MR imaging in intracystic hemorrhage of simple hepatic cysts

Intracystic hemorrhage of simple hepatic cysts is one of the most frequent complications. Ul-trasonography (US) and computed tomography (CT) may show abnormal findings and mimic other diseases. We describe magnetic resonance (MR) imaging in four patients with intracystic hemorrhage confirmed by surgery or percutaneous aspiration. In all cases the lesions were hyperintense on both T1- and T2-weighted sequences. In three of the four cases the signal was heterogeneous on T1-weighted sequences. Two cases of a thickened wall and one case of a fluid-fluid level were also observed. We suggest that MR imaging may be helpful to differentiate intracystic hemorrhage from other cystic lesions by showing high signal on T1- and T2-weighted sequences.     

Comparison of computed tomography and magnetic resonance imaging in the evaluation of focal hepatic lesions

Two combined magnetic resonance (MR) spin-echo pulse sequences at 0.35 T were compared with dynamic bolus contrast-enhanced computed tomography (CT) in the evaluation of focal hepatic lesions. Each combined MR sequence was performed in a separate group of patients. The first group consisted of 76 patients in whom a moderately T1-weighted sequence (spin echo [SE] 500/30 [repetition time/echo time]) was combined with a T2-weighted sequence (SE 2000/60). In the second group, consisting of 68 patients, a more heavily T1-weighted sequence (SE 250/15) was combined with the T2-weighted sequence. All studies were evaluated in a retrospective blinded fashion, with construction of receiver operating characteristic curves.We conclude that, in detection of patients with one or more focal hepatic lesions, either combined MR sequence was comparable to CT. In the detection of individual hepatic lesions, the sensitivity of the combined MR sequence with a moderately T1-weighted sequence (SE 500/30 and 2000/60) was essentially equivalent to CT (79 vs 77%, respectively). Additionally, a combined MR sequence with a heavily T1-weighted pulse sequence (SE 250/15 and 2000/60) was not statistically different than CT (86 vs 80%, respectively). These findings were supported by the receiver operating characteristic analysis.     

Small hepatic nodules in cirrhosis: ultrasonographic, CT, and MR imaging findings

Purpose: The purpose of this study was to assess the imaging findings of pathologically-proved small hepatic nodules 2 cm in size or smaller detected with ultrasonography in cirrhotic patients with suspected hepatocellular carcinoma (HCC). Materials and Methods: We evaluated sonographically detected 32 small hepatic nodules which were pathologically confirmed in 23 consecutive cirrhotic patients who were suspected of having HCC. Twenty-six lesions were confirmed with ultrasonographically-guided aspiration needle-core biopsy, and six with definitive surgery. Ultrasonographic examination records were retrospectively reviewed. CT, and MR images obtained with various imaging techniques were retrospectively reviewed by two radiologists in a blind fashion. Results: The 32 hepatic nodules were comprised of seven focal fatty changes, two large regenerative nodules, three low-grade dysplastic nodules, five high-grade dysplastic nodules, and fifteen HCCs. Ultrasonography showed various echogenicity for the hepatic nodules. The signal-intensity characteristics with T1-weighted spin-echo, in-phase gradient-recalled-echo, and dynamic MR imagings may be useful in distinguishing HCC from nonHCC nodules. Conclusions: Nearly half of small hepatic nodules detected with ultrasonography were nonHCC nodules. Ultrasonographic findings may not be reliable in characterizing small hepatic nodules in cirrhosis. CT and MR imaging obtained with the various techniques are still insensitive to these hepatic nodules. RID="ID="<e5>Correspondence to:</e5> M. Kanematsu Received: 25 August 1997/Revision accepted: 19 November 1997     

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.     

Echinococcal hepatic disease: Magnetic resonance appearance

The magnetic resonance (MR) appearance of an echinococcal hepatic cyst is described. A previous report has suggested that a low-intensity rim surrounding the cyst may be useful in differentiating hydatid cysts from other hepatic lesions. No such rim was identified in our case; however, MR was found to be superior to other modalities in delineating the internal contents of the hydatid cyst.     

肝结核误诊肝癌1例

患者男,61岁,间断性右上腹部疼痛2月余,不伴发热.查体未见阳性体征.化验结缔组织全套未见异常,结核菌素实验阴性,血沉29 mm/h.     

磁敏感加权成像与CT评价创伤性脑损伤

目的 比较磁敏感加权成像(SWI)与CT评价创伤性脑损伤(TBI)合并出血的作用,探讨其与临床评分的相关性。方法 25例TBI患者均接受16排MSCT和1.5T MR检查,对SWI图像采用SWI最小密度投影(SWI MinIP)观察出血灶,利用SPIN软件测量SWI MinIP及CT图像上出血灶面积及数目,并与患者格拉斯哥昏迷量表(GCS)临床评分结果进行相关性分析,比较不同格拉斯哥预后评分(GOS)组间的差异。结果 TBI患者SWI MinIP图像较相应层面CT图像显示的出血灶面积大(P=0.021),显示的出血灶数目多(P＜0.05);且SWI和CT显示出血灶面积、数目均与临床GCS评分呈明显负相关(P均<0.05)。SWI和CT显示预后差的TBI患者出血灶面积及数目均大于预后好者(P均＜0.05)。结论 与CT相比,SWI检测TBI患者出血灶的敏感度和评价出血灶的面积与数目等方面均具有明显优势,并在评价TBI损伤程度及预后方面与临床评分具有良好相关性。     

Compensated hepatitis C: unenhanced MR imaging correlated with pathologic grading and staging

Abstract Background We prospectively examined unenhanced MR imaging findings in relation to pathologic fibrosis, inflammation and steatosis in patients with compensated chronic hepatitis C viral infection (HCV). Methods Unenhanced MRI at 1.5 T was obtained within one month of core liver biopsy in 64 consecutive candidates for antiviral therapy for compensated HCV. Two pathologists independently graded inflammatory activity index (HAI) and steatosis, and staged fibrosis (grades 0–6). Morphologic MRI findings of cirrhosis, periportal lymph nodes, and MR fat signal ratio from dual gradient echo images were assessed independently by two radiologists blinded to clinical data. MRI and laboratory liver function results were correlated with pathologic results, using Spearman correlation coefficient and stepwise multiple regression. Results MR fat signal ratio correlation coefficient with pathologic steatosis was 0.71 (p < 0.0001). Coefficients with fibrosis stage were highest for surface nodularity (r _s = 47, p < 0.0001) and expanded gallbladder fossa (r _s = 0.42, p = 0.0006). Coefficients with HAI were highest for lymph node size (r _s = 0.355, p = 0.0040), surface nodularity (r = 0.47, p < 0.0001), expanded gallbladder fossa (r = 0.332, p = 0.0073), and caudate/right lobe ratio (r = 0.326, p = 0.0110). Combined lab and MRI variables provided the best prediction of fibrosis stage (r ² = 0.656) and HAI (r ² = 0.597). Conclusions A combination of MRI and laboratory findings was most predictive of fibrosis and inflammation.     

肝包虫病的CT和MR诊断

目的 探讨肝包虫病的CT和MRI表现.方法 临床手术、病理证实的肝包虫病42例,就其CT和MRI表现回顾性分析并就相关文献进行复习.结果 本组肝细粒棘球蚴病占85.71%,蛋壳样或条带状钙化、"囊内囊"、"飘带征"等为其主要表现;肝泡球蚴病占14.29%,钙化、"小泡征"、"半岛征"及囊腔或液化、坏死等为其主要表现;MR T2WI显示囊壁及纤维间隔、飘带征等优于CT,但钙化显示逊于CT.结论 CT和MR均可诊断肝包虫病,CT在综合诊断方面优于MR.     

Ultrasonic diagnosis of cirrhosis: Reference to quantitative measurements of hepatic dimensions

Hepatic echo patterns and right lobe to left lobe longitudinal diameter ratio were compared in age- and sex-matched 100 normal subjects and 76 patients with diffuse liver diseases (38 cirrhotics and 38 noncirrhotics) in a prospective sonographic study. Various echo patterns, assigned to cirrhotic livers (bright liver, micronodulation, beam attenuation), could not differentiate cirrhosis from other diffuse liver diseases. In cirrhotic livers, the right lobe manifested a significant shrinkage, while the left lobe exhibited almost no alteration. Considering the right to left lobe ratio of 1.30 as a discriminatory value, the cirrhosis could be diagnosed with a sensitivity of 74%, a specificity of 100%, and an accuracy of 93%; the sensitivity rates were seen to be higher in postnecrotic cirrhosis than in alcoholic cirrhosis.     

肝脏肿瘤的MR检查与诊断思路

肝脏肿瘤病变组织学类型多种多样,MR影像学有较为独特的信号改变及强化特点。该文总结MRI检查技术要点,对常见肿瘤病变的信号特征、强化特征进行对比分析,旨在理清肝脏肿瘤病变的诊断思路,进一步提高影像诊断水平。     

MR灌注加权成像评估创伤性脑损伤血脑屏障改变研究进展

血脑屏障(BBB)破坏是创伤性脑损伤(TBI)所致重要病理变化之一,及时治疗及判断预后具有重要临床意义。目前监测TBI后BBB改变越来越受到重视。本文对TBI后BBB改变、MR灌注加权成像(PWI)及MR PWI研究TBI进展进行综述。     

Hepatic and splenic sarcoidosis: Ultrasound and MR imaging

Abdominal imaging studies may be performed for various indications in patients known to have sarcoidosis. To assess magnetic resonance imaging (MRI) and sonographic ability to detect abnormalities in sarcoidosis patients with abdominal involvement, a prospective study on 18 selected patients was performed. Besides organomegaly, when present, ultrasound demonstrated normal or increased hepatic parenchymal echogenicity, coarsening of the liver parenchyma with or without discrete nodules, focal calcifications, as well as contour irregularity. Splenic discrete nodules were seen on ultrasound in a single patient. Besides organomegaly, MRI abnormalities include abnormal hepatic signal intensity, discrete nodules, contour irregularity, spiculation of small hepatic vascular branches, and a high periportal signal intensity. MRI splenic abnormalities include contour irregularity, nodularity, and abnormal signal intensity.The data presented in this study reveals the spectrum of ultrasound and MRI findings in sarcoidosis patients with abdominal organ involvement, potentially enabling the evaluation of the severity of the disease. MRI appears more sensitive than ultrasound for study of abdominal sarcoidosis.     

Computed tomographic findings of ruptured hepatic malignancy

Massive hemorrhage from ruptured hepatocellular carcinoma is uncommon. We report our experience in three cases of ruptured hepatocellular carcinoma diagnosed by computed tomography (CT). CT was useful in detecting ruptured hepatocelluar carcinoma showing the parenchymal tumor per se, defining the extent of the hematoma, and showing serial density changes with the age of the hematomas.     

Focal hepatic lesions: Detection by dynamic and delayed computed tomography versus short TE/TR spin echo and fast field echo magnetic resonance imaging

Eighteen patients with focal hepatic lesions were evaluated with two computed tomographic (CT) techniques including dynamic sequential bolus contrast CT and delayed contrast CT, and 3 magnetic resonance (MR) techniques including a spin echo pulse sequence with TE/TR of 21/310 msec and 2 fast field echo sequences using a TE/TR of 15/300 msec and 80° flip angle (T1-weighted) and TE/TR of 15/500 msec and 10–20° flip angle (T2-weighted). We concluded that CT, using delayed contrast and dynamic sequential bolus contrast techniques, was consistently superior to the 3 MR pulse sequences used on our imagers in terms of number of lesions detected, lesion-to-liver contrast, and quality of scan.     

Evaluation of focal hepatic masses: a comparative study of MRI and CT

We evaluated suspected hepatic lesions in 30 patients using both nongated spin-echo magnetic resonance imaging (MRI) on a 0.35 T superconducting magnet and contrast-enhanced dynamic incremental computed tomography (CT). In the 27 patients with focal lesions, both modalities detected abnormalities in 26 patients. Liver lesions were equally well demonstrated using MRI and CT in 15 patients, better demonstrated by CT in 11 patients, and better demonstrated by MRI in 1 patient. Small lesions (<2 cm) were much better demonstrated using CT than MRI; this was significant when knowledge of the precise extent of disease was necessary for planning surgical therapy or for evaluating response to chemotherapy. Five patients had significant extrahepatic disease detected by CT; MRI identified extrahepatic abnormalities in only 2 of these 5 patients. We conclude that at the current time CT is more useful than nongated spin-echo MRI in the evaluation of suspected hepatic masses.     

MR imaging of malignant mesenchymal tumors of the liver

Magnetic resonance (MR) features of five primary malignant mesenchymal neoplasms (plasmocytoma, leiomyosarcoma, undifferentiated sarcoma, epithelioid hemangioendothelioma, and angiosarcoma) of the liver were reported. All tumors were hypointense on T1-weighted images and hyperintense on T2-weighted images. No halo and intravenous extension were noted. A target appearance was revealed in epithelioid hemangioendothelioma. MR findings of angiosarcoma were essentially the same as those of cavernous hemangiomas (markedly hyperintense with hypointense linear septa on T2-weighted images). MR findings of these rare hepatic malignancies were nonspecific, although they were quite different from those of typical hepatocellular carcinomas. This study suggested that MR differentiation of primary hepatic mesenchymal tumors from other common benign and malignant neoplasms was difficult; however, the number of studied cases was limited.     

MR imaging of intrahepatic cholangiocarcinoma

Background: The purpose of this study was to determine the magnetic resonance (MR) features of intrahepatic cholangiocarcinoma. Methods: MR imaging studies of seven cases of pathologically proven intrahepatic cholangiocarcinoma were retrospectively reviewed. Results: On MR images the tumors presented as a single mass (N = 5) or multiple nodules (N = 2), as welldelineated (N = 5) or ill-defined (N = 2), and as non-encapsulated (N = 7). Mean tumor diameter ranged from 6–14 cm (mean, 10 cm). On T1-weighted (TR/TE = 400–600/10–17 msec) images, the tumors were hypointense compared to the liver. The five tumors studied with dynamic MR imaging showed progressive centripetal filling-in after intravenous administration of a gadolinium chelate. On T2-weighted (TR/TE = 2000–2500/80–100 msec) images, all tumors were hyperintense compared to the liver; five were markedly hyperintense and two moderately hyperintense. Vascular encasement, bile duct dilatation within the tumor, and central scar were depicted on MR images in four, three, and two tumors respectively. Conclusion: The typical MR appearance of intrahepatic cholangiocarcinoma is a large well-delineated nonencapsulated tumor associated with intrahepatic venous encasement.     

原发性肝癌的MR功能成像研究进展

原发性肝癌是世界上最常见恶性程度最高的肿瘤之一,我国原发性肝癌患病率高于欧美及其他发达国家,严重影响了患者及其家庭的生活质量。目前,原发性肝癌的影像学检查主要有B超、CT、DSA及MR。B超价格便宜、操作简单及对软组织病变灵敏度高,但容易受到检查者经验和细致程度的限制且对早期小肝癌（直径<1 cm）诊断的准确率较低;CT有较高的空间和密度分辨率,缺点是有辐射,且时常出现假阳性;DSA为有创检查。MR成像为无创检查,且无辐射、软组织分辨率较高,可进行多参数、多方位成象及各种功能成像,在临床中应用越来越广泛,本文就MR成像技术在原发性肝癌的诊断、鉴别诊断及评价治疗疗效的应用进行综述。     

Hemobilia: Calcified hepatic artery aneurysm presenting with massive gastrointestinal bleeding

A case of a calcified and ruptured hepatic artery aneurysm presenting with hemobilia and massive gastrointestinal bleeding is reported and illustrated. The clinical diagnosis should be entertained whenever the trial of findings (abdominal colic, gastrointestinal bleeding, elevated bilirubin levels) is present. Angiography is the method of choice in confirming this diagnosis. A short review of the clinical and radiographic syndrome of hemobilia with emphasis on the occurence, significance, and prognosis of hepatic artery aneurysms is presented.