Liver stiffness measurement using acoustic radiation force impulse elastography in overweight and obese patients.

BACKGROUND: Obesity and overweight are global health problems. AIM: To evaluate the diagnostic accuracy of liver stiffness measurement (LSM) using acoustic radiation force impulse (ARFI) elastography in overweight and obese patients for staging liver fibrosis. METHODS: Ninety-seven patients (mean age: 50 years, 50% male) with body mass index (BMI) ≥25 kg/m(2) (mean BMI: 31 kg/m(2) ) were prospectively enrolled. All patients underwent ARFI elastography and liver biopsy. In 87/97 patients, transient elastography (TE) was performed (M- and XL-probes). Patients were divided into two groups respectively: overweight: BMI <30 kg/m(2) (n = 61); and obese: BMI ≥30 kg/m(2) (n = 26). RESULTS: Acoustic radiation force impulse elastography correlated with liver fibrosis in overweight (r = 0.84, P < 0.0001) and obese patients (r = 0.85, P < 0.0001), while no correlation was observed with steatosis, steatohepatitis and BMI. Area under the curve detecting liver cirrhosis for ARFI and TE were 0.97 in overweight and 0.94 and 0.92 in obese patients. In both groups, the failure rate was lower for ARFI than TE. ARFI of liver segment 8 showed a lower discordance than TE in both groups (overweight: 3% vs. 12%, P = 0.002; obese: 8% vs. 27%, P = 0.034). Steatosis and steatohepatitis were neither predictors of discordance nor of performance in LSM by ARFI or TE in both groups. CONCLUSIONS: In overweight and obese patients, acoustic radiation force impulse can diagnose liver cirrhosis and significant fibrosis with high diagnostic accuracy. Liver stiffness measurement using the XL-probe reduces the influence of BMI, steatosis and steatohepatitis. The failure and discordance rates were lower for acoustic radiation force impulse than transient elastography in both patients groups.

[Diagnostic and interventional abdominal ultrasonography]. / Diagnostische und interventionelle Abdomensonographie.

Abdominal ultrasonography is an essential tool for physicians. In contrast to other imaging methods, ultrasound examination is a cost-effective real-time imaging method without radiation effects. As in all other imaging methods, abdominal ultrasound requires an experienced examiner and high quality equipment to maintain a high quality. Abdominal ultrasonography is at least equal to cross-sectional imaging methods in most clinical issues, e.g., in inflammatory bowel disease, vascular liver diseases, or real-time surveillance of interventions. The range of applications for ultrasound has been markedly expanded by using contrast-enhanced ultrasound to detect and characterize space occupying lesions or perfusion aberrations in- and outside the liver.Ultrasound-guided fine needle aspiration biopsy or drainage of space occupying lesions and pathological liquids are minimally invasive standard ultrasound-guided interventions. Ultrasound-based tumor therapy as well as sclerotherapy of symptomatic nonparasitic cysts of the liver, kidneys, or spleen are also performed. By being able to provide quantitatively reproducible measurement of tissue stiffness, ultrasonography has entered a new era. The development of mechanical elastography also promises a new form of tissue characterization.

The type of arterial anastomosis influences hepatic hemodynamics and overall survival in liver graft recipients.

AIM: Evaluation of the influence of arterial anastomoses on hepatic hemodynamics and overall survival in liver graft recipients using color Doppler ultrasound. METHOD: 224 patients recruited retrospectively were divided into five groups according to arterial anastomoses: (1) common hepatic (CHA)/gastro duodenal, (2) CHA/CHA, (3) aorta/celiac trunc, (4) aorta/aorta, (5) more than one anastomosis. We compared maximum portal [(P)Vmax], systolic [(A)Vmax] and end diastolic [(A)Vmin] arterial velocities, resistance indexes(RI), spleen and liver size between the groups. We analyzed further in a multivariate analysis the influence of time elapsed since orthotopic liver transplantation, age of recipient and donor on significant parameters as well as the overall survival of the patients between the groups. RESULTS: Significant differences were found for: (A) Vmax between groups 2/4 (p<0.007) and 2/5 (p<0.010), (A) Vmin between groups 1/3 (p<0.029) and 2/3 (p<0.015) and RI between the groups 1/3 (p<0.018) and 3/4 (p<0.006). (A)Vmax and RI were only dependent on the type of arterial anastomosis (p<0.008 and p<0.014). The overall survival of the patients between the groups was significantly different (p<0.047). CONCLUSION: In this study we report the natural course of the mean values of portal and arterial velocities in different arterial reconstructions for the first time. (A) Vmax of the hepatic artery is identified as the most promising candidate prognostic parameter for the assessment of hemodynamic alterations after liver transplantation originating in the type of arterial anastomosis performed. The group of patients with more than one anastomosis had the lowest arterial (A) Vmax and simultaneously the lowest overall survival.

[Splenosis--important differential diagnosis in splenectomized patients presenting with abdominal masses of unknown origin]. / Splenose -- eine wichtige Differenzialdiagnose unklarer abdomineller Raumforderungen bei splenektomierten Patienten.

A 40-year-old female patient was admitted for work-up of multiple abdominal masses. The lymphoma-mimicking tumors were detected accidentally during an ultrasound course. The past medical history was unremarkable besides a status post-traumatic splenic rupture and splenectomy. The patient was asymptomatic, especially there were no complaints of fever, night sweats or weight loss. Laboratory tests did not show pathological results. Ultrasound of the abdomen revealed multiple hypoechoic mesenterial and peritoneal enlarged tumors as well as a subhepatic mass (30 x 20 mm). Transmission computed tomography (CT) showed a normal chest, excluded abnormal thoracal masses and confirmed the multiple abdominal nodules. Microparticles were trapped only by tissue with phagocytosis function as cells of the reticulohistiocytary system in liver and spleen. Uptake of (99 m)Tc-labeled microparticles is specific for splenic tissue. All abdominal masses were detectable by single photon emission computed tomography (SPECT) after intravenous administration of this radiotracer. Ultrasound-guided biopsy proved the presence of spleen tissue with follicular hyperplasia. In conclusion, we report a case of post-traumatic splenosis. In 16 - 67 % of patients who experienced traumatic splenic rupture autotransplanted spleen tissue can be detected. Splenosis therefore is an important differential diagnosis of abdominal masses in splenectomized patients.

[Transcutaneous perianal ultrasound (PAUS) for the imaging of fistulas and abscesses in Crohn's disease]. / Aktuelle Sonographie: Transkutaner, perianaler Ultraschall (PAUS) zur Diagnostik von Fisteln und Abszessen bei M. Crohn.

Pelvic MRI and transanal ultrasound constitute the gold standard for the imaging of perianal inflammatory lesions in Crohn's disease. Perianal ultrasound (PAUS), however, is rarely considered in recent literature. In contrast to the established methods, perianal ultrasound represents an easy, cost-effective and at the same time sensitive method for the imaging of perianal abscesses and fistulas. This article illustrates the performance of perianal ultrasound and shows typical images of pathological findings such as abscesses and fistulas. PAUS is especially useful for acute diagnostics to rule out perianal abscesses and for follow-up evaluation of fistula treatment. For example, complications such as abscesses can be detected in a timely manner.

Malignant lymphoma accompanied by renal cell carcinoma - a not so rare coincidence?

We report a case of a patient who presented with a left sided inguinal swelling. Ultrasound examination clearly revealed a bilateral inguinal lymphoma. In addition, a renal cell carcinoma was diagnosed through ultrasound. The differences in texture between lymph nodes and renal tumour as well as the even concentric swelling of the lymph node sinus permitted a clear cut differentiation between the two entities. CT could not provide this clear distinction. Despite some controversy several case reports as well as a few retrospective studies showed an increased coincidence of renal cell carcinoma and malignant lymphoma. However, a pathophysiological connection has not yet been discovered. This report presents another case of synchronous appearance of renal cell carcinoma and malignant lymphoma and demonstrate the relevance of ultrasound in the discrimination between the two clinical entities. It is essential for physicians performing either sonography and/or CT to be aware of this coincidence to avoid misdiagnosis of lymphadenopathy in patients with renal cell carcinoma as metastasis and, vice versa, renal tumours in lymphoma patients as renal manifestation of the lymphoma.

Diagnostic techniques in assessing vessels of the gastrointestinal tract.

Vascular disorders of the gastrointestinal tract include a variety of different underlying diseases, thus requiring different and, in many cases, more than one imaging procedure. Only a knowledge of the newest developments in vascular imaging techniques with all the possibilities and limits will ensure a time- and cost-effective, accurate and reliable diagnosis. In many acute cases and also as a screening procedure, ultrasound in combination with colour Doppler and duplex sonography, plays an important role in setting the right course for further imaging techniques, and can provide the correct diagnosis in many cases.Depending on the most prominent symptoms and the expected disease, the right choice of technique saves valuable time. Computed tomography (CT) and magnetic resonance imaging (MRI) are cross-sectional imaging techniques that not only demonstrate lesion vascularization, but also provide information about neighbouring structures and complications in an understandable and demonstrable way. The use of angiography as an invasive tool should be limited to cases where a high temporal and spatial resolution is necessary to make the diagnosis or where therapeutic interventions are also likely to be performed within the same setting. For the diagnosis of gastrointestinal vascular diseases, often no generally valid recommendation can be given, since the impact of all imaging techniques will depend on the examiner's experience, the technical equipment and on their 24-h availability in a hospital. This chapter tries to give some information about the inherent limits and indications of the different imaging techniques, as well as the newest study results concerning the most frequent vascular diseases of the gastrointestinal tract.

Use of Doppler ultrasonography to predict the outcome of therapy for renal-artery stenosis.

BACKGROUND: Prospectively identifying patients whose renal function or blood pressure will improve after the correction of renal-artery stenosis has not been possible. We evaluated whether a high level of resistance to flow in the segmental arteries of both kidneys (indicated by resistance-index values of at least 80) can be used prospectively to select appropriate patients for treatment. METHODS: We evaluated 5950 patients with hypertension for renal-artery stenosis using color Doppler ultrasonography, and we measured the resistance index ([1 - end-diastolic velocity divided by maximal systolic velocity] x 100). Among 138 patients who had unilateral or bilateral renal-artery stenosis of more than 50 percent of the luminal diameter and who underwent renal angioplasty or surgery, the procedure was technically successful in 131 (95 percent). Creatinine clearance and 24-hour ambulatory blood pressure were measured before renal-artery stenosis was corrected; 3, 6, and 12 months after the procedure; and yearly thereafter. The mean (+/-SD) duration of follow-up was 32+/-21 months. RESULTS: Among the 35 patients (27 percent) who had resistance-index values of at least 80 before revascularization, the mean arterial pressure did not decrease by 10 mm Hg or more after revascularization in 34 (97 percent). Renal function declined (defined by a decrease in the creatinine clearance; of at least 10 percent) in 28 (80 percent); 16 (46 percent) became dependent on dialysis and 10 (29 percent) died during follow-up. Among the 96 patients (73 percent) with a resistance-index value of less than 80, the mean arterial pressure decreased by at least 10 percent in all but 6 patients (6 percent) after revascularization; renal function worsened in only 3 (3 percent), all of whom became dependent on dialysis; and 3 (3 percent) died (P<0.001 for the comparison with patients with a resistance-index value of at least 80). CONCLUSIONS: A renal resistance-index value of at least 80 reliably identifies patients with renal-artery stenosis in whom angioplasty or surgery will not improve renal function, blood pressure, or kidney survival.

Detection of significant renal artery stenosis with color Doppler sonography: combining extrarenal and intrarenal approaches to minimize technical failure.

BACKGROUND: Renal artery disease can cause both hypertension and renal failure, and color Doppler sonography (CDS) may be a good screening method to detect it. Presently reported techniques of Doppler sonography have either a high rate of technical failure (4-42%), or low sensitivity and specificity, or detect only stenoses greater than 70%, or exclude patients with renal failure from analysis. In previous studies Doppler detection of renal artery stenosis (RAS) was based either on increased intrastenotic velocity or on the detection of post-stenotic Doppler phenomena. In the present prospective study these two approaches were combined to detect RAS (> or = 50% diameter reduction) in 226 consecutive patients (144 with normal and 82 with impaired renal function). METHODS: Stenosis of 50% or more was diagnosed if the maximal systolic velocity in the main renal artery was more than 180 cm/sec and velocity in the distal renal artery less than one quarter of the maximum velocity. When these velocities could not be determined a diagnosis of RAS was made when the acceleration time in intrarenal segmental arteries exceeded 70 msec. All patients subsequently underwent arteriography as the gold standard for the detection of RAS. RESULTS: With this combined approach, the technical failure rate of CDS was 0% in both patients with normal and those with impaired renal function. The mean time required for the Doppler investigation was 17 minutes. The sensitivity and specificity for detection of a significant stenosis in a given vessel (including accessory arteries), as compared to angiography, were 96.7% and 98.0%. CONCLUSION: Color Doppler sonography, evaluating both main renal and intrarenal arteries is an ideal screening method for detection of RAS of 50% or more because it allows accurate and rapid detection of stenosis in all patients, irrespective of renal function.