Biomedical subjects
Publications and source records attributed to A Rahmouni.
Extrahematologic manifestations, such as symptoms of rheumatic disease, have been recorded in association with myelodysplastic syndromes, including chronic myelomonocytic leukemia (CMML). We report the case of a 51-year-old woman with tumoral infiltration of the Achilles tendons bilaterally, indicating CMML. This diagnosis was confirmed at postmortem examination.
Seventeen patients with 19 lesions of focal nodular hyperplasia (FNH) underwent prospective examination with color Doppler ultrasound (US) and magnetic resonance (MR) imaging. In 13 lesions, color Doppler US demonstrated central spots with an arterial Doppler spectrum. The frequency shifts ranged from 1.02 to 1.94 kHz (mean, 1.56 kHz). On flow-sensitive unenhanced gradient-echo images, hyperintense central dots were depicted in only five of these 13 lesions. All the MR features of FNH were present in 12 lesions. Among the seven lesions without all of the MR features, central color spots were present with an arterial Doppler spectrum in four lesions. In the remaining three lesions, color Doppler examination demonstrated either peritumoral pulsatile flow (two lesions) or no flow (one lesion). Color Doppler US adds information about the intratumoral flow characteristics of this vascular malformative lesion and appears to be superior to MR imaging in detection of the arterial intratumoral abnormalities.
To assess the value of magnetic resonance (MR) imaging of the breast in the differentiation of late postirradiation fibrosis from recurrent carcinoma, 35 women with a history of breast carcinoma treated conservatively with radiation therapy underwent MR imaging. Nine patients had recurrent tumors confirmed at biopsy and surgery. Twenty-six patients had a localized fibrotic mass confirmed at biopsy and/or during long-term clinical and radiologic follow-up. In all cases, a localized hypointense area was present on plain spin-echo T1-weighted images. In all recurrent tumors, dynamic gadolinium-enhanced T1-weighted images demonstrated early increased signal intensity of the lesion within 3 minutes after bolus injection. The signal intensity over time in localized fibrosis differed from that in tumor recurrence, with no substantial enhancement on post-contrast T1-weighted images. Short inversion time inversion recovery and spin-echo T2-weighted images were not useful in the differential diagnosis of recurrent tumor versus radiation fibrosis.
To assess the potential value of magnetic resonance (MR) imaging in monitoring disease status, 34 patients with residual masses underwent MR imaging at sequential intervals. Patterns of signal intensity suggestive of active and inactive residual disease were compared to changes in tumor size. The signal intensity pattern was suggestive of persistent disease in 18 patients, even though tumor size was stable or decreased. Three of these patterns, seen within 6 months of initiation of therapy, were due to necrosis or inflammation. The MR imaging assessment of inactive disease was confirmed in 15 of the remaining 16 patients. In no case was an increase in tumor size seen in conjunction with a decrease in signal intensity. Because tumor size and signal intensity changes are not parallel in many cases, MR imaging may have a role in monitoring masses in patients with lymphoma. Signal intensity patterns, however, reflect gross histologic characteristics and cannot be considered specific, especially in the first 6 months after initiation of therapy.
OBJECTIVE: To determine the efficacy of fat-suppressed sequences and contrast-enhanced MR imaging for the detection of focal spinal lesions caused by multiple myeloma, we obtained MR images in 32 patients with newly diagnosed myeloma who had back pain. SUBJECTS AND METHODS: All patients had biopsy-proved myeloma and had MR imaging at the painful level of the spine. Spin-echo T1-weighted, T2-weighted, and short TI inversion-recovery (STIR) images; dynamic ultrafast low-angle shot (turbo-FLASH) images after IV injection of a bolus of paramagnetic contrast material; and contrast-enhanced T1-weighted images were obtained. We qualitatively compared the signal intensities and contrast enhancement of focal lesions with those of the surrounding vertebral bodies. RESULTS: Multiple lesions were detected in all but two of the 32 patients. On T2-weighted and STIR images, all lesions had homogeneously high signal intensity. On T1-weighted images, the lesions were visible as hypointense areas compared with surrounding bone in all except four patients, in whom the lesions were isointense or hyperintense. All tumor nodules enhanced on turbo-FLASH images obtained in the arterial phase. No additional lesions were seen on STIR or contrast-enhanced images. MR findings resulted in a change in the staging of the disease in one patient and led to prompt treatment in five patients with epidural involvement. CONCLUSION: MR imaging appears to be helpful in detecting spinal involvement in patients with multiple myeloma. The diagnosis of spinal lesions is best achieved by using either fat-suppressed or T2-weighted images. Although myeloma lesions enhanced in all patients, contrast material appears to be of no value for the detection of additional lesions.
OBJECTIVE: The aim of this study was to describe the changes in the MR appearance of painful lesions of the spine before and after treatment in 18 patients with multiple myeloma and to correlate these changes with the clinical response to treatment. SUBJECTS AND METHODS: Eighteen patients with multiple myeloma and tumor nodules in the spine had MR imaging of the same site in the spine before and after treatment. Unenhanced T1- and T2-weighted spin-echo images, dynamic ultrafast low-angle shot (turbo-FLASH) images before and after IV bolus injection of paramagnetic contrast material, and contrast-enhanced T1-weighted spin-echo images were obtained. Characteristic signal and contrast enhancement before and after treatment were compared and were correlated with clinical data and the results of immunochemical and pathologic tests. RESULTS: Changes in signal intensity and enhancement of the lesions occurred after treatment in 14 of 18 patients. The characteristics of the lesions after treatment had three patterns: (1) rim enhancement or no enhancement of the lesions, (2) early enhancing lesions associated with other nonenhancing lesions or lesions with rim enhancement, and (3) no change from the enhancement pattern seen before treatment. In 13 of 18 patients, these patterns correlated well with the response to treatment. A discrepancy was observed in five patients. CONCLUSION: The MR appearance of spinal myeloma is different before and after treatment. MR images, particularly contrast-enhanced images, may be helpful in monitoring the response to treatment of focal bone lesions of myeloma.
A prospective study was performed on 14 patients with histologically proven focal nodular hyperplasia (FNH) using a hepatobiliary scan with trimethylbromoimino-diacetic acid (TBIDA) and a colloid scan with rhenium sulfur colloids. TBIDA uptake was relatively normal in the region of the tumor, but during the clearance phase 23/25 of the tumors were detected by a hot spot of radioactivity. Depending on the relative contrast achieved between the tumor and normal liver, this hot spot appeared early or later, but was always present at 60 min. In three tumors, a "doughnut" pattern was observed within the hot spot due to a central defect. Hypervascularization was observed during the perfusion phase in 76% of the tumoral sites and normal colloid uptake in only 64%. The detectability of FNH appears greater with TBIDA (92%) than with CT or MRI (84%). The high prevalence of hot spots may be due to careful technological conditions when obtaining hepatobiliary scans. Late images, overexposed films, multiple views and stimulation of gallbladder excretion increased tumor detectability. The hot spot sign may be a useful tool when combined with the results of other imaging modalities in the diagnosis of FNH. The peculiar pathology of FNH with fibrosis, hyperplastic hepatocytes and cholangiolar proliferation might explain this scintigraphic appearance.
Fourteen files of patients having had Hodgkin's disease have been analyzed retrospectively to assess the justification of systematic surveillance after complete remission has been achieved. The data of successive CT exams, compared with the findings of clinical and biological studies performed on the same dates, confirm the primordial role of imaging, since computed tomography was predictive for 7 of 18 events (14 relapses and 4 second progressions). The occurrence of subphrenic recurrence in 3 cases for which the initial site was mediastinal leads to discussing the merits of a yearly thoraco-abdomino-pelvic examination during the two years following complete remission.
One case of cardiac metastasis of epidermoid carcinoma discovered with CT during the preoperative assessment is reported. The authors stress that the discovery of cardiac metastases in vivo is relatively infrequent. They emphasize the role of imaging, which allows ruling out the operation in these cases.
Hepatocellular carcinoma is a malignant tumor derived from hepatocytes. It is the most frequent of primary liver cancers. In 90% of the cases, it occurs in a cirrhotic liver and is now more and more detected by ultrasonographic screening of cirrhotic patients. Hepatocellular carcinoma can also be diagnosed at a more advanced stage, when complications, such as ascites, jaundice or digestive hemorrhage, occur. CT scan and magnetic resonance imaging are useful to confirm ultrasonographic findings, but angiography with infusion of Lipiodol in hepatic artery followed by CT scan remains the most sensitive method for diagnosis. Intrahepatic cholangiocarcinoma is derived from intrahepatic bile duct cells and does not occur in a preexisting cirrhotic liver. Diagnosis is usually late. Clinical features are those of hepatic malignancy with jaundice and abdominal pain. Morphological examination of the liver shows an intrahepatic tumor, sometimes associated with a dilatation of the surrounding bile ducts. Other primary malignancies are very rare. Fibrolamellar carcinoma presents as an abdominal mass occurring in a young adult with a non cirrhotic liver. Prognosis is better than that of hepatocellular carcinoma. Cystadenocarcinoma is a cystic tumor of bile ducts that can develop in a preexisting cystadenoma. Angiosarcoma is a highly malignant tumor derived from sinusoidal endothelial cells. Exposure to various carcinogens is found in 30% of the cases. Epithelioid hemangio-endothelioma differs from angiosarcoma by its occurrence in young adults and a more favorable prognosis.
Acute splenoportal and superior mesenteric venous thrombosis were diagnosed on sonography and computed tomography (CT) in six patients. Sonography demonstrated the presence of echoic material filling the involved vessels in all patients. Precontrast CT scans demonstrated an increased, intra luminal density of the clots in four patients with splenoportal thrombosis. However, in two cases of superior mesenteric venous thrombosis, no hyperdensity was observed within the lumens. Nevertheless, the clots were always visualized as low-density regions in the vessel lumens after bolus injection. Intravenous anticoagulant therapy was started immediately after the diagnosis. All patients were evaluated twice a week with sonography and/or CT until recanalization occurred. The patency of the previously involved vessels was assessed from 6 days to 4 weeks after the acute episode (average time of recanalization: 17 days) without development of collateral pathways. It is concluded that, in the absence of clinical signs of a life-threatening process, a conservative management of acute splanchnic thrombosis can be successfully achieved by (1) early diagnosis, (2) efficacious intravenous anticoagulant therapy, (3) careful imaging follow-up of these patients by sonography and/or CT during the acute phase and, finally, (4) by an extensive search for a hypercoagulable state.
A prospective study was conducted on 9 patients with suspected obstruction of the inferior vena cava on ultrasonography, dynamic computerized tomography and/or inferior venacavography during the course of a retroperitonal tumor to assess the value of magnetic resonance imaging with gradient echo sequences. The findings on gradient echo magnetic resonance imaging were compared with the other imaging modalities and surgical or necropsy results. Our results suggest that gradient echo magnetic resonance imaging is the most appropriate imaging modality to diagnose and delineate the extent of inferior vena caval obstruction.
PURPOSE: To prospectively quantify the degree of accuracy of portable chest x-ray film examination in the detection of postoperative lung consolidations. STUDY: Nineteen patients had a chest x-ray film and computed tomography (CT) scan the day before and 48 h following elective abdominal aortic replacement. RESULTS: The diagnosis of lung consolidations by x-ray film examination showed sensitivity of between 0.33 and 1.00, depending on the lung zone considered (lower at the lung bases). Specificity always was greater than 0.79. Radiologic lung volume decreased 16 percent postoperatively (p < 0.01) on average and noninflated parenchyma increased by a factor of 3 (p < 0.0001). Postoperatively, PaO2 correlated with the amount of condensed lung by CT scan (p < 0.002). CONCLUSION: In postoperative conditions, x-ray film examination is a method which presents good specificity but poor sensitivity in the diagnosis of lung consolidations.
On chest radiographs, the precise assessment of thoracic injuries consecutive to blunt trauma is often compromised by the nonspecific appearance of many lesions. Furthermore, significant injuries are frequently overlooked. However, the management of the patients with chest trauma is still often based primarily upon clinical and radiographic findings and Computed Tomography (CT) is often performed secondarily on the basis of unexplained clinical signs or suspected radiographic abnormality. Some authors have reported that CT was a highly sensitive method for detecting thoracic lesions frequently not seen or underestimated on conventional supine chest radiographs. However, the value that these new CT findings could have in the therapeutic management of these patients, have not been systematically investigated to our knowledge, except in a limited series suggesting that the course of critically ill patients could be substantially altered after thoracic CT. In order to estimate the role of early CT in the management of patient care, we report the therapeutic consequences of CT findings in forty patients who we report the therapeutic consequences of CT findings in forty patients who had a thoracic CT within few hours following a chest injury. We showed that early thoracic CT scan in patients with blunt trauma detected significantly more lesions than did chest X-Ray and appreciably modified the treatment modalities in 70% of our patients. We then recommend that all the patients admitted in ICU after chest trauma undergo a thoracic CT scan as soon as possible in order to optimize their treatment modalities.
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OBJECTIVES: The diagnosis of renal vein thrombosis (RVT), a frequent complication of adult nephrotic syndrome (NS), is generally made by means of invasive methods, i.e. renal venography, venous time of renal arteriography and, more recently, computed tomography (CT). We undertook a prospective study to evaluate the use of Doppler ultrasonography (DUS) and urinary fibrin-fibrinogen degradation products (FDPU) for the diagnosis of asymptomatic RVT. METHODS: Thirty-one adult NS with non proliferative glomerulonephritis were studied. Reference procedures [(selective renal arteriography (n = 18) and renal vein CT (n = 13)] were performed blindly within a few days (48 hours in 17 patients) of renal vein DUS (search for a lack of venous flow) and measurement of FDPU (5 micrograms/min) (in 24 patients). RESULTS: DUS was not interpretable in one patient and positive in nine. Of these 9 patients, RVT was detected by reference methods in only two (sensitivity: 1, specificity: 0.75; positive predictive value: 0.22; negative predictive value: 1). Increased FDPU was observed in 4 patients, 2 of whom had an RVT (sensitivity: 1, specificity: 0.9; positive predictive value: 0.5; negative predictive value: 1). CONCLUSION: We conclude that DUS and FDPU are helpful for screening of RVT in asymptomatic NS patients; their negativity allow further radiological investigations to be avoided while positive results must be confirmed by reference methods.
Twenty-two patients with 25 cases of focal nodular hyperplasia (FNH) proved with pathologic study were imaged with a TurboFLASH (fast low angle shot) sequence combined with bolus administration of gadolinium tetraazacyclododecanetetraacetic acid (DOTA), spin-echo (SE) T2-weighted sequences, and postcontrast T1-weighted sequences. FNH-liver signal-difference-to-noise ratios were quantified; the features of the central scar were qualitatively analyzed. On SE T2-weighted images, all FNHs were hyperintense; in two cases the central scar exhibited a high signal intensity associated with hypointense areas corresponding to fibrous tissue within the branches of the scar. Unenhanced TurboFLASH images always demonstrated the FNHs as hypointense and always depicted the central scar as a hypointense area within the lesion. After bolus injection, arterial enhancement of FNH was clearly seen, and in 10 of 25 lesions, enhancement within the scar was seen 40-80 seconds after injection. Both unenhanced and enhanced TurboFLASH sequences produced the best signal-difference-to-noise ratios in comparison with T2-weighted images.
The capability for studying noninvasively vessels has been dramatically improved with the use of gradient echo sequences. Twenty-one patients presenting a suspected inferior vena cava obstruction on cavography underwent MR examination with axial, sagittal and coronal gradient echo images. Eighteen patients were also imaged with ultrasound and/or CT. Gradient echo sequences visualized a thrombus in 19 cases and a normal vein in the remaining 2 cases. The potential MR pitfalls are illustrated and the two cases of false positive on cavography are discussed. Gradient echo sequences allow a fast and performant examination of the vessels.