Radiologic appearance of implantable cardiac defibrillators.

Since the original descriptions of the radiologic appearance of implantable cardiac defibrillators by Lurie et al. [1] and Goodman et al. [2] in 1985, rapid growth has occurred in the complexity and variety of models available. Originally, all devices were surgically placed in or on the pericardium. Now, some devices are inserted by intravascular catheters with part of the device buried in the chest wall, avoiding the need for thoracotomy. Initially, these devices were used as defibrillators for treatment of tachyarrythmia and ventricular fibrillation. Now they serve as pacemakers for both tachy- and bradyarrhythmias and can act as cardioverters or defibrillators if required. Radiologists must be familiar with the appearances of these devices as their use becomes more widespread. In this article, the electrophysiology of these devices is briefly reviewed and the typical radiologic appearances are presented along with common radiologically recognizable complications.

A comparison of different doses of non-ionic contrast media in i.v. urography.

This study attempts to find out what is the appropriate dose of non-ionic contrast media to provide an acceptable study at the lowest possible cost. 139 adults with normal renal function were studied. Four different dose regimes were employed and a standardised set of I.V.U. films were obtained. These were reviewed by two independent assessors who were unaware of the dose regime used. Each I.V.U. was scored on a modified Fry regime. This survey showed a clear relationship between quality and dosage.

Aortic dissection: effect of prospective chest radiographic diagnosis on delay to definitive diagnosis.

PURPOSE: To determine the effect of the interpretation of plain chest radiographs on the time to definitive diagnosis of aortic dissection. MATERIALS AND METHODS: The authors evaluated chest radiographs from 75 patients in whom chest radiography was performed before aortic dissection was diagnosed. The radiographs and available comparison images were retrospectively reviewed to identify cases in which aortic dissection should have been suggested before the diagnosis was made. RESULTS: Radiographic reports suggested that only 19 patients (25%) had an aortic dissection or thoracic aortic aneurysm or needed additional imaging of the aorta. No statistically significant correlation existed between interpretation of the chest radiographs and delay to diagnosis, type of dissection, availability of previously obtained images, or presence of characteristic clinical symptoms. Retrospective analysis showed that the chest radiographs of 36 patients (48%) contained sufficient findings to suggest the diagnosis. In five patients, failure to prospectively suggest dissection was associated with a delay to diagnosis of more than 24 hours. CONCLUSION: Although prospective interpretation of the chest radiograph shortened the delay to definitive diagnosis for only a limited number of patients, retrospective analysis suggests that the delay can be shortened for additional patients.

Prevalence of gallbladder disease in diabetes mellitus.

A study was undertaken to compare the prevalence of gallstone disease (gallstones observed on ultrasound or history of cholecystectomy) in 308 diabetics and 318 controls. There was a higher prevalence of gallstone disease (GSD) in diabetics (32.7%) compared to controls (20.8%; P < 0.001 chi-squared test). However, when gender was taken into account, the difference was only significant in females (diabetics 41.8% versus controls 23.1%; P < 0.001). Analysis by type of diabetes revealed that subjects with non-insulin-dependent diabetes mellitus (NIDDM) had a higher prevalence of GSD than controls for both genders: males-controls 18.1%, NIDDM 33.3% (P < 0.05), IDDM 15.6% ns; females-controls 23.1%, NIDDM 48.6% (P < 0.001), IDDM 36.3% (P < 0.05). On univariate analysis the following risk factors were associated with gallstones (P < 0.1): increased age, body mass index (BMI), triglycerides, LDL cholesterol, decreased HDL cholesterol, alcohol intake, family history of GSD, and female parity > 3. Using stepwise multiple, logistic regression, the following variables were identified as independently predictive of gallstones for each gender/diabetic combination: Males-NIDDM (N = 54), increased age, and decreased HDL; IDDM (N = 90), age and family history; Females-NIDDM (N = 74), increased age, diabetes, increased BMI, and decreased alcohol; IDDM (N = 91), increased BMI, age, decreased alcohol and family history. The proportion of subjects who underwent cholecystectomy was higher in females (46.7%) compared to males (21.7%; P < 0.01) but there were no differences between diabetics and controls in either sex. In conclusion, there was a higher prevalence of GSD in diabetics compared to controls. However, GSD is multifactorial and only in NIDDM females was diabetes an independent risk factor. The proportion of diabetics and controls with GSD who underwent cholecystectomy was equivalent.