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.

Evaluation of Liver and Spleen Stiffness with Acoustic Radiation Force Impulse Quantification Elastography for Diagnosing Clinically Significant Portal Hypertension.

PURPOSE: Hepatic vein pressure gradient (HVPG) is the gold standard for diagnosing clinically significant portal hypertension (CSPH). The aim of this study was to investigate-in comparison to HVPG-the ability to diagnose CSPH by liver and spleen stiffness measurements obtained by acoustic radiation force impulse (ARFI) imaging. MATERIALS AND METHODS: A total of 78 patients (mean age: 53 ±â€Š13 years, 62 % male) with chronic liver disease were enrolled in this study. Each patient received liver (LSM) and spleen (SSM) stiffness measurements by ARFI, an HVPG measurement and a transjugular liver biopsy on the same day. Patients were classified according to their HVPG into three different groups: HVPG < 10 mmHg, HVPG ≥ 10-< 12 mmHg and HVPG ≥ 12 mmHg. RESULTS: LSM, SSM were significantly higher in patients with HVPG ≥ 10 - < 12 in comparison to HVPG < 10 mmHg (p < 0.001 and p < 0.001, respectively), and in patients with HVPG ≥ 12 mmHg in comparison to ≥ 10 - < 12 mmHg (p < 0.001 and p < 0.001, respectively). LSM and SSM were able to diagnose HVPG ≥ 10 mmHg and HVPG ≥ 12 mmHg with high diagnostic performance (AUC LSM: 0.93 and 0.87, respectively; AUC SSM: 0.97 and 0.95, respectively). The AUC of SSM in predicting esophageal varices (EVs) plus HVPG ≥ 10 mmHg and EVs plus HVPG ≥ 12 mmHg were higher compared to LSM in both groups of patients (SSM: 0.90 and 0.93 vs. LSM: 0.84 and 0.88, respectively). No significant difference between both AUCs was detected in the different HVPG groups. In the multivariate -analysis SSM remained a factor predicting HVPG (HVPG > 10 mmHg p = 0.007; HVPG ≥ 12 mmHg p = 0.003). CONCLUSION: LSM and SSM by ARFI are noninvasive diagnostic tools that may help in diagnosing CSPH. LSM and SSM could be used as a guiding noninvasive screening tool in patients with esophageal varices requiring endoscopic evaluation.

Point Shear Wave Elastography by Acoustic Radiation Force Impulse Quantification in Comparison to Transient Elastography for the Noninvasive Assessment of Liver Fibrosis in Chronic Hepatitis C: A Prospective International Multicenter Study.

PURPOSE: The aim of the present prospective European multicenter study was to demonstrate the non-inferiority of point shear wave elastography (pSWE) compared to transient elastography (TE) for the assessment of liver fibrosis in patients with chronic hepatitis C. MATERIALS AND METHODS: 241 patients with chronic hepatitis C were prospectively enrolled at 7 European study sites and received pSWE, TE and blood tests. Liver biopsy was performed with histological staging by a central pathologist. In addition, for inclusion of cirrhotic patients, a maximum of 10 % of patients with overt liver cirrhosis confirmed by imaging methods were allowed by protocol (n = 24). RESULTS: Owing to slower than expected recruitment due to a reduction of liver biopsies, the study was closed after 4 years before the target enrollment of 433 patients with 235 patients in the 'intention to diagnose' analysis and 182 patients in the 'per protocol' analysis. Therefore, the non-inferiority margin was enhanced to 0.075 but non-inferiority of pSWE could not be proven. However, Paired comparison of the diagnostic accuracy of pSWE and TE revealed no significant difference between the two methods in the 'intention to diagnose' and 'per protocol' analysis (0.81 vs. 0.85 for F ≥ 2, p = 0.15; 0.88 vs. 0.92 for F ≥ 3, p = 0.11; 0.89 vs. 0.94 for F = 4, p = 0.19). Measurement failure was significantly higher for TE than for pSWE (p = 0.030). CONCLUSION: Non-inferiority of pSWE compared to TE could not be shown. However, the diagnostic accuracy of pSWE and TE was comparable for the noninvasive staging of liver fibrosis in patients with chronic hepatitis C.

Overview and evaluation of the value of fine needle aspiration cytology in determining the histogenesis of liver nodules: 14 years of experience at Hannover Medical School.

Fine needle aspiration (FNA) is a sensitive and specific method (95%), often helpful in characterizing suspected liver lesions. It is appropriate to distinguish between primary and secondary liver neoplasia. Moreover, in most cases, the use of cell block preparations of small specimens allows immunocytochemical evaluation to determine the nature of the primary tumour. In a retrospective study at Hannover Medical School (MHH) from 1998 to 2012 (14 years), 4,136 sonographically guided FNAs were performed. The patients provided consent and the study protocol was approved by the local ethics committee. There were 39.6% malignant and 57.5% benign lesions in the liver, while 2.8% of the cases were undetermined. FNA was non-representative in 1.1% of the cases. The diagnostic utility of highly differentiated hepatocellular carcinoma (HCC; G1) remains difficult; cell bridges with cell atypia are pathognomonic for diagnosis. Ancillary techniques and immunocytochemical investigations will increase the sensitivity and specificity, particularly by using the cell block technique.

[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.

ARFI elastography of the spleen is inferior to liver elastography for the detection of portal hypertension.

PURPOSE: To date, the use of transient elastography has been limited to the liver. Acoustic radiation force impulse imaging (ARFI) is a new technology offering elastography of different tissues. Here, we present initial spleen elastography data and evaluate its influencing factors, especially portal hypertension. MATERIALS AND METHODS: Elastography of the spleen and liver using the ARFI method was performed in 30 patients with portal hypertension, 70 patients with chronic liver disease without portal hypertension and 25 healthy controls. RESULTS: ARFI elastography of the spleen was feasible in 99% of patients and valid in 78%. The mean propagation velocity inside the spleen was 2.95 ± 0.60 m/sec, thus much higher than in the normal liver (< 1.10 m/sec). Spleen stiffness was higher in the patients with portal hypertension (p < 0.008) but did not correlate to spleen size. Spleen stiffness increased with patient age and liver stiffness (both p < 0.0001) as confirmed by multivariate analysis (R2 = 0.19, p < 0.01). In ROC analysis, spleen elastography was inferior to liver elastography for the detection of portal hypertension (area under the curve 0.68 vs. 0.90). CONCLUSION: The new ARFI method allows accurate elastography of the spleen. The stiffness of the normal spleen is much higher than that of the normal liver and increases with age. However, spleen elastography is inferior to liver elastography for the detection of portal hypertension.

[Ultrasound education by simulator training--analysis of the largest simulator-based training in Germany]. / Ausbildung am Ultraschallsimulator--Analyse der größten simulatorbasierten Fortbildung in Deutschland.

Teaching ultrasound (US) has not been sufficiently standardised yet. Most educational devices in US consist of 2-dimensional B-mode images. However, the identification of anatomic structures in the 3-dimensional space can only be learned by practical hands-on education. In US simulators, US images of real pathologies are created by the examination of a dummy with a mock transducer. The resulting US images were previously recorded in a 3-dimensional format and were processed in a way which facilitates the reconstruction and projection of the images on a screen corresponding to the sectional plane of the mock transducer, simulating the conventional B-mode images. This enables standardised, real-time, hands-on training of US pathology detection. In June 2007, a hands-on workshop on US simulators was performed in the 1st Department of Internal Medicine of the Johannes Gutenberg-University in Mainz/Germany. During 15 days, 209 participants from all parts of Germany were trained. The workshop included an evaluation to elucidate the value and acceptance of this kind of US training. 149 evaluation forms could be analysed (72 %). The participants were fairly heterogeneous and belonged to the following subspecialties: internal medicine (50 %), surgery (11 %), others (18 %). 72 % were residents, 22 % consultants. 40 % of the participants worked in university hospitals, 12 % in hospitals of highest clinical level, and 42 % in hospital of basic care. Baseline knowledge in US was quite different, too, reflected in the number of independently performed US examinations prior to this course: 0 - 400 examinations (44 %), 401 - 1000 examinations (14 %), 1001 - 4000 examinations (7 %), and > 4000 examinations (2 %). Of note, 56 % of the participants had not received any kind of formal training in US. In daily practice 77 % were trained by tutors, whose formal qualification in US was unknown. Only a small proportion of the tutors had received training in US according to the standards of the German Association of US in Medicine (DEGUM). This evaluation shows the high level of acceptance of simulator-based training in US despite the heterogeneity of the participants. 95 % rated the teaching value as "high" and 95 % wished an integration of US simulators in training curricula. In summary, this analysis proves the need for standardised training programmes in US teaching in Germany and a high level of acceptance of simulator-based US training.

[CMV-enterocolitis as a cause for repeated intestinal intussusceptions in an adult patient after liver transplantation?]. / CMV-Enterokolitis bei einer erwachsenen lebertransplantierten Patientin als Ursache rezidivierender Invaginationen?

Intestinal intussusception in the adult is often idiopathic but also known to be associated with chronic inflammatory bowel disease, coeliac disease, tumours or previous abdominal operations. A 22-year-old women after liver transplantation due to Crigler Najar Syndrome suffered from repeated episodes of abdominal pain. The diagnosis of repeated self-limited intestinal intussusceptions was made by computed tomography and ultrasonography. A laparoscopy revealed no cause for the intussusceptions. During a new episode of abdominal pain caused again by an intussusception a colonoscopy was performed that showed aspects of a discreet colitis. In the biopsies CMV was detected by qualitative PCR, while blood tests for CMV pp65 antigen were negative. A therapy with gancyclovir was initiated which lead to remission of the patient's symptoms. A colonoscopy six weeks later showed a completely normal colon, while in the biopsies CMV was not detectable. After a follow-up of one year the patient has not suffered from any further episodes. This case demonstrates the role of chronic intestinal CMV infection as a possible causative factor for repeated intussusceptions in immunosuppressed patients. Whenever possible a PCR for CMV in colon biopsies should be carried out to detect an intestinal CMV infection because as shown in our case results for immunohistopathology and CMV pp65 can be negative despite a chronic infection.

Occupational risks for adenocarcinoma of the nasal cavity and paranasal sinuses in the German wood industry.

OBJECTIVES: To examine the risk of wood dust and chemical exposures for adenocarcinoma of the nasal cavity and paranasal sinuses (ADCN) among German wood workers. METHODS: An industry-based case-control study with 86 male ADCN cases and 204 controls was conducted in the German wood-working industries. Cumulative and average wood-dust exposure was quantified with a job-exposure matrix based on wood-dust measurements at recent and historical workplaces. Probabilities of exposure to wood preservatives, stains, varnishes, and formaldehyde were semi-quantitatively rated. Odds ratios and 95% confidence intervals were calculated with logistic regression analysis conditional on age and adjusted for smoking and other factors. For estimating the risks of either wood dust or chemical additives, the authors additionally adjusted for the corresponding co-exposure. RESULTS: ADCN occurred relatively more frequently among wood workers that had ever worked as cabinet makers or joiners (OR 2.96, 95% CI 1.46 to 6.01) than as saw millers (OR 0.15, 95% CI 0.03 to 0.68). Average exposure to inhalable wood dust >/=5 mg/m(3) was associated with a high risk (OR 48.47, 95% CI 13.30 to 176.63) compared to levels below 3.5 mg/m(3). Assuming 40 years of exposure under these concentrations, the corresponding OR was 4.20 (95% CI 1.69 to 10.43). Exposure between 3.5 and 5 mg/m(3) was also found to pose a risk (OR 10.54, 95% CI 3.34 to 33.27). Exposure to pigment stains before 1970 was associated with an increased risk (OR 3.03; 95% CI 1.11 to 8.26). No significant associations were estimated for wood preservatives, varnishes, and formaldehyde. CONCLUSIONS: The authors found an elevated ADCN risk for exposure to inhalable wood dust above 3.5 mg/m(3). The rareness of the disease does not allow the exclusion of risk below that concentration. For pigment stains, there is evidence for an association of historical exposure with the development of ADCN in German wood workers.

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.

[Diagnostic imaging of liver tumours. Current status]. / Bildgebende Diagnostik von Lebertumoren: Aktueller Stand.

Nowadays, contrast enhanced ultrasound (CEUS) is an imaging technique equivalent to multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) for the detection and characterization of focal liver lesions. These methods have comparable sensitivity and specificity in differentiating a liver lesion as "benign" or "malignant". For benign lesions, CEUS is the recommended method of the choice. In unclear cases, or if CEUS is not available, MRI or CT are the methods of the second choice. If a benign tumor remains unclear, then a needle biopsy is recommended. In the case of a malignant tumor, it is necessary to use a second imaging technique besides CEUS. In addition to the detection and characterization of a liver tumor, CT and MRI provide information on the extrahepatic spread of a tumor, particularly into the lung or retroperitoneum. The rapid development of surgical and interventional approaches requires accurate information on the character and number of malignant liver lesions. Therefore, the combined use of CEUS and MDCT or MRI currently represents the most modern and optimal standard of imaging. The standardization of CT and MRI protocols has increased the general diagnostic level of these images. Adequate training and a certificate for the use of CEUS is recommended in order to maintain the high diagnostic level of this method (EFSUMB guide lines). An optimal interdisciplinary imaging strategy for focal liver lesions minimises unnecessary invasive or potentially harmful imaging and reduces health costs.

[Ultrasound education by simulator training high acceptance by ultrasound trainees of all qualification levels]. / Ultraschallausbildung am Ultraschallsimulator.

Ultrasound education improves by simulator training, however, the acceptance of ultrasound simulator training has not been investigated. Therefore we evaluated the participants response to simulator education during an ultrasound course of abdominal emergencies at an international ultrasound congress, at a regular ultrasound course and during courses at a regional hospital and an university hospital. Altogether, 62.3% of the participants judged the simulator image quality to be good. 84.3% considered the case selection to be good and 92.7% of the participants viewed the educational benefit to be good. 98.5% whished to have further ultrasound simulator courses to be developed and 95.3% of the participants opted for the integration of simulator training into the conventional ultrasound education.

[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.

[Incarcerated Spieghel-Hernie mimicking an acute exacerbation of Crohn's disease]. / "Akute Exazerbation des Morbus Crohn" erweist sich sonographisch als inkarzerierte Spieghel-Hernie.

We report on a 25-year-old woman with long-standing Crohn's disease. Upon admittance to the emergency department, the patient complained of abdominal pain with increasing intensity over the last few days. Clinical examination revealed an abdominal mass in the right lower quadrant, and blood tests showed elevated markers of inflammation. Surprisingly, abdominal ultrasound did not show the suspected complication of Crohn's disease, but rather an incarcerated abdominal wall hernia, which turned out to be a spigelian hernia upon surgical repair. This case stresses the importance of abdominal ultrasound to rule out other diagnoses in patients with chronic inflammatory bowel disease in the emergency setting before starting a potentially dangerous treatment with high-dose steroids.

[Improvement of ultrasound education by simulator training]. / Verbesserung der Sonographieausbildung durch Schulung am Ultraschallsimulator.

Ultrasound education is complicated by varying quantities and qualities of specific pathologies resulting from distinct patient collectives. Furthermore, under current clinical conditions ultrasound educators as well as trainees frequently lack the time necessary for a sufficient ultrasound education. Finally, current ultrasound education materials including "gold standard" images are not ideally suited for teaching scanning three-dimensional pathologies. An improvement of ultrasound education is feasible by training ultrasound trainees on an ultrasound simulator we developed. By using this simulator as well in the classical beginner and advanced level courses as in focused courses of abdominal emergencies or general practice for instance, ultrasound trainees are able to practice scanning of numerous well defined pathologies under realistic conditions.

[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.

[New concepts in ultrasound education in gastroenterology by simulator training]. / Neue Konzepte in der gastroenterologischen Sonographieausbildung durch Schulung am Ultraschallsimulator.

Ultrasound is one of the most important imaging methods in medicine. However, ultrasound education is complicated by varying quantities and qualities of specific pathologies resulting from distinct patient collectives. Furthermore, under current clinical conditions ultrasound educators as well as trainees frequently lack the time necessary for a sufficient ultrasound education. Finally, current ultrasound education materials including "gold standard" images are not ideally suited for teaching scanning three-dimensional pathologies. In a direct cross over study we recently proved, that the ultrasound simulator we developed simulated the real patient examination reliably and reproducibly. By using this simulator as well in the classical beginner and advanced level courses as in focused courses of abdominal emergencies for instance, ultrasound trainees are able to practice scanning of well defined pathologies under realistic conditions, which has not been possible before. Furthermore, the ultrasound simulator is well suited for a structured ultrasound training in single hospitals as well as in continuous medical education. Finally, objective, standardized ultrasound quality control has become possible with the simulator.

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.

Simulation of abdomen sonography. Evaluation of a new ultrasound simulator.

AIM: We developed and evaluated a simulator for the sonography of the abdomen in order to improve the teaching quality in sonography training. METHOD: Eleven medicine residents who had received 4 to 12 months full time sonography training performed ultrasound examinations of the right upper quadrant in 5 consecutive patients and in 5 simulator cases. The correctness of their findings and the time required for the examinations were measured. The subjective confidence in their findings and the handling of the ultrasound machines were rated on a visual analogue scale. RESULTS: During patient ultrasound examination 75 % (SEM 9%) of all pathologic findings were recognized by the residents, whereas 71 % (SEM 8%) of the pathologies of the simulator cases were found. This minimal difference was not significant in the paired, two sided t-test (p = 0.15). Severe pathologies did not escape detection. The time required for patient examination(10.57 min, SEM 3.25 min) was not significantly different (p = 0.53) to the time required for the simulator cases (9.59 min, SEM 2.98 min). The subjective confidence in the sonographic findings did not differ significantly (p = 0.39) between the real patient situation (68%, SEM 6%) and the simulation (64%, SEM 12 %). Only the handling of the ultrasound machines was judged to be significantly better (p=0.008) than the simulator (74%,SEM 7% vs. 61 %, SEM 12%). CONCLUSION: In this first direct crossover comparison between real patient sonography and simulator based scanning we proved that the simulator we developed simulates the real patient examination reliably and reproducibly.