autonomous PTH hypersecretion after long-standing renal insufficiency) develops. Vasoconstriction induced by severe hypercalcaemia is an important contributing cause of the acute renal failure observed in this patient. The resultant decline in glomerular filtration rate (GFR) most likely accounted for his normal to slightly elevated serum phosphorus concentrations, which are typically low–normal in primary HPT. Indeed, as the patient’ s hypercalcaemia and kidney function worsened on transfer to our institution, his hyperphosphataemia worsened as well with the serum phosphorus reaching a peak of 5.6 mg/dL on the day of surgery. In the setting of hypercalcaemia where primary or tertiary HPT is suspected, physicians should investigate other aetiologies (e.g. malignancy, thiazide or lithium use, milkalkali syndrome, hypervitaminosis D and granulomatous disease) in addition to HPT (Table 1). Iatrogenic hypercalcaemia can also result from use of high-dose oral calcium and activated vitamin D derivatives, which are commonly given to patients with end-stage renal disease but are rarely used in patients with lesser degrees of impaired kidney function.

Second, the markedly elevated PTH concentration (>2400 pg/mL) observed in this case is more typical of secondary (or tertiary) HPT. We are confident in the accuracy of these values; at our institution, PTH was measured using a non-competitive immunoassay (Immulite 2000, Siemens Medical Solutions Diagnostics, Newark, DE) with precision documented at 5% CVand linearity verified across the analytically measurable range of 3–2500 pg/ml (R2= 0.99). In a recent series of 80 patients with primary HPT from adenoma, the highest reported PTH concentration was 2578 pg/mL [11].

Third, the size of this patient’ s parathyroid adenoma was quite large. In primary HPT, adenoma size is an important determinant of disease severity, but the reason for the large variation (100-fold) in size is unknown. Two recent studies reported normal parathyroid glands weights from 62.4 ± 31.6 mg [12] and from 42.6 ± 20.3 mg [13], respectively.

The mean parathyroid adenoma weight was 553.7 ± 520.5 mg [12]. This patient’ s parathyroid adenoma weighed 2 g, making it significantly larger than most reported parathyroid adenona.

Table 1. PTH concentrations in various aetiologies of hypercalcaemia

Adenomas weighing more than 60 g have been rarely reported [14,15]. Fourth, this patient suffered acute-on-chronic renal failure, most likely due to hypercalcaemia (peaking at more than 17.0 mg/dL). Serum calcium concentrations from 12.0 to 15.0 mg/dL have been shown to decrease GFR by direct vasoconstriction and natriuresis leading to volume depletion and pre-renal azotemia [16]. Additionally,

aquaporin-2 downregulation along with tubulointerstitial injury resulting in impaired osmotic gradient formation may preclude effective urine concentrating mechanisms [17]. In addition to impaired kidney function related to hypercalcaemia-induced vasoconstriction, nephrocalcinosis and possibly acute tubular necrosis (associated with radiocontrast administration and/or hypotension) may have con-

tributed to the acute kidney injury.

Rather than an exceptional case of primary HPT, most of this patient’ s clinical features are more consistent with either tertiary HPT or parathyroid carcinoma. Parathyroid carcinoma accounted for only 0.74% of more than 22 000 cases of ‘primary HPT’ in a large retrospective study [8].

Total serum calcium concentrations were >14 mg/dL in more than two-thirds of carcinoma cases [9,18]. Nephrolithiasis, nephrocalcinosis and impaired kidney function are found in 32–80% of patients with parathyroid carcinoma compared with 4–18% in benign primary HPT [19]. In this case, there was no evidence of malignancy.

All physicians encountering patients with HPT must be familiar with the multiple aetiologies of hypercalcaemia and understand that ionized calcium is typically maintained in the normal range unless CKD is quite advanced (GFR well below 30 mL/min/1.73 m2) [20]. While uncommon, hypercalcaemia and HPT may exist concurrently from unrelated aetiologies. Malignancies, including multiple myeloma, non-Hodgkin’ s lymphoma and tumours metastatic to bone can lead to frank or relative hypercalcaemia. However, elevated PTH concentrations typically only occur with concomitant primary HPT (adenoma, carcinoma), and current assays are able to distinguish PTH from rare PTH-related peptide-secreting neoplasms [21]. Thiazide diuretics [22], oral calcium supplementation (including milk–alkali syndrome) and hypervitaminosis D can also result in iatrogenic, PTH-independent hypercalcaemia.

If HPT is confirmed, secondary HPT should be entertained. While most patients with moderate to advanced CKD and evidence of elevated PTH have normal or low serum calcium concentrations, a fraction with low bone turnover may have mild hypercalcaemia. More commonly, iatrogenic hypercalcaemia develops from overzealous management of hyperphosphataemia with calcium-based phosphate binders (calcium carbonate and acetate) and activated vitamin D derivatives. When secondary HPT is refractory to medical therapy and/or PTH fails to suppress in the presence of hypercalcaemia (as in this case), tertiary HPT should be suspected. Subtotal parathyroidectomy should be considered in patients with signs or symptoms referable to HPT, including calcific uremic arteriolopathy (calciphylaxis), fracture, bone pain, myopathy, neuropathy, recalcitrant pruritus or refractory hypertension.

While secondary HPT is the dominant disorder of parathyroid structure and function in patients with CKD, hypercalcaemia in the absence of culprit medications and/or non-suppression of PTH should direct clinicians toward ‘non-secondary’ HPT—either tertiary or, as in this case, primary. The latter may co-exist with secondary HPT and be more subtle and difficult to diagnose. This case illustrates the importance of understanding endogenous and iatrogenic aetiologies of hypercalcaemia and HPT along with an effective diagnostic approach to identify and promptly treat patients with this severe syndrome.

Sinh lý bệnh học cường tuyến cận giáp thứ phát: Suy thận ----> Giảm Ca, tăng P, giảm vitamin D3 ---> Tuyến cận giáp tăng tiết PTH ---> ảnh hưởng ngược trở lại trên thận và các xương.

Preoperative Ultrasound Used to Avoid Missing Metastases in Differentiated Thyroid Cancer

Preoperative Ultrasound Used to Avoid Missing Metastases in Differentiated Thyroid Cancer

By Medimaging International staff writers Posted on 31 Oct 2013

Ultrasound imaging is typically used to identify and assess patients with differentiated thyroid cancer (DTC), and to determine whether the disease has metastasized to lymph nodes in the neck that should be taken out at the time of thyroidectomy. A retrospective review of cases covering more than 12 years found that nearly one-third of patients with DTC and neck metastases would not have had adequate surgical procedures if the surgeons had relied on pre-referral imaging studies and had not performed ultrasound themselves.

A team of researchers from the Cleveland Clinic Foundation (OH, USA) presented these new findings at the 83rd annual meeting of the American Thyroid Association, October 16-20, 2013, held in San Juan (Puerto Rico). The study was presented by Dr. Kevin Parrack, and offered several major findings. Preoperative ultrasound performed by a surgeon detected affected lymph nodes that could not be felt on physical exam and were not identified on earlier imaging scans performed by a radiologist in 31% of instances. Earlier imaging tests performed by radiology could have included ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI).

Among the patients who had radiologist-performed ultrasound specifically before being referred to an endocrine surgeon, 35% had nonpalpable cancerous lymph nodes detected on clinician-performed ultrasound. The discovery that the cancer had spread beyond the thyroid gland altered the surgical plan and allowed for removal of the affected lymph nodes at the time of the thyroidectomy.

“Ultrasound prior to thyroidectomy is an important tool for planning surgery, in that it can delineate local extent of tumor and likely nodal metastases better than physical exam and alternative imaging modalities,” said Julie Ann Sosa, MD, program committee co-chair; professor of surgery and medicine; chief, section of endocrine surgery; and director of health services research, department of surgery, Duke University School of Medicine (Durham, NC, USA). “Different providers can perform the ultrasound and neck mapping, including surgeons, radiologists, endocrinologists, and pathologists. These data are significant in that they suggest the surgeon is uniquely positioned to perform ultrasound in a way that it affords critical information that would not otherwise be available for optimizing surgical approach.”

Modifying Moods with Brain Ultrasound

Modifying Moods with Brain Ultrasound

from MII 12-2013

 

Ultrasound vibrations applied to the brain may affect mood, according to scientists. These new findings could potentially lead to new treatments for psychological and psychiatric disorders.

University of Arizona (UA; USA;Tucson, USA; www.arizona.edu) researchers have found in a recent study that ultrasound waves applied to specific areas of the brain appear able to alter patients’ moods. The discovery has led the scientists to conduct additional investigations with the hope that this technique could one day be used to treat disorders such as anxiety and depression.

Dr. Stuart Hameroff, professor emeritus of the UA’s departments of anesthesiology and psychology and director of the UA’s Center for Consciousness Studies, is lead author on the first clinical study of brain ultrasound, which was published May 2013 in the journal Brain Stimulation. Dr. Hameroff became interested in applying ultrasound to the human brain when he read about a study by colleague Dr.Jamie Tyler at the Virginia Polytechnic Institute (Blacksburg, USA; www.vt.edu), who discovered physiologic and behavioral effects in animals of ultrasound applied to the scalp, with the waves passing through the skull.

Dr. Hameroff knew that ultrasound vibrates in megahertz frequencies at about 10 million vibrations per second, and that microtubules, protein structures inside brain neurons tied to mood and consciousness, also resonate in megahertz frequencies. Dr. Hameroff suggested evaluating ultrasound treatment for mood on human brains. “I said to my anesthesiology colleagues, ‘we should try this on chronic pain patient volunteers.’”

His colleagues respectfully suggested he try it on himself, first, Dr.Hameroff concurred. After 15 seconds with an ultrasound transducer, a traditional ultrasound imaging device, placed against his head, Dr. Hameroff felt no effect.

“I put it down and said, ‘well, that’s not going to work,’” he said. “And then about a minute later I started to feel like I’d had a martini.”

His mood was elevated for the next hour or two, according to Dr. Hameroff. Aware that his experience could be a placebo effect, Dr. Hameroff set out to properly test the treatment with a clinical trial. Dr.Hameroff and his colleagues applied transcranial ultrasound to 31 chronic pain patients at the University of Arizona Medical Center-South Campus, in a double-blind study in which neither clinicians nor study

participant knew if the ultrasound unit had been turned on or off.

Patients reported improvements in mood for up to 40 minutes following treatment with brain ultrasound, compared with no difference in mood when the machine was switched off. The researchers confirmed the patients’ subjective reports of increases in positive mood with a Visual Analog Mood Scale (VAMS), a standardized objective mood scale frequently employed in psychologic studies. “Encouraging,” Dr. Hameroff remarked. “We’re referring to transcranial ultrasound as ‘TUS,’” he added. “Which is also the airport code for Tucson. This was a pilot study, which showed safety, and some efficacy, for clinical use of TUS. Because important structures called microtubules in all brain neurons vibrate in the ultrasound range, and help mediate mood and consciousness, TUS may benefit a variety of neurological and psychiatric disorders.”

The discovery may provide prospects for a possible range of new applications of ultrasound in medicine. “We frequently use ultrasound in the operating room for imaging,” said Dr. Hameroff. “It’s safe as long as you avoid excessive exposure and heating.”

Harmless at low intensities, the mechanical waves penetrate the body’s tissues and bones, and an echo effect is used to generate images of anatomic structures such as organs and blood vessels and fetuses in the womb. Furthermore, the high-frequency vibrations of ultrasound, which far exceed the range of human hearing and are undetectable when passing through the body, may be more desirable than existing brain stimulation techniques such as transcranial magnetic stimulation (TMS). Used to treat clinically depressed patients, TMS can have side effects including what some report as a disagreeable sensation of magnetic waves moving through the head.

After finding encouraging early findings in chronic pain patients, Dr. Hameroff and his colleagues set out to discover whether transcranial ultrasound stimulation could improve mood in a larger group of healthy volunteer test subjects. Jay Sanguinetti, a doctoral candidate in the department of psychology and his adviser Dr. John Allen, a UA distinguished professor of psychology,were fascinated by Dr. hameroff’s conception of evaluating ultrasound. They conducted a follow-up study of ultrasound on UA psychology student volunteers, recording vital signs such as heart rate and breath rate, and narrowed down the optimum treatment to 2 megahertz for 30 seconds as the most likely to produce a positive mood change in patients.

The investigators then began a double-blind clinical trial to verify the statistical significance of their findings and to rule out any possibility of a placebo effect in their patients. Results of the trials are being analyzed, according to Mr.Sanguinetti. “What we think is happening is that the ultrasound is making the neurons a little bit more likely to fire in the parts of the brain involved with mood,” thereby stimulating the brain’s electrical activity and possibly leading to a change in how participants feel.

The UA researchers are collaborating with the company Neurotrek (Los Gatos, CA, USA; http://neurotrek.com), which is developing a device that potentially could target specific regions of the brain

with ultrasound bursts. The researchers will work with a prototype of the Neurotrek device to evaluate its effectiveness and potential applications.

Mr. Sanguinetti concluded, “The idea is that this device will be a wearable unit that noninvasively and safely interfaces with your brain using ultrasound to regulate neural activity.”

Image: A recent clinical study showed that transcranial ultrasound affects mood (Photo courtesy of Stuart Hameroff / University of Arizona).

High Intensity Focused Ultrasound, Liver Disease and Bridging Therapy.

Abstract

High-intensity focused ultrasound (HIFU) is a non-invasive modality that uses an extracorporeal source of focused ultrasound energy. This technique was introduced by Lynn et al  and is able to induce coagulative necrosis in selected tissues without damaging adjacent structures. Although HIFU has been studied for 50 years, recent technological developments now allow its use for tumours of the liver, prostate and other sites.

In liver disease, HIFU has been used to treat unresectable, advanced stages of hepatocellular carcinoma (HCC) and liver metastases. Hepatocellular carcinoma is a serious health problem worldwide and is endemic in some areas because of its association with hepatitis B and C viruses (in 20% of cases). Liver transplantation (LT) has become one of the best treatments available because it removes both the tumour and the underlying liver disease such as cirrhosis (which is present in approximately 80% of cases).The prerequisite for long-term transplant success depends on tumour load and strict selection criteria regarding the size and number of tumour nodules.The need to obtain the optimal benefit from the limited number of organs available has prompted strict selection criteria limited to only those patients with early HCC who have a better long-term outcome after LT. The so-called “bridging therapy” has the aim of controlling disease burden for patients who are on the organ transplant waiting list. Amongst various treatment options, transarterial chemoembolisation and radiofrequency ablation are the most popular treatment choices. Recently, Cheung et al  demonstrated that HIFU ablation is a safe and effective method for the treatment of HCC patients with advanced cirrhosis as a bridging therapy and that it reduced the drop-out rate from the liver transplant waiting list. In this commentary, we discuss the current value of HIFU in the treatment of liver disease, including its value as a bridging therapy, and examine the potential advantages of other therapeutic strategies.

© 2013 Baishideng Publishing Group Co., Limited. All rights reserved.

Key words: High-intensity focused ultrasound; Hepatocellular carcinoma; Liver transplantation; Bridging therapy; Waiting list

 

Core tip: High-intensity focused ultrasound (HIFU) is a non-invasive modality used to destroy tissue. It has been used to treat unresectable advanced stages of hepatocellular carcinoma (HCC) and liver metastases.

In some HCC cases, liver transplantation has become one of the best treatments because it removes the tumour and the underlying liver disease such as cirrhosis.

The so-called “bridging therapy” has the aim of controlling disease burden for patients who are on the organ transplant waiting list. Here, we discuss various treatment options including transarterial chemoembolisation and radiofrequency ablation, and we examine the utility of HIFU as a safe and effective method of bridging therapy that can reduce the dropout rate of patients who are on the liver transplant waiting list.

 

____________________________________________

Mearini L. High intensity focused ultrasound, liver disease and bridging therapy. World J Gastroenterol 2013; 19(43): 7494-7499 

Available from: URL: http://www.wjgnet.com/1007-9327/full/v19/i43/7494.htm 

DOI: http://dx.doi.org/10.3748/wjg.v19.i43.7494