Reversible avascular necrosis of the femoral head in tumor-induced osteomalacia.

OBJECTIVE: To document the course and reversal of avascular necrosis of the femoral heads (ANFH) in a 27-year-old woman with tumor-induced osteomalacia (TIO). METHODS: We describe clinical, biochemical, and magnetic resonance imaging changes in a patient who sought medical assistance because of pain in her back, hips, and knees and an enlarging mass on her right thigh. RESULTS: The patient proved to have TIO, an unusual condition characterized by humorally controlled renal phosphate wasting, low to undetectable levels of 1,25-dihydroxyvitamin D(3), and osteomalacia. Eleven months after removal of a small spindle cell tumor of the right thigh and without other treatment, complete clinical and biochemical remission was observed, and the magnetic resonance images revealed resolution of the ANFH. CONCLUSION: Prompt treatment of ANFH in TIO can lead to complete radiologic and clinical remission.

Effect of slice acquisition direction on image quality in thoracic MRI.

OBJECTIVE: We tested the basic observation that imaging the heart and pericardium in systole improves image quality compared with that in diastole. MATERIALS AND METHODS: Twenty consecutive patients and two volunteers underwent sequential ECG-gated short TE transaxial prospective multislice SE MRI with both caudocranially and craniocaudally directed slice prescriptions, keeping other imaging parameters constant. Images of the heart and pericardium were obtained in systole and diastole and examined by three independent reviewers for image quality. RESULTS: In the lower mediastinum, cardiac structures and the pericardium were better seen in 49 of 57 individual evaluations when imaged in systole, 15 of which were judged markedly better. Vascular structures and the pericardium in the upper mediastinum were imaged equally well with both prescriptions. CONCLUSION: The findings suggest that in systole, the more mobile heart can maintain a more consistent shape during the acquisition of successive phase-encoding steps and preserve luminal flow void, factors critical to optimizing image quality in the transaxial plane.

Computerized tomography in acute gastrointestinal disorders.

In recent years, computerized tomography (CT) has become one of the most important imaging modalities in evaluation of patients with acute gastrointestinal disorders. Its role, diagnostic accuracy, indications, and limitations in some of the most commonly encountered acute abdominal conditions are succinctly presented and reviewed. CT should not be used indiscriminantly, but is best considered a valuable primary or complimentary diagnostic tool in critically ill patients. Its selective use in a variety of emergency abdominal diseases will significantly improve accuracy of clinical diagnoses, leading to a prompt and adequate medical or surgical management.

Computed tomography of pancreatic masses.

High resolution sequential bolus dynamic computed tomography (CT) has become the modality of choice for the diagnosis, evaluation, and staging of pancreatic masses. The reliable visualization of the pancreatic gland by CT allows detection of small pancreatic masses, as well as accurate morphologic characterization and preoperative staging. Although CT has proven to be the most accurate imaging modality for the detection and diagnosis of pancreatic masses, the presumptive pathologic diagnosis should always be confirmed by appropriate biopsy and histologic examination. The other imaging modalities now play a secondary or accessory role, and are used mainly when the CT examination is equivocal or nondiagnostic.

Breast and axillary tissue MR imaging: correlation of signal intensities and relaxation times with pathologic findings.

We tested a variety of inversion-recovery (IR) and spin-echo (SE) sequences by imaging the breast masses of 22 patients before surgery and 23 tissue specimens with magnetic resonance (MR) imaging at 0.6 T to determine the most effective pulse sequences to evaluate breast disease. An SE pulse sequence using a long repetition time (TR) of 1,600 msec and a long echo time (TE) of 90 msec was found to be the most sensitive in depicting carcinoma in the excised tissue specimens, with all of the carcinomas (n = 15) demonstrating irregular areas of higher signal intensity (SI) than that of the adjacent fat. However, only five of 11 breast carcinomas present in the preoperative patients produced a higher SI than that produced by fat on the same T2-weighted sequence. Five of the remaining six carcinomas in the preoperative patients appeared as localized distortions of fibroductular architecture on both T2-weighted SE and IR sequences. In axillary tissue specimens, both metastatic carcinoma and hyperplastic lymph nodes produced a high SI on T2-weighted SE sequences. However, metastatic carcinoma had a significantly longer T2 relaxation time than did hyperplastic lymph nodes.