Progression of steroid-associated osteoporosis after heart transplantation.

BACKGROUND: Osteoporosis has been recognized as an important side effect of long-term and of pulsed steroid application after heart transplantation. METHODS: In June 1989 a prospective clinical trial was started to study bone demineralization by quantitative computed tomographic scan. All patients received vitamin D and calcium. In group I (n = 30) synthetic calcitonin (40 Medical Research Council Standard Units subcutaneously per day was administered in 14-day cycles, whereas group II patients (n = 31) received a placebo preparation. Repeat trabecular and cortical quantitative computed tomographic scans of the thoracic (T12) and lumbar spine (L1, L2, L3) were obtained within 48 weeks after heart transplantation. RESULTS: Expressed as the means of T12, L1, L2, and L3, trabecular bone density decreased significantly from 100+/-24 to 79+/-29 mg/mL within 3 weeks after heart transplantation, followed by a further reduction to 67+/-29 mg/mL after 3 months in the calcitonin group. The values for cortical bone density decreased significantly from 229+/-37 to 202+/-40 mg/mL (calcitonin) 3 weeks after heart transplantation. Comparable results were obtained in the placebo group. In both groups bone density remained stable thereafter. Intergroup differences were not of statistical significance. CONCLUSIONS: In heart transplant recipients progressive trabecular bone demineralization is limited to the first 3 postoperative months. Thereafter, bone density remained stable. A positive effect of synthetic calcitonin in addition to prophylactic calcium and vitamin D application could not be proved by repeat quantitative computed tomography.

[Pneumocystis carinii pneumonia (pneumocystosis)]. / Pneumocystis-Carinii-Pneumonie (Pneumocystose).

In former times Pneumocystis carinii (PC) primarily affected premature infants. More recently, it has proved to be one of the major infectious complications among immunocompromised patients, particularly those with AIDS. The most frequent radiographic feature is diffuse, bilateral alveolar and interstitial perihilar shadowing, spreading in a butterfly pattern. The typical findings may mimic other infectious diseases, but the presence of large pleural effusions of hilar adenopathy is evidence against the diagnosis of PC-pneumonia.

Renal arterial stenoses: spiral CT angiography.

PURPOSE: To evaluate the role of spiral computed tomography (CT) in diagnosis of renal arterial stenoses. MATERIALS AND METHODS: In 22 patients with suspected renovascular hypertension, spiral CT angiography of the renal arteries was compared with arterial digital subtraction angiography (DSA). For each patient, the peak transit time t (from intravenous injection to maximum enhancement of the abdominal aorta) was determined with a bolus injection of 15 mL of contrast medium. Spiral scanning started at the level of the superior mesenteric artery with a delay of t + 5 seconds after the start of injection of 100-150 mL of contrast medium. RESULTS: Spiral CT angiography demonstrated multiple renal arteries in five patients. A renal artery stenosis or occlusion was found in 15 of 22 patients (22 of 54 arteries). All findings were confirmed with arterial DSA. Vessel contrast on spiral CT scans was good to excellent in 19 of 22 patients. For diagnosis, axial-section and multiplanar reformatted images were superior to three-dimensional surface reconstructions and maximum-intensity projections. CONCLUSION: Spiral CT angiography is a promising screening method for renal artery stenosis.

Storage phosphor versus screen-film radiography: effect of varying exposure parameters and unsharp mask filtering on the detectability of cortical bone defects.

Diagnostic performance with storage phosphor radiography is influenced by exposure parameters and digital filtering algorithms. The authors compared the detectability of cortical lesions in excised human femoral shafts on state-of-the-art screen-film radiographs and storage phosphor digital radiographs. For the digital system, the effect of varying exposure parameters (photon flux and tube voltage) and unsharp mask filtering (kernel size and enhancement factor) was tested. Analysis of receiver operating characteristics was performed for 10,560 observations made by eight radiologists. Under identical exposure conditions, storage phosphor imaging yielded no significant advantages over conventional screen-film radiography. Although large variations in exposure dose are possible with storage phosphors, the potential for dose reduction was limited even by means of an increase in tube voltage. The performance with unsharp masked images declined with decreasing kernel size and pronounced enhancement.