PURPOSE: To determine the relation between characteristic findings of hepatic arteriography and nontumorous perfusion defects which on CT arterioportography (CTAP) had been inadequately described. MATERIALS AND METHODS: To identify pseudolesions, the CTAP results of 46 patients with perfusion defects which were not recognized on conventional CT or ultrasonography were reviewed and compared with MRI, iodized-oil CT, surgical findings, and histopathologic reports. Typical and atypical pseudolesions were divided according to location, shape and cause, as revealed in previous reports. The number, shape and the location of pseudolesion seen on CTAP were determined and hepatic arteriography correlatively reviewed to determine vascular change in the corresponding area. RESULTS: Seventy-two additional lesions of 46 patients were detected. Among these, 12 cases were true lesions. Sixty pseudolesions were divided into typical (n = 18) and atypical (n = 42) ; the typical pseudolesions were found in familiar locations adjacent to the porta hepatis, falciform ligament or gall bladder and except for increased vascular staining around the gall bladder in two lesions, specific vascular changes were not seen. The shapes of the atypical pseudolesion were wedged (n = 22), nodular (n = 15) and flat (n = 5). They were located subcapsularly (n= 30) or nonspecifically within liver parenchyma (n = 12). The early appearance of a small portal vein branch with subsequent focal hepatic parenchymal staining, which suggests a small AP shunt, was identified on the hepatic arteriography, and on CTAP matched the areas of 96% atypical pseudolesions (26/34) which were more than 1cm in size. CONCLUSION: A small AP shunt should be regarded as a cause of nontumorous, nonsegmental perfusion defectson CTAP.
Angiography* ; Humans ; Ligaments ; Liver* ; Magnetic Resonance Imaging ; Perfusion* ; Portal Vein ; Portography* ; Ultrasonography ; Urinary Bladder

PURPOSE: To document the findings of a small arterioportal(AP) shunt on hepatic angiography through the various diagnostic modalities, and to determine whether this shunt is related to hepatocelluar carcinoma. MATERIALS AND METHODS: During the hepatic angiography in 223 patients, a small AP shunt and subsequent focalparenchymal staining more than 1cm in diameter were found in 28 patients. We compared this angiographic abnormality using MR imaging(n=10), CTAP(n=12), iodized-oil CT(n=23), intraoperative ultrasonography(n=5) and follow-up hepatic angiography(n=11), as well as with conventional ultrasonography and CT scan. RESULTS: Arterioportal shunts noted on angiographic study matched with perfusion defects noted in CTAP(10/12) and also with the area of arterial enhancement seen on dynamic CT scan(3/4). In no case was a lesion found on MR and no Lipiodol uptake was seen on CT. There was no evidence of tumor growth around the AP shunts on follow-up angiographies, andno tumor was found during surgery. CONCLUSION: A small AP shunt was not related to the presence of a tumor. Ifthe hemodynamic changes resulfing from a small AP shunt are understood, confusion can be avoided in the interpretation of vascular imaging including CTAP and dynamic CT.
Angiography* ; Carcinoma, Hepatocellular* ; Follow-Up Studies ; Hemodynamics ; Humans ; Perfusion ; Tomography, X-Ray Computed

PURPOSE: To document the relative usefulness of true Fast-imaging steady-state precession(FISP) comparing to breath-hold turbo spin-echo(TSE), and half-Fourier single-shot turbo spin-echo(HASTE) as a fast T2-weighted sequence during hepatic MR imaging. MATERIALS AND METHODS: For 46 patients with 87 focal hepatic lesions(hepatocellular carcinoma, n=26; metastasis. n=5; cavernous hemangioma, n=37; cyst, n=19), we obtained MR imaging of the liver at 1.5T. True FISP, TSE with and without fat-suppresion(FS), and HASTE with and without FS images were obtained during one breath-hold. Images were compared on the basis of tumor detectability and lesion-to-liver contrast-to-noise ratio(CNR). Qualitative analysis of each imaging sequence was also performed in terms of hepatic contour, visibility of vascular landmarks and imaging artifacts. RESULTS: TSE-FS depicted more focal lesions(78/87, 90%) than other sequences(TSE, 75/87=86%;HASTE, 74/87=85%; HASTE-FS, 75/87=86%;true FISP,73/87=84%). However, there was no statistical significance between each sequence(p> .05). Using true FISP or HASTE, there was a statistically significant difference(p< .01) between the CNRs of solid tumors, crystal and hemangiomas. Additionally, true FISP sequence showed better hepatic contour, vascular landmarks and less artifacts comparing with TSE or HASTE regardless of FS(p< .001). CONCLUSION: True FISP sequence allows differentiation between solid tumors, hemangiomas and cystic lesions in terms of CNR, and provides better imaging quality than other fast T2-weighted MR sequences.
Artifacts ; Hemangioma ; Hemangioma, Cavernous ; Humans ; Liver* ; Magnetic Resonance Imaging* ; Neoplasm Metastasis

The solitary fibrous tumor, of rare mesodermal origins, primarily affects the pleura and occasionally occursin the peritoneum and at nonserosal sites. Although this is a pathologically well established entity, it isfrequently confused radiologically and pathologically with other tumors of mesenchymal origin. We report one case of a solitary fibrous tumor in the retroperitoneum. The 15X10X7cm mass, lacated in the left perirenal space just above the left kidney, had relatively homogeneous consistency and was well-delineated from surrounding organs inCT and MR images. It showed intense, gradual, centripetal enhancement during dynamic scans, and partially unenhanced areas which matched the high signal intensity portions in T2 weighted MR images, pathologically correlated to myxoid degeneration. Although not specific, when a large, well-delineated mass of strong contrast enhancement with lack of massive necrosis is encountered, solitary fibrous tumor must be included in the differential diagnosis of a refroperitoneal soft tissue mass.
Diagnosis, Differential ; Fibroma ; Kidney ; Mesoderm ; Necrosis ; Peritoneum ; Pleura ; Solitary Fibrous Tumors*

The aim of this study was to determine the usefulness of quantitative analysis of multiphasic dynamic contrast-enhanced magnetic resonance (MR) imaging in differentiating early homogeneously enhancing hemangiomas from hepatocellular carcinomas (HCCs). Four-phased dynamic MR imaging at 10 sec (first phase of dynamic contrast-enhanced imaging, P1), 35 sec (second phase, P2), 60 sec (third phase, P3) and 300 sec (delay phase, P4) immediately after intravenous administration of 0.1 mmol/kg Gadolinium-DTPA was obtained with 1.5-T unit with breath-hold multisection FLASH (fast low angle-shot) sequence (TR/TE, 113-130 msec/4.1 msec; flip angle, 80 degrees). Thirty-three HCCs and 18 hemangiomas, homogeneously enhanced on P1, were included in the study. The images were evaluated quantitatively (SNR, signal-to-noise ratio; and CNR, contrast- to- noise ratio of lesions). Quantitatively, mean CNR was higher for hemangiomas than for HCCs on all phases, and the difference in CNRs between hemangioma and HCCs was statistically significant on P3 and P4 (p < 0.0001). When the cutoff for CNR was set at a value of 7.00 on P3 and 1.00 on P4, sensitivity, specificity and accuracy were 94.4%, 93.9%, and 94.1% on P3, and 94.4%, 81.8%, and 86.3% on P4, respectively. There was no statistically significant difference in SNRs between HCC and hemangioma. The differential diagnosis between early, homogeneously enhancing hemangiomas and HCCs was more confidently made with CNRs of lesions on P3 and P4 in dynamic contrast-enhanced MR imaging.
Adult ; Aged ; Carcinoma, Hepatocellular/diagnosis* ; Contrast Media ; Diagnosis, Differential ; Female ; Hemangioma/diagnosis* ; Human ; Image Enhancement ; Liver Neoplasms/diagnosis* ; Magnetic Resonance Imaging/methods* ; Male ; Middle Age

PURPOSE: To compare the usefulness of single-slice acquisition imaging and conventional maximum intensity projection imaging, as employed in magnetic resonance cholangiopancreatography (MRCP) using the Half-Fourier Acquisition Single Shot Turbo Spin-Echo(HASTE) sequence. MATERIALS AND METHODS: Five healthy volunteers underwent MRCP using the HASTE sequence on a 1.5T MR unit. Two data acquisition techniques were used : 1) single slice acquisition, with 20 mm slice thickness (imaging time, 2 sec), 2) multi-slice acquisition, with 5 mm slice thickness (imaging time, 19 sec), followed by maximum intensity projection reconstruction. Two radiologists independently evaluated the MRCP images obtained using these two techniques; based on the depiction by each of ten anatomic structures, their quality was graded as excellent (3 points), good (2 points), fair(1 point) or poor(0). Mean scores were totalled, and to compare the quality of the two techniques, these scores were compared. Data was statistically analyzed using the paired student t-test. RESULTS: There was no difference in bile duct image quality between the two techniques. The pancreatic duct was more conspicuous on single-slice (mean score, 1.94) than on maximum intensity projection imaging (mean score, 0.7). The sum of the mean scores of single-slice imaging was 18.75, and that of maximum intensity projection imaging was 14.7 (p=0.42); the general difference between the two techniques was thus statistically insignificant. CONCLUSION: Compared with maximum intensity projection imaging, single-slice imaging had a distinct advantage : acquisition time was short (within 2 sec), thus motion artifacts could be avoided, and there was no need for post-processing. There is a close and direct connection between the avoidance of motion artifact and short acquisition time, but lack of need for post-processing is independent. On single-slice images, the pancreatic duct was more conspicuous than on maximum intensity projection images. The former can therefore be used with patients who experience respiratory difficulty or are suspected to be suffering from disease of the pancreotic duct.
Artifacts ; Bile Ducts ; Cholangiopancreatography, Magnetic Resonance ; Healthy Volunteers ; Humans ; Pancreatic Ducts

PURPOSE: To characterize the MR findings of nontumorous focal low attenuated areas around the falciformligament on contrast enhanced CT scan. MATERIALS AND METHODS: MR was used to study twelve patients who oncontrast-enhanced CT scan showed focal low attenuated areas around the falciform ligament. Imaging was carried outwith T1, FSE-T2, fat-suppressed T1, and fat-suppressed FSE T2-weighted pulse sequences at 1.5 T. Dynamic fastlow-angle shot(FLASH) imaging was performed in seven patients and chemical shift images were obtained in five. The findings on contrast enhanced CT scan were compared with those on MR. RESULTS: In five cases, the lesions were slightly hyperintense on T1 and FSE T2-weighted images, hypointense on fat-suppressed images, hyperintense on in-phase image, and presented a considerably diminished signal intensity on opposed-image. Focal hypointensity areas were visualized at 50-75 sec after contrast enhancement in three cases in which a lesion was not depicted oneither T1-or FSE T2-weighted images. CONCLUSION: Nontumorous focal low attenuated areas around the falciformligament were shown on MR imaging as focal fatty infiltrations or pseudolesions.
Humans ; Ligaments* ; Magnetic Resonance Imaging ; Tomography, X-Ray Computed

PURPOSE: To compare the image quality and diagnostic efficacy of turbo spin-echo (TSE) T2WI with breath-holdturbo SE T2WI and to evaluate the clinical usefulness combined breath-hold turbo SE T2WI with FLASH(fast low-angleshot) MR imaging for the evaluation of focal hepatic lesions. MATERIALS AND METHODS: A total of 47 patients with known or suspected hepatic mass were prospectively evaluated using a commercially available 1.5-T MR system. All patients were examined with conventional spin-echo T1WI, TSE T2WI, breath-hold TSE T2WI, and T1-weighted FLASHwith and without Gd-DTPA. The images were compared quantitatively (liver-lesion C/N ; CNR [contrast-to-noiseratio] and lesion detectability) and qualitatively (sharpness of anatomic structure, artifact, and overall imagequality). RESULTS: A total of 69 hepatic lesions were detected in 47 patients. Sixty-seven lesions (97.1%) were detected with Gd-FLASH, 66 (95.7%) with TSE T2WI, 65 (94.2%) with breath-hold TSE T2WI, 62 (89.9%) withnon-enhanced FLASH, and 55 (79.7%) with conventional SE T1WI. The CNR of cysts and hemangiomas was significantly greater on turbo SE T2WI and breath-hold TSE T2WI than on other sequences, but there was no significant difference between turbo SE T2WI and breath-hold TSE T2WI. For solid lesions, CNR was greatest on turbo SE T2WI and was similar on breath-hold TSE T2WI and Gd-FLASH without statistical significance, but was significantly higher than conventional SE T1WI. Breath-hold TSE T2WI and Gd-FLASH were qualitatively superior to other sequences except the vascular pulsation artifact of FLASH. Non-enhanced FLASH was also superior to conventional T1WI for CNR, lesion detectability, sharpness, respiratory motion artifact, and overall image quality. CONCLUSION: Breath-hold TSET2WI may replace turbo SE T2WI, and as well as conventional SE T1WI, FLASH with or without Gd-DTPA may be used for the evaluation of focal hepatic lesions. The combination of FLASH and breath-hold TSE T2WI may be an excellent technique that can be used to rapidly evaluate liver lesions, and at the same time offer superior overall imagequality.
Artifacts ; Gadolinium DTPA ; Hemangioma ; Humans ; Liver ; Magnetic Resonance Imaging* ; Prospective Studies

Cytogenetic analysis of 4 cases of meningiomas from 3 male and 1 female patients is reported. One of male patients suffered from neurofibromatosis type 2. Histologically, the meningiomas were meningotheliomatous (1), transitional (2), and psammomatous (1). Chromosomal abnormalities were found in all cases with a karyotype 45,XY,-22, 45,XY,-16, 45,XX,-2, and 45,XY,t (15p;22q), respectively. Monosomy of chromosome 22 was detected only in the patient with neurofibromatosis type 2. These cytogenetic analysis demonstrates that variable clonal karyotype aberrations exist in meningiomas.
Adolescent ; Adult ; *Chromosome Aberrations ; Female ; Humans ; Male ; Meningeal Neoplasms/*genetics ; Meningioma/*genetics ; Neurofibromatosis 2/genetics

PURPOSE: To assess the usefulness of breath-hold fast MR imaging of liver with fat suppression (FS) by application of chemical saturation technique in the diagnosis of regional fatty changed suspected in sonography. MATERIALS AND METHODS: Thirteen patients who had focal lesions with diffuse, homogeneous signal changes after FS through chemical saturation technique without additional changes of imaging parameter during MR imaging of liver were selected. T1-weighed fast low-angle shot and T2-weighted turbo spin-echo sequences were obtained with or without FS during each single breath-holding session. Subjective changes of signal intensity between the pre-FS and the FS images were compared with the sonographic findings in each lesion. RESULTS: Seven lesions of decreased signal intensity after FS on T1 or T2-weighted images, including three lesions only at FS T1 images, were regarded as focal fat infiltration. All seven lesions had compatible sonographic findings as homogenously echogenic areas. Another six lesions of subjectively increased signal intensity including two lesions only at FS T2 images were regarded as focal fat sparing. All six lesions had sonographic findings as homogenous echo poor areas suggesting focal fat sparing. In cases regarded as fat infiltration, score changes were more prominent at FS T1 images than FS T2 images(p=0.0002). In cases regarded as fat sparing, score changes were more prominent at FS T2 images than FS T1 images(p=0.042). CONCLUSION: Breath-hold fast T1 and T2-weighted MR imaging with and without chemical saturation pre-pulse may be sufficient for characterization of regional fatty changes in the different ferential diagnosis of focal hepatic lesion found at sonography.
Diagnosis ; Humans ; Liver* ; Magnetic Resonance Imaging* ; Ultrasonography