Iodized oil retention due to postbiopsy arterioportal shunt: a false positive lesion in the investigation of hepatocellular carcinoma

BACKGROUND: Iodized-oil computed tomography (CT) is useful for the diagnosis of hepatocellular carcinoma, but there may be false-positive results in patients who have undergone some percutaneous transhepatic interventional procedures. The purpose of the present study was to verify the correlation between subsegmental hepatic parenchymal retention of iodized oil on CT and the arterioportal shunt caused by liver biopsy. METHODS: Iodized-oil CT scans were reviewed in 24 patients with hepatic tumors who had liver biopsy and subsequent iodized oil chemoembolization. Iodized oil chemoembolization was performed shortly after biopsy (1-10 days; mean = 2.6 days). The results were correlated with hepatic arteriography, with a special emphasis on the presence of hepatic arterioportal shunt. RESULTS: Wedge-shaped subsegmental retention of iodized oil along or adjacent to the biopsy needle path was observed in iodized-oil CT in 17 of the 24 patients. In three patients, there was subsegmental enhancement on prebiopsy helical dynamic liver CT at the same area of iodized oil retention, and therefore iodized oil retention was considered to be due to hepatocellular carcinoma. In the remaining 13 (54%) patients, the peripheral iodized oil retention was considered to be due to biopsy-induced arterioportal shunt. In all these patients, arterioportal shunt was confirmed by hepatic arteriography. CONCLUSION: Wedge-shaped hepatic parenchymal retention of iodized oil is commonly observed in iodized-oil CT due to biopsy-induced arterioportal shunt, and this appearance should not be confused with a hepatocellular carcinoma.     

Combined hepatocellular and cholangiocarcinoma of the liver: Sonography,CT, Angiography,and Iodized-Oil CT with pathologic correlation

To evaluate the characteristics of combined hepatocellular and cholangiocarcinoma of the liver by imaging techniques, six patients (five male and one female), aged 46–60 years, with proved combined tumors were selected for this study from the review of 500 resected specimens of liver tumors. Images obtained from sonography, computed tomography (CT), angiography, and CT after intraarterial injection of iodized oil (iodized-oil CT) were retrospectively reviewed and correlated with the appearance of pathologic specimens. Sonographic findings were round or ovoid hypoechoic masses with central hyperechoic area (target appearance) in all patients. On CT scans, tumors were relatively well-defined low- and/or iso-attenuation masses in all patients. Angiography showed hypovascular masses in five patients. In one patient, the tumor appeared as a hypovascular mass with a central hypervascular area. On iodized-oil CT scans, all patients showed partial retention of iodized oil in tumors. Echogenicity in tumors at sonography or attenuation in tumors at CT could not be correlated with histologic difference in tumors at pathologic specimens. However, the hypervascular area at angiography and the compact retention areas of iodized oil at iodized-oil CT corresponded to portions of hepatocellular carcinoma within the combined tumor. On the basis of our results, imaging features, including target appearance at sonography, hypovascular mass with central hypervascular portions at angiography, and partial retention of iodized oil in tumors at iodized-oil CT, might be helpful in making accurate diagnosis of these rare tumors.     

Methodological assessment of combined spiral CT angiography and CT arterial portography

Background: To assess an optimal methodology of combined spiral computed tomographic (CT) angiography (CTA) and CT arterial portography (CTAP) for detection and characterization of liver tumors. Methods: We performed spiral CTAP only in five patients with 30–32% contrast (subset A), CTAP combined with preceding spiral CTA using 30–32% contrast in 19 (subset B), and CTAP combined with preceding spiral CTA with 60–64% contrast in seven (subset C). The CT numbers of the aorta immediately before preceding CTA and subsequent CTAP and the CT numbers of malignant tumor and liver parenchyma with CTAP were measured. Results: The differences of the CT number between the malignant tumor and liver parenchyma on CTAP were 61.1–161.8 (mean ± SD, 114.5 ± 39.3) HU, 50.7–164.8 (104.2 ± 31.2) HU, and 101.2–368.3 (219.5 ± 90.5) HU in subsets A, B, and C, respectively. Two cavernous hemangiomas showed pathognomonic findings with preceding CTA. Conclusion: Combination of preceding spiral CTA and subsequent spiral CTAP using 30% contrast with a 5-min interval is an optimal method for detection and characterization of liver tumors. Received: 14 December 1995/Accepted after revision: 13 February 1996     

Transcatheter arterial embolization in the treatment of symptomatic cavernous hemangiomas of the liver: a prospective study

Background: This prospective study evaluated the clinical and radiologic results of transcatheter arterial embolization (TAE) for the treatment of symptomatic cavernous hemangiomas of the liver. The technique, its complications, and effectiveness also were analyzed. Methods: Eight patients (five male, three female; mean age ± SD = 47.75 ± 8.59 years) with symptomatic cavernous hemangiomas of the liver were treated by TAE with polyvinyl alcohol particles or gelfoam and steel coils (single session) followed by supportive treatment. Tumor characterization (including the extent and number of lesions) was done on triple-phase helical computed tomography or gadolinium-enhanced dynamic magnetic resonance imaging. Results: The lesions were located in the right lobe in five patients, left lobe in one, and both lobes in two. The largest diameter of the lesions was 6–18 cm (9.28 ± 5.13 cm). The treatment response was assessed on follow-up ultrasound and color Doppler and/or contrast-enhanced helical computed tomography. There were no treatment-related deaths and morbidity was minimal. Embolization was the only method of treatment in seven patients; however, one patient had surgery after TAE because the symptoms were only partly relieved. Indications for embolization were abdominal pain (eight patients), rapid tumor enlargement (four of eight), and recurrent jaundice (one of eight). Symptomatic improvement was documented in all patients after embolization. Symptoms did not worsen in any patient. The mean size of the tumor did not show any statistically significant change on follow-up radiologic examinations. However, in one patient, the tumor significantly regressed in size after embolization. Conclusion: TAE of hepatic cavernous hemangioma is a useful procedure in the therapy of symptomatic hemangiomas. Received: 13 July 2000/Revision accepted: 27 December 2000     

Focal hepatic nodules after transcatheter oily chemoembolization; detection with spiral CT versus conventional CT

Background: The objective of this study was to determine if spiral computed tomography (CT) results in increased rate of detection of focal hepatic nodules containing iodized oil after transcatheter oily chemoembolization when compared with conventional CT. Methods: Spiral CT with single 24-s breath-hold technique was compared with conventional sequential CT in 42 patients with suspected hepatocellular carcinomas. Two sets of CT scans obtained after transcatheter oily chemoembolization were independently reviewed by two radiologists. The slice thickness was 10 mm for both data sets. The number and sizes of focal hepatic nodules containing iodized oil were documented. All 42 patients had at least one hepatic nodule. The lesion size varied from 2 mm to 12 cm. Results: In six of the 42 patients, more hepatic nodules could be identified on spiral CT compared with conventional CT. When scans with spiral CT were used, 107 nodules were detected, whereas 98 nodules were detected with conventional CT. Overall, nine (9%) more nodules were detected with spiral CT (<+>p= .002). If lesions larger than 2 cm are excluded, nine (15%) more lesions were detected with spiral CT (<+>p= .002). Conclusion: Spiral CT results in increased rate of detection of focal hepatic nodules after transcatheter oily chemoembolization, particularly in lesions smaller than 2 cm. Received: 11 October 1994/Accepted: 6 November 1994     

Altered flow dynamics of intravascular contrast material to the liver in superior vena cava syndrome: CT findings

Background: To evaluate the findings of altered flow dynamics in the livers of patients with obstruction of superior vena cava (SVC) on helical computed tomography (CT). Methods: In six patients (age range = 28–80 years) with SVC obstruction, CT findings were retrospectively reviewed to identify the abnormal enhancement patterns of the liver and the relation with the extrahepatic collateral vessels and hepatic vessels. Results: Abnormal hepatic enhancement was observed in the following four (A–D) portions: (A) anterior portion of segment IV (n = 5), (B) subdiaphragmatic portion of the liver (n = 4), (C) posterior portion of the right lobe (bare area; n = 1), and (D) lateral segment of the left lobe (n = 2). Two major collateral pathways to the liver were demonstrated as follows: A and D → from the umbilical vein to the left portal vein, and B and C → from the subcapsular vein to the bare area of the liver or to the hepatic veins. On helical CT, these collateral pathways were also clearly visualized. Conclusion: When these abnormal enhancements of the liver on CT are recognized within the liver, these findings indicate diversion of contrast material into collateral pathways to the liver with SVC obstruction. Received: 31 March 1999/Revision accepted: 25 June 1999     

Spiral CT of the abdomen after distention of small bowel loops with transparent enema in patients with Crohn's disease

Background: To evaluate the capability of a computed tomographic (CT) technique that combines distention of the small bowel loops with a transparent enema with contrast-enhanced spiral CT of the abdomen in patients with Crohn's disease. Methods: We evaluated the abdomen with spiral CT after distention of the small bowel loops with a transparent enema of methylcellulose in 40 patients consecutively referred for radiologic evaluation of Crohn's disease of the small bowel. Fluid was infused through a nasojejunal catheter with a peristaltic pump. Ultrasonography was used to prevent bowel overdistention and detect arrival of methylcellulose to the cecum. Contrast-enhanced spiral CT of the abdomen was then performed, and the degree of contrast enhancement and the thickness of the walls of the involved loops were evaluated. A series of 10 patients with retrograde distention of the last ileal loop from large bowel water enema was used as a control. The results of the CT were compared with those of conventional radiographic small bowel studies. Results: The normal small bowel wall was 1.9–2.5 mm thick (mean = 2.1 mm); density values of the normal enhanced wall varied between 25 and 60 HU (mean = 32 HU) and presented a homogeneous structure. Bowel segments involved by the disease were 4–12.5 mm thick (mean = 9.2 mm), had density values of 75–150 HU (mean = 105 HU), and showed a multilayered appearance. Compared with conventional radiography, CT detected longer lesions or additional segments involved by the disease process in 14 cases, 11 additional fistulas, two abscesses, and mesenteric changes in 21 cases. Conclusions: The small bowel CT enema technique provides good results in the study of patients with Crohn's disease and can be used to evaluate patients with advanced lesions. Received: 24 June 1998/Revision accepted: 27 January 1999     

Xanthogranulomatous cholecystitis: a radiological study of 12 cases and a review of the literature

Background: Twelve cases of xanthogranulomatous cholecystitis (XGC) are presented, and their radiologic appearance is described. Methods: Four men and eight women, aged 31–82 years old, with XGC were reviewed. Abdominal ultrasound (US) was performed in all patients. Computed tomography (CT) was performed in five patients, barium enema examination in two, and percutaneously CT-guided fine-needle aspirative biopsy of the gallbladder in one. Results: Barium enema examination showed an indentation of the hepatic flexure. Cholelithiasis was present in all patients, and sludge was present in six. The gallbladder wall was thickened in all patients, irregular in nine, and could not be properly differentiated from surrounding liver parenchyma or from other adjacent structures in most patients. A curvilinear halo, hypoechoic on US and with low attenuation on CT, within the gallbladder wall was found in three patients and pericholecystic fluid in two others. On CT, the pericholecystic fat had streaky soft tissue densities in three cases. Percutaneously CT-guided fine-needle aspirative biopsy of the gallbladder was nondiagnostic. The diagnosis of gallbladder carcinoma was considered preoperatively in three patients. Conclusion: Despite the characteristic histologic appearance of XCG, radiologic findings are nonspecific, varying from signs observed in other forms of cholecystitis to the appearance of a gallbladder neoplasm. Received: 5 April 1995/Accepted: 15 May 1995     

MR findings of hepatic cavernous hemangioma after intraarterial infusion of iodized oil

Magnetic resonance (MR) imaging was performed on five tumors of three patients who had hepatic hemangiomas. Four tumors were given an intraarterial infusion of 3–8 ml of iodized oil, while one tumor was not. MR images were obtained at 2.0 or 0.5 T. A single spin echo sequence with TE of 30 ms and TR of 500 ms and a double echo sequence with TEs of 60 and 150 ms and TR of 2000 ms, were used to produce relatively T1-, T2-weighted, and heavily T2-weighted images, respectively. Follow-up MR imaging was done 1–5 months after infusion of iodized oil. On relatively T1 weighted images, hemangiomas showed iso or hypointensity. On T2-weighted images, all tumors showed hyperintensity. However, on heavily T2-weighted images, tumors with iodized oil showed heterogeneous, slight hyperintensity, while tumors without iodized oil showed characteristic appearance of marked hyperintensity in hemangiomas. In hepatic cavernous hemangiomas with intraarterial infusion of iodized oil, familiarity with this unusual MR intensity of tumors on heavily T2-weighted images is useful to avoid the incorrect diagnosis and to reduce the frequency of inappropriate hepatic resection.     

Omental infarction: report of three cases and review of the literature

Omental Infarction, the end result of impaired perfusion to the greater omentum, is a rare entity (JBCM Puylaert, Radiology 1992;185:169–172). We recently encountered three patients in whom computed tomography (CT) showed the characteristic findings of omental infarction. The diagnosis was subsequently confirmed intraoperatively and pathologically in two of the cases. The third case showed partial resolution on follow-up computed tomography. All three cases are presented with a brief review of the literature. Received: 9/19/96/Accepted: 10/30/96     

Significance of hyperattenuating and contrast-enhancing hepatic nodules detected in the cirrhotic liver during arterial phase helical CT in pre–liver transplant patients: radiologic–histopathologic correlation of explanted livers

Background: Hyperattenuating nodules detected by arterial phase helical computed tomography (HCT) in patients with cirrhosis usually are believed to represent hepatocellular carcinomas (HCCs). We correlated HCT morphology of hyperattenuating hepatic nodules detected during arterial phase scans with the histopathology of explanted livers of patients with hepatic cirrhosis undergoing liver transplantation. Methods: Three hundred fifty-four patients had arterial and portal phase HCT performed before subsequent hepatic transplantation. Each patient received 180 mL of contrast by power injection at 5 mL/s. All hyperattenuating nodules detected on arterial phase HCT were assessed for morphology and evidence for contrast enhancement. Explanted livers in all patients were then sectioned at 10-mm intervals, and the histology of the nodules was correlated with the HCT findings. Results: Sixty-one hyperattenuating nodules were detected on the arterial phase HCT in 43 patients: 41 nodules were benign regenerating nodules (RN), three were dysplastic nodules (DP), and 17 were HCCs. Most RN/DP nodules were 5–20 mm in diameter, had distinct margins, were homogeneous, and were isoattenuating on precontrast, portal, and delayed scans. Thirty-six showed positive contrast enhancement and displayed a wide range of attenuation profiles. HCC nodules were 6–50 mm. All showed positive contrast enhancement and displayed a wide range of attenuation profiles. Conclusion: Hyperattenuating nodules seen on arterial phase HCT are likely to be RN/DP nodules. In many cases, it is not possible to distinguish between RN/DP and HCC. Thus, clinical decisions regarding inclusion criteria for transplantation based on CT morphology of liver lesions may be tenuous.     

Evaluation of pancreatic carcinoma with FDG PET

Background: To assess the diagnostic usefulness and clinical impact of positron emission tomography with [F-18]fluorodeoxyglucose (FDG PET) on the management of patients with known or suspected pancreatic carcinoma. Methods: Attenuation-corrected FDG PET was performed in 20 patients (12 male, eight female) with pancreatic carcinoma at the time of initial diagnosis (n = 7), for tumor surveillance after Whipple surgery (n = 11), and for reevaluation after chemoradiation therapy (n = 2). Visual analysis of PET images were correlated with the results of abdominal computed tomography (CT) and carbohydrate antigen (CA) 19-9 serum tumor marker level that were obtained within 1 month of the PET study. Diagnostic validation was by histology in nine patients and by clinical or radiologic follow-up (5–48 months) in 11 patients. Changes in therapeutic management that were prompted by PET were tabulated. Results: PET was concordant with the findings of abdominal CT in 14 patients (13 true positive, 1 true negative). PET detected clinically unsuspected lung lesions, confirmed subsequently by a chest CT, in one of these 14 patients. PET was discordant with CT in six patients. PET detected tumor recurrence in three patients in this group (15% of total) with nondiagnostic CT findings and elevated CA 19-9 serology. In two of these three patients, chemotherapy with gemcitabine was initiated based on PET localization of disease. Tumor was confirmed in the remaining one of the three patients at autopsy shortly after the PET study. FDG localization in a displaced loop of bowel resulted in an apparent false-positive hepatic lesion in one of six patients in the discordant group. PET underestimated the extent of metastatic disease in the remaining two of six patients due to hyperglycemia. Conclusion: In patients with suspected pancreatic carcinoma at the time of initial presentation, PET is complementary to abdominal CT and allows detection of unsuspected distant metastases. In patients with suspected recurrent pancreatic carcinoma, based on elevated or rising CA 19-9 serology, PET can localize the disease when abdominal CT is nondiagnostic as a result of posttherapy anatomic alteration. Imaging evaluation with PET may impact the clinical management of patients with pancreatic carcinoma. Received: 1 August 2000/Accepted: 20 September 2000     

Hepatocellular carcinoma recurrence after percutaneous ablation therapy: helical CT patterns

Background: To categorize the helical computed tomographic (CT) intrahepatic recurrence patterns of hepatocellular carcinoma (HCC) after treatment with percutaneous ablation procedures. Methods: Double-phase helical CT studies of 67 patients with HCC recurrence were reviewed. The study population had undergone percutaneous ablation therapy procedures (multisession or single-session ethanol injection therapy, radiofrequency thermal ablation therapy, and interstitial laser photocoagulation therapy) for 120 HCC nodules. Results: Four patterns were defined. (A) Enhancing tissue within the edge of the ablated nodule on arterial phase images (ingrowth): this pattern was seen in five treated lesions (4.2% of all treated nodules) in five patients (7.5% of all patients with recurrence) 3–7 months after treatment (mean = 4 months). (B) Enhancing tissue around the treated nodule but continuously to its border on arterial-phase images (outgrowth): this pattern was found in 12 (10%) treated lesions in 12 patients (18%) 3–6 months after ablation (mean = 4 months). (C) Enhancing tissue within the same segment of the treated nodule on arterial phase images (spread): this pattern was detected in 10 (8%) treated lesions in 10 patients (15%) 3–6 months after treatment (mean = 5 months). (D) Enhancing tissue within different segments from the treated nodule on arterial phase images (progression): this pattern was identified in 34 patients (51%) with 53 (44%) treated tumors 5–22 months after ablation (mean = 8 months). A mixed pattern was found in six subjects (9%) with seven (6%) treated nodules. Among the 61 patients with a nonmixed pattern, there were 85 treated nodules with persistent necrosis, 17 treated nodules with local recurrence (pattern A or B), and 107 new nodules due to nonlocal recurrence (pattern C or D). Portal phase enhanced images and especially unenhanced images showed a lower detection rate and a lower lesion-to-liver conspicuity score (for all patterns but mainly for pattern C). Conclusion: Four patterns of recurrence after percutaneous ablation procedures can be categorized on double-phase helical CT and are best depicted on arterial phase images. Knowledge of these patterns is relevant for early detection and may be helpful in understanding the recurrence mechanism. Received: 25 September 2000/Accepted: 15 November 2000     

Renal and perirenal space involvement in acute pancreatitis: spiral CT findings

Background: This study was conducted to estimate the prevalence and morphologic computed tomographic (CT) features of renal and perirenal space abnormalities in acute pancreatitis in correlation with the severity of pancreatitis. Methods: One hundred fifty-nine contrast-enhanced CT scans of 100 consecutive patients with acute pancreatitis were retrospectively and independently reviewed by three observers. All CT images were obtained using contrast-enhanced helical CT (collimation width = 5 mm, table increment = 7 mm/s, reconstruction interval = 5 mm, scan delay time = 30–50 s). Additional maximized images (field of view = 260 mm) of the perirenal space were available for review. All CT scans were scored with the CT Severity Score Index: pancreatitis was graded as mild (0–2 points), moderate (3–6 points), and severe (7–10 points). Interobserver agreement for both the severity score and the presence of renal and perirenal involvement was calculated. Correlation between the prevalence of complications and the degree of pancreatitis was estimated. Results: CT scans were graded as mild (n= 59), moderate (n= 82), and severe (n= 18). Abnormalities detected included perirenal stranding (n= 37 patients, 26 bilateral), perirenal fluid collections (n= 10 patients, one bilateral), ureteral encasement (n= 2 patients), renal vein thrombosis (n= 1 patient), and renal parenchymal abnormalities (n= 1 patient). The interobserver agreement range for scoring the degree of pancreatitis and the overall presence of abnormalities was 75.5–79.2% and 59.8–100%, respectively. Except for stranding of the perirenal fat, no statistically significant differences between the presence of abnormalities and the severity of pancreatitis (moderate or severe) was observed with Fisher's exact test. Also, no preferential left-sided localization of complications was observed. Conclusions: The incidence of renal and perirenal complications from acute pancreatitis is higher than previously estimated (7%). We found no significant correlation between the prevalence of major complications and the severity of pancreatitis. These findings are important because these complications may have an impact on therapeutic strategy and can affect prognosis. Received: 31 March 1999/Revision accepted: 25 August 1999     

Hepatic pseudolesion around the falciform ligament: prevalence on CT examination

Background: The purpose of this study was to determine the prevalence of hepatic pseudolesions seen around the falciform ligament on computed tomography (CT) of the abdomen obtained with intravenous administration of contrast material. Methods: We first retrospectively reviewed the CT scans of six patients in whom hepatic pseudolesions were seen around the falciform ligament. The abdominal CT scans of 587 patients were then prospectively analyzed for the presence of hepatic pseudolesions around the falciform ligament to determine the prevalence of this finding on CT examinations. Results: CT scans in the first six patients showed two types of hepatic pseudolesion around the falciform ligament. In three patients, hepatic pseudolesions were focal spared areas in fatty liver. In three patients, hepatic pseudolesions were developed in nonfatty liver. Prospectively, hepatic pseudolesions were found on five of 587 CT examinations (prevalence = 1%). A single hepatic pseudolesion was found in segment 4 on two examinations. Two hepatic pseudolesions (one in segment 4 and one in segment 3) were found together on three CT examinations. Conclusion: Hepatic pseudolesions around the falciform ligament are seldom seen on CT scan. However, recognition of these pseudolesions is crucial because they may be interpreted as true tumors. Received: 28 February 1995/Accepted: 29 March 1995     

CT of the mesenteric vascular anatomy

Background: To evaluate the appearance of the arrangement of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) on computed tomography (CT) in normal patients and in patients with abdominal masses. Methods: One hundred seventy-seven consecutive abdominal CT examinations of 143 adults and two children were reviewed. The relationship of the SMV to the SMA was recorded at four locations: the beginning of the mesenteric vessels and levels 3 cm, 6 cm, and 9 cm caudad to the beginning. The relationship of the SMV to the SMA was divided into four quadrants in relation to the SMA: I, ventral right or directly ventral; II, dorsal right or directly right; III, dorsal left or directly dorsal; and IV, ventral left or directly left. Results: In the beginning of the SMV–SMA complex and levels 3 cm, 6 cm, and 9 cm caudal to the beginning, the SMV was located in quadrant I in 146, 84, 69, and 43 examinations, in quadrant II in 31, 93, 71, and 27 examinations, in quadrant III in zero, zero, five, and three examinations, and in quadrant IV in zero, zero, nine, and 15 examinations, respectively. The cases with SMV inversion had neither malrotation nor adjacent tumor compression. All the cases with an adjacent tumor-induced compression of the SMV–SMA complex had a normal SMV–SMA relationship. Conclusion: In the first 3 cm, the SMV is always to the right of the SMA. Caudal to the level of 6 cm, the SMV may be located to the left of the SMA without evidence of malrotation. A midgut nonrotation is more likely to be present when a proximal SMV inversion is coexistent with a rightward direction of the proximal jejunal vessels. A hypothetical depiction of the step-by-step change of the SMV–SMA relationship during embryologic development may explain the arrangement patterns of the mesenteric vessels in normal rotation and midgut nonrotation. Received: 6 May 1996/Accepted: 22 May 1996     

Cavernous transformation of the portal vein secondary to tumor thrombosis of hepatocellular carcinoma: spiral CT visualization of the collateral vessels

Background: We investigated the constituting collateral vessels in cavernous transformation of the portal vein (CTPV) caused by tumor thrombosis of hepatocellular carcinoma (HCC) by using contrast-enhanced spiral computed tomographic (CT) examination. Methods: Fifty-four histopathologically proven HCC patients with tumor thrombosis-induced CTPV were retrospectively included and assigned to cirrhosis negative (n= 31) and positive (n= 23) groups. Another 15 cirrhotic patients with portal hypertension but no HCC and CTPV were used for comparison. Standardized dual-phase contrast-enhanced spiral CT was performed for all patients. CT appearances of the collateral vessels of CTPV were observed, and their visualization rates were analyzed. Results: Biliary (cystic and paracholedochal veins) and gastric (left and right gastric veins) branches of the portal vein were the most frequently visualized collateral vessels of CTPV. There was a marked difference in CT visualization rates for biliary branches between patients with and without CTPV (83–94% vs. 0). No difference existed in visualization rates for gastric branches across the three groups (77–87% for left gastric, 58–61% for right gastric vein). Conclusions: Biliary and gastric branches of the portal vein are the major collateral vessels of CTPV. The intergroup differences in CT visualization rates may provide clues to the roles that they might play in the hemodynamic adaptation process of CTPV. Received: 13 October 1999/Accepted: 12 January 2000     

Fascioliasis: US, CT, and MRI findings with new observations

Background: The purpose of this study is to describe the ultrasonographic (US), computed tomographic (CT), and magnetic resonance imaging (MRI) findings in fascioliasis and to emphasize the impact of radiology in diagnosis. Methods: Radiologic findings in 23 consecutive patients with fascioliasis were prospectively recorded. All patients had at least one US and CT examination, and 10 of them were studied by MRI. All diagnoses were confirmed by serologic methods. In the first three cases, initial diagnosis was reached by microscopic demonstration of the parasites' eggs in bile obtained by US-guided gallbladder aspiration. Results: In the hepatic phase of fascioliasis, multiple, confluent, linear, tractlike, hypodense, nonenhancing hepatic lesions were detected by CT. On US, the parasites could be clearly identified in the gallbladder or common bile duct as floating and nonshadowing echogenic particles. MRI showed the lesions as hypo- or isointense on T1-weighted images and as hyperintense on T2-weighted images. Conclusions: CT findings in the hepatic phase and US findings in the biliary phase are characteristic of fascioliasis. Because clinical and laboratory findings of fascioliasis may easily be confused with several diseases, radiologists should be familiar with the specific radiologic findings of the disease to shorten the usual long-lasting diagnostic process. Received: 15 December 1999/Accepted: 26 January 2000     

Cryotherapy of metastatic carcinoid tumors

Background: To describe the use of hepatic cryotherapy to treat patients with symptomatic carcinoid metastates. Methods: Hepatic cryotherapy was performed on five patients with carcinoid syndrome resulting from metastatic carcinoid tumors. Intraoperative ultrasound was used to guide the cryotherapy and to assess the adequacy of freezing. Results: All five patients had relief of the carcinoid syndrome after treatment. In four of the five patients, the relief was prolonged (>3 months); in one patient, the relief of symptoms was transient (2 months). Four of five patients had a transient reduction in hormonal tumor markers (the fifth patient did not have hormonal-level follow-up). During a follow-up period of 2.5 years, four of the five patients died. The 6-month survival rate was 80%, the 1-year survival rate was 60%, the 2-year survival rate was 40%, and the 2.5-year survival was 20%. One patient is alive 30 months after treatment. Conclusion: Hepatic cryotherapy can provide symptomatic relief for patients with hepatic metastates producing the carcinoid syndrome. Received: 1/17/97/Accepted: 2/19/97     

Percutaneous MR imaging-guided laser-induced thermotherapy of hepatic metastases

Background: Many primary tumors may cause liver metastases, which are generally treated with surgical resection and/or chemotherapy. After resection of liver metastases in patients with colorectal carcinoma, 5-year survival rates are achieved in 25–38%, and two-thirds of patients will experience recurrent metastases. We examined percutaneous, minimally invasive, laser-induced thermotherapy (LITT) as an alternative outpatient procedure. Local tumor control rate and survival data were analyzed prospectively. Methods: Between June 1993 and August 2000, 7148 laser applications were performed in 1981 lesions in 705 consecutive patients and 1653 treatment sessions. The complications of the procedure were evaluated by clinical examination and magnetic resonance imaging (MRI) and computed tomography. Local tumor control was evaluated by plain and contrast-enhanced follow-up MRI using T1- and T2-weighted spin-echo and gradient-echo sequences every 3 months after treatment. Cumulative survival times were calculated using the Kaplan–Meier method. Results: The overall rate of complications and side effects was 7.5%. The rate of clinically relevant complications was 1.3%. Local tumor control rate after 3 months was 99.3%; 6 months after laser treatment, plain and contrast-enhanced MRI documented a local tumor control rate of 97.9%. In patients treated with MR-guided LITT for unresectable colorectal liver metastases, the mean survival was 41.8 months (95% confidence interval = 37.3–46.4 months). The 1-year survival rate was 93%, the 2-year survival rate was 74%, the 3-year survival rate was 50%, and the 5-year survival was 30%. In patients treated with LITT for liver metastases from breast cancer, the mean survival was 4.3 years (95% confidence interval = 3.6–5.0 years). Conclusion: In patients with liver metastases, local tumor destruction using minimally invasive, percutaneous LITT under local anesthesia results in improved clinical outcomes and survival rates and can be a potential alternative to surgical resection.