Our purpose was to evaluate the accuracy of unenhanced helical computed tomography in the diagnosis of ureteral lithiasis, to establish the frequency of the main computed tomography findings, and to assess and compare the interobserver agreement with the results of conventional intravenous urography. A prospective double-blind study was carried out in 25 patients referred for unenhanced helical computed tomography and conventional intravenous urography due to nephretic colic. Both methods were employed to evaluate the size of the kidneys, hydronephrosis and the size and location of ureteral stones. Perirenal hyperdensities, periureteral edema and the halo sign were also assessed by unenhanced helical computed tomography. In 23 of the 25 unenhanced helical computed tomography examinations (92%) and in 17 of the 25 conventional intravenous urography examinations (68%) there was agreement on the results of the two observers. In 21 of the 25 patients, there was agreement between the results of both methods. We concluded that unenhanced helical computed tomography is as efficient as conventional intravenous urography in the evaluation of patients with nephretic colic, is a reproducible method, and avoids the discomfort of the use of intravenous contrast.

Keywords: Lithiasis. Ureter. Kidney. Computed tomography.

Mesenteric panniculitis is an inflammatory process that represents the second stage of a rare progressive disease involving the adipose tissue of the mesentery. Imaging methods used in the diagnosis of mesenteric panniculitis include barium studies, ultrasonography, computed tomography and magnetic resonance imaging. Computed tomography is important for both, diagnosis and evaluation of the extension of the disease and treatment monitoring. Computed tomography findings may vary according to the stage of the disease and the amount of inflammatory material or fibrosis. There is also good correlation between the computed tomography and anatomical pathology findings. The authors studied 10 patients with mesenteric panniculitis submitted to computed tomography. Magnetic resonance imaging was also performed in one patient. In all patients, computed tomography revealed a heterogeneous mass in the mesentery with density of fat, interspersed with areas of soft tissue density and dilated vessels.

Keywords: Mesenteric panniculitis. Radiology. Computed tomography.

Thirty-three patients with chronic schizophrenia and 21 normal subjects were submitted to magnetic resonance imaging studies using a 1.5 T scanner. Axial and coronal T2-weighted images were obtained. The volumes of the brain, intracranial, supratentorial, infratentorial and the total, ventricular and subarachnoid cerebrospinal fluid volumes were measured using semi-automated morphometric methods. The volumes of the amygdala-hippocampus complex, parahippocampal gyrus cortex, putamen, globus pallidus, temporal lobe , gray and white matter of temporal lobe were also measured. These volumes were normalized using the intracranial volume as reference. The most relevant findings observed were reduced brain volume and increased total, ventricular and subarachnoid cerebrospinal fluid volumes in patients with schizophrenia when compared to the controls. Patients with schizophrenia had also smaller amygdala-hippocampus complexes, temporal lobes and temporal lobe white matter than the controls, as well as increased putamen volumes.

Keywords: Schizophrenia. Magnetic resonance imaging. Morphometry.

Oligodendrogliomas are neuroepithelial neoplasms that originate from oligodendrocytes. These tumors account for 4% to 7% of all primary brain tumors and are most supratentorial. The purpose of this study was to evaluate the findings of computed tomography and magnetic resonance imaging examinations of patients with oligodendrogliomas and correlate these findings with clinical and pathological data. Oligodendrogliomas may be pure or mixed, present astrocytic elements and vary from well differentiated to anaplastic. The most common finding observed was a lesion that appeared hypodense on CT or had low-intensity signal on T1-weighted and high-intensity signal on T2-weighted magnetic resonance images. Cystic elements, mild surrounding edema and calcifications (usually coarse) in 2/3 of the cases were also observed. Tumor enhancement was generally mild and was observed in 80% of the cases.

Keywords: Oligodendrogliomas. Computed tomography. Magnetic resonance imaging. Anatomopathology.

Gaucher's disease has a genetic background and is characterized by the deficiency of enzyme glucocerebrosidase, resulting in secondary accumulation of glucocerebrosides in the reticuloendothelial organs. The objective of the present study is to evaluate the x-ray findings in the skeleton of a group of 32 male and female patients of different ages, with biochemical diagnosis of Gaucher's disease. The following bone lesions were observed: diffuse osteopenia (100% of the patients), "Erlenmeyer flask" deformities (93.7% of the patients), abnormalities of the joints (40.6% of the patients), necrosis of the femoral head (28.1% of the patients), lytic lesions (28.1% of the patients), pathological fractures (9.3% of the patients) and necrosis of the humeral head (6.2% of the patients). These results are concordant with the literature, and demonstrate the importance of conventional x-ray as a complementary method in the diagnosis of Gaucher's disease.

Keywords: Gaucher's disease. Radiology. Osseous abnormalities.

This paper presents the results of 50 patients with trauma of the knee submitted to magnetic resonance imaging in the period of January 1996 to December 1997. The appearance and incidence of the main bone lesions were evaluated and correlated with the mechanisms of aggression and with clinical data. Associated lesions were also evaluated. Bone contusions were the most commonly findings encountered and were observed in 38 patients (76%). Osteochondral fractures occurred in five patients (10%) and bone fractures were detected in five patients (10%), of which two were associated with contusions in other adjoining bone compartments. Chondromalacia of the patella was observed only in two patients (4%). We concluded that magnetic resonance imaging is the imaging method of choice for the diagnosis of bone lesions in patients with trauma of the knee.

Keywords: Magnetic resonance imaging. Bone injuries. Trauma. Knee.

Magnetic resonance imaging has become the first choice imaging method for the evaluation of the joints due to its exceptional tissue differentiation, high resolution, multiplanar images and kinematics studies. The knee is probably the most common joint evaluated by magnetic resonance imaging and the knowledge of anatomy, physiology and imaging features is essential for an accurate interpretation of these studies. However, anatomical structures that are only observed sporadically, normal variants and artifacts may sometimes make it difficult to interpret these examinations. The purpose of this article is to review the most frequent pitfalls of magnetic resonance imaging of the knee, discuss their causes and how to avoid them.

Keywords: Magnetic resonance imaging. Knee. Pitfalls. Errors. Pseudolesions.