PubMed Health⌕ Search

Biomedical subjects

G D Dodd

Publications and source records attributed to G D Dodd.

At least 19 recordsLinked to original sources
PubMed1995

Percutaneous fine-needle aspiration of portal vein thrombi as a staging technique for hepatocellular carcinoma. Cytologic findings of 46 patients.

BACKGROUND: Detection of portal vein tumor invasion in patients with hepatocellular carcinoma (HCC) is important in determining therapy and prognosis. Fine-needle aspiration (FNA) of a portal vein thrombus under ultrasound guidance facilitates the distinction of malignant from benign thrombus without resorting to laparotomy. In this study, the FNA findings of 46 patients who underwent this procedure are described. METHODS: Cytologic findings of 48 aspirations from 46 patients who underwent percutaneous ultrasound-guided portal vein FNA were reviewed. RESULTS: Twenty-nine of the 46 patients had a prior or concurrent biopsy-confirmed diagnosis of HCC at the time of portal vein FNA. On cytologic review, 39 of the aspirates were positive for malignancy, 6 were negative, and 3 were suspicious. Histologic follow-up of three of the six patients with negative aspirates confirmed bland thrombi in their portal veins. No complications resulted from the FNA procedure. Of the 39 aspirates positive for HCC, 22 were well differentiated, 5 were well to moderately differentiated, 9 were moderately differentiated, and 3 were poorly differentiated. In all except the poorly differentiated tumors, a trabecular cellular arrangement was detected in either smears or cell blocks. The cytologic findings in these aspirates, in general, mirror those found in aspirates of HCC in the liver proper. CONCLUSIONS: Portal vein FNA is an effective, well tolerated method for disease staging of patients with HCC. When used as the initial diagnostic procedure, in selected patients, it can provide the diagnosis and staging information simultaneously.

Adolescent↗
PubMed1995

Does advanced cirrhosis with portosystemic shunting affect the value of CT arterial portography in the evaluation of the liver?

OBJECTIVE: The purpose of this study was to determine the extent to which reduced portal blood flow in patients with advanced cirrhosis affects contrast enhancement of the liver during CT arterial portography (CTAP). We postulated that reduced and/or irregular hepatic enhancement would limit the efficacy of CTAP for the detection of hepatic tumors in these patients. MATERIALS AND METHODS: We reviewed the records of 82 patients who had biopsy-proved advanced cirrhosis and who underwent CTAP. Three experienced radiologists evaluated the CTAP studies for adequacy of hepatic parenchymal enhancement. The presence or absence of varices also was documented in an attempt to select a subgroup of patients in whom CTAP showed better hepatic parenchymal enhancement. RESULTS: Forty-seven (57%) of 82 patients had inadequate hepatic parenchymal enhancement to allow an evaluation of the entire liver. Inadequacy was attributable to areas of hyperdense parenchymal enhancement, areas of diffuse nontumoral mottling, or zones of poor parenchymal enhancement (soft-tissue attenuation equal to that of the paraspinal muscle). Parenchymal enhancement was inadequate in 62% of patients with varices and in 28% of patients without demonstrable varices. CONCLUSION: Our results show that contrast enhancement of the liver during CTAP is altered significantly in patients with cirrhosis. Thus, it is likely that CTAP has limited usefulness for the detection or characterization of hepatic neoplasms in patients with cirrhosis.

Evaluation Studies as Topic↗
PubMed1995

Detection of transjugular intrahepatic portosystemic shunt dysfunction: value of duplex Doppler sonography.

OBJECTIVE: Recent reports have shown that a high percentage of patients with transjugular intrahepatic portosystemic shunts (TIPS) have postprocedural shunt complications, including thrombosis of the stent, stenosis of the stent, or stenosis of the hepatic vein draining the stent. We did a prospective study to determine the utility of Doppler sonography as a screening technique for the detection of these complications. SUBJECTS AND METHODS: From September 1991 to September 1992 we placed TIPS in 45 patients. After the procedure, patients were routinely evaluated with both Doppler sonography and angiography. The sonographic protocol consisted of insonation of the stent, portal vein, and hepatic vein to determine the presence of flow, peak velocity, and direction of flow. The angiograms were evaluated for stenoses of the stent or hepatic vein that caused an increase in the portosystemic pressure gradient greater than 15 mm Hg, increased intrahepatic portal venous filling, retrograde filling of the draining hepatic vein, or opacification of varices. The sonographic findings were statistically evaluated to determine if sonography could demonstrate the complications shown by angiography. RESULTS: Adequate follow-up was obtained in 29 of the 45 patients. Sixteen of the 29 patients had shunt complications that consisted of one stent thrombosis, three stent stenoses, nine hepatic vein stenoses, and three concomitant stenoses of the stent and hepatic vein. Flow was not detected by sonography in the stent of the patient with thrombosis. There was a significant difference (p = .003) between the temporal change in peak stent velocity in patients with stenoses versus those without. Use of a change (increase or decrease) in peak stent velocity greater than 50 cm/sec from the post-TIPS baseline sonogram as the diagnostic criterion for the detection of shunt stenoses resulted in a 93% sensitivity and 77% specificity. Five patients with stenosis had reversed flow in the draining hepatic vein. Only one patient with a stenosis had a peak stent velocity less than 50 cm/sec. CONCLUSION: Our results suggest that Doppler sonography is an excellent noninvasive screening technique for the detection of complications of TIPS. We have found a temporal change in peak stent velocity greater than 50 cm/sec to be a more sensitive sonographic sign of TIPS stenosis than the previously reported low-velocity parameters. Our experience suggests that nearly all complications of TIPS can be detected by using three criteria: (1) no flow for thrombosis, (2) a temporal change in peak stent velocity greater than 50 cm/sec for stent and/or hepatic vein stenosis, and (3) reversed flow in the hepatic vein draining the stent for hepatic vein and, rarely, stent stenosis.

Adolescent↗
PubMed1995

Portal vein thrombosis in patients with cirrhosis: does sonographic detection of intrathrombus flow allow differentiation of benign and malignant thrombus?

OBJECTIVE: The objective of our study was to determine if the detection by Doppler sonography of blood flow in portal vein thrombi occurring in patients with cirrhosis could be used to distinguish benign from malignant portal vein thrombi. SUBJECTS AND METHODS: Color and duplex Doppler sonographic examinations were performed in 47 patients with proven cirrhosis and portal vein thrombi. The examinations were directed at the detection of continuous or pulsatile flow within the portal vein thrombi. The nature of the portal vein thrombi was proven histologically in 27 patients and by CT findings and clinical history in 20 patients. The frequency, type, and direction of portal vein thrombus flow was evaluated to determine if there was any correlation with the benign or malignant nature of the portal vein thrombi. RESULTS: Of the 47 patients, 26 had malignant portal vein thrombi and 21 had benign portal vein thrombi. Blood flow was detected in 22 of the malignant and in 15 of the benign portal vein thrombi. The blood flow was pulsatile in 16 malignant and three benign portal vein thrombi and continuous in six malignant and 12 benign portal vein thrombi. The direction of the pulsatile flow in the malignant portal vein thrombi was predominantly (13/16) hepatofugal. All continuous flow in both benign and malignant portal vein thrombi was hepatopetal. The detection of pulsatile flow in portal vein thrombi yielded a 62% sensitivity and 95% specificity for the diagnosis of malignant portal vein thrombus. CONCLUSION: The detection by Doppler sonography of pulsatile flow in portal vein thrombi occurring in patients with cirrhosis is a moderately sensitive but highly specific sign for the diagnosis of malignant portal vein thrombus. However, continuous flow can be detected in benign and malignant portal vein thrombus and is thus not useful in differentiating between the two.

Adult↗
PubMed1995

Sonography of renal transplantation.

Marked improvements in graft survival have made renal transplantation the treatment of choice for end-stage renal disease. Ultrasound, because it is an accurate and noninvasive screening examination for graft dysfunction, clearly has had an impact upon graft survival rates. Gray scale sonography easily detects hydronephrosis and perinephric fluid collections. Vascular complications of transplantation--AVFs, pseudoaneurysms, arterial/venous thrombosis and stenosis--are readily identified by color and duplex Doppler sonography. Initial enthusiasm for the gray scale and Doppler identification of acute rejection largely has been proved to be unfounded. Ultrasound guidance, however, clearly minimizes the risk and discomfort of definitive percutaneous renal transplant biopsy.

Humans↗
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↗