Improved sensitivity of MRI in multiple sclerosis by use of extensive standardized procedures.

The relative value of two different MRI procedures for the assessment of infratentorial extension in multiple sclerosis (MS) was studied. Multislice spin-echo techniques were used overall. Procedure A consisted of parasagittal T1-weighted images (500/30) and axial T2-weighted images (2500/30, 2500/120). Procedure B consisted of parasagittal T2-weighted images (1600/35, 1600/90). In the parasagittal T2-weighted images clear visualization of MS lesions is achieved because signal intensities of CSF and normal nervous tissue are nearly identical. All images were performed with a 0.5 Tesla MR system. Data were obtained in 98 patients with definite (N = 30) or probable MS (N = 68). Areas with abnormal signal intensity in the infratentorial regions (brainstem, cerebellum, and/or cervical spinal cord) were identified in 44% of the patients with procedure A and in 64% with procedure B. The standard application of the combination of both procedures improves the sensitivity of the MR examination for the diagnosis of MS, the delineation of infratentorial lesions and the correlation between clinical and MR data without excessively increasing imaging time.

Reject analysis: a pilot programme for image quality management.

The radiographic film wastage and the different parameters affecting this wastage were analysed for a 9-week period at a 600-bed University Hospital. An overall reject rate of 7.6% was found. The different reasons for rejection were evaluated, while retake rate, relation between working experience of the personnel, amount of rejected films and total film wastage in surface (m2), were registered and analysed.

Vascular ring in annular pancreas associated with rare variant of celiac trunk. Case report.

A 12-year-old patient with annular pancreas (AP) is presented. The AP was diagnosed preoperatively by angiography which not only clearly demonstrated a vascular ring around the duodenum, but also revealed an extremely rare upper abdominal vascular anatomy.

Statistical analysis of MRI parameters predicting malignancy in 141 soft tissue masses.

Since well-known grading parameters such as cellularity, mitotic rate, matrix and presence of necrosis all influence MRI signal intensity, the value of MRI in predicting malignancy is potentially high. To assess this value we studied retrospectively the findings in 141 soft tissue tumours (84 benign, 57 malignant) and evaluated a wide variety of MRI features (size, margins, signal homogeneity, shape, signal intensity, neurovascular and bone involvement, degree and pattern of enhancement and evidence of necrosis after injection of Gd-DTPA). Statistical analysis was carried out to determine accuracy of parameters individually and in combination, for predicting malignancy. Highest sensitivity was obtained for "absence of low signal intensity on T2" (100%), "mean diameter greater than 33 mm" (90%), and "inhomogeneous signal on T1" (88%). Highest specificity was obtained for "evidence of necrosis" (98%), "bone or neurovascular involvement or metastases" (94%), and "mean diameter greater than 66 mm" (87%). Association of best sensitivity and specificity was seen for "absence of low signal intensity on T2", "signal inhomogeneity on T1", and "mean diameter of the lesion greater than 33 mm" (81 and 81%).

Roentgenographical detection of cocaine smuggling in the alimentary tract.

We report five cases of cocaine smuggling, by hiding multiple drug-filled foreign bodies in the colon, either after oral ingestion or by placing them in the colon per rectum. Several smuggling methods in the gastrointestinal (GI) tract and their radiological findings on abdominal plain film are presented. Computed tomography (CT) is found to be a more accurate method in the detection of the drug-filled bags, because of its improved contrast resolution and the absence of projections of overlapping structures on the transversal sections. Subsequently, CT is highly recommended in cases of negative or doubtful findings on conventional abdominal radiographs. In all cases conservative management was used and the drug-filled capsules and condoms passed spontaneously. No complications, such as intestinal obstruction by the bags of cocaine or intoxication by rupture of their wall were observed.

Magnetic resonance imaging of soft tissue tumors.

The value of magnetic resonance imaging (MRI) in histological classification was studied in a series of 164 histologically proven soft tissue tumors (STT) and was rather limited. MRI was only valuable in characterization of lipomatous, vascular and fibrous tumors. There are two main reasons for this limitation i.e. STT belonging to the same histological group may have different composition or different proportions in tumor components resulting in different MRI signals. Secondly tumor components may change individually or proportionally during natural evolution or as a consequence of therapy. Because well known grading parameters such as cellularity, mitotic rate, matrix and presence of necrosis all influence MRI signal intensity, the value of MRI in predicting malignancy is potentially high. To assess this value we retrospectively studied the findings in the first 141 soft tissue tumors (84 benign, 57 malignant) and evaluated a wide variety of MRI features (size, margins, signal homogeneity, shape, signal intensity, neurovascular and bone involvement, degree and pattern of enhancement and evidence of necrosis after injection of Gd-DTPA). Statistical analysis was carried out to determine accuracy of parameters individually and in combination, for predicting malignancy. Highest sensitivity was obtained for "absence of low signal intensity on T2" (100%), "mean diameter > 33 mm" (90%) and "inhomogeneous signal on T1" (88%). Highest specificity was obtained for "evidence of necrosis" (98%), "bone or neurovascular involvement or metastases" (94%) and "mean diameter > 66 mm" (87%). Association of best sensitivity (81%) and specificity (81%) was seen for "absence of low signal intensity on T2", "signal inhomogeneity on T1" and "mean diameter of the lesion > 33 mm". In a prospective study of 23 consecutive patients we reevaluated sensitivity and specificity in predicting malignancy of all parameters. Excellent correlation with the results of the retrospective study was found. Although a quantitative approach to the staging potentials of MRI was not possible, well known staging parameters are evaluated to the best by this method (size, depth, compartmental versus extra-compartmental location, relationship to adjacent structures).

Magnetic resonance imaging of extraabdominal desmoid tumors.

The authors describe the MR appearance of extra-abdominal desmoid in three patients, with longitudinal follow-up during a period of up to 29 months in two of them. For the MR examinations various pulse sequences, including spin-echo and gradient-echo sequences, were used. Both non-enhanced and Gd-DTPA contrast enhanced studies were made. We found gradient-echo T2*-weighted sequences best suited for the detection of extra-abdominal desmoids. Best correlation between MR features and histologic findings was obtained on spin-echo T2- and contrast enhanced T1-weighted studies. Although preliminary, our results suggest that MRI might predict evolution of extra-abdominal desmoids by providing data about cellularity and relative amount of mucoid matrix of the lesions.

Unusual presentation of ovarian pathology on CT.

A prospective study including seventy-seven consecutive patients suspected of having ovarian tumoral or pseudotumoral pathology on CT was carried out. Fifty-nine patients had surgery with histological diagnosis. When comparing the CT and histological findings in benign and malignant lesions we obtained an overall accuracy of 95% with only three misdiagnosed cases on CT. False positive diagnosis of malignancy was established in a case of abdominal actinomycotic infection, a case of chronic appendicitis, and in a ruptured ectopic pregnancy. These three cases are discussed in detail.

Aphthoid esophageal ulcers in Crohn's disease of ileum and colon.

We report 4 cases of tiny aphthous ulcers of the esophagus occurring in patients with confirmed Crohn's disease of the terminal ileum and the colon. These ulcers presented as small collections of barium surrounded by a radiolucent halo, and were demonstrable on double-contrast radiographs of the esophagus. They were located in the middle and distal thirds of the otherwise normal esophagus. A more advanced stage of Crohn's ileocolitis was present in these patients.

Computed tomography of the polysplenia syndrome in the adult.

The computed tomographic appearance of the polysplenia syndrome in 2 cases is presented. Both are associated with absence of the hepatic segment of the inferior vena cava. Computed tomography can determine the exact location of the malpositioned organs, the presence of multiple spleens, and the type of the associated venous anomalies, which are the major features of the polysplenia syndrome.

Calcific tendinitis of the vastus lateralis muscle. A report of three cases.

Three cases of calcific tendinitis occurring at an unusual site (vastus lateralis tendon) are described. Findings on conventional radiography and computed tomography together with the clinical history are characteristic for this disorder and reflect its natural evolution. The actual role of magnetic resonance imaging seems limited to excluding neoplasm and to demonstrating inflammatory changes better in the early stages of disease.

Clinical significance of focal echogenic liver lesions.

During a 4-year period, 53 focal echogenic liver lesions were demonstrated by sonography in 41 patients, in whom there was no evidence of metastatic origin. Most of the lesions were hemangiomas. One of the purposes of this study was to determine the characteristic ultrasound features for liver hemangioma. Small (less than 2 cm), homogeneous, echogenic, well-circumscribed, subcapsular lesions almost prove their hemangiomatous nature. Lesions with a diameter of more than 2 cm are usually more lobulated and heterogeneous. They are located more centrally in the liver and nearly all show a close anatomical relation with 1 of the hepatic veins. Very large lesions (greater than 5 cm) with a heterogeneous and irregular aspect suggest focal nodular hyperplasia, which must be proven by a Tc-isotopic liver scan.

Polypoid hamartoma of the jejunum.

The authors report an unusual case of jejunal mesenchymal hamartoma which presented as a bleeding pedunculated polyp in a 67-year-old woman. The lesion was detected by enteroclysis and resected after localization by intraoperative endoscopy.

Magnetic resonance imaging in the evaluation of patients with eosinophilic fasciitis.

Two cases of eosinophilic fasciitis are described, in which magnetic resonance imaging (MRI) clearly demonstrated thickening of the fascia and increased signal intensity in the superficial muscle fibers correlating with inflammation. MRI is a useful noninvasive imaging technique in the diagnosis of eosinophilic fasciitis and can guide biopsy of selected abnormal areas.

Herpes simplex virus type 1 colitis: an unusual cause of diarrhea.

Herpetic infections of the gastrointestinal tract are a well-recognized entity. Involvement of the colon seems to be very rare. A 78-yr-old woman developed bloody diarrhea and abdominal discomfort 2 months after surgical treatment for adenocarcinoma of the transverse colon. Colonoscopy revealed diffuse hemorrhagic, erosive, aphtoid, and ulcerative lesions. Histology showed nonspecific inflammatory changes. Herpes simplex virus type 1 (HSV-1) was isolated from endoscopic biopsy and stool specimens. The patient responded rapidly to symptomatic treatment with loperamide. This case demonstrates the potential for HSV-1 to induce infectious colitis; failure to obtain microbiologic evaluations and the rapid response to empiric, symptomatic treatment may be responsible for the rarity of diagnosis of this infection. The implications of this diagnosis are probably more relevant in immunosuppressed individuals, and may be important in the elderly population.

Randomised double blind trial of the safety and efficacy of two gadolinium complexes (Gd-DTPA and Gd-DOTA).

The main difference between macrocyclic Gd-DOTA and linear Gd-DTPA complexes is the greater stability of the former which theoretically might reduce biological interactions in man. To evaluate the clinical relevance of this property, 300 unselected neurological patients were included in a randomised double-blind comparison involving five European centres, focused mainly on the tolerance of these two contrast media. Clinical tolerance was assessed immediately after the procedure and 24 h later. Adverse events were found with a similar frequency in the two groups (17.3% for Gd-DOTA and 19.3% for Gd-DTPA). Minor neurological symptoms were the most frequent (48.6%) headache being the most common (29.2% of adverse events). No difference in efficacy was found.

Acoustic schwannoma: MR findings in 84 tumors.

MR imaging is the study of choice for the examination of patients with suspected acoustic schwannoma, because of its high sensitivity, especially after the use of contrast material. This essay illustrates the common MR features of acoustic schwannomas as seen in a study of 84 tumors. We pay special attention to the role of MR imaging in the distinction between acoustic schwannoma and meningioma.