PubMed Health⌕ Search

Biomedical subjects

L R Clark

Publications and source records attributed to L R Clark.

At least 19 recordsLinked to original sources
PubMed1995

Alternative nursing environments: do they affect hospital outcomes?

1. A dayroom program focused intensively on functional needs and was implemented for confused geriatric inpatients who otherwise might have been restrained or required sitters. 2. There were fewer complications from hospitalization documented for dayroom patients. 3. There was an increase in family satisfaction regarding the nursing care provided for patients in the alternative environment.

Aged↗
PubMed1989

CT evaluation of suspected hepatic metastases: comparison of techniques for i.v. contrast enhancement.

Although IV injection of contrast material is widely used for detection and follow-up of hepatic metastases on CT, the optimal method of contrast enhancement has not yet been defined. A prospective study was performed in 50 consecutive patients with suspected hepatic metastases. Lesion size and detectability were compared on unenhanced CT scans, scans obtained during a bolus injection of contrast material (early bolus phase), and scans obtained during a rapid infusion after the loading bolus. A total of 60 hepatic lesions were evaluated in 26 patients, 19 with histologic confirmation of metastases and seven with strong supportive evidence. The bolus phase allowed detection of 15% more lesions than did examination during the rapid-infusion phase. Lesion size varied, depending on the timing and method of contrast administration; the largest measurements were obtained during bolus injection of contrast material. In addition, bolus administration of contrast material subjectively resulted in the best lesion detection. Because the three techniques of IV contrast enhancement may produce different size measurements, sequential examinations must be tailored appropriately. Scanning during the bolus phase is technically possible with current CT equipment and is recommended as the primary CT screening examination for hepatic metastases.

Contrast Media↗
PubMed1988

Renal cell carcinoma: dynamic thin-section CT assessment of vascular invasion and tumor vascularity.

Dynamic thin-section computed tomography (CT) was used to evaluate renal cell carcinoma in 80 patients. The lesion was correctly staged with CT in 90% of patients. With use of the dynamic technique, the ipsilateral renal vein was depicted in 99% of patients. Extension of the tumor to the renal vein or the inferior vena cava was correctly detected in 18 of 19 patients. Actual depiction of tumor thrombus was a far more accurate indicator of renal vein invasion than was the identification of isolated renal vein enlargement. Dynamic thin-section CT of the kidney should be considered the routine method for comparison studies with other newer cross-sectional techniques in the evaluation of renal cell carcinoma.

Carcinoma, Renal Cell↗
PubMed1988

CT of the liver: a survey of prevailing methods for administration of contrast material.

The members of the Society of Body Computed Tomography were surveyed to determine the most frequently used method of administering contrast material in CT studies of the liver. The respondents represented CT departments performing liver examinations in 22 institutions. No department relied solely on noncontrast scans. In 12 (54%) of 22 institutions, only contrast-enhanced scans were performed. The preferred dose for enhancement was 150 ml of 60% contrast material. Eight (36%) of the 22 respondents obtained images during the administration of a bolus of contrast material, whereas nine (41%) obtained images during the administration of a sustained drip infusion given after a loading bolus. Follow-up in 1987 revealed that two departments had switched to obtaining images during the administration of a bolus. The availability of CT power injectors and refinements in the rapid-scanning capabilities of CT scanners have increased the popularity of obtaining images of the liver during the administration of a bolus of contrast material. Despite this, in many departments, contrast material is still administered via drip infusion in CT studies of the liver.

Contrast Media↗
PubMed1987

Renal metastases: clinicopathologic and radiologic correlation.

The clinical and radiologic features of 27 patients with renal metastases arising from eight different types of nonlymphomatous primary malignancies are presented. Renal metastases were generally detected late in the course of the malignancy. In 23 patients there were no symptoms referable to the kidney. Urinalysis was normal in nine patients and showed microscopic hematuria in nine, gross hematuria in four, and proteinuria in four. Radiologically, metastases were usually multifocal; however, metastases arising from colon, lung, and breast carcinoma were sometimes large, solitary, and otherwise indistinguishable from primary renal cell carcinoma. Three of four melanoma metastases and three of seven lung metastases infiltrated the perinephric space. Computed tomography was the most sensitive modality, depicting renal metastases in all 24 cases in which it was employed, followed by ultrasound and intravenous urography. In patients with a history of malignancy, renal metastases outnumbered renal cell carcinomas by approximately 4:1. This study indicates that a new renal lesion in a patient with advanced, noncurable cancer is more likely metastatic than primary and that biopsy in this setting is unlikely to be of aid.

Adult↗
PubMed1987

Esophageal malignancy: imaging results and complications of combined endoscopic-radiologic palliation.

Fifty-one patients with advanced cancer of the esophagus underwent 191 endoscopic palliative procedures, including bouginage, laser therapy, bipolar electrocoagulation, and stent placement. In three patients free perforations developed; these were treated immediately and no sequelae developed. Perforations confined within the tumor mass were diagnosed with CT in two patients and did not require treatment. Methods of endoscopic palliation are discussed with reference to the radiologic studies and techniques. The radiologist must evaluate tumor topography and esophageal wall thickness with computed tomography and esophagography to aid in the choice of palliative therapy. Knowledge of each technique and its risks by the radiologist is essential for useful consultation with the endoscopist before, during, and after the procedure.

Adenocarcinoma↗
PubMed1986

Gastric tuberculosis: a manifestation of acquired immunodeficiency syndrome.

A Haitian man with acquired immunodeficiency syndrome (AIDS), fever, malaise, and diarrhea is described. A computed tomographic (CT) scan showed a retrogastric mass with an associated ulcer. An upper gastrointestinal tract study showed an ulcer with both benign and malignant features. Endoscopy revealed a malignant-appearing ulcer, but cultures and histologic examinations of surgical biopsy specimens indicated gastric tuberculosis. The relationship between tuberculosis and AIDS is discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Enhanced pancreatic CT imaging utilizing a geometric magnification technique.

Computed tomography (CT) using a geometric magnification technique was found to improve spatial resolution in phantom studies when compared with conventional third-generation geometry images. The clinical feasibility of using geometric magnification, small focal spot size, and dynamic contrast enhancement was studied in 143 patients referred to CT for clinically suspected pancreatic disease. This population included 46 patients with a normal pancreas and 36 patients subsequently proven to have primary pancreatic carcinoma. Using this new technique in conjunction with dynamic contrast enhancement resulted in high quality pancreatic images. Despite the limitations in tube current associated with a small focal spot size and low total heat capacity of the system, clinical imaging was not adversely affected. Use of the geometric magnification technique is recommended in departments where it is technically feasible.

Adult↗
PubMed1985

Iatrogenic sclerosing cholangitis following hepatic arterial chemotherapy infusion.

A case of common hepatic duct stricture secondary to hepatic artery chemotherapy infusion is described. CT and endoscopic retrograde cholangiopancreatography (ERCP) may be used in concert to differentiate this entity from other causes of jaundice--namely, hepatic replacement by tumor, porta hepatis adenopathy, and chemotherapy hepatotoxicity.

Adenocarcinoma↗
PubMed1985

The clinical and imaging spectrum of pancreaticoduodenal lymph node enlargement.

Pancreaticoduodenal lymph node enlargement, regardless of cause, has been a source of imaging confusion because of its propensity to mimic pancreatic malignancy yet not cause biliary obstruction. Thirty-eight patients with pancreaticoduodenal adenopathy were imaged with several methods. Pancreaticoduodenal lymphadenopathy could be distinguished from intrinsic pancreatic abnormality on only 44% (14/32) of CT scans and 54% (6/11) of sonograms. Demonstration of intact tissue planes separating adenopathy from pancreas and, to a lesser degree, extrapancreatic vascular displacement were the most helpful diagnostic signs. Surprisingly, 31% of patients had biliary obstruction. Care must be taken in distinguishing metastatic lymphadenopathy from primary pancreatic tumors. The presence or absence of jaundice should not be considered a helpful sign.

Adult↗
PubMed1985

Pancreatic imaging.

In this article, the pancreas is evaluated with regard to the controversies surrounding this organ from a clinical standpoint, and an approach to imaging modalities is examined. The roles of computed tomography, ultrasound, endoscopic retrograde cholangiopancreatography, and magnetic resonance imaging are put into proper perspective.

Acute Disease↗
PubMed1985

Imaging approach to the suspected renal mass.

The authors present their algorithmic approach to the detection, characterization, and staging of renal masses. Based on classification of urographic findings, the patient may be triaged to the appropriate cross-sectional or invasive imaging modality that will result in the most cost-effective management.

Abscess↗