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Biomedical subjects

M P Capp

Publications and source records attributed to M P Capp.

At least 19 recordsLinked to original sources

Standardization of network addressing in picture archiving and communications systems utilizing the ISO OSI protocols.

The establishment of a communications network requires the definition of addressing schemes to identify systems attached to the network. When it is anticipated that such a network will interconnect to, or communicate with, other similar networks it is beneficial to define standardized addressing schemes. This paper discusses the need for the standardization of network service access point (NSAP) addresses in picture archiving and communications systems (PACS) which use the open systems interconnect (OSI) communications protocols. Possible methods for establishing the necessary hierarchy of address registration authorities are discussed, along with the corresponding address formats.

Computer Communication Networks

Computed radiographic evaluation of simulated pulmonary nodules. Preliminary results.

We evaluated the capabilities of a computed radiography system (CRS) and a standard radiography system (SRS) in the detection of simulated solitary pulmonary lung nodules of various sizes and contrast. A phantom simulated the pulmonary anatomy, and specially shaped plexiglass disks were externally mounted to simulate solitary pulmonary nodules of different diameters and thicknesses. ROC curves were generated based on the performance of each of the radiologists observing each film set. In this preliminary study, the overall performance for both the CRS and the SRS were comparable in detecting simulated pulmonary nodules.

Humans

Total digital radiology department: spatial resolution requirements.

The minimum spatial resolution required for a total digital radiology department has yet to be defined. A pilot study designed to provide this information was performed. Abnormal and normal radiographic images of children were digitized and redisplayed on film at spatial resolutions of 5.0, 2.5, 1.25, and 0.625 lp/mm. These resolutions are comparable to a digital display of a 14 X 14 in. chest image having pixel elements of 4096 X 4096, 2048 X 2048, 1024 X 1024, and 512 X 512, respectively. Contrast resolution was maintained at 12 bits or 4096 gray levels. The three phases of data acquisition were (1) the standard analysis of receiver operating characteristics, (2) a checklist evaluation of the "seeability" of important structures, and (3) a comparison of all resolutions and a discernment of usability. Fifteen radiologists participated in the study. On the basis of the pediatric cases used, the results showed that the needed spatial resolution for a total digital radiology department may be around 2.5 lp/mm (2048 X 2048). Checklist data on seeability of structures and comparisons of all resolutions give information on specific changes that are occurring as the resolution is decreased, and, when included with the receiver-operating-characteristic data, they become a major component in developing a resolution standard. The finding that 2.5 lp/mm is the required spatial resolution makes construction of a total digital radiology department possible with present state-of-the-art technology.

Child

The digital radiology department of the future.

The boom in microelectronics, including cost-effectiveness, has now allowed us to consider the use of these objects to store digital images. There remains much research, development, and clinical evaluation to be done in receptor technology. Further improvements in image processing, optical laser disk storage, and optical transmission and further commercial development of display technology must take place. All of these developments are occurring simultaneously. Within 5 to 10 years, radiology departments will most likely be totally electronic, probably cost-effective, and, it is hoped, more diagnostically accurate.

Data Display

Comparison of conventional pulmonary angiography with intravenous digital subtraction angiography for pulmonary embolic disease.

Intravenous digital subtraction pulmonary angiography was performed in 33 patients with suspected pulmonary embolism. It was performed as the initial examination, followed immediately by conventional film-screen pulmonary angiography performed with selective right or left main pulmonary injections. Intravenous studies of diagnostic quality were obtained in 31 of 33 patients (93.9%). Of the satisfactory intravenous studies, pulmonary embolism was correctly diagnosed in 12 cases and excluded in 18 cases. Emboli were detected in major and second-order branches, and occasionally in third-order branches as well. There was one false-positive intravenous pulmonary study, but the overall accuracy was 90.9% considering all studies and 96.8% excluding the two inadequate intravenous examinations. It is concluded that intravenous pulmonary angiography is an acceptable substitute for routine pulmonary angiography in most patients with suspected major pulmonary embolism. The technique is less expensive, and is safer, faster, and easier to perform than conventional pulmonary angiography.

Diagnosis, Computer-Assisted

Rolls Royces and compacts. Selection of radiological instrumentation.

The technological revolution that has occurred in radiology since World War II has greatly improved patient care, and some initially expensive high-technology innovations are now becoming cost effective. Some of these innovations are reviewed, and the importance of not judging new technology prematurely is emphasized.

Cost-Benefit Analysis

The potential impact of digital video subtraction angiography on screening for renovascular hypertension.

The success of digital video subtraction angiography (DVSA) in screening hypertensive patients for renal artery stenosis and the apparent value of percutaneous transluminal angioplasty (PTA) prompted re-evaluation of the philosophy of indiscriminate medical therapy for newly discovered cases of hypertension. DVSA was diagnostic in 87% of cases. The cost of screening for renovascular hypertension by DVSA and treatment by PTA when feasible is about the same as that of medical therapy. Considering the problems of noncompliance and drug side effects associated with medical antihypertensive therapy, DVSA screening for renovascular hypertension in a broader population seems both medically and economically sound.

Angiography

Digital subtraction angiography of peripheral vascular bypass procedures.

Without premedication or special preparation, digital video subtraction angiography, also known as photoelectronic intravenous angiography, was effectively used for evaluating patients who had undergone peripheral vascular reconstructive procedures. Thirty-eight studies in 20 patients were performed using computer contrast enhancement after an intravenous injection. Patency of arterial grafts was thereby evaluated, thus obviating further routine angiography. Graft patency, even of small complex graft sites, was easily recognized. Occlusions were also readily identified. Patient acceptance was excellent since the procedure is almost painless and can be done on an outpatient basis. The technique is fast, safe, and less expensive than routine angiography.

Angiography

Radiological imaging--2000 A.D.

The future promises accelerated growth for radiology, and advances more startling than those of its first 80 years. Improved technology, well-planned radiology departments, good fiscal sense, and federal support will improve the contributions of radiology to clinical medicine.

Angiography

Digital video subtraction angiography of renal vascular abnormalities.

A digital subtraction system for performing intravenous angiography has been developed and applied to the diagnosis of renal vascular abnormalities. A total of 35 patients underwent 39 intravenous angiographic examinations for a variety of renal-related clinical indications. Satisfactory examinations were achieved in 36 cases (92%) with a high degree of diagnostic accuracy. Digital video subtraction angiography is an outpatient procedure that is accurate, safe, and inexpensive to perform.

Adult