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Biomedical subjects

H Nahum

Publications and source records attributed to H Nahum.

At least 19 recordsLinked to original sources
PubMed1992

Facial nerve neuromas: MR imaging. Report of four cases.

Four cases of facial nerve neuroma were evaluated by computed tomographic (CT) scan and magnetic resonance imaging (MRI). The extension of the tumor in the petrous bone or the parotid gland was well defined by MRI in all cases. CT scan was useful to demonstrate bone erosions and the relation of the tumor to inner ear structures. In cases of progressive facial palsy, CT and MRI should be combined to detect a facial neuroma and to plan the surgical approach for tumor removal and nerve grafting.

Adult↗
PubMed1992

Haemangioma of the petrous bone: MRI.

Gd-DTPA-enhanced MRI provided accurate demonstration of the site and extension of a haemangioma of the petrous bone. Enhanced-MRI could allow early detection and differentiation from the other more common tumours of the geniculate ganglion area, thereby permitting the surgeon to remove the tumour, while preserving the facial nerve. CT is, however, required to display the characteristic ossification in these tumours.

Contrast Media↗
PubMed1992

Focal nodular hyperplasia of the liver: MR imaging and pathologic correlation in 37 patients.

Thirty-seven patients with 48 lesions of focal nodular hyperplasia (FNH) underwent preoperative magnetic resonance (MR) examination and surgical resection. Sixteen lesions were imaged at 0.5 T with T1- and T2-weighted spin-echo sequences; 32 lesions were imaged at 2 T with T1-and T2-weighted spin-echo and gradient-recalled-echo sequences. Contrast material-enhanced MR imaging was performed in 20 lesions. MR imaging failed to depict six tumors that were less than 3 cm in diameter. Typical appearance was present in 18 of the 42 (43%) lesions seen at MR. Atypical lesion features included no scar (n = 15), hypointense scar on T2-weighted images (n = 7), pseudocapsule (n = 6), strong hyperintense lesion on T2-weighted images (n = 3), diffuse hyperintensity on T1-weighted images (n = 3), and heterogeneous lesion (n = 1). Comparison between findings at MR imaging and at histopathologic examination was performed in 38 lesions: There was good correlation between presence and size of the scar on both examinations. In 13 of 20 (65%) of the hyperintense scars on T2-weighted images, edema was prominent, whereas in five of the seven (71%) hypointense scars on T2-weighted images, edema was absent or low.

Adult↗
PubMed1992

US-guided percutaneous liver biopsy with plugging of the needle track: a prospective study in 72 high-risk patients.

The efficiency, accuracy, and safety of ultrasound-guided liver biopsy with plugging of the needle track were prospectively assessed in 72 patients at high risk for hemorrhage. Seventy-eight biopsy procedures were performed in 72 consecutive patients prospectively classified into four different groups on the basis of coagulation parameters. Sixty-two patients (86%) had severe or moderately severe coagulation disorders. Fifty-four biopsy procedures were performed in 50 patients with diffuse liver disease, and 24 were performed in 24 patients with focal liver lesions. The biopsy track was embolized with gelatin particles and thrombin. Biopsy specimens adequate for histologic diagnosis were obtained in 69 of the 72 patients (96%). In focal lesions, accuracy and sensitivity in the diagnosis of malignancy were 75% and 89%, respectively. Two serious bleeding complications (2.8%) were encountered in two of the patients with major coagulation disorders. Liver biopsy with plugging of the needle track is a practical technique and is a feasible alternative to the transjugular approach. Respective indications for both methods depend on the severity of coagulation disorders and the presence of focal lesions.

Adult↗
PubMed1992

[Prospective comparison between a clinical and biological score and ultrasonography for the diagnosis of benign or malignant hepatic lesions].

The purpose of this study was to compare ultrasound with a clinical and biological score to differentiate benign and malignant liver lesions. The study was carried out prospectively in 100 consecutive patients with liver masses of unknown origin. The accuracy of ultrasound and the score was 84% and 76%, respectively (P = 0.02). Ultrasound and the score gave the same results for the diagnosis of hepatic lesions in 68% of cases. When both ultrasound and the score were in agreement, the prediction of malignancy was 94% ant that of benignity was 100% accurate. Although ultrasound was superior to the score in this series, it is interesting to calculate the score because of the higher predictive values when both methods are associated.

Adult↗
PubMed1992

MRI anatomy of the acoustic-facial bundle in vivo.

In this study performed on 5 healthy volunteers the authors used oblique axial, coronal and sagittal MRI sections suitable to be anatomical configuration of the acoustic-facial bundle and were able to individualize the nerves forming this bundle throughout their course, with the sole exception of the intermediate nerve (VII2). They also analysed the relations of these nerves between themselves and with the other elements of the cerebellopontine angle. In addition, a proton-density sequence (SE, 6,000/30 ms) made it possible to differentiate in vivo between the grey matter and the white matter sufficiently to individualize the principal nuclei and tracts of the brain stem, and in particular the main vestibulo-cochlear central pathways.

Adult↗
PubMed1991

Diagnosis of abdominal venous thrombosis by means of spin-echo and gradient-echo MR imaging: analysis with receiver operating characteristic curves.

The authors compared the accuracy of spin-echo (SE) and gradient-echo (GRE) magnetic resonance images in diagnosis of abdominal venous thrombosis. Images of 292 abdominal veins in 72 patients were reviewed in a blinded manner by three radiologists, with seven levels of confidence for diagnosis. Corroborative studies proved thrombosis (n = 95) and vessel patency (n = 197). Receiver operating characteristic (ROC) curves were constructed for SE images alone, GRE images alone, and SE and GRE images combined. At specificities of 90% and 95%, thrombi were identified with sensitivities, respectively, of 76% and 63% with SE images, 74% and 58% with GRE images, and 88% and 82% with combined SE and GRE images. The area under the ROC curve for SE and GRE images combined (0.958 +/- 0.011 [standard deviation]) was significantly larger (P less than .001) than that for SE images alone (0.913 +/- 0.018) and GRE images alone (0.921 +/- 0.016). It is concluded that combination of SE and GRE images significantly increases the accuracy of diagnosis of abdominal venous thrombosis.

Abdomen↗
PubMed1991

[Contribution of magnetic resonance imaging in the evaluation of chronic otitis].

Thirty four patients with a chronic otitis were evaluated prospectively by magnetic resonance imaging (MRI) to delineate its contribution in the diagnosis of middle ear masses. The results were correlated to the CT and the surgical and pathological findings. MRI permitted to differentiate the inflammatory tissues from either cholesteatoma, cholesterol granuloma and cerebromeningeal hernia.

Chronic Disease↗
PubMed1991

[Value of computed tomography and celiomesenteric angiography in assessing vascular involvement in cancer of the exocrine pancreas. Apropos of 31 cases].

The prediction of vascular involvement by computed tomography (CT) with intravenous bolus contrast medium enhancement was compared to that of angiography in 31 patients with pancreatic carcinoma. CT was performed in 29 patients, angiography in 18 patients, while 16 had both investigations. Results of both radiological investigations were reviewed and compared with surgical findings. Sensitivity and specificity of CT was 88 and 100 percent respectively. Sensitivity and specificity of angiography was 57 and 100 percent respectively. The four false-negative results of CT concerned the superior mesenteric and portal veins. The ten false-negative results of angiography concerned the superior mesenteric and portal veins in four cases, and the celiac and superior mesenteric arteries in six cases. Comparison of results of CT and angiography revealed that the two methods concurred in 12 patients, five without and seven with vascular involvement. In three other cases, CT detected more abnormal vessels than angiography. In another case, only CT demonstrated nonresectability. In conclusion, CT with enhancement seems to be more accurate than angiography in the prediction of vascular involvement of pancreatic carcinoma.

Adenocarcinoma↗
PubMed1990

Gadolinium-DTPA enhanced MR imaging in tuberous sclerosis.

Ten patients with clinical tuberous sclerosis were examined with CT and MR imaging, before and after IV contrast in order to determine the role of Gd-DTPA. Gd-DTPA enhancement occurred in eleven subependymal nodules which did not enhance on CT after IV contrast. As illustrated by previous CT and pathologic observations and related to the histologic similarity of the subependymal nodules and giant-cell astrocytomas, these hyperintense nodules could represent active lesions with the potential to evolve. Four giant-cell astrocytomas were detected both with CT and Gd-DTPA-enhanced MRI; tumor conspicuity and size assessment were improved by postcontrast MRI in two cases. No cortical tuber or heterotopic cluster enhanced; T2-weighted sequences therefore remain necessary for their detection. If pre and post-Gd-DTPA T1- and T2-weighted imaging is negative, CT is clearly the most sensitive modality in the detection of the small calcified subependymal nodules.

Adolescent↗
PubMed1990

Primary choroid plexus papilloma of the cerebellopontine angle: MR imaging.

The authors report the CT and MR findings of a rare benign primary choroid plexus papilloma developed in the CPA with invasion of the neighboring structures, apparently the first description of such a case. Differential diagnosis with other CPA tumors is discussed. Papillomas should be considered among the vascular, calcified enhancing masses of the CPA even in adulthood.

Aged↗
PubMed1990

Comparison between ultrasonographic signs and the degree of portal hypertension in patients with cirrhosis.

The sensitivity of ultrasonography (US) for the diagnosis of portal hypertension was assessed in 48 patients with known cirrhosis. These results were compared to the hemodynamic values obtained on the same day by hepatic vein catheterization. The sensitivity of US in detecting portal hypertension was about 40% considering either a greater than 13 mm diameter of the portal vein, or the lack of mild caliber variation of the superior mesenteric vein. The sensitivity was more than 80% considering the presence of portosystemic venous collaterals. Presence of numerous portosystemic shunts was significantly associated with high hepatic venous pressure gradients which reflected the severity of portal hypertension.

Female↗
PubMed1990

Cholangiographic appearance simulating sclerosing cholangitis in metastatic adenocarcinoma of the liver.

Three patients with liver metastases and clinical and biochemical signs of cholestasis are reported in this study. In the three patients, cholangiography showed shifted and stretched intrahepatic bile ducts and multifocal strictures simulating intrahepatic primary sclerosing cholangitis. In two patients, histological examination showed periductal fibrosis or inflammation. Hepatic metastases should be included among the conditions considered to simulate intrahepatic primary sclerosing cholangitis during cholangiography.

Adenocarcinoma↗
PubMed1990

Follicle cysts after menstrual versus midluteal administration of gonadotropin-releasing hormone analog in in vitro fertilization.

The incidence and behavior of follicle cysts after different timing of gonadotropin-releasing hormone analog (GnRH-a) administration was studied in 321 in vitro fertilization (IVF) cycles. Group M included 198 cycles in which GnRH-a was injected at menstruation. Of these, 171 (88.6%) were without cysts (group M1) and 27 (13.6%) with cysts (group M2). Group L comprised of 123 cycles in which GnRH-a was administered in the midluteal phase. Of them, 70 (56.9%) were without cystic finding (group L1), 19 (15.4%) with follicle cysts (group L2), and 34 cases (27.6%) with visible corpus luteum at the time of GnRH-a initiation (group L3). Both groups with follicle cysts demonstrated a higher luteinizing hormone peak and continuous elevated estradiol (E2) levels. In group M2, the E2 rise and the cysts persisted longer compared with group L2. Gonadotropin treatment was accordingly postponed until the cysts regressed spontaneously. Only two cases of group M2 required aspiration of the cysts. Follicle cyst formation is not related to the timing of GnRH-a administration and their occurrence did not have adverse effects on IVF outcome.

Embryo Transfer↗
PubMed1990

Ovarian response in repetitive cycles induced by menotrophin alone or combined with gonadotrophin releasing hormone analogue.

The number of oocytes retrieved for in-vitro fertilization (IVF) has a major influence on the number of embryos developed and pregnancy success. This study was designed to investigate the ovarian response in the same patient under the same and different stimulation protocols. In group A, 19 patients underwent two consecutive cycles, both stimulated with human menopausal gonadotrophin (HMG). Group B comprised 27 patients who experienced two successive cycles treated with the combination of long-acting gonadotrophin releasing hormone analogue (GnRHa) and HMG. Group C included 27 patients whose first cycle was stimulated with HMG alone, and their second with a GnRHa/HMG combination. The mean number of HMG ampoules administered and the duration of treatment were similar in both cycles of group A and B patients while in group C, both the amount and duration of HMG administration were significantly higher and longer in the combined protocol compared to HMG alone. This study demonstrates an identical ovarian response using the same mode of stimulation in repeated cycles, and a significantly improved response with the GnRHa/HMG combination compared with HMG alone in the same patient.

Chorionic Gonadotropin↗
PubMed1990

Chronic inflammatory disease of the middle ear cavities: Gd-DTPA-enhanced MR imaging.

Twenty-seven patients with chronic middle ear infection were prospectively studied with pre- and post-contrast magnetic resonance (MR) images to assess the role of MR imaging in the recognition of middle ear tissue abnormalities. The findings were correlated with computed tomographic (CT) scans and surgical and pathologic data. Granulation tissue constantly appeared enhanced on studies done with gadolinium diethylenetriaminepentaacetic acid (DTPA), unlike cholesteatoma, cholesterol granuloma, or brain herniation into the middle ear cavities. Evaluation of extension and thickness of the inflammatory tissue with MR imaging was in accordance with surgical findings. In six cases, isolated granulation tissue misdiagnosed as either a cholesteatoma or herniated brain on CT scans was accurately evaluated on postcontrast MR images. When granulation tissue was associated with other soft-tissue masses, Gd-DTPA-enhanced MR images allowed accurate definition of the site and the extension of each lesion. Furthermore, abnormal meningeal enhancement was precisely depicted by MR images in two cases.

Adolescent↗
PubMed1990

Staging of esophageal carcinoma: comparison of results with endoscopic sonography and CT.

We compared the results of endoscopic sonography and CT in the preoperative staging of 46 patients with esophageal carcinoma studied prospectively. All patients had surgery and 44 had pathologic examination of the mediastinal and celiac lymph nodes. The results of CT and endoscopic sonography were compared with surgical and pathologic findings. A total of 51 tumors were found in 46 patients. Sonographic estimation of tumor extension through the different layers of the esophagus was correct in 37 (73%) of all 51 tumors and in 22 (85%) of the 26 tumors in which the examination was complete. The echoendoscope (13-mm diameter) could not pass through the tumor in 23 cases (50%). Infiltration to adjacent organs was found in 15 cases at surgery. In four of these 15, the extension was detected by CT; in seven of the 15 cases, it was detected by sonography. False-negative determination of tumor extension occurred with endoscopic sonography in patients with stenotic tumor. There were no false-positive results with either CT or endoscopic sonography. For detection of mediastinal lymph-node involvement, the sensitivity of CT was 48%. The sensitivity of sonography was 50% if metastatic nodes unexplored by sonography were included, or 84% if only cases in which stenosis was passed were considered. Statistical comparison revealed that sonography was superior to CT for the detection of metastases to lymph nodes. CT and endoscopic sonography provide complementary information. When the echoendoscope can be maneuvered past the tumor, sonography can be used accurately to define extension through the layers of the esophagus, extension to the adjacent organs, and involvement of the lymph nodes. When the tumor cannot be passed by the echoendoscope, CT is superior to sonography for detection of mediastinal extension.

Adult↗