Biomedical subjects
Publications and source records attributed to G D Dodd.
The aim of this article is to present pictorially the spectrum of appearances of the appendix and appendicitis on CT. The images presented were selected from the database of our hospitals. The various appearances of the normal appendix on CT are shown. Appendicitis can be divided into four categories on the basis of CT findings. Examples of each category are shown.
We report a case of esophageal hemangioma presenting with dysphagia and odynophagia. To our knowledge, very few cases have been reported in the radiological literature.
To evaluate diagnostic computed tomographic (CT) angiograms of transjugular intrahepatic portosystemic shunts (TIPS), helical CT angiography was performed in 10 patients with (n = 7) or without (n = 3) shunt dysfunction. CT angiography was performed with 3-mm-thick sections, pitch of 1, 120 kV, and 180-220 mA, after injection of 150 mL nonionic contrast material at 5 mL/sec, with a 50-second scanning delay after initiation of injection. All patients underwent transjugular portography within 1 week after CT angiography. In all cases, CT angiography correctly showed the presence or absence of the abnormality. These preliminary data suggest that CT angiography can provide diagnostic images of normal and abnormal TIPS.
PURPOSE: To determine the frequency, distribution, size, and cause of enlarged abdominal lymph nodes in patients with end-stage cirrhosis. MATERIALS AND METHODS: Preoperative computed tomographic (CT) scans from 507 hepatic transplantation patients with end-stage cirrhosis were reviewed for the presence, size, and location of enlarged (short-axis diameter > 1 cm) abdominal lymph nodes. Enlarged lymph nodes were identified and resected at surgery. Resected livers were evaluated for malignant neoplasms. CT findings were correlated with histopathologic results. RESULTS: Enlarged abdominal lymph nodes were detected with CT in 253 (50%) of the patients. The enlarged nodes were 1.1 x 1.1 to 3.0 x 4.5 cm in size and were most common in the portacaval space and porta hepatis. The frequency of enlarged nodes varied according to type of cirrhosis: They were most common in patients with primary biliary cirrhosis (86% [43 of 50]) and least common in patients with alcohol-induced cirrhosis (37% [42 of 113]). Histologic evaluation revealed that the enlarged lymph nodes were due to benign nodal hyperplasia in 251 patients and malignant neoplasm in two patients. CONCLUSION: Enlarged abdominal lymph nodes are common in patients with all forms of end-stage cirrhosis. In the absence of other evidence of malignancy, enlarged nodes in these patients should be considered a benign process, with no additional evaluation warranted.
PURPOSE: To determine the imaging appearance and frequency of detection of bile duct calculi in patients with primary sclerosing cholangitis. MATERIALS AND METHODS: Images (169 computed tomographic [CT] scans, 155 sonograms, and 109 cholangiograms) of 189 patients with primary sclerosing cholangitis, five of whom were prospectively included, were reviewed. Pathologic records were reviewed for proof of the presence of calculi. RESULTS: Bile duct calculi were visualized on images in 14 (7.6%) of the 184 retrospective patients and in all five of the prospective patients. The presence of calculi was confirmed with pathologic or imaging findings in 19 patients, in whom calculi were visible on 16 of 18 CT scans, 15 of 19 sonograms, and 14 of 17 cholangiograms. Calculi were in the intrahepatic ducts in 11 patients and in the intra- and extrahepatic bile ducts in eight patients. At CT, calculi appeared as foci of faint high attenuation or as coarse calcifications in nondilated or variably dilated ducts. At sonography, they appeared as unique echogenic casts with variable posterior acoustic shadowing or as discrete, echogenic, variably shadowing foci in variably dilated ducts. Calculi were depicted at cholangiography as rounded filling defects. CONCLUSION: Intrahepatic bile duct calculi are present in approximately 8% of patients and can have a unique imaging appearance.
OBJECTIVE: The purpose of this study was to determine if unique characteristics revealed by CT can allow radiologists to reliably distinguish benign from malignant portal vein thrombus (PVT) in patients with cirrhosis. MATERIALS AND METHODS: CT examinations of 58 patients with cirrhosis and PVT were retrospectively reviewed. Images were assessed for location, extent, enhancement, neovascularity, and maximal diameter of PVT. The type of PVT was proven histologically in 42 patients and clinically in the remaining 16 patients. Using different threshold PVT diameters or the presence of PVT neovascularity, we calculated the sensitivity and specificity of CT for revealing malignant PVT. RESULTS: Forty-seven patients had malignant and 11 patients had benign PVT. CT scans of patients with malignant PVT showed direct extension of hepatocellular carcinoma into the portal vein in 15 patients. In 29 patients with malignant PVT, CT scans showed PVT adjacent to tumor; CT scans showed tumor PVT remote from hepatocellular carcinoma in the remaining three patients with malignant PVT. The mean diameters of malignant and benign portal vein thrombi were significantly different (23.4 mm versus 16 mm; p = .0001). CT scans of 83% (39/47) of patients with malignant PVT and 18% (2/11) of patients with benign PVT showed generalized enhancement. Neovascularity was seen on CT scans in 43% (20/47) of patients with malignant PVT and in no patient with benign PVT. Identification of a main PVT diameter greater than or equal to 23 mm or PVT neovascularity resulted in a sensitivity and specificity for the CT characterization of malignant PVT of 86% and 100%, respectively. CONCLUSION: Malignant and benign thrombi can often be differentiated by radiologists on the basis of CT imaging characteristics.
OBJECTIVE: This study was done to determine if the detection of pericolic lymph nodes on CT scans could be used to differentiate cancer of the colon from diverticulitis. MATERIALS AND METHODS: We retrospectively evaluated 58 CT scans from 57 patients with proven diverticulitis or cancer of the colon. The CT scans were evaluated by five board-certified radiologists who were unaware of the proven diagnosis. Consensus opinions regarding the presence and size of pericolic lymph nodes were recorded. These data were correlated with the proven diagnoses to determine the correlation between the observed findings and the type of colonic abnormality. Fisher's exact test was used to determine statistical significance. RESULTS: Lymph nodes were seen in 22 (71%) of 31 cases of colonic cancer and in four (15%) of 27 cases of diverticulitis. The lymph nodes were 0.5-2.5 cm in short-axis diameter. We saw no difference in node size for patients with colonic cancer versus patients with diverticulitis. The nodes were most commonly located along the blood vessels in the mesenteric fat. Statistical analysis showed a significant difference (p < .001) in the frequency but not in the size of nodes between the two groups of patients. The detection of nodes resulted in a diagnostic sensitivity and specificity for colonic cancer of 71% and 85%, respectively. CONCLUSION: Pericolic lymph nodes are seen much more frequently in patients with colonic cancer than in patients with diverticulitis. The detection of pericolic lymph nodes in patients suspected of having diverticulitis should raise the suspicion of underlying colonic cancer that should, in turn, prompt additional evaluation.
Transjugular intrahepatic portosystemic shunt (TIPS) is becoming an accepted procedure as a bridge to orthotopic liver transplantation (OLT) in patients with end-stage liver disease (ESLD) and bleeding from portal hypertension. It allows the immediate control of acute bleeding and decreases the risk of recurrent acute bleeding while the patient is awaiting OLT. We review in this report, our experience with 85 patients who underwent a TIPS procedure for gastrointestinal variceal bleeding from September 1991 until April 1994. All patients had liver cirrhosis and all had previous sclerotherapy before TIPS. Child-Pugh score was calculated at enrollment, and all patients were evaluated for possible OLT. Thirteen patients were Child A, 49 were Child B, and 23 were Child C. Fifty-three patients were candidates for OLT, and 32 were not. TIPS was performed urgently in 25 patients. At a median follow-up of 582 days (range, 1 to 1,095), 35 patients underwent transplantation, 21 patients died, and 29 patients are still alive and did not undergo transplantation. Technical complications were observed in 7% of patients and new onset of clinical encephalopathy in 37%. The 30-day mortality rate after TIPS was 13%. Actuarial survival was 60% at 1 and 3 years. Child class C and urgent TIPS were shown to be two independent predictor factors for mortality. TIPS was shown to be a valuable procedure, not only as a bridge to OLT but also as palliation for bleeding from portal hypertension in patients who were not candidates for either surgical shunt or OLT. However, its role in bleeding patients with acceptable liver function needs further investigation.
The hypervascular nature of carcinoid tumors and their metastases allows a more aggressive role by the radiologist in diagnosis and interventional management. Double-contrast gastrointestinal studies still best define the primary neoplasms. Appendiceal tumors, the most frequent site of carcinoids, frequently escape radiologic detection until large enough to be discovered by computed tomography (CT). Superior mesenteric arteriography of the small bowel and cecum is useful when the scanning procedures are not revealing. The "spokewheel" configuration of the desmoplastic mesenteric masses and lymph node metastases are best seen by CT, whereas hepatic metastases can be demonstrated by CT, CT-angioportography (CTAP), ultrasonography (US), magnetic resonance imaging (MRI), and octreotide scintigraphy. Percutaneous needle biopsy with radiologic guidance confirms the diagnosis of carcinoid tumors and their metastases. Hepatic arteriography is frequently performed in preparation for hepatic embolization or chemoembolization. Hepatic vascular occlusion therapy, the procedure of choice for the management of inoperable carcinoid liver metastases, results in a partial response in at least 50% of patients and a mortality rate of 5%. Chemoembolization with microencapsulated cytotoxic agents and direct percutaneous ethanol injection should also be considered for the treatment of liver metastases.
Because most radiologists in the United States have been taught that fluoroscopy and computed tomography (CT) are the best guidance techniques for nonvascular interventional procedures, sonography has been greatly underused in this regard. Recently, sonography has been gaining recognition as a highly useful and versatile guidance technique. It has many advantages over CT and fluoroscopic guidance, including real-time imaging with vessel visualization, decreased procedure time and cost, portability, and lack of ionizing radiation. Sonography should be the primary guidance technique for many nonvascular interventional procedures, and use of sonography as an adjunct guidance technique increases the ease and speed with which many other interventional procedures are performed. Sonography should generally be used instead of CT for guidance of abdominal and pelvic biopsy and drainage. Sonographic guidance should replace CT and fluoroscopic guidance for biopsy and drainage of accessible peripheral thoracic and mediastinal masses. Use of sonographic guidance should be integrated into all interventional radiology suites to reduce radiation exposure and facilitate the performance of many nonvascular and some vascular interventional procedures that have traditionally been performed under fluoroscopic guidance.
PURPOSE: To correlate computed tomographic (CT) and serum tumor marker (alpha-fetoprotein [AFP] and des-gamma-carboxy-prothrombin [DGCP]) findings in recurrent hepatocellular carcinoma (HCC) after orthotopic liver transplantation (OLT). MATERIALS AND METHODS: At retrospective review of the cases in 124 patients, CT findings were recorded by consensus of at least two nonblinded observers and compared with levels of AFP and DGCP. RESULTS: In 35 patients (68 sites), CT depicted recurrent HCC (most frequently in lungs [n = 18] and liver allograft [n = 16]) in a single site in 19 patients (54%) and in more than one site in 16 patients (46%). No stage I or II HCC recurred after 18-78 months (mean recurrence, 39 months). Stage IVA HCC recurred four times as often as stage III HCC (P < .001). Abnormally high serum AFP and DGCP levels indicated 69% and 43%, respectively, in patients with recurrent disease. CONCLUSION: HCC recurrence after OLT correlates with initial stage, and CT is more sensitive than serum tumor markers in its detection.
PURPOSE: To determine if image-guided percutaneous hepatic biopsy is contraindicated in patients with ascites. MATERIALS AND METHODS: The records of 476 patients (173 with ascites and 303 without) who underwent image-guided hepatic biopsy were reviewed retrospectively for number of passes, type of needle, and indications. Coagulopathy was corrected with appropriate blood products before biopsy. Complications were classified as minor (decrease in hematocrit value not necessitating treatment) of major (bleeding that necessitated transfusion or surgery or resulted in death). RESULTS: Major complications occurred in six patients with ascites and 10 without. Minor complications occurred in 10 patients with ascites and 15 without. With ascites, all major complications necessitated blood transfusions but not surgery. Five patients with major complications had a documented moderate or severe amount of perihepatic ascites. without ascites, nine of the 10 patients required blood transfusions and one required surgery. No deaths occurred in either group. CONCLUSION: Perihepatic ascites does not statistically significantly affect the major of minor complication rate of image-guided percutaneous hepatic biopsy.
PURPOSE: To evaluate the added value of hepatic arterial-dominant phase (HAP) imaging to portal venous-dominant phase (PVP) imaging in patients with hepatocellular carcinoma (HCC) at computed tomography (CT). MATERIALS AND METHODS: Sixty-six patients with proved HCC underwent biphasic contrast-enhanced CT. HAP and PVP images were obtained at 20-50 and 60-100 seconds, respectively. PVP images were evaluated for the number of HCC foci. Then, HAP images were reviewed to determine whether any additional HCCs were seen. RESULTS: Three hundred twenty-six tumor foci were seen. HAP images depicted 309 foci (95%) and PVP images 268 (82%). In seven patients (11%), tumor was visible only on HAP images. During the HAP, tumors were hyperattenuating compared with liver in 26 patients, of mixed attenuation in 26, and hypoattenuating in 14 without correlation with histologic appearance. Portal vein thrombosis was identified in 17 of 21 patients on HAP images; in 12 patients, the thrombosis was diagnosed as malignant with neovascularity within the thrombus or diffuse thrombus enhancement. CONCLUSION: Use of both HAP and PVP contrast-enhanced CT optimizes the evaluation of patients with or at risk for HCC.
PURPOSE: To determine the CT imaging appearances of liver infarction due to arterial insufficiency and to attempt to understand reasons for apparent discrepancy of appearance in prior reports. MATERIALS AND METHODS: Thirty-seven CT examinations from 18 patients with proven hepatic infarction were evaluated for character, location, and evolution of lesions by all investigators, with a consensus interpretation. Etiologies of infarction included posttransplant complication (15), laparoscopic cholecystectomy complication (2), and traumatic arterial injury (1). Proof of hepatic infarction was made by hepatectomy (11), biopsy (1), or clinical course compatible with infarction with angiographic (3) or surgical (3) evidence of hepatic arterial abnormality. In patients without histologic proof of infarction, all lesions seen at CT were considered to be due to hepatic infarction, except those meeting the criteria for hemangioma. In 10 patients, serial examinations were available over 2-180 days and a determination of serial changes in specific lesions was made using a similar image analysis. RESULTS: Of 55 lesions identified, 53 could be classified into three shapes--wedge-shaped (18), rounded or oval (26), or irregularly shaped low-attenuation lesions paralleling bile ducts (9). The other two lesions were flat hypodense areas along the posterior aspect of the medial left hepatic lobe. Wedge-shaped lesions were peripherally located; rounded lesions were either peripheral (10) or central (26). The caudate lobe was spared except in one patient. Of 16 serially followed wedge-shaped lesions, four evolved into rounded lesions. No rounded lesions became wedge-shaped. CONCLUSION: Hepatic infarction caused by arterial disease produces a spectrum of CT findings. Prior reported discrepancies in appearance may be due to the small number of cases in each report and the variety of potential imaging appearances,aas well as evolutionary changes.
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OBJECTIVE: In the United States, CT is generally considered the guidance technique of choice for biopsy of abdominal, pelvic, and retroperitoneal lymph nodes. The aim of this study was to evaluate the efficacy of sonography for this purpose. SUBJECTS AND METHODS: We attempted 26 sonographically guided biopsies of five abdominal, six pelvic, and 12 retroperitoneal lymph nodes in 23 patients. The patients included 19 women and four men who were 26-76 years old (mean, 50 years old). The nodes were less than 2 cm in 16 patients, 2-3 cm in four patients, and greater than 3 cm in three patients. Biopsies were considered successful if the nodes could be visualized and biopsied using sonographic guidance and the pathologist's final report indicated that the tissue specimens obtained were adequate for diagnosis. The length of the procedures and the number of complications were recorded. RESULTS: Lymph nodes were visualized and biopsied with sonographic guidance in 23 (88%) of the 26 attempts. Three biopsies could not be performed with sonography because of poor visualization of the nodes. Adequate tissue for cytologic or histologic evaluation was obtained in 21 (91%) of the 23 sonographically guided procedures. In the 21 successful procedures, clinical and imaging follow-up showed no evidence of false-negative diagnoses. The time from the placement of the patient in the interventional sonography room to completion of the procedure ranged from 25 to 60 min (mean, 35 min) for sonographically guided biopsies. We had no procedure-related complications. CONCLUSION: Sonography is an accurate and safe guidance technique for lymph node biopsies in the abdomen, pelvis, and retroperitoneum. This technique is efficacious for deep nodes as small as 1 cm in diameter. The advantages of sonography over CT include no need for ionizing radiation, portability, shorter procedure time, and real-time visualization of the needle throughout the procedure. These advantages, and the fact that sonography costs less than CT, suggest that sonography is a more appropriate guidance technique in this era of cost containment.
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.
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