[Magnetic resonance imaging of multiple myeloma].
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Aftercare↗
Biomedical subjects
A Rahmouni
Publications and source records attributed to A Rahmouni.
Misleading clinical aspects of hydroxyapatite deposits: a series of 15 cases.
OBJECTIVE: To study the characteristics of radiographs in diagnosis of hydroxyapatite deposits in sites other than the shoulders and hips. METHODS: We reviewed the records of patients hospitalized during the last 3 years whose final diagnosis was apatite deposits in sites other than the shoulders and hips. RESULTS: Ten women and 5 men were studied. The initial presentation mimicked septic arthritis or periarticular soft tissue abscess in 12 patients, corresponding to calcifications in the fingers (6), toes (2), wrists (2), elbow (1), and ankle (1). One patient presented with a spontaneous coccygeal pain (precoccygeal deposit), one with a pseudotumoral process of the thigh (paradiaphyseal calcification), and one with acute cervical pain and dysphagia (longus coli muscle calcification). Complete clinical healing was observed after an average of 4.9 days; 11 patients used nonsteroidal antiinflammatory drugs (NSAID), 2 used colchicine, one used oral steroids, and one had brief antibiotic therapy and used NSAID. CONCLUSION: Initial clinical aspects of apatite deposits in sites other than the shoulders and hips can often be misleading, especially by mimicking an infectious process. Careful analysis of immediate radiographic films can help to rapidly ascertain the diagnosis and thus avoid useless investigations or treatment.
Adult↗
Calcification in focal nodular hyperplasia: a new problem for differentiation from fibrolamellar hepatocellular carcinoma.
PURPOSE: To describe calcification in focal nodular hyperplasia (FNH) of the liver, which poses a new problem for the differentiation of FNH from fibrolamellar hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Ultrasound, computed tomography, and magnetic resonance imaging findings of 357 FNH lesions diagnosed in the past 5 years in 295 patients (274 female, 21 male; aged 14-72 years) were retrospectively reviewed with emphasis on intralesional calcification. RESULTS: Calcifications were seen in five FNH lesions (1.4%) as small, solitary spots located centrally or peripherally within the lesions. Morphologic features of these calcifications were similar to those of calcifications in two of six fibrolamellar HCCs in the same period. CONCLUSION: Calcification in FNH is a rare and atypical finding that poses further difficulty for differentiation from fibrolamellar HCC.
Adult↗
Color Doppler twinkling artifact in hyperechoic regions.
PURPOSE: To investigate a new color Doppler ultrasound (US) artifact that manifested as a rapidly changing mixture of red and blue behind a strongly reflecting structure. MATERIALS AND METHODS: In 140 consecutive patients with parenchymal calcifications seen at US, the presence of color signal was assessed in calcified areas relative to adjacent noncalcified tissue. The artifact, called the twinkling color artifact, was stimulated with various strongly reflecting structures immersed in still water. RESULTS: The artifact was found in 42 parenchymal calcifications. In vitro experiments showed that the twinkling artifact was present in granular structures, whereas no color signal was noted in smooth surfaces. The "twinkling sign" appeared to be generated by a strongly reflecting medium composed of individual reflectors. CONCLUSION: The presence of a color signal close to calcifications should be interpreted with caution, and a flow spectrum should always be recorded to eliminate the twinkling artifact.
Artifacts↗
Bronchoalveolar lavage in adult sickle cell patients with acute chest syndrome: value for diagnostic assessment of fat embolism.
Fat embolism of necrotic bone marrow could be a frequent cause of acute chest syndrome (ACS) in sickle cell syndromes (SC), as suggested by postmortem findings. To check this hypothesis in living patients, we evaluated the presence of fatty macrophages recovered by bronchoalveolar lavage (BAL) in ACS. We investigated 20 consecutive cases of ACS by BAL, and identification of alveolar cells containing fat droplets was performed using oil red O (ORO), a specific neutral fat stain. The specificity of the method was determined on control groups, including eight SC patients without acute chest syndrome and 15 non-SC patients. A cut-off of > 5% of alveolar macrophages containing fat droplets was determined from the control groups to assess the diagnosis of fat embolism. In 12 ACS episodes, BAL exhibited > 5% of fatty macrophages, ranging from 10% to 100% (median value 46.5%). In 11 cases, fat embolism was associated with proven (n = 8) or probable (n = 3) bone marrow infraction, which mostly predated ACS. Eight ACS episodes were associated with a low percentage (< or = 5%) of fatty alveolar macrophages and could be related to a cause other than fat embolism in six episodes, such as sepsis, in-situ thrombosis, or rib infarcts generating hypoventilation. This study supports the diagnostic yield of BAL for fat embolism, which can be incriminated in 60% of cases of ACS in this adult population.
Adolescent↗
MR-guided biopsy using ultrafast T1- and T2- weighted reordered turbo fast low-angle shot sequences: feasibility and preliminary clinical applications.
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Adult↗
[In adult urology, when should ultrasonography, computed tomography, intravenous urography be requested?].
The authors recall the indications for the medical imaging examinations most frequently used in adult urology, depending on the organ, syndrome or disease to be investigated. The indications for intravenous urography (IVU) are increasingly rare, but it remains the reference examination to study the pyelocaliceal cavities. Ultrasonography, combined with KUB, generally provides a diagnosis, especially in the emergency setting. Computed tomography (CT) is the reference examination for the investigation of all types of renal lesions, but also lesions of other organs, especially in the case of neoplastic disease.
Adult↗
Impact of magnetic resonance imaging on the diagnosis of abdominal complications of paroxysmal nocturnal hemoglobinuria.
Magnetic resonance (MR) imaging is a method of choice for assessing vascular patency and parenchymal iron overload. During the course of paroxysmal nocturnal hemoglobinuria (PNH), it is clinically relevant to differentiate abdominal vein thrombosis from hemolytic attacks. Furthermore, the study of the parenchymal MR signal intensity adds informations about the iron storage in kidneys, liver, and spleen. Twelve PNH patients had 14 MR examinations of the abdomen with spin-echo T1- and T2-weighted images and flow-sensitive gradient echo images. Vessels patency and parenchymal signal abnormalities--either focal or diffuse--were assessed. MR imaging showed acute complications including hepatic vein obstruction in five patients, portal vein thrombosis in two patients, splenic infarct in one patient. In one patient treated with androgens, hepatocellular adenomas were shown. Parenchymal iron overload was present in the renal cortex of eleven patients with previous hemolytic attacks. On the first MR study of the remaining patient with an acute abdominal pain showing PNH, no iron overload was present in the renal cortex. Follow-up MR imaging showed the onset of renal cortex iron overload related to multiple hemolytic attacks. Despite the fact that all our patients were transfused, normal signal intensity of both liver and spleen was observed in three of them. MR imaging is particularly helpful for the diagnosis of abdominal complications of PNH.
Abdominal Pain↗
Intrahepatic cholangiocarcinoma. Results of aggressive surgical management.
OBJECTIVE: To report the results of a deliberately aggressive surgical management in patients with intrahepatic cholangiocarcinoma. DESIGN: A case series of patients with intrahepatic cholangiocarcinoma. SETTING: A tertiary care university hospital in a metropolitan area. PATIENTS: From 1989 to 1993, 19 patients with intrahepatic cholangiocarcinoma underwent laparotomy, with a 74% resectability rate (14 liver resections). In addition, two selected patients with a slow-growing tumor underwent orthotopic liver transplantation after limited recurrence following resection in one case and after exploratory laparotomy in the other. INTERVENTIONS: The 14 liver resections included six right or left hepatectomies and eight extended right or left hepatectomies. Total vascular exclusion of the liver was used in nine cases (64%) and resection of the biliary confluence with reconstruction was used in six cases (43%). RESULTS: There was one postoperative death (7%). There were four postoperative biliary fistulas (28%). Overall actuarial 1- and 2-year survival rates were 58% and 32%, respectively. The 1- and 2-year survival rates were 100% after curative resection (no lymph node invasion, clearance margin of < or = 1 cm, and solitary tumor [five cases]) and 48% and 10% after palliative resection. Median survival was 14 months for the whole series and 27 and 9 months following curative and palliative resections, respectively. The two liver transplant recipients are alive and free of disease at 25 and 31 months. CONCLUSION: These results support aggressive surgical management in patients with intrahepatic cholangiocarcinoma, including complex liver resection procedures and selective use of orthotopic liver transplantation.
Actuarial Analysis↗
Intraarticular tolerability and kinetics of gadolinium tetra-azacyclododecane tetraacetic acid.
RATIONALE AND OBJECTIVES: We assessed the tolerability and the intraarticular kinetics of gadolinium tetra-azacyclododecane tetraacetic acid (Gd-DOTA) using magnetic resonance (MR) imaging. METHODS: Twelve of 18 dogs received an intraarticular injection of Gd-DOTA solution. Pathologic examination of all joints was performed with assessment of Gd-DOTA bone absorption. Effects of Gd-DOTA on chondrocyte viability and proliferation in vitro were determined using cultures of rabbit chondrocytes. Four dogs underwent MR imaging of the stifle joint before and after intraarticular injection of 0.8 ml Gd-DOTA at a concentration of 2 mmol/l (300 mOsm/l). Intraarticular kinetics of Gd-DOTA were determined from quantitative measurements using repeated sagittal spin-echo T1-weighted images. RESULTS: No microscopic changes of the joints or Gd-DOTA bone absorption were detected. No cytotoxicity for chondrocytes was observed at a concentration of 5 mmol/l, but a decreased cell count was observed at a high concentration (50 mmol/l). The intraarticular Gd-DOTA concentration decreased with time according to a logarithmic curve with an intraarticular half-life of 103-152 min (M = 127 min). CONCLUSION: Gd-DOTA is a safe intraarticular contrast agent with a long half-life in the joint cavity.
Absorption↗
Prevention of thrombotic complications of the nephrotic syndrome by the low-molecular-weight heparin enoxaparin.
The nephrotic syndrome (NS) carries one of the highest risks of thrombotic complications. Consequently, over the last 15 years, some nephrologists have treated patients risk (i.e. those with albuminemia < 20 g/l and membranous nephropathy) with anticoagulants: either subcutaneous heparin (Kakkar protocol) or antivitamin K. Low-molecular-weight heparin (LMWH) has a longer plasma half-life and better bioavailability than standard heparin and can thus be administered as a single daily injection. LMWH also carries a lower risk of hemorrhage. We prospectively studied the safety and efficacy of the LMWH Enoxaparin for preventive anticoagulation in NS. In a preliminary study, 10 adult nephrotic patients with biological markers of thrombosis risk (severe hypoalbuminemia and/or anomalies of the fibrinolytic pathway and/or deficiency in coagulation inhibitors) were given 40 mg (4,000 U) of Enoxaparin daily for at least 3 months; 3 patients were treated for 3 months, 1 for 6 months and 6 for 12 months. Patients were assessed for silent thrombosis, using renal vein Doppler ultrasonography, lower leg vein Doppler ultrasonography and lung ventilation-perfusion scintigraphy, before entry to the trial and subsequently at 3-month intervals. As LWMH caused no obvious side effects and no thrombosis was observed during the pilot study, we then placed 55 adult nephrotic patients free of thrombosis on the same treatment. Patients were seen according to the usual calendar required by their individual illnesses. At each examination, patients were assessed for clinical signs and symptoms of thrombosis and side effects; plasma D-dimer and urinary fibrin-fibrinogen degradation products were also measured at each visit.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Hepatocellular adenoma: MR imaging features with pathologic correlation.
OBJECTIVE: The purpose of this study was to describe the MR imaging characteristics of hepatic adenomas and to correlate these features with pathologic findings. MATERIALS AND METHODS: Sixteen patients from four institutions who had 31 hepatocellular adenomas underwent MR imaging with T1- and T2-weighted pulse sequences at 1.5 T. Dynamic gadolinium-chelate-enhanced gradient-recalled-echo (GRE) MR imaging was done in eight patients with 15 lesions. Twenty-three lesions in 15 patients were confirmed by surgical excision. MR images were retrospectively reviewed by three experienced radiologists for signal intensity of lesions relative to liver, heterogeneity, contrast enhancement, and presence of signs of histopathologic correlates. These imaging findings were then compared with histopathologic findings. RESULTS: Nearly all (29 of 31 lesions) hepatocellular adenomas showed heterogeneous signal intensity on MR images. Most (19/31) were predominantly hyperintense on proton density- or T2-weighted images; the predominant signal intensity on T1-weighted images varied. Thirteen of 15 lesions showed early arterial enhancement relative to liver on dynamic GRE MR images. MR imaging was most successful in showing intratumoral hemorrhage (10 of 12 histopathologically proven lesions), large intratumoral vessels (five of five), fatty change (three of six), and peliosis (three of three cases). In two lesions, capsules (one of five) and central scars (one of three) were detected. CONCLUSION: Hepatocellular adenomas have a highly variable appearance on MR images because of their varied histologic appearances. Although no definitive MR imaging signal or structural characteristics can be identified, tumor heterogeneity, particularly when related to hemorrhage, and early arterial enhancement can suggest a diagnosis of hepatocellular adenoma in the proper patient population.
Adenoma, Liver Cell↗
Management of focal nodular hyperplasia and hepatocellular adenoma in young women: a series of 41 patients with clinical, radiological, and pathological correlations.
Preoperative distinction between focal nodular hyperplasia (FNH) that should be managed conservatively and hepatocellular adenoma (HA) that should be resected remains difficult. The result is controversial management of these patients. The aims of this study were to report the value of modern imaging procedures for noninvasive diagnosis of these lesions, to assess the value of intraoperative frozen section studies, and to propose a management strategy in those patients. Forty-one consecutive women with FNH (35 cases) or HA (6 cases) treated at our institution between 1985 and 1992 were studied. New imaging techniques, including enhanced magnetic resonance imaging (MRI) and color Doppler ultrasonography (US), were prospectively appraised in addition to usual techniques. Histological examination of surgical specimens was obtained in all cases. A sixfold increase in the number of patients with FNH was observed during this study, whereas the number of patients with HA did not change. FNHs were incidental US findings in 74% of the cases. The best imaging procedure in the diagnosis of FNH was enhanced MRI with a sensitivity of 70% and a specificity of 98%. Color Doppler US was a useful adjunct. Intraoperative frozen section studies were performed in 16 patients with 19 tumors with a sensitivity of 89% and a specificity of 100%.(ABSTRACT TRUNCATED AT 250 WORDS)
Adenoma, Liver Cell↗
Magnetic resonance imaging of penile rupture: aid to diagnosis.
We report on a patient with atypical clinical findings in whom magnetic resonance imaging confirmed the suspicion of penile rupture. The tear appeared as an obvious discontinuity of the low signal intensity of the tunica albuginea and was associated with a hematoma. We conclude that magnetic resonance imaging is useful for confirming the diagnosis of penile rupture when clinical findings are atypical, indicating surgical repair.
Adult↗
Hepatocellular adenoma: color Doppler US and pathologic correlations.
PURPOSE: To describe the color Doppler ultrasound (US) features of hepatocellular adenoma (HA) and correlate these findings with pathologic findings, with special emphasis on the blood vessels. MATERIALS AND METHODS: Color Doppler US was prospectively performed in eight patients with histologic proof of HA. Eleven lesions were studied. RESULTS: In seven lesions, color Doppler US demonstrated central color flow. In six of these lesions, pulse-wave Doppler US demonstrated a continuous and flat venous spectrum with frequency shifts of 0.20-0.60 kHz (mean, 0.37 kHz), which corresponded to pathologic findings of intratumoral veins 1-5 mm in diameter. The other lesion with central color flow demonstrated a triphasic venous waveform with 1.20-kHz frequency shift, which corresponded pathologically to a central vein 10 mm in diameter. In these seven lesions, color Doppler examination demonstrated both venous and arterial peritumoral flow. CONCLUSION: Color Doppler US enables detection of intratumoral veins associated with peritumoral veins and arteries in patients with HA; these findings correlate well with pathologic data. These results might help in the differential diagnosis of HA and focal nodular hyperplasia.
Adenoma, Liver Cell↗
MR imaging in acute infectious cellulitis.
PURPOSE: To describe magnetic resonance (MR) imaging findings in acute infectious cellulitis and assess its value for the diagnosis of severe necrotizing forms. MATERIALS AND METHODS: Spin-echo (SE) T1- and T2-weighted imaging was performed in 36 patients with acute infectious cellulitis. T1-weighted SE images obtained after injection of a paramagnetic contrast agent were also obtained when an abscess was suspected on precontrast images. Sixteen patients underwent surgical débridement, along with fascial and muscle biopsy. RESULTS: Distinct MR imaging features were found in patients with necrotizing soft-tissue infections, that is, hyperintense signal on T2-weighted images at the deep fasciae, poorly defined areas of hyperintense signal on T2-weighted images within muscles, and peripheral enhancement on contrast material-enhanced T1-weighted images. In nonnecrotizing cellulitis, signal intensity abnormalities were seen only in the subcutaneous fat. CONCLUSION: The precise extent of acute cellulitis and the presence of necrotizing soft-tissue infections can be determined with MR imaging, particularly on T2-weighted images.
Abdominal Muscles↗
Evaluation of magnetic resonance imaging for the assessment of renal vein thrombosis in the nephrotic syndrome.
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Adolescent↗
MR imaging of the breast in the follow-up evaluation of conservative nonoperatively treated breast cancer.
Because of postradiation changes in the breast, evaluation of the efficacy of conservative local radiation treatment is difficult, and early detection of recurrent disease is often a diagnostic challenge. MR imaging of the breast aids in the follow-up of conservatively treated breast cancers. When recurrent disease is suspected, MR imaging allows for the differentiation between late postradiation changes in the breast and recurrent carcinoma.
Breast↗