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Biomedical subjects

G D Dodd

Publications and source records attributed to G D Dodd.

At least 91 records · Page 5Linked to original sources
PubMed1991

Imaging of vascular complications associated with renal transplants.

Vascular complications associated with renal transplants are a significant cause of graft dysfunction. The most common complications are arterial and venous stenoses and thromboses and intrarenal and extrarenal arteriovenous fistulas and pseudoaneurysms. Although angiography is the imaging gold standard for the diagnosis of these disorders, Doppler sonography, scintigraphy, and occasionally CT are capable of detecting them. An awareness of the different imaging appearances of each complication will aid in their early detection and treatment. In this review, we present this information and provide a perspective on the relative roles of these techniques in the detection of vascular complications from renal transplants.

Diagnostic Imaging↗
PubMed1990

Lipomatous tumors of the pelvis in women: spectrum of imaging findings.

Pelvic tumors that contain fat are common findings in women. Although the majority of these lipomatous tumors are benign cystic ovarian teratomas, other diseases should be considered in the differential diagnosis: malignant degeneration of a benign cystic ovarian teratoma, nonteratomatous lipomatous ovarian tumors, lipomatous uterine tumors, benign pelvic lipomas, and pelvic liposarcomas. Although these diseases are rare, their differentiation can be clinically significant. While most of these tumors are treated by surgical excision, asymptomatic lipomatous uterine tumors and benign pelvic lipomas may require no therapy. Additionally, correct identification of a malignant lipomatous tumor will affect both prognosis and surgical planning. The purpose of this essay is to illustrate the imaging findings of these conditions.

Dermoid Cyst↗
PubMed1990

Lymphoma of the hollow abdominal viscera.

Autopsy evidence of gross or microscopic GI involvement can be found in up to 51% of all lymphoma cases. In descending order of frequency the stomach, small intestine, colorectum, and esophagus may be involved. Radiologically, GI lymphomas tend to have similar morphologic characteristics regardless of their site of origin. Additionally, the diverse radiologic manifestations may mimic a variety of diseases. Nevertheless, growing clinical experience and improvements in imaging techniques have increased the frequency with which the proper diagnosis can be suggested. The extramucosal origin of a mass or masses is often detectable by double-contrast examination and dictates a diagnostic spectrum fundamentally different from that of tumors arising from the mucous membrane. Similarly, the ability of CT to determine the wall thickness of the involved segment and its relationships to adjacent structures has further increased radiologic specificity. These capabilities are important, not only from the diagnostic standpoint, but also with respect to staging, prognosis, and, ultimately, increased survival.

Esophageal Neoplasms↗
PubMed1989

Gastrointestinal and pancreatic endocrine tumours.

The radiological diagnosis and interventional management of neuroendocrine tumours of the gastrointestinal tract and pancreas are challenging, demanding the complete gamut of available resources. Carcinoid tumours are most commonly found in the appendix and small bowel. Barium studies usually disclose a small solitary mucosal or submucosal mass in the distal ileum at times associated with smooth muscle hypertrophy and thickening of the mucosal folds. Intussusception and bowel obstruction may be the presenting finding. Mesenteric involvement may evoke a desmoplastic reaction with rigidity, fixation, angulation and tethering of small bowel loops. Angiography may demonstrate a hypervascular primary neoplasm but more frequently reveals vascular encasement and distortion from the mesenteric desmoplastic reaction. Pancreatic islet cell tumour is best defined radiologically by angiography and computed tomography as a well circumscribed hypervascular mass which enhances with contrast material. Portal venous sampling is of considerable assistance in localizing insulinoma. Metastases from neuroendocrine tumours to lymph nodes and to the liver are usually hypervascular. In the evaluation of the liver by CT scanning prior to contrast as well as dynamic scanning during the bolus intravenous injection of contrast material are necessary. At times the precontrast scan is more revealing. Computed tomography with the catheter in the superior mesenteric artery followed by selective hepatic arteriography is the most accurate combination for the detection of hepatic metastases. Interventional radiological management by sequential hepatic arterial embolization is the treatment of choice for multiple hepatic metastases from neuroendocrine tumours. Thus far, the maximum number of embolic episodes in a single patient has been 13. The carcinoid syndrome has been controlled in 87% while 79% of islet cell tumour hepatic metastases have responded. Contraindications to HAE includes a combination of all of the following: (i) replacement of more than 50% of the liver by tumour, (ii) serum lactic dehydrogenase above 425 mU/ml, (iii) serum glutamic oxaloacetic transaminase above 100 mU/ml, and (iv) bilirubin above 2 mg/dl. In the face of occlusion of the portal vein by intravascular neoplasm, HAE is contraindicated only if portal flow through collateral vein is away from the liver.

Diagnostic Imaging↗
PubMed1988

Screening for the early detection of breast cancer.

The mortality rate of carcinoma of the breast has remained unchanged for the last 60 years. Screening by means of physical examination and mammography can significantly improve the mortality associated with this disease, but the procedures have been underutilized. Surveys indicate that among the major reasons for the failure of utilization are questions concerning efficacy, fear of radiation and costs. The amount of radiation delivered to the breast during mammography no longer poses a significant risk and there is ample documentation that screening mammography can detect occult disease. Although there is an unequivocal benefit for those older than 50 years of age, debate concerning the 40 to 50 age group continues. Objections center primarily about the expense of mammography. Current cost-cutting techniques suggest that the procedure can be justified for all women older than 40 years.

Adult↗
PubMed1988

Passive hepatic congestion in heart failure: CT abnormalities.

Using bolus-enhanced CT, we encountered an unusual constellation of findings in seven patients with clinical evidence of right heart failure. These included retrograde hepatic venous opacification on the early bolus scans and a diffusely mottled pattern of hepatic enhancement seen only during the vascular phase of contrast administration. Ancillary CT findings include cardiomegaly, pleural effusions, ascites, and intrahepatic perivascular radiolucency. We believe that these CT abnormalities are caused by passive hepatic congestion. This pattern of abnormal hepatic enhancement represents a potential pitfall in the use of dynamic bolus-enhanced CT for the detection of focal hepatic masses. Recognition of passive hepatic congestion as a possible cause of mottled hepatic enhancement on CT may help explain clinical abnormalities of liver function in patients with heart failure and prevent confusion with other disease processes that produce abnormalities of hepatic attenuation.

Adult↗
PubMed1987

The history and present status of radiographic screening for breast carcinoma.

Many of the perceived and actual difficulties in the creation of screening centers have been solved or are amenable to solution. The amount of radiation delivered to the breast during mammography no longer poses a significant risk and there is ample evidence that screening mammography can detect occult disease. While substantial evidence is lacking with respect to a decrease in mortality in patients under 50 years of age, there is an unequivocal gain in those over 50 years of age. Other concerns center around the number of trained radiologists available to interpret large numbers of screening mammograms, the use of lay screeners to minimize the physician shortage and the availability of instruction centers to educate those radiologists not formally trained in mammography. The question of quality control is closely tied to the training of the radiologist and must be addressed if screening centers are to function efficiently. All of the above are correctable to a greater or lesser degree, but the problem of cost remains. To survey all women over 40 years of age at a cost of $50.00 per examination would require an expenditure in excess of two billion dollars a year, a staggering sum even in the context of the economy of the 1980s. It is necessary that these costs be lowered if the full potential of a major cancer detection procedure is to be realized. This conference has both the responsibility and opportunity to perform a significant service for the women of the US. We ask all of you to devote your greatest ingenuity to achieving its major purpose, the development of a practical strategy for cost reduction in mammography. While it may not be possible to achieve all that we wish, the formulation of any reasonable plan to increase public access will be a major accomplishment. I remind you of a French aphorism: "The greatest crime is to do nothing because we fear we can only do a little."

Breast Neoplasms↗
PubMed1987

Experimental comparison between hepatic artery infusion and occlusion-infusion of adriamycin.

Adult mongrel dogs were used to compare hepatic arterial infusion and arterial occlusion-infusion with regard to local and systemic Adriamycin levels. The drug was infused into the right proper hepatic artery of each dog after occlusion of the gastroduodenal artery. Blood and tissue samples were collected at regular intervals for Adriamycin determination. Four weeks later, each dog again received the same agent in the right proper hepatic artery, but this time arterial flow was blocked with an inflated balloon during drug infusion (arterial occlusion-infusion). Blood and tissue drug levels were determined and compared with those obtained using infusion without occlusion. Results indicate that when Adriamycin is administered into the hepatic artery of dogs, occlusion-infusion produces significantly greater hepatic venous drug levels, drug uptake, and drug metabolism than does infusion alone.

Animals↗