A pictorial review of coronary artery anatomy on spiral CT.

Coronary artery calcification quantification (scoring) has been done with electron beam CT (EBCT), but is now being done with spiral or helical CT. Many radiologists and cardiologists who do not have EBCT but do have access to spiral CT will now be able to do coronary artery calcification scoring, and will now need to know the spiral CT appearance of the coronary artery anatomy. This pictorial review will demonstrate the anatomy needed for coronary artery calcium scoring.

The 1995 Lindberg Award. Nonthermally mediated muscle injury and necrosis in electrical trauma.

Joule heating has long been considered the principal component of tissue damage in electrical injury. Recent studies suggest electroporation, a nonthermally mediated mechanism of cell membrane damage, is also a factor. We investigated whether electroporation-mediated muscle necrosis can occur in vivo without significant Joule heating. Pulsed electric fields approximately 150 V/cm were produced in the hind limbs of anesthetized rats. In shocked limbs core muscle temperature rose less than 1.8 degrees C, yet significant damage occurred as determined by technetium-99m pyrophosphate uptake, elevated serum creatine phosphokinase, and prominent hypercontraction band degeneration of myofibers on histopathologic examination. This study is significant because it directly addresses whether nonthermal mechanisms of cell damage can cause tissue necrosis. These results indicate that electroporation effects can mediate skeletal muscle necrosis without visible thermal changes. Thus the phenomenon of "progressive recognition" may be characteristically largely explained by the occurrence of nonthermally mediated tissue damage.

A miniature gamma camera.

We have described a mobile miniature-gamma-camera system for use in electrical trauma units and have presented images and imaging characteristics of a prototype system. The system has as its principal component a miniature gamma camera based on a PSPMT. The camera is 92 mm x 92 mm x 190 mm in size, weighs 5 kg, has a 48 mm x 48 mm field of view, and has an intrinsic resolution of approximately 3 mm FWHM and 6 mm FWTM. It is expected that devices of this type will be useful as imaging tools in electrical trauma units and laboratories where imaging studies regarding uptake mechanisms of radiopharmaceuticals for assessing tissue viability are carried out.

Air gap technique for digital subtraction angiography of the extracranial carotid arteries.

The technique of applying an air gap between the patient and the x-ray detector reduces scattered radiation from the patient's neck sufficiently to allow performance of DSA of the extracranial carotid arteries with the antiscatter grid removed. When compared with the conventional grid technique, air gap allows 25 to 88% reduction of mA without increasing the kVp or exposure time and without loss of spatial resolution or diagnostic image quality. These considerable patient radiation-exposure savings can be implemented on DSA systems that use ordinary under-table x-ray tube fluoroscopic equipment without the purchase of additional hardware.

Transient spontaneous regression of an anterior mediastinal mass.

A case of spontaneous regression of lymphoma is presented. Regression of the tumor occurred during an episode of mechanical small bowel obstruction. Elevated circulating endogenous corticosteroids are thought to have acted against the tumor cells.

Use of linear tomography to confirm the diagnosis of allergic bronchopulmonary aspergillosis.

Allergic bronchopulmonary aspergillosis (ABPA) has been recognized increasingly in the past few years. In minimal disease, plain chest films may be insensitive. Early detection of pulmonary involvement may help prevent irreversible damage to the lungs and bronchi. Bronchography, while both sensitive and specific, is not without hazard, particularly to the asthmatic patient. We evaluated the usefulness of linear tomography in confirming ABPA prior to initiation of corticosteroid therapy. We find that tomography is a simple, noninvasive instrument for detecting the presence of or proving the absence of the earliest manifestations of ABPA.

Indurative mastopathy: a cause of false-positive mammograms.

Indurative mastopathy is a benign, elastotic lesion of the breast characterized by a stellate appearance, with surrounding compressed and distorted ducts causing a pseudo-infiltrative pattern. In previously reported cases of benign sclerosing lesions of the breast there has been no evidence of local recurrence of metastasis following excisional biopsy. The significance of identifying indurative mastopathy lies in recognizing its benign nature despite clinical, radiographic, and gross histologic features that are indistinguishable from malignancy, thereby saving the patient additional surgery or radiotherapy once an excisional biopsy has been performed.

Roentgenographic and clinical staging of allergic bronchopulmonary aspergillosis.

Allergic bronchopulmonary aspergillosis (ABPA) is a disease of asthmatics that follows a protracted course. When ABPA is treated with high dose corticosteroids, it presents a difficult problem in clinical management. Five stages, based on clinical, roentgenographic, and immunologic criteria, have been identified as follows: (I) acute, (II) remission, (III) exacerbation, (IV) corticosteroid-dependent asthma, and (V) pulmonary fibrosis. We studied 24 ABPA patients actively followed for up to 11 years at our institution. We conclude that while there are no unique roentgenographic findings to define a particular stage, clinicoroentgenographic staging does aid in therapeutic management. Two major roentgenographic contributions are (1) to establish the diagnosis by demonstrating proximal bronchiectasis, and (2) to provide a baseline for an individual patient against which to monitor progressive changes and remissions.

Mammography in women less than 40 years of age.

Carcinoma of the breast in women less than 40 years old is a significant problem, representing 7.4 per cent of the total number of carcinomas of the breast at our institution. It is apparent that mammography in this age group is of value in confirming the clinical suspicion of a malignant condition of the breast and in evaluating the remainder of the parenchyma of the breast for clinically occult lesions. However, one cannot over emphasize that a negative result from the mammogram should not delay biopsy in the presence of clinically suspicious lesions (1, 4). It is obvious that a larger series of patients is necessary to define the role of mammography in "young women."

Evaluation of the prone position in digital subtraction angiography of the kidneys.

In visualizing the kidneys and renal arteries, the digital subtraction angiography (DSA) image is degraded by peristalsis and overlying bowel gas. In 25 patients we evaluated the efficacy of the prone position to counter these technical difficulties and found that the prone position offers visualization superior to the supine, especially in obese and uncooperative patients and those with abundant bowel gas. We advocate that prone imaging be included routinely in renal DSA.

An unusual case of rounded atelectasis.

An unusual case of rounded atelectasis (RA) is described. This entity is likely to develop as a consequence of asbestos-induced pleural disease. The sine qua non of RA is a curvilinear tail extending from the inferior medial surface of a peripheral mass. Recognition of this "comet tail" prevents the necessity for surgery.

Abnormal course of nasogastric tube in traumatic rupture of left hemidiaphragm.

In a review of 17 surgically proven cases of acute traumatic diaphragmatic hernia, a nasogastric tube had been inserted preoperatively in eight. In six of these patients the tube followed a characteristic course, indicating the diagnosis of gastric herniation into the left hemithorax. In four cases the passage of the tubing established the diagnosis; in the other two cases the diagnosis was suggested by plain films alone, but subsequent passage of the nasogastric tube provided confirmation.