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Biomedical subjects

H Nahum

Publications and source records attributed to H Nahum.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Correlation of MR changes with Doppler US measurements of blood flow in exercising normal muscle.

Muscle data from phosphorus-31 magnetic resonance (MR) spectroscopy and hydrogen-1 MR imaging and popliteal artery data from duplex Doppler ultrasound were compared during an exercise test of the anterior compartment of the leg, in nine healthy volunteers. Significant variations (mean +/- standard deviation) were observed at the end of exercise versus rest in intracellular pH (pHi) (6.32 +/- 0.02 vs 7.02 +/- 0.04, P < .001), T2 (38.2 msec +/- 2.3 vs 29.5 msec +/- 1.1, P < .001), and popliteal output (652 mL/min +/- 232 vs 149 mL/min +/- 65, P < .001). These variables showed the following significant correlations at the end of exercise: T2 and pHi (r = -.784, P < .01), T2 and popliteal output (r = .737, P < .03), and pHi and popliteal output (r = -.902, P < .001). However, during recovery, the T2 curve was significantly different from those of pHi and popliteal output. This suggests that even if circulatory conditions play a role in the maximum T2 variation during exercise, they do not directly explain T2 changes. Furthermore, the correlations involving pHi suggest the role of the metabolism of exercising muscle in transcapillary fluid movement.

Adult↗
PubMedDate not supplied

Association of multiple liver cell adenomas with spontaneous intrahepatic portohepatic shunt.

The association of multiple liver cell adenomas containing foci of focal nodular hyperplasia with a spontaneous intrahepatic portohepatic venous shunt is reported in a 13-year-old male patient. At least eight nodules less than 10 cm in diameter were recognized and proved by means of surgical resection or surgical biopsies. These lesions were heterogeneous and hypodense on precontrast computed tomographic (CT) scans, and were slightly enhanced after injection of contrast medium. At magnetic resonance (MR) imaging, the signal intensity of these nodules varied. It was either hyperintense or hypointense on T1-weighted SE images. Sonography and angiography demonstrated a portohepatic venous shunt and hepatic arterialization was observed. These findings emphasize the hypothesis that hepatic arterialization may cause the development of liver cell adenomas. Moreover, it is suggested that liver cell adenoma and focal nodular hyperplasia have a common pathogenesis.

Adenoma, Liver Cell↗
PubMedDate not supplied

Disappearance of liver cell adenoma: CT and MR imaging.

We report the disappearance of liver cell adenoma, documented by computed tomography (CT) and magnetic resonance (MR) imaging. A 42-year-old woman with a diagnosis of hepatic adenoma was followed up by CT and MR imaging after cessation of oral contraceptive use. At the time of diagnosis, the adenoma was 4 cm in diameter and appeared hypervascular on CT. At MR imaging, the lesion was hypointense on T1-weighted sequences, and hyperintense on T2-weighted sequences. The lesion disappeared 4 years after cessation of oral contraceptive use. We conclude that in nonoperated patients CT scans and MR imaging are useful for following the evolution, and documenting the regression, of liver cell adenomas.

Adenoma, Liver Cell↗
PubMedDate not supplied

Sarcoidosis of the pineal region: CT and MR studies.

An isolated sarcoid involvement of the pineal region is reported. This case is of interest because of an unusual clinical onset, an exceptional location, and a positive response to radiotherapy after unsuccessful steroid therapy. The evolution of this case as shown by CT and magnetic resonance studies is discussed.

Adolescent↗
PubMedDate not supplied

MRI and cine MRI of asymmetric septal hypertrophic cardiomyopathy.

OBJECTIVE: This study was designed to determine MR and cine MR characteristics of asymmetric septal hypertrophic cardiomyopathy and to correlate MR and cine MR features with the severity of left ventricular outflow tract obstruction. MATERIALS AND METHODS: Ten consecutive patients with asymmetric septal hypertrophic cardiomyopathy [resting obstructive (n = 3), latent obstructive (n = 4), nonobstructive hypertrophic (n = 3)] and five healthy volunteers underwent MRI and cine MRI. Oblique two chamber and four chamber views were obtained in all cases. RESULTS: In the 10 patients, the mean +/- SD end-diastolic myocardial thickness was 22.7 +/- 6.3 mm in the basal septum and 13 +/- 3.9 mm in the posterolateral wall with a ratio of 1.76 +/- 0.30; the corresponding values were 10.6 +/- 1.1, 10.4 +/- 1.1, and 1.02 +/- 0.08 mm, respectively, in five healthy volunteers. The mean systolic thickening of the basal septum was 22 +/- 12%. This value was 49 +/- 4% in the five healthy volunteers. In resting obstructive hypertrophic cardiomyopathy, septal wall thickness was > or = 25 mm with a systolic thickening of 10%. A systolic anterior motion of the mitral valve was demonstrated in four patients with resting subaortic pressure gradients ranging from 28 to 120 mm Hg. A signal void area was demonstrated within the left ventricular outflow tract during systole in the seven patients with obstructive cardiomyopathy. This signal void area reached its maximum during early systole in the most severe obstructions and during midsystole in the less severe obstructions. CONCLUSION: In patients with asymmetric septal hypertrophic cardiomyopathy, gross correlation was demonstrated between severity of obstruction and several MR and cine MR features including increased end-diastolic thickness of the septal wall, decreased systolic thickening of the septal wall, systolic anterior motion of the mitral valve, and signal void area within the left ventricular outflow tract during systole.

Adult↗
PubMedDate not supplied

Cine MRI of mitral regurgitation in planes angled along the intrinsic cardiac axes.

OBJECTIVE: This prospective study was designed to evaluate the mechanism and severity of mitral regurgitation (MRG) by means of cine MRI using planes angled along the intrinsic cardiac axes. MATERIALS AND METHODS: In 25 patients with MRG, analysis of the direction, extent, and distribution of left atrial signal void area was performed on both two chamber and four chamber cine MRI views. Cine MRI features including qualitative grading, maximal length of regurgitant jet, and ratio of regurgitant jet area to left atrial area were compared with the results of color flow Doppler (CFD) mapping (n = 25), angiography (n = 20), and regurgitant fraction as determined at catheterization (n = 15). RESULTS: In the four chamber view, cine MRI demonstrated central extension of regurgitant jet (n = 8) in cases with dilatation of valve annulus or retraction of both mitral valve leaflets, anterior extension (n = 8) in cases with prolapse of the posterior leaflet, and posterior extension (n = 7) in cases with prolapse of the anterior leaflet or retraction of the posterior leaflet. In two cases of mild MRG with small signal void area, evaluation of mechanism was not feasible. The results of cine MRI and angiographic qualitative gradings were the same in 19 of the 20 patients and differed by one grade in the other patient. In the 25 patients, maximal length of the regurgitant jet was well correlated with both regurgitant jet area and ratio of the jet area to the left atrial area as determined by CFD mapping (r = 0.91, r = 0.85, p < 0.0001, respectively). In 15 patients the maximal length of regurgitant jet was correctly correlated with regurgitant fraction determined at catheterization (r = 0.76, p < 0.001). CONCLUSION: Cine MRI by means of planes angled along the intrinsic cardiac axes allows assessment of both the mechanism and the severity of MRG.

Adult↗
PubMedDate not supplied

Nontumorous attenuation changes on CT arterial portography.

OBJECTIVE: We prospectively studied the frequency and the distribution of nontumorous attenuation changes during CT arterial portography. MATERIALS AND METHODS: Computed tomography arterial portograms were obtained in 67 consecutive patients. The frequency and distribution of nontumorous attenuation changes (pseudolesions, areas of hypo- or hyperperfusion) were analyzed and related to the size of the tumor, the vascular status assessed by Doppler examination, and the presence of chronic liver disease. RESULTS: Pseudolesions were detected in 19 patients (28%). They were typical in 13 cases and atypical (round shaped or located in the caudate or right lobe) in 6. Segmental, lobar, or diffuse perfusion defects were seen in 36 patients (54%). In 56% of the cases, they were adjacent to large tumors and related to compression or thrombosis of intrahepatic portal branches as demonstrated by sonographic and Doppler findings. Areas of hyperperfusion were detected in 14 patients (21%). Of these cases, eight (57%) were peritumoral hyperperfusion. In all cases, the mean diameter of the tumors was large and there was compression of adjacent hepatic vein as demonstrated by sonographic and Doppler findings. CONCLUSION: Nontumorous attenuation changes are common in CT arterial portography. Factors leading to these artifacts include size of the tumor and vascular consequences of the tumor. Sonographic and Doppler studies may play a role in predicting these factors.

Adolescent↗
PubMedDate not supplied

Inflammatory pseudotumor of the liver: radiologic-pathologic correlation.

OBJECTIVE: To report the imaging appearance of inflammatory pseudotumor of the liver with pathologic correlation in three cases. MATERIALS AND METHODS: Sonography and CT were performed in all cases. Two lesions were evaluated with MRI. All lesions were resected, and imaging data and histopathology were correlated. RESULTS: In all three cases ultrasonography revealed a hypoechoic well-circumscribed mass. In one case CT showed a hypodense homogeneous lesion with central calcifications. No enhancement was demonstrated on postcontrast CT. The lesion appeared hypointense relative to the adjacent liver on T1-weighted MRI and isointense on T2-weighted MRI. A perilesional rim was detected in all cases on postcontract CT and/or MRI. This rim correlated with the histopathologic demonstration of a fibrous capsule in all three cases. CONCLUSION: The following features may be encountered in inflammatory pseudotumor: a homogeneous avascular appearance on CT, isointense signal on T2-weighted MRI, and the presence of a capsule. All these findings correlated well with histopathologic findings.

Adult↗
PubMedDate not supplied

[Treatment of headache in neuro-radiological investigations (author's transl)].

The aim of this study was to try the efficiency of tiapridal in preventing headache during neuro-radiological procedures. In spite of indiscutable curative effect, this drug does not prove to be efficient in preventive effect. The authors described a new protocol using IV infusion at the end of the radiological procedure, followed by pills per os. No side effect was observed.

Administration, Oral↗
PubMedDate not supplied

Hypertrophic cranial pachymeningitis: assessment with CT and MR imaging.

Three patients with diffuse idiopathic cranial pachymeningitis with predominant involvement of the tentorium and falx are reported. Progressively increasing headaches were the usual symptoms, along with ataxia and various cranial nerve palsies. CT in all cases and MR imaging in two cases detected isolated thickened dura mater. In one case, MR depicted dural involvement as a very large, hypointense area with fine hyperintense edges on T2-weighted images. Microscopic examination of thickened dura revealed extensive fibrotic tissue with a chronic inflammatory infiltrate containing lymphocytes, plasma cells, and scattered eosinophils; these findings closely paralleled the MR features. Only four cases with similar pathologies have been described, all before the advent of CT and MR. We discuss the different causes of thickened dura mater as well as the significance of the fact that dural thickening can be responsible for occlusion of the dural sinuses. Cranial pachymeningitis is a rarely reported disease that can resemble other disorders associated with tentorial thickening; CT and MR can help differentiate it from these other disorders.

Adult↗
PubMedDate not supplied

[Pancreatic cystadenomas. Pitfalls and limitations of radiologic diagnosis].

Pancreatic cystadenoma (CA) are rare tumors. According to the classification described by Compagno and Oertel, microcystic and macrocystic CA are differentiated. The former is a benign tumor with slow growth, but the latter has a malignant potential. According to the literature, these tumors may be differentiated on the basis of US and CT findings in a high percentage of cases. We report a series of 11 cases (5 microcystic CA, 4 mucinous CA, 1 leiomyoblastoma and 1 adrenal cyst) representing all cases of radiologically suspected CA and all cases of histologically proved CA. A correct diagnosis of microcystic CA was possible in 2 out of 5 cases, and in 3 out of 4 cases of mucinous CA. The 2 extra-pancreatic tumors were misinterpreted as mucinous CA. No patient had a false positive diagnosis of microcystic CA. The diagnosis of mucinous CA was made in 7 cases, but only 3 were true positives. There was 1 false negative of mucinous CA. In other cases, laparotomy and resection are mandatory as sonography and CT cannot accurately detect malignancy or differentiate pancreatic CA from adjacent sites tumors.

Adult↗
PubMedDate not supplied

[Intramural hematoma of the esophagus after endoscopic sclerotherapy. X-ray computed tomographic aspect and course].

A case of intramural oesophageal hematoma following endoscopic sclerotherapy is reported. CT showed a spontaneous hyperdense masse without enhancement after intravenous bolus of contrast material which confirmed the diagnosis; it permitted to eliminate another abnormality (e.g. perforation) and to survey the evolution (complete recovery without treatment in about four weeks).

Adult↗
PubMedDate not supplied

[Complications of colonic esophagoplasty. Radiologic aspects].

Early or late postoperative complications in 52 patients undergoing colic esophagoplasty for benign (27 cases) or malignant (25 cases) lesions of esophagus are discussed in relation to radiologic findings. Immediate postoperative complications due to infection were mainly bronchopneumopathies (14 cases), their incidence being increased by recurrent nerve palsy, and mediastinitis (3 cases). The frequency of upper anastomotic fistulae (16 cases) emphasizes the need for routine radiologic follow up on the 7th postoperative day by upper digestive tract follow-through examination with water-soluble contrast. Stenosis of upper part of graft may be of ischemic or fibrous origin. Ischemic stenosis develops 2 weeks to 4 months after surgery as a long filiform narrowing. Fibrous stenosis occurs in upper anastomosis at a later stage, after the 3rd month, as a short regular narrowing. Other complications are rare.

Adolescent↗