Allergic bronchopulmonary aspergillosis.

Since 1968 the number of reported cases of allergic bronchopulmonary aspergillosis in the United States has risen secondary to increased awareness by physicians and to improved diagnostic criteria for identifying the disease. The eight diagnostic criteria, the five clinical stages of the disease, the common radiographic changes, the pathologic findings, the common laboratory findings, the possible pathogenetic mechanisms involved, the differential diagnosis, the acute and chronic pulmonary function changes, and the importance of corticosteroid therapy in treatment of exacerbations and prevention of further lung damage are reviewed.

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.

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.

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.

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.

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.

The radiologic significance of the left pulmonary ligament. Experience with 26 patients.

Pathologic processes confined to or by the left pulmonary ligament present a confusing radiographic appearance. Such processes may simulate pleural scarring, parenchymal scarring, or even left lower lobe collapse. Radiologic awareness of this structure is limited because in the normal state, it is not visualized on either posteroanterior or lateral chest x-ray films. The absence of secondary signs of left lower lobe collapse, together with a process which may extend above the level of the left hilum, is valuable in confirming that such a triangular density seen behind the left cardiac border is disease in or confined by the pulmonary ligament, rather than left lower lobe collapse.

Dose reduction in mammography.

Two mammographic imaging systems (Xerox and Kodak Min-R) were evaluated. Three hundred consecutive mammographic examinations were performed utilizing both imaging systems. Results of these studies indicated equivalency of image detail at identical source-to-image receptor distance (SID). Patient exposure as measured by the thermoluminescent dose meter for Kodak Min-R system was approximately 25% that of Xeromammography system. Due to reduced power requirement, it is possible to increase the SID when Min-R system is employed for imaging. Improved geometric arrangement provided superior diagnostic images in 5.5% of 200 comparison cases.

The effect of geometric and recording system unsharpness in mammography.

Modulation transfer functions (MTFs) and test object radiographs were used to study the effect of geometric and recording system unsharpness in mammography with the CGR Senographe x-ray unit. Results show that geometric unsharpness can be a significant factor in the detection of microcalcifications within the breast, depending on the size and shape of the focal spot, the focal spot-to-recording system distance, and the object-to-recording system distance (o.r.d.). A new recording system for mammography, the DuPont Lo-dose system, requires approximately 1/15th the exposure of a direct x-ray film, such as Kodak RP/M, to provide mammograms with comparable photographic density. With the Lo-dose system, geometric unsharpness can be reduced by use of a specially designed long cone with an increased focal spot-to-recording system distance. This cannot be accomplished with direct x-ray films because the x-ray unit is operating at near-maximum output conditions even when short cones are used. Although direct x-ray films have a higher resolution than the Lo-dose system, at certain o.r.d.s total resolution is found to be affected more significantly by geometric unsharpness than by the Lo-dose recording system. In several cases, clinical results show improved detection of microcalcifications at larger o.r.d.s by the Lo-dose system with a long one, combined with a reduction by a factor of 15 in patient exposure.

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.

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.

Gastrointestinal complications of spinal cord injury.

The incidence, nature, and radiographic features of gastrointestinal complications encountered in a group of 567 consecutive spinal-cord-injury patients are reported. Eighty-seven episodes of gastrointestinal complications developed in 63 (11%) patients. During the first month postinjury, these complications consisted of ileus, gastric dilatation, the body cast syndrome, peptic ulcer disease, and pancreatitis. More chronically these patients presented with fecal impactions, peptic ulcer disease, the superior mesenteric artery syndrome, hepatitis, amyloidosis, and the precocious appearance of diverticulosis, hiatus hernia, and gastroesophageal reflux. Radiographic findings were diagnostic in the majority of cases and aided in the early diagnosis of these potentially life-threatening complications.

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.