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Biomedical subjects

M Gebel

Publications and source records attributed to M Gebel.

At least 19 recordsLinked to original sources
PubMed2007

[Diagnostic imaging of liver tumours. Current status].

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.

Contrast Media↗
PubMed2006

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

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.

Attitude of Health Personnel↗
PubMed2005

[Improvement of ultrasound education by simulator training].

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.

Abdomen↗
PubMed2005

[Incarcerated Spieghel-Hernie mimicking an acute exacerbation of Crohn's disease].

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.

Abdomen↗
PubMed2004

[New concepts in ultrasound education in gastroenterology by simulator training].

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.

Computer Simulation↗
PubMed2003

[Ultrasound of acute abdomen].

Ultrasound is an important tool in the diagnosis of acute abdominal pain, which is mainly caused by gastrointestinal diseases. This article gives an overview on the important differential diagnosis related to pain localization. Sonomorphological signs and their sensitivity and specificity are discussed. In contrast to other imaging methods ultrasound is hand guided. The present article differentiates the diagnostic capability of ultrasonic diagnosis depending on technical equipment and sonographer's educational level. These facts are important to stabilize the position of ultrasound in the ensemble of other imaging methods. The use of mobile ultrasound machines and an improved training (e.g. by computer assisted sonosimulator systems) will lead to an increasing importance of ultrasound.

Abdomen↗
PubMed2003

Increasing sensitivity of morphological diagnosis in hepatocellular carcinoma (HCC) by combination of cytological and fine-needle histological examination after ultrasound guided fine needle biopsy.

UNLABELLED: Increasing sensitivity of morphological diagnosis by combination of cytological and fine-needle histological examination after ultrasound guided fine needle biopsy in hepatocellular carcinoma (HCC). AIM: We investigated the factors which may affect the sensitivity of morphological diagnostics (cytology and fine-needle histology) in HCC after ultrasound guided biopsy. METHOD: In 62 patients, an ultrasound guided cytological (n = 62) and fine-needle histological (n = 45) biopsy was performed. In addition, the smears were investigated by cytophotometry (n = 62). RESULTS: Considering each method separately, the sensitivity of both cytological and histological diagnostics was about 80%. The sensitivity could be raised to 89% by combining the two methods. In seven patients, the HCC could not be primarily confirmed morphologically. In nine patients, the result of histological and cytological investigation was not congruent. With regard to the size of the biopsied lesion, tumor stage, cytophotometric finding and survival these 16 patients (group A) were compared with the 46 patients in whom the HCC could be primarily confirmed morphologically (group B). The statistical analysis did reveal a significantly lower percentage of tumors with diploid or tetraploid (euploid) cells in group B. Euploid tumors were significantly more highly differentiated. In patients with euploid tumors, the sensitivity of the cytological investigation was 67% and respectively 75% of the histological investigation. The sensitivity could be raised to 82% in this population by combining the two investigations. On the other hand in aneuploid tumors, the sensitivity could only be increased from 93% and 88% respectively to 97% by combining cytology and fine-needle histology. SUMMARY: Our investigations show that the sensitivity of morphological diagnostics can be raised especially in the highly differentiated HCC with a physiological DNA content by combination of cytological and fine-needle histological investigations.

Adult↗
PubMed2003

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.

Abdomen↗
PubMed2002

[Doppler imaging of hepatic vessels - review].

Hepatic blood flow has been investigated using color Doppler ultrasonography in patients with liver disease, especially in patients with portal hypertension (e. g. liver cirrhosis, portal vein thrombosis, Budd-Chiari-syndrome). Duplex examination protocols, however, differ considerably because no standard technique has been established so far. Whereas there is an agreement about the angle of the ultrasound application (< 60 degrees ), neither the exact location nor the relevant examination parameters have been standardized. Based on a search of the relevant literature, published examination techniques and results were analyzed. These findings are to serve as a basis for a prospective multicenter study for the determination of standard values.

Blood Flow Velocity↗
PubMed2002

[Imaging of the abdomen.

In the last decade, innovative ultrasound technology has become the primary imaging method in Gastroenterology. Compared to other imaging techniques (e. g., computed tomography and magnetic resonance imaging), conventional ultrasound images have the disadvantage of a restricted field-of-view (width), thus producing images that are not always easy to read. During the examination, the many mosaic-like single images obtained in real-time sonography must be mentally pieced together by the user, in order to obtain a complex 3-dimensional picture of the anatomical structure and its surrounding tissue. The extended field-of-view of the Panoramic Imaging technique is a useful addition to conventional diagnostic ultrasound since it provides the enhanced overview required for exact topography of surrounding structures. This is especially true for the Power Mode Panoramic Imaging technique that allows the trading of vessels over greater distances, e.g., in the extremities. Thus, accuracy and reproducibility of measurements in the examination of larger structures and organs has improved. A clearer representation of these anatomical structures increases understanding and acceptance by referring clinicians. An exact diagnosis based on ultrasound imaging will certainly result in cost savings in health-care, since the use of further imaging methods (and therefore the total examination time) may be reduced.

Abdomen↗
PubMed2001

The role of Doppler velocity histograms of hepatic veins in early detection of cirrhotic changes of the liver parenchyma.

AIM: In a prospective study we measured the velocity ranges of the Doppler Velocity Histogram (DVH) of the hepatic venous system at two levels (-3 dB and -6 dB) below the maximum power level of the Doppler wave in order to investigate if that allows a higher selectivity between the Doppler tracings in hepatic veins of patients with liver cirrhosis and healthy subjects. METHODS: The DVH was measured in 23 healthy subjects and 31 patients with liver cirrhosis of different etiologies at power levels of -3 and -6 dB in the right and middle hepatic vein after an overnight fast. The DVH measurements were performed at the maximum of phase I of the hepatic venous flow in which we assessed the Peak-, Mode-, Mean-Value, and the velocity range (bandwidth). RESULTS: At both power levels the bandwidth (BW) of the DVH in the right and middle hepatic vein was significantly higher in cirrhotics than in healthy subjects (-3 dB: RHV: p = 0.048, MHV: p = 0.006; -6 dB: RHV and MHV: p < 0.0005). The selectivity between healthy subjects and cirrhotics is higher at the -6 dB level than at the -3 dB level. CONCLUSION: The DVH-measurement is a useful additional device in early sonographic detection of cirrhotic liver parenchyma changes. DVH-velocity range measurements at a level of -6 dB below the maximum power level reveal a better selectivity between healthy subjects and cirrhotic patients than measurements at the -3 dB level. It is recommendable to perform velocity range measurements at different power levels within a single frozen image.

Adult↗
PubMed2001

Surgical removal of a distinct subcutaneous metastasis of multilocular hepatocellular carcinoma 2 months after initial percutaneous ethanol injection therapy.

Subcutaneous tumor seeding after percutaneous ethanol injection therapy (PEI) for hepatocellular carcinoma is a rarely seen complication. It is reported due to needle track seeding during PEI after a distance of 6-46 months. Metastatic tumor spread is described subcutaneously, to the chest wall, abdominal wall and diaphragm. We report the case of a 76-year-old patient with chronic hepatitis B infection and cirrhosis which let to a multilocular hepatocellular carcinoma who underwent PEI. This patient developed 2 months after primary PEI a subcutaneous tumor formation confined to the right lower chest wall. Surgical tumor resection was performed. The histopathological evaluation confirmed subcutaneous seeding of the preknown hepatocellular carcinoma with a maximum of 30 mm in diameter. As a risk of PEI subcutaneous metastasis of the primary tumor should be considered even in early stage of therapy and close follow-up of the patient during treatment is required. Surgical tumor resection to ensure the curative intention of PEI is advisable.

Aged↗
PubMed2001

[Intestinal tuberculosis: Easier overlooked than diagnosed].

Intestinal tuberculosis: Easier overlooked than diagnosed. The medical history of two Asian immigrants suffering from intestinal tuberculosis demonstrates the difficulties in finding the correct diagnosis. Intestinal tuberculosis resembles Crohn's disease with regard to clinical symptoms, macroscopic and microscopic intestinal findings. Sonographic, radiologic, endoscopic, and histological examinations facilitate distinguishing both entities. Diagnosis of intestinal tuberculosis is made by identification of the causative microorganism in tissue specimens. As this may be difficult and time-consuming, a therapeutic trial with anti-tuberculous agents may be warranted.

Adult↗
PubMed2000

Comparison of portal venous flow in cirrhotic patients with and without paraumbilical vein patency using duplex-sonography.

AIM: In a prospective study we examined the effect of paraumbilical vein patency on the portal venous blood flow in patients with liver cirrhosis by Duplex-sonography. In this context we investigated the influence of the aetiology and the severity of cirrhosis on the development of venous paraumbilical shunts. METHOD: In 70 patients (Child A: 16; Child B: 27; Child C: 27) with cirrhosis of different aetiologies the portal venous flow velocity, the blood flow volume, and the diameter of the portal vein were examined by Duplex sonography after an overnight fast. RESULTS: 16 patients had a patent paraumbilical vein. The mean portal venous flow velocity (19.2 +/- 7.8 cm/s) and the flow volume (1.29 +/- 0.50 l/min) were significantly higher in patients with paraumbilical vein patency than in patients without paraumbilical shunts (14.4 +/- 4.6 cm/s; p = 0.029 and 0.88 +/- 0.34 l/min; p = 0.007 respectively). The prevalence of shunts of the paraumbilical vein in cirrhotics was significantly lower in category Child A (6.3%) than in Child B (25.9%; p = 0.011) and Child C (33.3%; p = 0.006). CONCLUSION: The occurrence of relatively high portal blood flow velocities in cirrhotics must remind the examiner of the potential existence of spontaneous portosystemic shunts. Those shunts must be carefully looked for with colour-Doppler ultrasound. In order to assess the true parenchymal blood flow we suggest to perform additional measurements of the right portal trunk and the left portal vein distal to the shunt. With an increase in the severity of liver cirrhosis the incidence of paraumbilical vein patency rises.

Adult↗