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Biomedical subjects

K R Lee

Publications and source records attributed to K R Lee.

At least 145 records · Page 8Linked to original sources

A digital radiology imaging system: description and clinical evaluation.

We have successfully interfaced an advanced microcomputer system to a 47-cm image intensifier for direct digital radiology. Our development effort has included the design and construction of hardware and the implementation of software. The system matrix (spatial resolution) is 1024 X 1024 and contrast resolution is 8 bits deep. A receiver-operator-characteristic analysis comparing conventional and digital laser chest radiographs for the detection of lung nodules demonstrated no statistical difference. Dosimetry measurements identified decreased patient dose. The intensifier-based digital imaging system is being increasingly used for a variety of examinations including IV pyelograms, all kinds of barium studies, and skeletal, trauma, and chest studies. Hard-copy laser-printed digital images with "bones black" are preferred by the radiology staff and have been well accepted by referring clinicians.

Evaluation Studies as Topic↗

Intraarterial digital subtraction arteriographic evaluation of extremity tumors: comparison with conventional arteriography.

Conventional arteriography and intraarterial digital subtraction arteriography (IADSA) were compared in 36 patients with primary bone or soft-tissue tumors of the extremities. The sensitivity of IADSA was at least equal to conventional arteriography for demonstrating normal or abnormal major arteries and feeding arteries, equal to or superior for depicting tumor stains or draining veins, but slightly inferior for revealing minute tumor vessels. An increase of the matrix size from 256 X 256 to 512 X 512 improved these sensitivities. IADSA with 15% diatrizoate contrast material eliminated the contrast material-induced pain in all patients. With a computer-controlled iris setting, an average of 5 minutes of procedure time and 1.7 R of radiation (0.44 mC kg) per examination could be saved. IADSA reduced the cost of an examination by an average of $67. The results indicate that IADSA was diagnostic in all instances and can replace conventional arteriography for the evaluation of extremity tumors.

Angiography↗

False-negative peritoneal cytology in metastatic ovarian carcinoma.

Seventy-nine laparotomies for disseminated intraperitoneal ovarian carcinoma were reviewed to determine the frequency and possible causes of false-negative peritoneal cytology. Negative peritoneal cytology (defined as any reading other than positive) was found in 16 of 79 cases (20%). False-negative cytology occurred more frequently with peritoneal washings (48%) than with ascites (6%; P less than .001); with second-look surgery (50%) than at primary surgery (12%; P = .004); with peritoneal metastasis less than 0.5 cm (50%) than with metastasis greater than 0.5 cm (16%; P = .02); and with bloody cytology specimens (25%) rather than specimens without blood (0%; P = .06). Volume of peritoneal specimen, architectural grade, cytologic grade, and stage of disease (III versus IV), did not affect the frequency of false-negative cytology. The high prevalence of negative cytology associated with peritoneal washings, small tumor size, and second-look surgery suggests that negative cytology is a result of poor distribution of peritoneal washings and infrequent exfoliation of malignant cells rather than misinterpretation of malignant cells present in cytology specimens.

Ascitic Fluid↗

Analog image recording using a laser printer and paper system.

This article describes a method for generating gray scale analog hard copy images on ordinary paper using a laser printer system. Operation of the computer-controlled laser printer is described. The cost of the laser printer/paper technology is estimated and compared with the cost of multiformat camera/conventional film systems. Results of an initial clinical evaluation of laser printed paper images are presented.

Angiography↗

Inferior vena caval replacement after resection of left renal tumor in canine model.

An animal model simulating the necessity of replacing the inferior vena cava (IVC) with a prosthetic graft is described. Six dogs underwent replacement of the IVC with an expanded polytetrafluoroethylene (E-PTFE) graft using an interrupted-suture technique. Three dogs served as controls, undergoing resection and autograft of the native IVC. Distal side-to-side femoral arteriovenous fistulas were constructed in each case and allowed to remain for six weeks. Subcutaneous heparin and prophylactic antibiotics were administered in the early postoperative period. All grafts were patent at six months, indicating a potentially successful technique for reconstruction of the IVC involved in disease or trauma.

Animals↗

Renal cell carcinoma--angioinfarction.

In our experience the mortality rate in 46 patients who underwent angioinfarction for renal cell carcinoma was 4 per cent. Fever, ileus and leukocytosis were noted in 86 to 90 per cent of our patients. The use of absolute ethanol as a medium for renal infarction was associated with a significant incidence of damage to other organs. A 30 per cent decrease in tumor volume following angioinfarction using absorbable gelatin sponge and Gianturco coils was noted in 75 per cent of the patients. There was no evidence of metastatic tumor reduction and we could not document any significant decrease in operative time or blood loss. It would appear that there is some increased survival rate in patients with metastasis who are given adjuvant immune ribonucleic acid therapy. However, the numbers in our series are not significant to draw any definite conclusion. It is apparent that patients treated with infarction, delayed nephrectomy and medroxyprogesterone acetate did not have any significant survival over those treated with palliative nephrectomy or chemotherapy. The macrophage maturation assay may be useful during clinical followup.

Adenocarcinoma↗

Computer graphics for digitally formatted images.

The increasing use of digitally formatted imaging systems requires high-quality interactive gray-scale computer raster graphics systems for the management, display, and analog film recording of digital image and alphanumeric information. These systems are a combination of computer hardware and software and implement a set of graphics protocols. This paper describes a set of interactive graphics protocols that has been developed for clinical use.

Computers↗

An on-line digital image management system.

The continuing increase in diagnostic examinations using digitally formatted image instrumentation imposes new requirements on the acquisition, display, transmission, recording, and archiving of all diagnostic data. The fabrication decisions and initial clinical testing of a prototype on-line, decentralized digital image management system are described. With this system, raw digital data can be viewed by multiple users as soon as it is acquired by an acquisition node and transmitted to a display node. Radiologists and clinicians have given this system a favorable reception.

Computers↗

Takayasu's arteritis: reversal of pulse deficit after early treatment with corticosteroids.

Takayasu's arteritis is a rare disease characterized by inflammation and stenosis of large arteries. The aortic arch and its branches are most often affected. Initial symptoms are nonspecific and the diagnosis may be delayed until signs of vascular insufficiency appear. Results of medical treatment have been conflicting. We report a case of a young woman with a short history of pulse deficits, high erythrocyte sedimentation rate, narrowing of the subclavian arteries on arteriography, and a complete return of pulses after high dose corticosteroids. Takayasu's arteritis is a treatable disease in its early phase, but treatment response may be disappointing after irreversible vascular lesions develop.

Adult↗

CT findings of suprapatellar synovial cysts.

The computed tomographic (CT) findings of two suprapatellar (SP) synovial cysts are presented, and the correlated anatomicopathologic changes are discussed. The cysts show characteristically semilunar shapes and anteromedial locations in the SP regions with superolateral extension. The cyst walls vary in thickness, and the cyst contents also vary from a transudate to a thick mucoid fluid, which may show a high attenuation value on CT. Differential diagnoses include liposarcoma, hematoma, xanthoma, fibrosarcoma, or other soft tissue tumors.

Adolescent↗

The computed tomographic findings of popliteal cysts.

The computed tomographic (CT) findings of two popliteal cysts are presented, and the correlated anatomico-pathologic changes are discussed. The characteristic findings include thin, well-defined cyst wall, fluid density contents, central septum or septi, and medial popliteal location with mediocaudal extension. These findings, however, may vary due to herniation or rupture of the synovial membrane, gelatinous cyst contents, or metaplastic change of the cyst wall. Differential diagnoses include liposarcoma, popliteal aneurysm or hematoma, thrombophlebitis, xanthoma, fibrosarcoma, or other soft tissue tumors.

Bursa, Synovial↗

The cost of managing digital diagnostic images.

A study of the cost of recording and archiving digitally formatted diagnostic images is presented for an academic radiology department serving a 614-bed university hospital and a large outpatient population. The radiological examinations include computed tomography, nuclear medicine, ultrasound, and digital radiography. The archiving management strategies studied include the combined use of computer magnetic tapes, computer disc storage, and multiformat video film recordings. The estimated cost per patient for the archiving of digital diagnostic images is presented.

Archives↗