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G D Dodd

Publications and source records attributed to G D Dodd.

At least 19 recordsLinked to original sources
PubMed1992

The role of the barium enema in the detection of colonic neoplasms.

The variability in the published results for colonoscopy and barium enema examinations is confusing. With both, optimum studies depend on meticulous preparation, technical excellence, and operator proficiency. The equivalency of results and the lower cost of the radiologic study indicate that the double-contrast barium enema is the technique of choice for the examination of asymptomatic patients or symptomatic individuals without known antecedent disease. The relatively small difference between the cost of the double-contrast enema examination and sigmoidoscopy ($193 versus $135) suggests that it should replace the latter on the 3-5-year screening schedule because, on average, 50% more of the colon is examined by the barium study. It is a mistake to place colonoscopy and barium enema in competitive positions; the two methods ideally complement one another. The exclusion of significant pathologic findings by the double-contrast enema can be accepted, but the detection of abnormalities should be followed, when necessary, by colonoscopic verification and/or biopsy. The number of times both will be required are few. Radiologically demonstrated colon carcinomas seldom require biopsy verification, and 90% of all polyps are smaller than 5 mm in diameter with a negligible incidence of malignant transformation. When the examinations are used in the proper sequence, they provide a cost-effective approach to the early detection and control of cancer of the large bowel.

Adult↗
PubMed1992

Reduction of canine myocardial infarct size by CI-959, an inhibitor of inflammatory cell activation.

CI-959, a cell-activation inhibitor that prevents the formation of oxygen-derived free radicals by inflammatory cells, was studied to determine its effects on myocardial infarct size and subsequent scar formation in dogs. The left circumflex coronary artery was occluded for 90 min, followed by 6 h of reperfusion. Drug infusion was started 15 min before reperfusion at a loading dose of 8 mg/kg i.v., followed immediately by 2 mg/kg i.v. infused over 80 min. The infarct size, assessed by TTC staining techniques, was significantly reduced in 12 dogs treated with CI-959 (23.3 +/- 3.6% of the area at risk) when compared to 11 vehicle-treated animals (35.5 +/- 4% of the area at risk, p less than 0.05). This reduction in infarct size was not attributed to changes in regional myocardial blood flow, as measured by radioactive microspheres, or to a reduction in myocardial oxygen demand, as estimated by changes in the rate-pressure product. The scar thickness, measured after a 6-week recovery period in 9 animals treated with CI-959, was not significantly reduced in comparison with 11 controls. In vitro, CI-959 effectively inhibited oxygen free radical formation by canine neutrophils. The results of this study show that CI-959 significantly reduces the myocardial infarct size without causing scar thinning, which might lead to ventricular aneurysm, and suggests the most likely mechanism for its beneficial action is the prevention of formation of toxic oxygen radicals.

Animals↗
PubMed1992

Posttransplant lymphoproliferative disorder: intrathoracic manifestations.

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication of organ transplantation and immunosuppression. Early diagnosis and treatment greatly affect prognosis. Chest radiographs (n = 13), chest computed tomographic (CT) scans (n = 2), or both (n = 20) from 35 patients with intrathoracic PTLD were retrospectively studied to define the intrathoracic manifestations of this disorder. Intrathoracic abnormalities consisted of pulmonary nodules (16 patients), patchy air-space consolidation (three patients), mediastinal and hilar adenopathy (17 patients), thymic enlargement (two patients), pericardial thickening and/or effusions (two patients), and pleural effusions (four patients). Multiple, well-circumscribed pulmonary nodules with or without mediastinal adenopathy are highly suggestive of PTLD. However, pathologic examination is usually necessary for a definitive diagnosis.

Adolescent↗
PubMed1992

Hepatic parenchymal perfusion defects detected with CTAP: imaging-pathologic correlation.

To determine whether characteristics of focal hepatic parenchymal perfusion defects detected with computed tomographic arterial portography (CTAP) correlate with underlying pathologic processes, 245 perfusion defects detected with CTAP in 60 patients who subsequently underwent definitive hepatic surgery were characterized by shape, location within the liver, and relative attenuation value and were prospectively correlated with sectioned pathologic specimens. Of 177 round perfusion defects, 102 (58%) were malignant and 75 (42%) were benign. Only one (2%) of 53 peripheral wedge-shaped defects was malignant. All 15 peripheral flat defects were benign. Defects in characteristic locations anterior to the porta hepatis (n = 15) and adjacent to the intersegmental fissure (n = 7) were uniformly benign. While 83 (56%) of 147 soft-tissue attenuation defects were malignant, only four (6%) of 68 intermediate-attenuation defects were malignant. Although these characteristics of parenchymal perfusion defects aid in differentiation of benign from malignant processes, all other types of perfusion defects are nonspecific and may require biopsy.

Adenoma, Bile Duct↗
PubMed1992

Epithelioid hemangioendothelioma of the liver: imaging findings with pathologic correlation.

Hepatic epithelioid hemangioendothelioma is a rare malignant neoplasm that has nonspecific clinical signs and symptoms and can be difficult to diagnose on the basis of biopsy results. Radiologists may suggest the diagnosis of this slowly progressive neoplasm by recognizing its characteristic radiologic features. We correlated images from CT (13), sonography (nine), and MR (six) with pathologic findings in resected whole livers (eight) and biopsy specimens (five) from 13 patients 25-58 years old. Gross pathologic examination showed a repetitive pattern of multiple solid tumor nodules, in a predominantly peripheral distribution, with coalescence as individual nodules exceeded 4 cm. Tumor nodules had a hyperemic rim. Lesions adjacent to the capsule often produced capsular retraction. These findings correlated well with imaging findings. On CT, the lesions were of low attenuation, peripherally based, and with capsular retraction or flattening in nine (69%) of 13 patients. Unenhanced CT scans showed superior conspicuity over contrast-enhanced CT scans (9/13, 69%) and showed the extent of lesions more accurately in all cases (13/13, 100%). In nine patients, lesions had a peripheral enhancement pattern of alternating attenuation values correlating with the hyperemic rim at pathologic evaluation. On sonograms, the tumors were solid and predominantly hypoechoic. On MR, tumor signal was low on T1-weighted and high on T2-weighted images, with a low-signal halo present around many of the lesions. CT, sonographic, or MR findings of coalescent peripheral hepatic masses with capsular retraction are highly suggestive of hepatic epithelioid hemangioendothelioma.

Adult↗
PubMed1992

Detection of malignant tumors in end-stage cirrhotic livers: efficacy of sonography as a screening technique.

OBJECTIVE: Patients with hepatic cirrhosis are at an increased risk of developing primary malignant tumors of the liver. If these tumors are discovered early, current therapies may be curative. We conducted a prospective study to assess the accuracy of sonographic screening for the detection of malignant tumors in cirrhotic livers as determined by correlation with resected whole livers. SUBJECTS AND METHODS: A total of 200 prospectively interpreted preoperative sonograms from 200 patients with cirrhosis who underwent hepatic transplantation were correlated with specimens of freshly resected whole livers. The results were analyzed to determine the sensitivity and specificity of sonography in identifying patients with malignant tumors and detecting individual tumors in each patient. RESULTS: Pathologic examination showed 80 malignant lesions in 34 patients (28 with hepatocellular carcinoma, three with cholangiocarcinoma, two with metastases, and one with non-Hodgkin's lymphoma) and three hemangiomas in two patients. Sonography correctly showed malignant tumors in 17 of the 34 patients, for a sensitivity of 50%. Sonograms were false-positive for malignant tumors in three patients, two of whom had a total of three hemangiomas. Sonography correctly showed 36 of the 80 malignant lesions, for a lesion sensitivity of 45% and specificity of 98%. Of the 44 missed lesions, 24 were 1 cm or less, 12 were between 1 and 3 cm, and eight were more than 3 cm in diameter. CONCLUSION: Our results show that sonography is highly insensitive in the detection of malignant lesions in end-stage cirrhotic livers and thus is not a reliable screening technique. However, because of sonography's very high specificity, any sonographically identified lesion in a cirrhotic liver should be considered malignant until proved otherwise.

Carcinoma, Hepatocellular↗
PubMed1992

Ultrasonographic evaluation of renal transplantation.

Ultrasonography of the renal transplant is still a key screening examination for transplant dysfunction. The addition of Doppler technology has permitted screening for hemodynamic alterations. Ambitious researchers predicted that these hemodynamic profiles would permit the differentiation of rejection from other complicating factors; however, recent research and clinical experience has shown this to be ineffective. Imaging identification of a dilated collecting system identifies the patient population that should undergo a Whitaker procedure. Identification of large or increasing fluid collections helps focus attention to possible hemorrhage or urine leak. Similarly, the ultrasonographic identification of a lymphocele as the cause of leg edema or hydronephrosis rapidly focuses surgical treatment. Doppler evaluation of hemodynamics must be performed on all renal transplant recipients. Although the role of the resistive index in predicting rejection has been minimized lately, numerous vascular complications, if untreated, would result in loss of the kidney. Doppler sonography identifies those patients who would benefit most from renal arteriography. The evaluation of renal morphology on the basis of ultrasonography alone has little role in predicting the cause of transplant dysfunction. We continue to evaluate renal size and to correlate it with the clinical presentation as well as resistive index to defer patients from biopsy if a more obvious cause of dysfunction is identified.

Humans↗
PubMed1992

Thoracic and abdominal manifestations of lymphoma occurring in the immunocompromised patient.

Organ transplant and AIDS patients are at a much higher risk for developing non-Hodgkin's lymphoma than is the general population. This increased risk is directly related to chronic immunosuppression and often is associated with viral infections. In contrast to lymphomas occurring in nonimmunocompromised patients, these tumors typically are of higher grade, are more aggressive, have a worse prognosis, and exhibit a higher frequency of extranodal disease. The most frequent organs involved are the head and neck, bowel, liver, and lungs. Thoracic manifestations of ARL and PTLD are similar, consisting of nodular, diffuse alveolar, and interstitial pulmonary disease, mild to moderate mediastinal adenopathy, and pleural effusions. Of these findings, pulmonary nodules are the most specific, although they can be difficult to differentiate from Kaposi's sarcoma and opportunistic infections. Abdominal findings are also similar for the two diseases, with the most common lesions appearing as low attenuation, hypoechoic masses in the solid abdominal organs; ulcerating nodular or diffusely infiltrating bowel lesions; and bulky retroperitoneal, mesenteric, or omental adenopathy. The identification of solid masses in the abdominal organs in AIDS and transplant patients is highly suspicious for ARL and PTLD. Due to the overlap of imaging characteristics of different pathologies, however, biopsy usually is necessary to confirm the diagnosis. Both ARL and PTLD respond to therapy; however, the prognosis for patients with ARL is uniformly poor, whereas the prognosis for treated PTLD is remarkably good. An awareness of the imaging characteristics of ARL and particularly PTLD can have significant impact on prognosis by allowing for timely diagnosis and therapy.

Abdominal Neoplasms↗
PubMed1991

Cancer control and the older person. An overview.

Cancer is essentially a disease of older persons, yet the efforts made toward prevention and detection in this age group are seldom as energetic as those expended on younger individuals. It is apparent that age in itself is not a reason for benign neglect of neoplastic disease in older persons. The underlying factors that affect the behavior of cancer in older patients require intensive study. Comprehensive cancer prevention and detection services are economically sound in this age group.

Aged↗
PubMed1991

Imaging techniques in the diagnosis of carcinoma of the colon.

The variability in the published results for colonoscopy and barium enema examinations is confusing. With both, optimum results are dependent on meticulous preparation, technical excellence, and operator proficiency. It is a mistake to place colonoscopy and the barium enema in competitive positions; the two methods ideally complement one another in the evaluation of high risk individuals, including those with positive Hemoccult tests. The exclusion of significant pathology by the double-contrast enema can be relied on and is less costly to the patient. Detection of abnormalities by a barium enema should, when necessary, be followed by colonoscopic verification and/or biopsy. When used in this sequence, the procedures provide a cost-effective approach to the early detection and control of cancer; it is estimated that observance of the ACS guidelines can reduce mortality rates by 30%.

Barium Sulfate↗
PubMed1991

Renal arterial duplex Doppler ultrasound in dogs with urinary obstruction.

Recent clinical studies using duplex Doppler sonography identified an alteration in renal arterial blood flow in obstructed hydronephrotic kidneys that reportedly can be used to distinguish obstructive from nonobstructive collecting system dilatation. We attempted to verify these clinical findings and establish the temporal relationship of the alteration in the Doppler spectrum to the onset of urinary obstruction by evaluating surgically induced urinary obstruction in dogs. We performed laparotomies on 11 dogs, with the left ureter isolated and ligated in five dogs, and left intact in six dogs (control group). Duplex Doppler examination of the left renal arteries performed nine times during the first postoperative month identified a statistically significant difference (p less than .05) in the Doppler resistive index calculation between the two groups on days 1, 2, 4, and week 4. A resistive index discriminatory threshold of 0.7 (greater than 0.7, obstructed; less than 0.7, nonobstructed) produced a test sensitivity of 74% and specificity of 77%. We conclude from our study that renal arterial duplex Doppler sonography can detect a change in renal perfusion as a result of urinary obstruction and that this change can be detected as early as 24 hours after obstruction. However, high false-positive and false-negative rates may limit the ability of this modality to reliably distinguish obstructive from nonobstructive collecting system dilatation.

Animals↗
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↗