Anorectal gastrointestinal stromal tumors: CT and MR imaging features with clinical and pathologic correlation

OBJECTIVE: The purpose of this study was to describe the imaging features of anorectal gastrointestinal stromal tumors with clinical and pathologic correlation. CONCLUSION: Anorectal gastrointestinal stromal tumors are mesenchymal neoplasms that typically arise in the muscularis propria of the intestinal wall. The cross-sectional imaging appearance is that of a well-defined mural mass that may have an exophytic component and may invade adjacent structures. A prominent intraluminal component is a rare feature.     

Brachial plexus: correlation of MR imaging with CT and pathologic findings

Thirty-two patients with symptoms referable to the brachial plexus were evaluated with magnetic resonance (MR) imaging. Sixteen patients had undergone concurrent computed tomography (CT). MR imaging demonstrated normal findings in 16, 12 neoplasms, three cases of trauma, and one case of possible neural edema. Of the 16 patients with normal findings on MR images, eight had CT scans that were also normal. In one patient, MR images showed that the "mass" seen on CT was actually a tortuous blood vessel. In six of the 12 cases of neoplasm in which CT scans were available, MR imaging revealed more extensive disease. In the other six cases of tumor, MR imaging provided sufficient clinical information to obviate the need for CT or any other imaging modality. MR imaging provided definitive diagnoses in the three cases of trauma without further imaging. In one patient with paresthesia, MR imaging showed high signal intensity of the nerves on T2-weighted images, which was compatible with neural edema. A concurrent CT scan was normal.     

CT and MR imaging findings of xanthogranulomatous cholecystitis: correlation with pathologic findings

The aim of this study was to evaluate CT and MRI findings in xanthogranulomatous cholecystitis (XGC) and to correlate the imaging findings with various pathologic parameters. The study included 13 patients with histopathologically confirmed XGC. The CT (n=13) and MRI (n=5) obtained in these patients were evaluated retrospectively. On CT, low-attenuation areas in the wall of XGC correlated with foam and inflammatory cells or necrosis and/or abscess in XGC. Areas of iso- to slightly high signal intensity on T2-weighted images, showing slight enhancement at early phase and strong enhancement at last phase on dynamic study, corresponded with areas of abundant xanthogranulomas. Areas with very high signal intensity on T2-weighted images without enhancement corresponded with necrosis and/or abscesses. Luminal surface enhancement (LSE) of gallbladder wall represented preservation of the epithelial layer. The early-enhanced areas of the liver bed on dynamic CT and MR images corresponded with accumulation of inflammatory cells and abundant fibrosis. Our results indicate that CT and MRI findings correlate well with the histopathologic findings of XGC.     

MR imaging of uterine carcinoma: correlation with clinical and pathologic findings

Thirteen patients with clinical stages I and II endometrial carcinoma were examined with magnetic resonance (MR) imaging before surgery. Depth of invasion and stage of disease were assessed, and the results were compared with those from MR images of the surgical specimens and pathologic findings. Staging with MR imaging was accurate in 11 of 13 patients (85%). Our results agree with previous reports that MR imaging is an accurate, noninvasive method of assessing depth of myometrial invasion and cervical involvement. We anticipate that MR imaging will have an increasing role in treatment of patients with endometrial carcinoma.     

Meniscal tears: pathologic correlation with MR imaging

Menisci from 12 autopsies and above-knee amputations were imaged with magnetic resonance (MR) at 1.5 T and then sectioned for gross and histologic examination. A histologic staging system was developed and showed a one-to-one correlation with corresponding grades of MR signal intensities. Histologic stages 1 and 2 represented a continuum of degeneration culminating in stage 3 fibrocartilaginous tears, seen most frequently in posterior-horn segments of the medial meniscus. Correlation of histologic stages with MR signal intensity allows for an improved diagnostic reading of MR images.     

Chondrosarcoma: MR imaging with pathologic correlation.

Magnetic resonance (MR) images of 21 surgically confirmed chondrosarcomas were retrospectively reviewed in conjunction with plain radiographs and computed tomographic scans and correlated with pathologic findings. The tumors appeared lobulated, and signal intensity, as analyzed visually (intermediate on T1-weighted, high on T2-weighted images), was similar for all lesions, regardless of pathologic type. Size of lesion was not an indicator of grade. The appearances of mesenchymal and dedifferentiated chondrosarcomas mimicked that of conventional chondrosarcoma. Extraskeletal chondrosarcoma was visualized as a lobulated soft-tissue mass. In all cases, MR imaging accurately depicted intraosseous and soft-tissue extent of tumor noted at surgery and pathologic examination. Histologic type or grade of chondrosarcoma generally cannot be characterized on the basis of visual analysis of signal intensity noted on routine MR images. However, MR imaging is excellent for exact delineation of tumor extent.     

Infarcted regenerative nodules in cirrhosis: CT and MR imaging findings with pathologic correlation

OBJECTIVE. The purpose of this article is to present the imaging findings and correlative pathologic findings of infarcted regenerative nodules in the cirrhotic liver. CONCLUSION. Infarcted regenerative nodules exhibit a spectrum of imaging appearances in the cirrhotic liver and can resemble hypovascular hepatocellular carcinoma or other neoplasms on CT and MR imaging. Although uncommon, this abnormality must be included in the differential diagnosis of focal liver lesions in patients with cirrhosis, particularly in patients with a history of substantial gastrointestinal bleeding. Serial imaging may help differentiate these lesions from malignant tumors.     

MR imaging of the corpus callosum: normal and pathologic findings and correlation with CT

The MR appearance of the corpus callosum was investigated in 80 normal volunteers. Normal variations in appearance were recorded with regard to age, gender, and handedness. The MR studies of 47 patients with a wide spectrum of callosal disease were also reviewed. Abnormalities included trauma, neoplasia, congenital abnormalities, vascular lesions, and demyelinating and inflammatory conditions. The information provided by MR was compared with that obtained from other radiographic examinations, particularly CT and angiography. In all cases MR provided as much, and frequently more, information than was obtained by other imaging techniques. We believe that MR should be the primary imaging technique for the evaluation of corpus callosal disease.     

韧带样型纤维瘤病的CT表现与病理对照

目的：探讨韧带样型纤维瘤病的CT特征。方法：回顾性分析15例经手术病理证实的韧带样型纤维瘤病CT表现,并与病理结果对照。结果：15例韧带样型纤维瘤病表现为腹壁或腹内软组织肿块,CT平扫病灶呈稍低密度或等密度,动态增强扫描动脉期病灶大部分呈不均匀轻度强化,静脉期病灶持续强化,延迟期病灶强化明显,周边部分残留有斑片状、条状无强化低密度区。结论：韧带样型纤维瘤病的CT表现有一定特征,CT对该病有较高的诊断价值。     

Thyroid masses: MR imaging and pathologic correlation

The authors explored the capability of high-field-strength surface coil magnetic resonance (MR) imaging in disclosing the gross pathologic characteristics of thyroid masses (especially pseudocapsular and hemorrhagic degeneration). Twenty-four patients were examined, including 12 with papillary carcinoma, eight with adenoma, and four with adenomatous goiter. All patients underwent surgery within 2 days after MR imaging. Specimens were cut and correlated directly with MR images. The appearance of the pseudocapsule was classified into four types: A, intact and even thickness around the tumor; B, only partially present or even absent; C, intact but with uneven thickness; D, partially destroyed by tumor. MR imaging findings corresponded precisely with those of gross pathologic examination in all cases but four of adenoma. Type A pseudocapsules were found only in adenoma and type D only in papillary carcinoma. Although the number of cases in the series was limited, the authors conclude that MR images reflect gross pathologic findings well and that some characteristic findings are suggestive of benign or malignant disease.     

颅咽管瘤:MRI 和CT 表现及与病理对照

分析颅咽管瘤ＣＴ、ＭＲＩ特征,探讨影像学表现和病理间的联系,尤其是ＭＲＩ的Ｔ１高信号的产生基础,方法：ＣＴ及ＭＲＩ检查２１例颅咽管瘤患者,均经手术病理证实,囊液进行内容物的镜下分析。结论ＣＴ、ＭＲＩ相结合可以准确诊断颅咽管瘤,颅咽管瘤囊液内的高信号主要与囊液内的蛋白质有关,与胆固醇类物关系较小。     

Sonography of diabetic muscle infarction with MR imaging, CT, and pathologic correlation

OBJECTIVE: The purpose of this article is to describe the sonographic findings of muscle infarction in patients with diabetes with MR imaging, CT, and pathologic correlation. CONCLUSION: Sonographic findings of diabetic muscle infarction include internal linear echogenic structures coursing through the lesion; an absence of internal motion or swirling of fluid with transducer pressure; and a lack of a predominately anechoic area. We believe that these sonographic characteristics may help differentiate diabetic muscle infarction from abscess or necrotic tumor. Additional study involving direct sonographic comparison of these entities is needed to establish the role of sonography in diagnosis of diabetic muscle infarction.     

Central nervous system disease in acquired immunodeficiency syndrome: prospective correlation using CT, MR imaging, and pathologic studies

A prospective study compared the abilities of high-resolution computed tomography (HRCT) and magnetic resonance (MR) imaging in detection and evaluation of central nervous system disease in neurologically symptomatic patients with acquired immunodeficiency syndrome (AIDS). Eighteen CT scans and 19 MR images in 14 patients were compared. HRCT images with contrast material enhancement were superior to unenhanced 0.35-T MR images for differentiating a lesion from surrounding edema, discriminating between lesions in close proximity, locating lesions for biopsy, judging lesion activity, detecting small cortical lesions with minimal edema, and spatial resolution. MR imaging was superior to CT scanning in evaluation of white-matter lesions and detection of small lesions surrounded by edema. MR imaging exhibited higher contrast resolution and greater sensitivity. Complementary uses of MR and CT imaging are suggested.     

子宫腺肌症的MRI表现及其病理学对照研究

目的：研究MRI在子宫腺肌症诊断中的应用价值。方法：对30例子宫腺肌症患者行矢状面快速自旋回波（Turbo SE)T1WI,T2TI,T1和T2频谱预饱和翻转恢复序列（T1SPIR和T2SPIR）扫描，必要时辅以横断面或冠状面扫描。所有病例均经手术病理证实。结果：弥漫型子宫腺肌症12例，在T2WI上表现为子宫结合带弥漫性增厚，厚度10－35mm，平均18mm，6例病变呈均匀低信号；6例病变内有散在的点高信号区，其中5例在T1WI仍表现为高信号。局限型子宫腺肌症（腺肌瘤）18例共23个病灶，在T2WI上表现为肌层内卵圆形，不规则形或类圆形肿块，呈与结合带信号相近的低信号，直径2．0－7.5cm，平均3.9cm，除1个病灶与周围肌组织有较清楚的界限外，其余病灶均与周围肌组织分界不清，15个病灶内有散在点状高信号区，其中12个在T1WI上也呈高信号，MRI上弥漫增厚的结合带和局限性低信号肿块，病理学上为异位内膜岛周围增生肥大的平滑肌，其内散在的点状信号区异异位内膜岛。仅在T2WI表现高信号的为示出血的内膜岛，在T1WI和T2WI均为高信号的为出血的内膜岛。结论：MRI是诊断子宫腺肌症的优越的无创性检查方法，T2WI最佳扫描序列，T2WI与T1WI，T1SPIR，T2SPIR4种序列相结合可大大提高断诊准确率。     

Pancreatic transplants: CT with clinical and pathologic correlation

A retrospective evaluation of 68 CT scans in 17 patients with pancreatic allografts was performed with clinical and pathologic correlation to better define the nature of abnormalities detected with CT and the role of CT in patient treatment. Patients with clinical complications demonstrated variable degrees of pancreatic inhomogeneity and peripancreatic inflammation on CT scans. These findings were similar in appearance to pancreatitis in the native gland. Most patients proved to be undergoing acute rejection. However, these findings were not specific and were also seen with peripancreatic infection, hemorrhage, and exocrine anastomotic leaks. No CT changes were detected in two of three patients with late rejection. Thus, CT was not helpful in the diagnosis of pancreatic rejection. The most beneficial role of CT was in the detection of intraabdominal fluid collections, including abscesses, hematomas, and pseudocysts. Percutaneous aspiration was invaluable in the distinction between infected and sterile fluid collections; however, percutaneous drainage was of limited use in treatment.     

Perineal angiomyofibroblastoma: CT and MR findings with pathologic correlation.

We present a case of a perineal angiomyofibroblastoma (AMFB) arising in the right perirectal fossa in a middle-aged woman, documented with CT and MRI. Compounding the rarity of the entity, this case is unique as it is the first radiological report illustrating the CT and MR features of this recently clinicopathologically described neoplasm.     

MR imaging of intrahepatic cholangiocarcinoma with pathologic correlation

OBJECTIVE: The objective of this study was to determine the MR imaging features of intrahepatic cholangiocarcinoma. MATERIALS AND METHODS: MR images of 50 patients with pathologically proven intrahepatic cholangiocarcinoma were reviewed retrospectively. T1- and T2-weighted spin-echo images were obtained in all patients. Contrast-enhanced T1-weighted imaging was performed in 25 patients. Signal intensity and enhancement pattern of the tumors were correlated with pathology findings. The frequency of central hypointense regions on T2-weighted images and the intrahepatic bile duct dilatation of several other hepatic tumor types were investigated. Results were compared with imaging results of cholangiocarcinoma. RESULTS: On T2-weighted images, central hypo- and hyperintense regions were detected in tumors in 27 and 17 patients, respectively. Contrast-enhanced T1-weighted imaging revealed central hypointense areas exhibiting homogeneous, heterogeneous, and no enhancement in six, three, and five, respectively, of 14 patients. Regions of fibrosis displayed enhancement, whereas those of coagulative necrosis showed no enhancement. The signal intensity difference on T2-weighted images between the center and the edge of the tumor correlated well with the fibrotic ratio difference between those two areas corresponding to the MR image (Spearman's rank correlation test, r = 0.72, 95% confidence interval = 0.48-0.86). T2-weighted images revealed central hypointense regions in 16 of 34 instances of hepatic colorectal metastases. However, hypointensity was observed in only 26 of 234 other hepatic tumors. Intrahepatic bile duct dilatation was evident in 27 of 50 cases of cholangiocarcinoma but occurred in only a single case of 34 instances of hepatic colorectal metastases. CONCLUSION: The combination of the signal intensity on T2-weighted images and the enhancement pattern on contrast-enhanced T1-weighted images showed good correlation with the pathologic findings of cholangiocarcinoma. The occurrence of a central hypointense area on T2-weighted images is not pathognomonic; however, this finding, which reflects severe fibrosis, appears to be a characteristic marker of intrahepatic cholangiocarcinoma. The presence of intrahepatic bile duct dilatation may indicate cholangiocarcinoma, although it is difficult to differentiate cholangiocarcinoma from hepatic colorectal metastasis.     

Carcinosarcoma of the urinary bladder: dynamic contrast-enhanced MR imaging with clinical and pathologic correlation

OBJECTIVE: This article describes the MR imaging features of carcinosarcoma of the urinary bladder with clinical presentation and pathologic correlation in three adults. CONCLUSION: Carcinosarcoma of the urinary bladder is a rare and aggressive tumor that has a clinical presentation similar to that of transitional cell carcinoma of the bladder. Dynamic gadolinium-enhanced MR imaging features are discussed.