Hilar cholangiocarcinoma. An evaluation of subtypes with CT and angiography.

Sixty-seven patients had hilar cholangiocarcinomas which were divided into 3 types based on tumor morphology as observed on cholangiography and CT. The pathology, vascularity, and pattern of tumor spread of these types were compared. Most of the infiltrative tumors (n = 44) were scirrhous adenocarcinomas, which on CT showed poor or no contrast enhancement with frequent lymph node metastases and liver atrophy. At angiography, there was vascular encasement in 52%, in rare cases neovascularity, and tumor stain. The exophytic type (n = 19) was divided into 2 subgroups depending on the main location of the tumor. The nodular subtype (n = 16) was mainly inside the liver and somewhat hypervascular similar to peripheral cholangiocarcinoma, often with intrahepatic metastases. The periductal subtype (n = 3) was hypovascular, similar to the infiltrative cholangiocarcinoma, and had a tendency to spread along the portal vein. The intraductal type (n = 4) was observed as a filling defect on cholangiography. CT revealed an intraluminal low density mass. Histologically, they were papillary adenocarcinomas. The radiologic types of hilar cholangiocarcinoma showed different characteristics with regard to pathologic findings, vascularity, and pattern of spread.     

Hilar cholangiocarcinoma: role of preoperative imaging with sonography, MDCT, MRI, and direct cholangiography

OBJECTIVE: The purpose of this article is to describe the roles of sonography, MDCT, MRI, and direct cholangiography in the evaluation of hilar cholangiocarcinoma. CONCLUSION: Hilar cholangiocarcinoma is a primary malignant tumor typically located at the confluence of the right and left ducts within the porta hepatis. Staging of hilar cholangiocarcinoma with various imaging techniques is crucial for management, and a comprehensive approach is needed for accurate preoperative assessment.     

Hilar biliary obstruction: preliminary results with Levovist-enhanced sonography

OBJECTIVE: The aim of this study was to investigate the value of using Levovist in the postvascular phase of sonography performed to assess hepatic hilar biliary obstruction. SUBJECTS AND METHODS: In our prospective study, 50 patients underwent routine sonography followed by postvascular Levovist-enhanced pulse inversion imaging of the liver. Thirty-six patients had malignant disease (28 invasive parenchymal tumors and eight intraductal tumors), and 14 had benign disease. The 36 malignancies included 29 cholangiocarcinomas, six invasive gallbladder carcinomas, and one colon metastasis. Fourteen patients had benign disease: benign strictures (n = 5), primary sclerosing cholangitis (n = 5), chronic Mirizzi's syndrome (n = 1), varicosities of the parabiliary venous plexus (n = 1), and inflammatory liver lesions (n = 2). Sonographic findings in all 50 patients were correlated with findings from other imaging modalities (n = 50) as well as surgical specimens (n = 20), core biopsies (n = 3), and both clinical and imaging follow-ups (n = 24). RESULTS: Seventeen (61%) of the 28 invasive intraparenchymal malignancies were visualized on routine sonograms, whereas all 28 (100%) were visualized on enhanced sonograms (p < 0.01). In 15 (88%) of 17 patients in whom tumor was seen on routine sonograms, contrast-enhanced sonography showed further mass extent, increased conspicuity, or satellite nodules not visualized on the baseline image. All eight noninvasive intraductal malignancies were correctly identified and staged on the routine sonography. In one of these patients, hepatic invasion was prospectively overcalled on the enhanced image. Of the 14 benign lesions, three had inflammatory periductal abnormalities seen exclusively or to advantage on the enhanced study. Correct prediction of resectability in the 16 patients with malignant disease who underwent surgery improved from 11 (69%) of 16 on unenhanced sonography to 15 (94%) of 16 on enhanced sonography (p = 0.13). CONCLUSION: Detection and staging of malignant hilar obstructions are improved by the use of Levovist in the postvascular phase of sonography compared with routine sonography.     

Hilar cholangiocarcinoma: radiological assessment of resectability

A pre-operative study of 31 patients with proximal cholangiocarcinoma was carried out with ultrasonography (US), duplex sonography (DS), computed tomography (CT), percutaneous transhepatic cholangiography (PTC), endoscopic retrograde cholangiography (ERC) and angiography. US, DS and PTC are the most effective techniques for pre-operative staging assessment of proximal cholangiocarcinoma. A tumour was visualised by US in 89% of cases, and the extent of extraductal tumour invasion was correctly established in 64%. Lobar segmental tumour extension was correctly documented in 80% of cases; however, the exact definition of tumour extension required the use of PTC. Vascular patency was correctly visualised by DS in 85% of cases. Altogether, tumour invasion was correctly documented in 68% in cases. In the event of radiologically localised tumour extension, radiological interpretation was correct in 64% of cases. The extent of tumour infiltration was radiologically underestimated in 36% of cases, especially in documenting lymph node metastases, infiltration of the hepato-duodenal ligament and segmental liver invasion. Correspondence to: J. Triller     

Tailgut cyst: diagnosis with CT and sonography

Tailgut cyst is a rare congenital lesion that presents as a presacral mass, found in infancy or persisting undetected into adulthood, and characterized by multiple cysts lined with a gastrointestinal type of epithelium. In a retrospective review of five patients whose ages ranged from 1 month to 42 years--three cases with CT and two with sonograms--tailgut cyst appeared as a complex mass on both procedures, representing its composition of multiple small cysts filled with keratinous material and other debris. Other CT and sonographic features include well-defined borders, and, in one case, presentation as a mass lateral to the midline. CT also shows preservation of adjacent fat planes. Tailgut cyst should be included in the differential diagnosis of a retrorectal mass at any age.     

Retained surgical sponge: diagnosis with CT and sonography

The diagnosis of a retained surgical sponge was made by CT and sonography in four patients. The plain abdominal radiograph was normal in all cases. In each of four cases of gauze granuloma, CT showed a well-defined round mass with a thick wall; internal heterogeneous densities with a wavy, striped, and/or spotted appearance; mottled calcifications; and gas bubbles. Sonography disclosed a well-defined hypoechoic mass containing highly echogenic foci with a strong posterior shadow. In these cases, CT and sonographic findings, together with a history of surgery, permitted the correct preoperative diagnosis of a retained foreign body.     

Helical CT of the larynx: A comparative study with conventional CT scan

Aim:

To compare helical and conventional CT scans of the larynx.

Patients and methods:

Thirty-three patients underwent helical and conventional CT studies of the neck and the larynx using 3 mm section collimation for both studies and a table feed of 4mm/sec for helical CT. Helical scans were reconstructed at 2mm increments. Two independent observers rated the visibility of the laryngeal structures from 1 (poor and non diagnostic) to 5 (excellent and diagnostic), and motion artifacts from 1 (≥ 10 degraded scans) to 5 (no motion artifacts).

Results:

The motion artifacts score was significantly better for helical CT. No significant difference was observed for the laryngeal structures score between helical and conventional CT studies. The interobserver kappa mean value was 0.756 and 0.68 for helical and conventional CT, respectively.

Conclusion:

Helical CT can be routinely performed and replace conventional CT study for the evaluation of laryngeal diseases.     

Detection of hepatic masses in patients with carcinoma: comparative sensitivities of sonography, CT, and MR imaging

To evaluate the sensitivity of sonography, CT, and MR imaging in the detection of hepatic masses in carcinoma patients, we conducted a prospective study of 75 consecutive patients with gastrointestinal tumors who were admitted for surgical resection of the primary tumor. Sonography was performed with convex transducers of 3.5 and 5.0 MHz. Three noninvasive CT techniques were used: unenhanced CT scans, the incremental bolus dynamic scanning technique, and delayed scanning 4-6 hr after bolus injection of 60 g of iodine. MR images (1.5 T) were acquired as presaturated T1- and T2-weighted spin-echo sequences and as breath-holding fast low-angle shot (FLASH) 60 degrees and FLASH 15 degrees sequences. As it is difficult to distinguish benign from malignant masses solely on the basis of morphologic criteria, the techniques for each imaging method were designed to detect and not to characterize hepatic lesions. Each examination was interpreted blindly, and the results were compared with surgical findings, intraoperative sonography, and biopsy of the liver as the gold standard. All focal hepatic masses verified at surgery, malignant or benign, were included in the analysis. Sixty-five (68%) of 95 focal hepatic masses were detected by CT, 60 lesions (63%) by MR, and 50 lesions (53%) by sonography. Although lesions 1-2 cm were shown almost equally well by CT and MR (74% and 77%, respectively), the detection rate of smaller lesions (less than 1.0 cm) decreased more drastically with MR (31%) than with CT (49%). Sonography had a sensitivity of only 20% with the smaller lesions. All imaging techniques had a sensitivity of 100% for focal hepatic masses larger than 2.0 cm. Our results show that CT has a higher overall sensitivity (68%) than MR and sonography for the detection of focal hepatic masses. When the results of the three procedures are combined, the overall sensitivity is 77%. This is unsatisfactorily low, as CT and MR have a size threshold of about 1.0 cm and are relatively unreliable for the detection of smaller lesions.     

Peripheral cholangiocarcinoma and clonorchiasis: CT findings

Sixteen patients with peripheral cholangiocarcinoma of the liver were examined with computed tomography (CT). None of the 16 patients presented with jaundice or had documented cirrhosis. On scans obtained both before and after the injection of contrast material, the tumors were depicted as low-attenuation masses in all cases, with wide variations in homogeneity. The tumor margin was irregular in 12 cases, and there was minimal contrast enhancement of the tumor in 14 cases. In 11 (69%) patients, CT demonstrated masses of markedly low attenuation, which corresponded to areas of diffuse microcystic change seen at histologic examination of resected specimens. In ten (63%) patients, the results of stool or intradermal tests for Clonorchis sinensis were positive. In all ten cases of clonorchiasis, mild, diffuse dilatation of the intrahepatic bile ducts was seen in addition to the low-attenuation masses, but there was no dilatation of the extrahepatic biliary tree. In five of the ten patients with clonorchiasis, stippled or aggregated, powderlike areas of high attenuation were seen on precontrast CT scans; at pathologic examination, those areas were found to be mucin. Extrahepatic metastases were demonstrated in ten (63%) patients. Peripheral cholangiocarcinoma should be the primary diagnostic consideration when these characteristic CT findings are detected in a noncirrhotic patient.     

胆管癌的螺旋CT诊断

目的 探讨螺旋CT扫描在胆管癌的定位，定性及鉴别诊断中的价值。方法 CT检查使用美国CE公司Hispeed CT/i及CT/e螺旋CT机，扫描范围由膈顶部至肝下，层厚：10mm,5mm,3mm，螺距为1。全部病人均行平扫及增强扫描。结果 16例胆管癌中，周围型1例，肝门型9例，肝外胆管型5例，壶腹型1例，CT表现主要为：胆管扩张，梗阻部位的软组织肿块，可伴胆囊炎，胆结石，术前CT正确诊断15例（94%），仅1例误诊为胆管炎。结论 螺旋CT扫描对于胆管癌的定位，定性诊断及分型有重要临床价值。     

MR imaging of brain contusions: a comparative study with CT

Ninety-eight brain contusions in 17 patients served as a data base for a comparative study of MR and CT for defining brain contusions. MR was the more sensitive technique, detecting 98% of the brain contusions compared with only 56% by CT. CT was slightly better for showing hemorrhagic components, documenting 77% of hemorrhages compared with 71% for MR. The appearance of the contusions on MR was variable, depending on the T1- and T2-weighting of the images and the constituents of the contusions, such as edema, hemorrhage, and encephalomalacia. On MR, hemorrhagic components appeared as high signal on T1-weighted images and as either low or high signal on T2-weighted images, depending on the age of the hemorrhage. The approximate ages of hemorrhagic contusions were often suggested by their appearance on T1- and T2-weighted images. CT is very effective for evaluating acute head trauma, but MR is recommended for documenting brain contusions during the subacute and chronic stages of head injuries.     

腹膜CT的形态学研究:实验犬与人的相应结构对照

目的 :阐述正常腹膜腔及腹膜结构的解剖关系。方法 :4只试验犬中 2只开腹后分别用实心和空心塑料丝线标记于小网膜、肠系膜、大网膜、脾胃韧带及横结肠系膜 ,另 2只犬分别行腹膜腔造影 ,平扫后行增强扫描。 4只犬CT扫描结束后处死 ,开腹观察实体形态、腹膜结构与脏器的关系、腹膜内动静脉走行及分布等。另选受检者 5 2例行CT平扫及增强扫描 ,与犬的腹膜结构对照观察 ,确定人腹膜结构的形态及其间隙 ,并测量正常人不同腹膜结构的CT值以及腹壁皮下脂肪的密度 ,比较同一腹膜结构平扫与增强后CT值。结果 :实验犬与人的腹膜结构及周围腹膜间隙相似。CT横断面图像上可显示腹膜结构的形态、位置和密度 ,但腹膜间隙为潜在的间隙 ,如无积液或对比剂填充则不能显示。人的腹膜结构及其间隙在轴位CT图像上更易辨认。同一腹膜结构平扫与增强后CT值差异无显著性意义 (P >0 .0 1)。结论 :对正常腹膜腔和腹膜结构影像形态的研究为进一步精确定位病变及评估病变侵袭范围奠定了重要基础。     

Mimics of appendicitis: alternative nonsurgical diagnoses with sonography and CT

OBJECTIVE: Our objective was to illustrate the imaging features of alternative nonsurgical disorders in patients presenting with clinical signs of appendicitis. CONCLUSION: This article illustrates the sonographic and CT features of various appendicitis-mimicking conditions that are self-limiting or that can be treated conservatively. A correct imaging diagnosis of these disorders may prevent a nontherapeutic appendectomy and unnecessary hospitalization.     

Hepatocellular carcinoma and intrahepatic peripheral cholangiocarcinoma: enhancement patterns with quadruple phase helical CT--a comparative study.

PURPOSE: To define the hemodynamic features of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma by using quadruple phase helical computed tomography (CT) and determine the value of this information in characterizing tumors. MATERIALS AND METHODS: Helical CT of the liver was performed in 45 patients with newly diagnosed HCC or peripheral cholangiocarcinoma. Scans were obtained before and 25 seconds, 70 seconds, and 2-6 minutes after the start of the contrast material injection. The intensity and spatial distribution of contrast material uptake were evaluated during all phases. Time-attenuation curves were established for each lesion. Relative attenuation and lesion conspicuity were assessed. A diagnostic confidence level was assigned to each lesion. RESULTS: In the majority of HCC lesions, a single, early peak of enhancement followed by a continuous decrease in tumor attenuation over time was seen. The greatest tumor conspicuity occurred during the delayed phase. In cholangiocarcinoma, tumor attenuation increased during the delayed phase. In the majority of lesions, the greatest tumor conspicuity was seen during the portal venous phase. In both tumor types, the diagnostic confidence level improved when the delayed phase was used. CONCLUSION: The variation over time in the intensity of contrast enhancement in HCC and cholangiocarcinoma differs sufficiently to make this a useful diagnostic criterion. The delayed phase is particularly important because it amplifies this difference.