Francis J. Shea

Patient flow and utilization of resources in a diagnostic radiology department.

Operation of the radiology department in a large university hospital has been analyzed in terms of patient movement and the utilization of technicians and examination rooms. Analysis of patient movement involved collating and statistically evaluating data on the time patients spent at each stage of the process, while utilization required the accounting for technician activities and examination room occupancies during all periods of the day. Comparison of the results with data from other similar institutions shows good agreement and indicates the possibility of increasing the utilization of available resources while decreasing the time patients spend in the department.

Metastatic Carcinoma of the Prostate Presenting Radiographically as Lymphoma

Anterior mediastinal and retroperitoneal lymphadenopathy is rarely clinically evident in patients with metastatic carcinoma of the prostate. We report a case in which the nodal disease was suggestive of the diagnosis of malignant lymphoma. Immunohistochemical stain for prostate specific antigen was useful in assuring the diagnosis.

Spatial Frequency Spectra of Radiographic Images

Abstract An analysis of the input to image processing systems is presented for input images recorded on radiographic film. The effects of combining simple structural elements to produce complex images are discussed. Mathematical models for idealized radiographic images of ribs, pulmonary nodules, and blood vessels are formulated and the effect of various combinations of these models on the frequency spectra of the complex image is examined in detail. The validity of these theoretical predictions is demonstrated by using a radiograph of real structures. The implication of these results for image processing by matched filters is discussed.

Patient flow analysis and the delivery of radiology service

Abstract In recent years there has been an increased awareness regarding the cost of radiologic health care, and the patient delays encountered in the delivery to the consumer. The purpose of this paper is to demonstrate that, at least in one case in the Diagnostic Radiology Department at Temple University, the assumption that better service can be given to patients provided more technicians and orderlies are available, is not valid. The facts tend to indicate that the real problem lies in scheduling techniques, and improved utilization of available equipment. Therefore, it is safe to conclude that for improved radiologic services, the emphasis should be directed towards the design of the management systems and scheduling techniques, and not the staff and/or facilities.

Visual System Transfer Function and Optimal Viewing Distance for Radiologists

The ability of an observer to detect correctly a well-defined pulmonary nodule as a function of viewing distance was experimentally determined at three different nodule brightness levels. Optimal viewing distance was shown to be more critical at low brightness levels. From the data obtained, the visual system transfer function (VSTF) was computed. Both peak frequency and peak amplitude of the VSTF curves were shown to decrease with decreasing nodule brightness. This study indicates that viewing radiographs at a fixed distance creates a considerable risk of failing to detect abnormalities.

Diverticular abscess of colon: Irritative bladder symptoms

Diverticular disease can affect the bladder in subtle ways. Presented herein is a case of a chronic abscess secondary to diverticulitis presenting as irritable vesical symptoms overlooked for several years. The value of pelvic computerized tomography in the diagnosis is stressed.

Corkscrew distal ureter: sign of extrinsic ureteral obstruction

Abstract An unusual radiographic lesion, corkscrew-shaped distal ureter, is described. Three cases demonstrating this finding are presented. All of these were due to extrinsic ureteral compression.

Linear Spatial Frequency Filtering for Enhancement of Radiographic Images

Abstract One-dimensional mathematical models were used to investigate the ability of a Wiener filter, a modified Wiener filter, a simple matched filter, and an optimal matched filter to improve radiographic detection. Selective enhancement was not possible. It was concluded that linear spatial frequency filters alone will not improve detection of nodules or radiographs, even if extended to two dimensions.

Serum Enzyme Changes Following Selective Superior Mesenteric Arteriography in Dogs

Abstract Methylglucamine diatrizoate (Renografin-60) was injected into the mesenteric circulation of mongrel dogs and its effects upon serum enzyme activity were studied. A significant elevation in both SGOT and alkaline phosphatase levels was demonstrated, most marked 24 hours after injection. This increase is attributed to possible liver damage.

Correlation of the Frequency Spectrum of a Pulmonary Nodule with Observer Detection Rate

Abstract Intercostal nodules were placed on chest films and a study made of the relationship between the frequency spectrum presented by an image and an observers ability to detect it. Both the cumulative frequency spectrum curve and the correct detection rate approach 100% at about 2.2 cycles/cm. Below 100%, detection rate lags significantly.