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Malignant external otitis (MEO) is a severe infection of the external auditory canal and skull base which most often affects elderly patients with diabetes mellitus. Early diagnosis and aggressive treatment are important in terms of reducing risks of dissemination. We report four cases of MEO in patients with diabetes mellitus who were observed with computed tomography (CT) and/or magnetic resonance imaging (MRI). MRI was superior to CT in patients with MEO in terms of estimating the anatomic extent of the disease, but it cannot be used for monitoring therapy.

This study was conducted to compare a three-dimensional (3D) multi-shot echo-planar imaging (EPI) sequence with fat-suppression (FS) with the 3D-fat-suppressed gradient echo (GRE-FS) sequence in imaging the cartilage of the knee. One hundred sixty-nine patients were studied prospectively. The cartilage was imaged in the sagittal plane with: (a) 3D-T1-EPI-FS and (b) 3D-T1-GRE-FS sequences using a 1T MR scanner. The signal-to-noise ratio (SNR) of bone (b) and cartilage (c), and relative contrast (ReCon) between bone and cartilage and meniscus and cartilage were measured in 60 patients with arthroscopically normal cartilage. The imaging accuracy was assessed by comparing with linear regression analysis (length and depth) 32 defects in the cartilage of cadaveric (human and bovine) knees. The 3D-T1-EPI-FS provided better bone marrow signal suppression, better SNRc and better ReCon(bc) and ReCon(cm) (p<0.01). The 3D-T1-EPI-FS showed better accuracy concerning the depth of the defects and the 3D-T1-GRE-FS better accuracy concerning the length of the defects. In conclusion, the 3D-T1-EPI-FS pulse sequence could be included in the routine protocol in imaging the cartilage of the knee because it achieves high SNR of the cartilage and high ReCon compared to the surrounding structures, at a reduced scan time.

A case of benign enlargement of peripheral subarachnoid spaces in twins is described. Computed tomography demonstrated identical findings, namely the enlargement of the sulci mainly in the frontal area bilaterally with slight dilatation of the ventricular system. Literature research did not reveal such a case in twins nor has any association of the situation with any genetic or family predisposition been found.

The purpose of this study is to present the imaging findings with particular reference to the FLAIR magnetic resonance (MR) pulse sequence, of four patients with epidermoid cysts. In all cases CT showed hypodense lesions with stippled peripheral calcifications and no enhancement. The MR showed low signal intensity lesions in T1-weighted images, high signal intensity in T2-weighted lesions, no or minor enhancement after gadolinium administration and characteristic heterogeneous appearance in FLAIR images. Including the FLAIR sequence in MR imaging, a specific diagnosis can be suggested.

A case with a clinical picture of a chronic low back pain radiating to both lumbar regions caused by malignant fibrous histiocytoma is reported. Radiological, surgical and histopathological findings and treatment of this rare case are discussed.

In order to reduce the acquisition time, we compared a three-dimensional multi-shot echo-planar imaging (EPI) sequence with fat-suppression with two widely used sequences, the fat-suppressed gradient echo (GRE) and the proton-density weighted turbo spin-echo (FSE) in imaging the menisci of the knee. Sixty patients with various indications were studied prospectively with MRI. The menisci were imaged in the sagittal plane with all three sequences using a 1T MR scanner with 15mT/m gradients. The signal-to-noise ratio (SNR) of bone (b), cartilage (c), and meniscus (m) as well as contrast-to-noise ratio (CNR) and relative contrast (ReCon) between menisci and cartilage and between bone and cartilage were measured. A qualitative analysis was performed on grading of meniscal pathology (0-IV). The imaging accuracy of meniscal pathology was assessed compared to arthroscopy in 13 patients. The EPI provided the highest SNR in cartilage and meniscus (p<0.001), the highest CNR and the highest ReCon between bone and cartilage (p< or =0.001). MR grading of meniscal abnormalities showed overestimation compared to GRE and FSE. The EPI sequence could not be included in the routine protocol in imaging the menisci since the overestimation of meniscal abnormalities could lead to unnecessary arthroscopy.

The location of echinococcal cysts inside pulmonary artery is extremely rare. The cause is usually rupture of intracardiac cysts. We report a case of a 67-year-old patient with known lung hydatid disease whose main clinical presentation was dyspnea. The patient did not have any surgery in the past. The importance of the present case lies in the demonstration of the MR angiographic findings.

In order to reduce the acquisition time, we compared the single-shot-TSE-MR myelography (MRm) and 3D-TSE-MRm. The T2-TSE sequence was the standard of reference. Fifty patients with low back pain, sciatica or cervical radiculopathy were examined at 1.0 T. The shortest AP diameter of the spinal canal, signal-to-noise ratio (SNR) for CSF and cord, contrast-to-noise ratio (CNR) and relative contrast (ReCon) between CSF and cord were calculated. No statistically significant difference was found between the three sequences with regard to the AP diameter of the spinal canal. A significant difference was found in: (i) SNRcord; (ii) SNRCSF; (iii) SS-TSE-MRm (showed the highest CNR) and (iv) SS-TSE-MRm (showed higher ReCon compared to 3D-TSE-MRm). In conclusion, SS-TSE-MRm can be used alternatively to 3D-TSE-MRm reducing the acquisition time down to only 8 s per image.

Amyotrophic lateral sclerosis (ALS) can cause hyperintense lesions in the corticospinal tract but rarely can also cause T2 shortening in the motor cortex bilaterally. The present case of ALS showed unilateral T2 shortening of the superior parietal lobule without corticospinal tract changes.

Fifty-six patients (age range, 15-79 yr, average, 37.0+/-18.5 yr), with a clinical and/or radiological diagnosis of acute maxillary sinusitis, were prospectively studied with ultrasound (US) and computed tomography (CT). The imaging finding which supported the diagnosis of acute sinusitis with US was the identification of the hyperechoic posterior antral wall through the hypoechoic inflammation. The findings were compared to CT (3 mm axial sections). The sensitivity of US for maxillary sinus disease was found to be 66.7% and the specificity was 94.9%, which were similar to the plain film ones (65.2 and 96.8%, respectively). The results of the present study suggest US as the method of first choice for acute sinusitis of the maxillary antra, particularly for children and pregnant women.

The authors analysed the CT-findings in 100 normal subjects who underwent a modified double-contrast technique (D.C.). The mean gastric wall thickness in four areas was measured and the contribution of the D.C. technique is discussed.