Extended mycophenolate mofetil administration beyond day 30 in allogeneic hematopoietic stem cell transplantation as preemptive therapy for severe graft-versus-host disease.

To prevent acute graft-versus-host disease (GVHD), mycophenolate mofetil (MMF) combined with calcineurin inhibitors have been used in allogeneic hematopoietic stem cell transplantation (allo-SCT). Previous studies commonly utilize MMF treatment until day 30 after allo-SCT. However, the feasibility of continuous administration after day 30 has not been well evaluated. We retrospectively assessed the safety and efficacy of extended drug administration. Twenty-five patients ceased MMF at day 30 (group A); whereas, 16 patients (group B) received extended regimens depending on individual risk factors for GVHD. No severe adverse events were observed in either group. Although the cumulative incidence (CI) of grade I to IV GVHD at day 100 was comparable between the 2 groups, the CI of grade II to IV GVHD was less among group B (12.5%) compared with group A (42.3%). Extended MMF administration may be safe and beneficial as preemptive therapy to reduce the development of moderate-to-severe acute GVHD.

Peritumoral spared area in fatty liver: correlation between opposed-phase gradient-echo MR imaging and CT arteriography.

BACKGROUND: The purpose of the present study was to evaluate the magnetic resonance findings of a spared area of fatty liver caused by hepatic tumors and clarify the etiology of this phenomenon by computed tomographic (CT) arteriography. METHODS: Six patients with hepatic tumors (metastases from colon cancer, n = 3; breast cancer, n = 2; hepatocellular carcinoma, n = 1) were examined. In-phase (IP) and opposed-phase (OP) T1-weighted spoiled gradient-echo images were obtained. CT during arterial portography (CTAP) and CT during hepatic arteriography (CTHA) were also performed. Pathologic confirmation was obtained in three patients with metastases from colon cancer. RESULTS: In all six patients, peritumoral ringlike or wedge-shaped hyperintense areas in relation to the tumor and the surrounding steatotic liver parenchyma were clearly visualized on OP images alone. This area appeared as a perfusion defect on CTAP and ringlike or wedge-shaped enhancement on CTHA. Pathologically, the peritumoral hyperintense areas on OP images were compatible with the spared area of fatty liver. CONCLUSION: A peritumoral spared area can be demonstrated with OP images. The etiology of the phenomenon is correlated with decreased portal flow and increased arterial flow in the peritumoral hepatic parenchyma.

Discrimination of small hepatic hemangiomas from hypervascular malignant tumors smaller than 3 cm with three-phase helical CT.

PURPOSE: To compare the appearance of small hepatic hemangiomas at nonenhanced and contrast material-enhanced helical computed tomography (CT) with that of small (<3-cm) hypervascular malignant liver tumors and to evaluate the accuracy of multiphase helical CT for differentiating small hemangiomas from small hypervascular malignant tumors. MATERIALS AND METHODS: Radiologists reviewed multiphase helical CT liver images in 86 patients with 37 hemangiomas and 49 malignant liver tumors. They evaluated lesion type and degree of enhancement for change from arterial to portal venous phase. They rated their confidence in the discrimination of hemangiomas from malignant tumors. RESULTS: At arterial phase CT, enhancement similar to aortic enhancement was observed in 19%-32% of hemangiomas and 0%-2% of malignant tumors; globular enhancement, in 62%-68% and 4%-12%, respectively. At portal venous phase CT, enhancement similar to blood pool enhancement was observed in 43%-54% of hemangiomas and 4%-14% of malignant tumors; globular enhancement, in 46%-49% and 0%-2%, respectively. For all readers and all phases of enhancement, the area under the receiver operating characteristic curves was 0.81-0.87, indicating that inherent accuracy of CT is high and that there was no significant difference (P >.28) in overall accuracy. Readers diagnosed hemangiomas with 47%-53% mean sensitivity with all enhancement phases and diagnosed malignant lesions with 95% mean specificity. CONCLUSION: Small hemangiomas frequently show atypical appearances at CT. Two-phase helical CT does not improve sensitivity but does improve specificity for differentiating hemangiomas from hypervascular malignant tumors.

CT arteriographic confirmation of focal hepatic fatty infiltration adjacent to the falciform ligament associated with drainage of inferior vein of Sappey: a case report.

We experienced a case of focal fatty infiltration in the anteromedial edge of the medial segment of the liver adjacent to the falciform ligament associated with advanced esophageal cancer. By using CT during selective right internal thoracic arteriography, we confirmed that the inferior vein of Sappey drained into the area of focal fatty infiltration. This is the first case to directly establish the relationship between drainage of the inferior vein of Sappey and occurrence of focal fatty infiltration of the liver.

Dynamic CT of hepatic abscesses: significance of transient segmental enhancement.

OBJECTIVE: The purpose of this study was to evaluate dynamic CT findings of hepatic abscesses, especially segmental hepatic enhancement, and to clarify the cause. MATERIALS AND METHODS: Twenty-four abscesses in eight patients were examined by early (30 sec) and late phase (90 sec) dynamic CT. Patients underwent abscess drainage (n = 1), hepatic resection (n = 2), or antibiotic therapy (n = 5). CT during arterial portography and CT during hepatic arteriography were performed in one patient. We retrospectively observed the frequency and changes of segmental hepatic enhancement on dynamic CT and determined its cause using radiologic and pathologic correlation. RESULTS: Sixteen abscesses (67%) showed transient segmental hepatic enhancement and three abscesses showed only segmental hepatic enhancement in the early phase. Four abscesses in one patient who underwent CT during arterial portography and CT during hepatic arteriography showed a segmental perfusion defect on CT during arterial portography and segmental enhancement on CT during hepatic arteriography. On follow-up dynamic CT performed 10-17 days after the initial CT, segmental hepatic enhancement surrounding hepatic abscesses decreased or disappeared in all abscesses. Pathologic examination of two patients showed marked inflammatory cell infiltration with stenosis of portal venules within the portal tracts surrounding hepatic abscesses without definite inflammation in the liver parenchyma. CONCLUSION: Segmental hepatic enhancement on dynamic CT is frequently associated with hepatic abscesses and may be caused by decreased portal flow resulting from inflammation of the portal tracts.

Accumulation of iodized oil within the nonneoplastic liver adjacent to hepatocellular carcinoma via the drainage routes of the tumor after transcatheter arterial embolization.

PURPOSE: After transcatheter arterial embolization (TAE) with iodized oil (Lipiodol), a relatively dense accumulation of Lipiodol is often seen in the nontumorous liver adjacent to a hypervascular hepatocellular carcinoma (HCC) nodule. We compared this phenomenon with the findings obtained with single-level dynamic CT during hepatic arteriography (SLDCTHA) and presumed its possible mechanism. METHODS: Fifty-six patients with HCC underwent hepatic angiography including SLDCTHA followed by segmental or subsegmental TAE with a mixture of an anticancer drug and Lipiodol. We compared the drainage area of the HCC depicted on SLDCTHA with the Lipiodol accumulation in the nontumorous liver adjacent to the HCC on CT after TAE (LpCT). RESULTS: In 26 of the 56 patients, a definite corona enhancement around the HCC, suggesting the drainage of blood from the tumor into the surrounding liver parenchyma, was seen on the late phase of SLDCTHA. In 17 of these 26 patients (65.4%), LpCT showed a more intense accumulation of Lipiodol in the nontumorous liver adjacent to the HCC that corresponded to the drainage area revealed on SLDCTHA. CONCLUSION: The drainage of blood from the HCC was considered to be a possible mechanism of the accumulation of Lipiodol in the nontumorous liver adjacent to the HCC.

Islet cell tumor of the pancreas: biphasic CT versus MR imaging in tumor detection.

PURPOSE: To compare the effectiveness of biphasic computed tomography (CT) and magnetic resonance (MR) imaging in the detection of pancreatic islet cell tumors. MATERIALS AND METHODS: Retrospective quantitative, qualitative, and receiver operating characteristic analyses of biphasic CT and MR imaging were performed in 19 patients with 26 histopathologically proved islet cell tumors. Delayed arterial dominant-phase (AP) and portal venous-phase (PVP) biphasic CT was performed after the administration of contrast material. MR imaging included T1-weighted spin-echo (SE) and T2-weighted SE or fast SE imaging, fat-saturated T1-weighted SE imaging, dynamic contrast material-enhanced T1-weighted gradient-echo imaging, and delayed enhanced T1-weighted SE imaging with or without fat saturation. RESULTS: PVP CT and delayed enhanced T1-weighted MR imaging had the highest A(z) values (0.98 and 0.97, respectively; P <.05). Delayed enhanced T1-weighted MR imaging had the highest relative sensitivity (14-15 [74%-79%] of 19 lesions), followed by PVP CT (18-19 [69%-73%] of 26 lesions), AP CT (17-19 [65%-73%] of 26 lesions), fat-saturated T1-weighted MR imaging (eight to 10 [57%-71%] of 14 lesions), T2-weighted (16-17 [62%-65%] of 26 lesions), T1-weighted (15-18 [58%-69%] of 26 lesions) MR imaging, and dynamic MR imaging (nine [56%] of 16 lesions). CONCLUSION: Biphasic (especially PVP) CT and MR imaging have similar effectiveness in the detection of islet cell tumors if fat-saturated T1-weighted and delayed enhanced T1-weighted MR imaging are included.

Correlation between the blood supply and grade of malignancy of hepatocellular nodules associated with liver cirrhosis: evaluation by CT during intraarterial injection of contrast medium.

OBJECTIVE: The purpose of this study is to evaluate the correlation between the intranodular blood supply revealed by CT during intraarterial injection of contrast medium, mainly using helical CT, and the grade of malignancy of hepatocellular nodules associated with liver cirrhosis as classified by the International Working Party of the World Congress of Gastroenterology. SUBJECTS AND METHODS: We studied 201 histologically proven nodules (101 resected and 100 biopsied nodules), including 47 low-grade dysplastic nodules (low-DNs), 56 high-grade dysplastic nodules (high-DNs), 24 well-differentiated hepatocellular carcinomas (wd-HCCs), and 74 moderately or poorly differentiated HCCs (mp-HCCs), in 139 cirrhotic patients. Findings on CT during arterial portography (n = 201) and CT during hepatic arteriography (n = 74) were reviewed and compared with the histologic diagnosis. RESULTS: CT findings were classified into four types relative to the surrounding liver: type A (isodense), type B (slightly hypodense), type C (partially hypodense), and type D (markedly hypodense) on CT during arterial portography and type I (isodense), type II (hypodense), type III (partially hyperdense), and type IV (hyperdense) on CT during hepatic arteriography. On CT during arterial portography, the distributions of each type were low-DN (n = 47 [A, n = 36; B, n = 8; C, n = 3]), high-DN (n = 56 [A, n = 18; B, n = 20; C, n = 10; D, n = 8]), wd-HCC (n = 24; [B, n = 4; C, n = 13; D, n = 7]), and mp-HCC (n = 74 [D, n = 74]). On CT during hepatic arteriography, the distributions were low-DN (n = 26 [I, n = 18; II, n = 7; III, n = 1]), high-DN (n = 19 [I, n = 6; II, n = 7; III, n = 4; IV, n = 2]), wd-HCC (n = 15 [I, n = 1; III, n = 8; IV, n = 6]), and mp-HCC (n = 14 [IV, n = 14]). We found a statistically significant correlation between the four types and the grade of malignancy of these nodules. CONCLUSION: Findings on CT during arterial portography and CT during hepatic arteriography correlated positively with histologic grading when overlap in appearance between dysplastic nodules and HCCs occurred. The concept revealed in this study can apply to diagnoses made on the basis of Doppler sonography, dynamic CT, and MR imaging.

Right hepatic arterial supply to the posterior aspect of segment IV of the liver: analysis by CT during hepatic arteriography.

OBJECTIVE: To examine the frequency of the right hepatic arterial supply to the posterior aspect of segment IV (PASIV) of the liver shown on computed tomography (CT) during hepatic arteriography (CTHA). MATERIALS AND METHODS: Seventy-four patients who underwent CTHA from the right and/or left hepatic artery were studied. The right arterial supply to the PASIV was determined when the PASIV was stained on CT during right hepatic arteriography without any opacified arteries originating from the right hepatic artery and distributing to segment IV through the left hepatic hilum or when no staining was seen in the PASIV on CT during left hepatic arteriography. The frequency of the right hepatic arterial supply to the PASIV demonstrated on CTHA was analyzed. RESULTS: In six of 74 patients (8%), the PASIV was supplied from the right hepatic artery. CONCLUSION: This PASIV was supplied by the right hepatic artery in a significant proportion of cases.

Pseudolesion in segment IV of the liver on MRI: prevalence and morphology in 250 cirrhotic livers compared with 250 normal livers.

PURPOSE: The goal of our study was to assess the prevalence of pseudolesion in segment IV of the liver on MRI in patients with and without liver cirrhosis. METHOD: Patients were divided into three groups: 10 patients with angiographically confirmed aberrant gastric venous drainage and liver cirrhosis (Group 1), 250 consecutively selected patients with liver cirrhosis (Group 2), and 250 with normal liver (Group 3). The signal intensity of pseudolesion in segment IV on T1- and T2-weighted MRI in the 510 patients was analyzed. RESULTS: In Group 1, five pseudolesions were visible and hyperintense on T1-weighted images. On T2-weighted images, four were visible and hypointense. In Group 2, 11 were seen (4.4%). All were hyperintense on T1-weighted images. Five were hypointense on T2-weighted images. In Group 3, one pseudolesion was seen (0.4%). CONCLUSION: The prevalence of pseudolesion in segment IV on MRI is higher in liver cirrhosis than in normal liver. The lesion is hyperintense on T1-weighted images when visible.

Giant hyperplasia of the caudate lobe of the cirrhotic liver: correlation with an anomaly of the caudate portal branch.

Different imaging appearances of giant hyperplastic change of the caudate lobe of the liver are presented in a patient with liver cirrhosis. The mass like caudate lobe was isoechoic on ultrasound, hypodense on postcontrast computed tomography (CT), hyperintense on T1-weighted magnetic resonance, images and isointense on T2-weighted images. These imaging findings are similar to those of dysplastic nodule in cirrhotic liver. The caudate lobe received normal portal flow on CT during arterial portography, but superior mesenteric arteriography showed precocious or early division of the caudate portal branch. We suspect that caudate hyperplastic change may be correlated to anomalous caudate portal vein branch.

Histochemical study of the distribution of nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd)-positive neurons in the chicken caecum.

The distribution of nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd)-positive neurones was investigated in the chicken caecum. Double staining combined NADPHd histochemistry with immunohistochemistry for neural nitric oxide synthase (nNOS) indicated that NADPHd-positive neurones also showed immunoreactivity for nNOS. NADPHd-positive nerve cell bodies were observed in both the myenteric and the submucous plexuses. Nerve fibres showing enzyme activity were mainly distributed in the circular muscle layer, but only a few fibres in the mucosal layer. Fine nerve fibres showing NADPHd activity were found running between germinal centres in the caecal tonsil. Quantitative analysis showed no significant differences in the number of enzyme-positive nerve cell bodies per ganglion of the myenteric and the submucous plexuses among three different caecal regions; proximal, middle and distal regions. Larger numbers of ganglia were detected in the submucous plexus than the myenteric plexus at all three regions. These data indicate that nitrergic neurones in the submucous plexus mainly project to the circular muscle layer in the chicken caecum. It is possible that nitrergic nerves regulate the motility of the chicken caecum.

[Usefulness of T2-weighted images using single shot fast spin echo (SSFSE) pulse sequence for the evaluation of pancreatobiliary diseases: comparison with MRCP using SSFSE].

Single shot fast spin echo (SSFSE) pulse sequence provides us with a thick single-slice MR cholangiopancreatography (MRCP) as well as thin multi-slice MRCP, and T2-weighted images are also obtained with SSFSE sequences. In comparison with conventional spin-echo and fast spin-echo sequences, T2-weighted image using SSFSE sequence has the advantages of the abscence of motion artifacts and the extremely short acquisition times. MRCP using SSFSE sequence is useful in the conspicuity of bile duct, pancreatic duct, and cystic lesions. However, T2 weighted image using SSFSE is superior to MRCP not only for the differentiation between solid and cystic lesions but also for the visualization of contour of different organs and lesions.

Differentiation of hypervascular hepatic pseudolesions from hepatocellular carcinoma: value of single-level dynamic CT during hepatic arteriography.

PURPOSE: The purpose of our study was to assess the efficacy of single-level dynamic CT during hepatic arteriography (D-CTA) in the differentiation between hypervascular hepatocellular carcinoma (HCC) and hypervascular pseudolesion. METHOD: D-CTA was performed in nine cases with HCC and nine cases with pseudolesion. Findings on D-CTA were retrospectively analyzed. RESULTS: The transition of the stain of pseudolesion on D-CTA was divided into three phases: (1) inflow of the contrast material into the portal vein within the lesion, (2) lesion staining, and (3) fading out of the stain; that of HCC was divided into four phases: (1) inflow of CM into tumor, (2) tumor staining, (3) inflow of CM into the adjacent liver, and (4) coronal stain of adjacent liver. The coronal stain was seen in all HCCs but not in any pseudolesions. CONCLUSION: The present study suggest that D-CTA is a helpful option in the differentiation between HCC and pseudolesion.

CTAP in budd-chiari syndrome: evaluation of intrahepatic portal flow.

BACKGROUND: To assess the intrahepatic portal flow in patients with Budd-Chiari syndrome (BCS) by computed tomography (CT) during arterial portography (CTAP). METHODS: Five patients with BCS [with (n = 3) and without (n = 2) inferior vena cava (IVC) obstruction] underwent both CTAP and postcontrast CT following CTAP. CTAP and postcontrast CT after angioplasty were also performed in one patient. Findings on CTAP and postcontrast CT were analyzed retrospectively. RESULTS: Patients with IVC obstruction and a patent large hepatic vein showed homogeneous hepatic enhancement on CTAP. Patients without IVC obstruction and with no patent large hepatic veins showed heterogeneous hepatic enhancement, which consisted of patchy enhancement and more definite enhancement in the central part of the liver. On postcontrast CT, the patchy enhancement was enlarged compared with that on CTAP in these patients. The heterogeneous hepatic enhancement became homogeneous in the patient who underwent angioplasty. CONCLUSION: We suggest that the more marked the blood congestion, the more heterogeneous the hepatic enhancement becomes on CTAP. Heterogeneous hepatic enhancement on CTAP is seen in such cases without any patent hepatic veins.

Delayed MR imaging of the liver: correlation of delayed enhancement of hepatic tumors and pathologic appearance.

BACKGROUND: The value of delayed magnetic resonance (MR) imaging (6 min) and ultradelayed MR imaging (1-4 h) for differentiating of hepatic tumors was studied. METHODS: Postcontrast delayed and ultradelayed MR images were obtained after administration of 0.1 mmol/kg of Gd-DTPA in 30 patients with various malignant hepatic tumors. RESULTS: Delayed enhancement in the center of the tumors was seen in 13 patients on the delayed MR images and in 22 patients on the ultradelayed MR images. On the ultradelayed images, peripheral hypointense rim was seen in 12 patients and central focal hypointense area was seen in eight patients. Pathologically, the portion showing delayed enhancement corresponded to abundant fibrous stroma, the hypointense rim to rich proliferation of tumor cells, and the central hypointense areas to coagulative necrosis. CONCLUSION: Ultradelayed MR imaging can characterize different tissue components within various hepatic tumors.