Branching patterns of right pulmonary artery in cardiovascular anomalies.

The branch of the right pulmonary artery (RPA) to the upper lobe of the right lung (RUL), the truncus anterior of the RPA, and the pars anterior of the left pulmonary artery, which supplies the left upper lung lobe (LUL), were demonstrated by both dissection of postmortem specimens and angiography for 20 infants and children, by angiography only for 57, and by specimen dissection only for 59 (total 136). In posteroanterior angiograms, the RUL artery branches from the RPA near the right lateral border of the vertebral column, while the LUL artery or arteries arise more laterally, near the left midclavicular plane. This pattern is reversed in situs inversus (eight patients studied). Thirty-nine patients in other categories of congenital cardiovascular disease showed an abnormal RUL or LUL arterial pattern, including pulmonary isomerism, right lung type (RUL artery pattern present bilaterally, 12 patients); pulmonary isomerism, left lung type (RUL artery pattern absent bilaterally, 11 patients); scimitar syndrome (RUL artery pattern normal, 1 patient; absent bilaterally, 4 patients); and left pulmonary artery sling (RUL artery normal, one; hypoplastic, one; absent, two patients). Five patients with tetralogy of Fallot (TOF) with right aortic arch (RAA) and 1 of 15 with RAA not TOF or situs inversus showed a relatively large RUL artery arising more laterally than usual. Three of six patients with double outlet right ventricle had the LUL artery larger than usual plus two accessory RUL arteries, and one patient with crossed pulmonary arteries showed a similar pattern. Two patients with single ventricle had an RUL artery of normal pattern although the RUL bronchus was absent, and one patient with single ventricle and situs inversus had a comparable pattern in the left lung. The ease of demonstration of the right and left upper lobe branches of the pulmonary artery by dissection or angiocardiography warrants greater attention to their patterns in patients with congenital cardiovascular disease. Dissociation of upper lobe bronchial and vascular patterns is unusual and may also be of diagnostic value.

Digital diagnostic imaging with a comprehensive PACS: hypothetical economic evaluation at a large community hospital.

Since 1983, the 422-bed Victoria General Hospital (VGH) and Siemens Electric Limited have been piloting the implementation of digital medical imaging, including digital acquisition of diagnostic images, in British Columbia. Although full PACS is not yet in place at VGH, experience to date has been used to project annual cost figures (including capital replacement) for a fully digital department. The resulting economic evaluation has been labeled hypothetical to emphasize that some key cost components were estimated rather than observed; this paper presents updated cost figures based on recent revisions to proposed departmental equipment configuration. Compared with conventional diagnostic imaging, digital imaging appears to raise overall annual costs at VGH by nearly $0.7 million, (Canadian currency) or 11.6%; this is more favorable than the previous results, which indicated extra annual costs of $1 million (16.9%). Sensitivity analysis still indicates that all reasonable changes in the underlying assumptions result in higher costs for digital imaging than for conventional imaging. Digital imaging appears likely to offer lower radiation exposure to patients, shorter waiting times, and other potential advantages, but as yet the price of obtaining these benefits remains substantial.

Digital chest imaging using a 57-cm image intensifier: a receiver-operating characteristic study of user performance.

Chest radiography provides one of the great challenges to digital diagnostic imaging because of (1) the relatively large size of the chest field, (2) the contrast range required to resolve subtle pathological changes in soft tissue density, and (3) the high degree of spatial resolution required to discriminate pathological detail. The field size problem was resolved by using a 57-cm image intensifier whose video output of the chest could be digitized. The issue of contrast resolution was addressed in a recently completed receiver-operating characteristic study of the detectability of low-contrast densities in a humanoid chest phantom. The latter indicated that, despite the smaller size of the digital image, they were adequate for resolving clinically significant soft-tissue densities. The question of spatial resolution in digital diagnostic images is addressed in the study presented. A set of 41 clinical cases were selected to provide the typical range of diagnostic type experienced in routine diagnostic radiology. The images were each presented as conventional film, digital laser-printer, and digital video images. The results of an ROC analysis of five readers' performance in each of the viewing modes is presented.

Signal detection in digital chest-phantom images acquired with an image intensifier.

Signal detection performance was evaluated on the basis of ROC analysis using both digital and conventional images of a humanoid chest phantom. Simulated focal (coin) lesions were the target pathology. Digital images were acquired using a 57-cm image intensifier, digitized to 1024 x 1024 x 10 bits, and compared, in both video and laser-printed film formats, with conventional 14 x 17-inch chest films. Signal detection using digital video and laser printed images, of the same image polarity as conventional images, was found not to differ significantly from that achieved using conventional images, despite the smaller size of the digital images.

Selective coronary arteriography in infants and children.

The recent increase in incidence of Kawasaki disease with attendant coronary artery aneurysms spurred our interest in developing a technique for selective coronary arteriographic examination of infants and children. Right and left coronary artery catheters were shaped according to the aortic root diameters and ascending aorta lengths predicted from the patient's heights. Thirty-eight studies were done in 34 patients who were 7 months to 18 years of age (median 3.2 years) and no permanent sequelae resulted. Advantages of the use of selective coronary arteriography include the ability to visualize stenoses, important branches, and intercoronary anastomoses. The technique is also useful in evaluation of anomalous coronary arteries, myocardial ischemia, and coronary artery distribution before right ventricular outflow tract reconstruction.

Pulmonary complications of influenza: a radiological review of 30 cases.

Thirty patients with pulmonary complications of influenza are described, with particular emphasis on the appearance on the chest films. A wide spectrum of radiological changes was found, partly due to virus and partly to bacterial infection, both modified by the presence of other diseases.