Transhepatic cholangiography: the radiological method of choice in suspected obstructive jaundice.

Twenty-five patients with severe jaundice were studied prospectively with computed tomography (CT), gray-scale ultrasonography (USG), and percutaneous transhepatic cholangiography (THC). Nineteen had obstruction of the biliary tree. The differentiation of obstructive from hepatic parenchymal causes of jaundice was 72% accurate with USG, 92% with CT, and 96% with THC. Biochemical studies when used alone were 72% accurate. Although the precise location of an obstructing lesion was determined in 12/19 cases by CT and 9/19 by USG, the cause was established in only 5 by CT and 7 by USG. THC was 100% successful in establishing both cause and site of obstructive jaundice without significant complications.     

Percutaneous transhepatic intraductal biliary sonography for lymph node staging at 12.5 MHz in malignant bile duct obstruction: Work in progress

Purpose To assess the value of intraductal ultrasound (US) for lymph node staging in malignant biliary obstruction. Methods Eighteen patients with malignant extrahepatic obstruction were imaged during percutaneous bile duct drainage with a mechanically rotating US transducer at 12.5 MHz. Detectable lymph nodes were classified as malignant when two of three criteria (hypoechoic, rounded, conspicuous margins) were fulfilled. The results were compared with histopathological data in 8 patients and follow-up CT findings in 10 patients. Results In 15 of 18 patients (83%) malignant lymph node involvement was suspected at intraductal US and in 5 of 18 patients (28%) during CT. Histopathological investigation after operation (n=8) and follow-up CT studies (n=10) revealed the presence of malignant nodal involvement in 13 of 18 (72%) patients. The sensitivity, specificity, and accuracy of transhepatic intraductal biliary US in determining merely the presence or absence of malignant lymph nodes without specific topographic assignment were 92%, 40%, and 78%, respectively. Conclusion These preliminary results suggest that intraductal US may develop into a promising adjunctive modality during percutaneous bile duct drainage in patients with suspected malignant regional lymph node involvement.     

Helical CT for nephrolithiasis and ureterolithiasis: comparison of conventional and reduced radiation-dose techniques

PURPOSE: To determine the accuracy of unenhanced helical computed tomography (CT) performed at reduced milliampere-second, and therefore at a reduced patient radiation dose, by using conventional unenhanced helical CT as the standard. MATERIALS AND METHODS: Fifty patients with acute flank pain who weighed less than 200 lb (90 kg) were prospectively recruited for this study. Conventional helical CT scans were obtained with patients in the prone position by using 5-mm-thick sections, 140 kVp, 135-208 mAs (mean, 160 mAs), and a pitch of 1.5 (single-detector row CT) or 0.75 (multi-detector row CT, 4 x 5-mm detector configuration). Conventional CT was immediately followed by low-dose scanning, whereby the tube current was reduced to 100 mA (mean, 76 mAs). All other technical parameters and anatomic coverage remained constant. Three independent readers who were blinded to patient identity interpreted the scans in random order. The observers noted the location, size, and number of calculi; secondary signs of obstruction; and other clinically relevant findings. High- and low-dose scans were compared by using paired t tests and the signed rank test. RESULTS: Calculi were found in 33 (66%) patients; 25 (50%) had renal calculi and 19 (38%) had an obstructing ureteral calculus. The accuracy rates (averaged over the three readers) for determining the various findings on the low-dose scan compared with the high-dose scan were as follows: nephrolithiasis, 91%; ureterolithiasis, 94%; obstruction, 91%; and normal findings, 92%. When interpretations between readers were compared, agreement rates were 90%-95% for standard-dose scans and 90%-92% for reduced-dose scans (P >.5). Uncomplicated mild diverticulitis was found in three patients. No other clinically important abnormality was identified. A reduction in the tube current to 100 mA resulted in a dose reduction of 25% for multi-detector row CT and 42% for single-detector row CT. CONCLUSION: In patients who weighed less than 200 lb, unenhanced helical CT performed at a reduced tube current of 100 mA, and therefore at a reduced patient dose, resulted in scans of high accuracy.     

CT、MRI、MRCP对胆道梗阻的诊断价值

目的　探讨CT、MRI、MRCP对胆道梗阻的诊断价值。方法　分析经病理和临床随访确诊 3 0例 (恶性 2 2例 ,良性 8例 )胆道梗阻患者CT、MRI、MRCP表现。结果　CT、MRI、MRCP对胆道梗阻定位诊断率分别为 86.7%、93 .3 %、10 0 % ,CT、MRI、CT MRI MRCP定性诊断率分别为 80 %、73 %、90 %。结论　综合分析CT、MRI、MRCP表现能提高胆道梗阻的定位、定性诊断率     

Distinguishing benign from malignant bowel obstruction in patients with malignancy: findings at MR imaging

PURPOSE: To retrospectively evaluate the features of benign versus malignant bowel obstruction on unenhanced and gadolinium-enhanced spoiled gradient-echo magnetic resonance (MR) images in patients with malignancy. MATERIALS AND METHODS: Forty-eight patients with malignancy and bowel obstruction underwent abdominal and pelvic MR imaging. Two blinded radiologists independently evaluated each study for dilated bowel, transition point, level of obstruction, obstructing mass, mural thickening and enhancement, and peritoneal disease. Benign obstruction was recorded if no mass was present and if mural thickening (when present) was segmental or diffuse. Malignant bowel obstruction was recorded if there was a mass, a disseminated abdominal tumor, or focal mural thickening. MR images were compared with surgical findings, follow-up imaging studies, and clinical outcome. chi2 test and Fisher exact test were used to assess the relationship between the MR features and benign versus malignant obstruction. RESULTS: Bowel obstruction had a benign cause in 19 patients and a malignant cause in 29 patients. Observer 1 correctly characterized benign bowel obstruction in 17 of 19 patients and malignant bowel obstruction in 27 of 29 patients. The sensitivity of observer 1 for characterizing malignant obstruction was 93%, specificity was 89%, and accuracy was 92%. Observer 2 correctly characterized benign bowel obstruction in 18 of 19 patients and malignant bowel obstruction in 26 of 29 patients. The sensitivity of observer 2 for characterizing malignant obstruction was 90%, specificity was 95%, and accuracy was 92%. Malignant bowel obstruction was present in 24 of 25 patients with an obstructing mass (P <.001). All 16 patients with focal mural thickening had malignant obstruction. Benign obstruction was present in four of five patients with diffuse mural thickening. Segmental mural thickening occurred in four patients with serosal metastases and in 11 patients with benign bowel obstruction. More extensive peritoneal thickening and enhancement correlated with malignant obstruction. CONCLUSION: In patients with malignancy who have symptoms indicative of bowel obstruction, gadolinium-enhanced MR imaging can help distinguish benign from malignant causes of bowel obstruction.     

Multislice CT cholangiography using thin-slab minimum intensity projection and multiplanar reformation in the evaluation of patients with suspected biliary obstruction: preliminary experience

Thirty-three patients with suspected biliary obstruction were prospectively evaluated with multislice CT cholangiography using thin-slab minimum intensity projection (MinIP) and multiplanar reformation (MPR) to determine its usefulness and to compare with the comparative studies of endoscopic retrograde cholangiography (ERC), magnetic resonance cholangiography (MRC), or percutaneous transhepatic cholangiography (PTC). CT cholangiography made correct diagnoses in all biliary obstructions except in two patients with common bile duct stones. The correspondence with the comparative study was 93.9%. Multislice CT cholangiography may be favorable in noninvasive evaluation of biliary obstructions.     

Pancreatic response to percutaneous biliary drainage: a prospective study.

To evaluate the effects of percutaneous biliary drainage (PBD) on the pancreas, serum amylase levels were measured for 7 consecutive days after PBD and compared with baseline values in 50 patients who underwent a total of 53 PBD procedures. Of the 45 patients with normal baseline serum amylase levels, 12 patients (24%) developed postprocedural hyperamylasemia without clinical symptoms and five patients (10%) developed postprocedural hyperamylasemia with clinical signs of pancreatitis. Five patients who presented with elevated baseline serum amylase levels demonstrated decreases into the normal range after placement of stents without initiation of bowel rest or liquid diet. The level of biliary obstruction proved insignificant, as did the nature of the obstructing disease, in determining which patients would experience hyperamylasemia or pancreatitis after PBD. It is concluded that the frequency of pancreatic insult from PBD may be more common than previously reported and that patient susceptibility is not dependent on the level of biliary obstruction or the nature of the disease.     

Nonenhanced helical CT and US in the emergency evaluation of patients with renal colic: prospective comparison

PURPOSE: To compare nonenhanced helical computed tomography (CT) with ultrasonography (US) for the depiction of urolithiasis. MATERIALS AND METHODS: During 9 months, 45 patients (mean age, 44 years; mean weight, 92.5 kg) prospectively underwent both nonenhanced helical CT (5-mm collimation; pitch of 1.5) and US of the kidneys, ureters, and bladder. US evaluation included a careful search for ureteral calculi. Presence of calculi and obstruction and incidental diagnoses were recorded. Clinical, surgical, and/or imaging follow-up data were obtained in all patients. The McNemar test was used to compare groups. RESULTS: Diagnoses included 23 ureteral calculi and one each of renal cell carcinoma, appendicitis, ureteropelvic junction obstruction, renal subcapsular hematoma, cholelithiasis, medullary calcinosis, and myelolipoma. CT depicted 22 of 23 ureteral calculi (sensitivity, 96%). US depicted 14 of 23 ureteral calculi (sensitivity, 61%). Differences in sensitivity were statistically significant (P: =.02). Specificity for each technique was 100%. When modalities were compared for the detection of any clinically relevant abnormality (eg, unilateral hydronephrosis and/or urolithiasis in patients with an obstructing calculus), sensitivities of US and CT increased to 92% and 100%, respectively. One case of appendicitis was missed at US, whereas medullary calcinosis and myelolipoma were missed at CT. CONCLUSION: Nonenhanced CT has a higher sensitivity for the detection of ureteral calculi compared with US.     

Diagnosis and treatment of jaundice

1. CT and sonography are helpful in distinguishing between an obstructing lesion and hepatocellular disease as the cause of jaundice. 2. CT and sonography can demonstrate the level and extent of an obstructing lesion, and can define its nature if a mass more than 1-2 cm is present; sonography is usually the preferred screening study because of its availability, relatively low cost and lack of radiation hazard. 3. PTC or ERCP is useful in the evaluation of jaundice when sonography and CT are equivocal, fail to provide information necessary to establish proper therapy, or are at variance with the clinical impression of obstructive jaundice; in addition to defining obstructions these techniques can detect atrophy, sequestra, stones, abscesses, fistulas, primary sclerosing cholangitis, etc. 4. PBD offers an expedient alternative to surgical decompression in patients with obstructive jaundice, since most cancers that cause biliary obstruction are not resectable for cure at the time of diagnosis.     

MRCP诊断梗阻性黄疸及其影像学对比研究

目的 探讨MRCP在梗阻性黄疸中的诊断价值。方法 对75例梗阻性黄疸患行MRCP检查，原始图像作三维重建，然后分析其影像表现及诊断结果，并与US、CT和直接胰胆管造影进行比较，对照手术病理结果进行分析结果本组75例中MRCP确诊71例，误诊4例，确诊率95％，与直接胰胆管造影(92％）相近，明显高于US(74％)和CT(75％)。MRCP对梗阻性黄疸定位诊断准确率为100％。结论 MRCP作为无创性检查技术，完整清晰地显示胰胆管系统结构，提高了，梗阻性黄疸的定位和定性诊断率，为临床保守或手术治疗提供可靠依据，可作为梗阻性黄疸患的首选影像学检查方法。     

Frequency and CT patterns of bowel wall thickening proximal to cancer of the colon

OBJECTIVE: This study was performed to determine the frequency and patterns of colon wall thickening seen on CT of patients with adenocarcinoma of the colon. MATERIALS AND METHODS: Preoperative abdominal and pelvic CT scans of 185 patients with surgically proven adenocarcinoma of the colon were retrospectively evaluated by three abdominal radiologists for the presence of colon obstruction and colon wall thickening proximal to the colon adenocarcinoma. The distributions and patterns of colon wall thickening were categorized by consensus. CT findings were compared with pathologic findings. Fisher's exact test was used to determine the statistical significance of any associations. RESULTS: Of 185 patients, CT findings of 20 (10.8%) showed colon wall thickening. Of these, the adenocarcinoma obstructed the colon in 19 patients (p < 0.01). Colon obstruction was partial in 10 patients (53%) and complete in nine (47%). Colon wall thickening was contiguous to the tumor in 14 (70%) patients and noncontiguous in six (30%). Segmental and pancolonic, patchy and diffuse, and dependent and nondependent colon wall thickening was observed in 10 patients (50%) in each category. Associated small-bowel wall thickening was shown in 10 (50%) of the 20 patients. Pathologic examination showed colon wall thickening to be due to edema in all cases. CONCLUSION: Colon wall edema can occur proximal to colon adenocarcinoma, is almost always associated with colon obstruction, and is predominantly contiguous with the obstructing adenocarcinoma.     

Acute biliary disease: initial CT and follow-up US versus initial US and follow-up CT

PURPOSE: To evaluate the utility of ultrasonography (US) versus that of computed tomography (CT) for assessment of acute biliary disease. MATERIALS AND METHODS: Radiologic reports and clinical charts were reviewed in all patients who underwent US and CT within 48 hours of each other for evaluation of acute right upper quadrant pain. Radiologic findings and clinical outcome were correlated. RESULTS: CT was the initial imaging study in 57 patients, and CT findings resulted in underdiagnosis or misdiagnosis of acute biliary disease in eight of 11 patients. Follow-up US results were suggestive of the correct diagnosis and provided additional clinical information in seven of these eight patients. US findings resulted in altered clinical treatment in six of 11 patients with acute biliary disease. US was the initial study in 66 patients, and US findings were suggestive of biliary disease or the correct diagnosis in seven of seven patients with acute biliary disease. Follow-up CT did not result in changes in clinical treatment in any patient with acute biliary disease. CONCLUSION: Initial US is better than initial CT in patients suspected of having acute biliary disease. Follow-up CT provides no additional information regarding the biliary system, and its use should be limited to those patients with a wider differential diagnosis or with confusing clinical symptoms and signs.     

Chronic diffuse infiltrative lung disease: comparison of diagnostic accuracy of high-resolution and conventional CT

We compared the accuracies of high-resolution CT (HRCT) and conventional CT in determining the specific diagnoses in 75 consecutive patients with chronic diffuse infiltrative lung disease. Without knowledge of clinical or pathologic data, two reviewers independently assessed three separate sets of CT scans in random order: three HRCT scans, three 10-mm collimation CT scans obtained at the same levels as the HRCT scans, and a complete conventional CT scan. The HRCT scans were obtained at the level of the aortic arch, tracheal carina, and 1 cm above the right hemidiaphragm by using 1.5-mm collimation and a high spatial resolution algorithm. Observers gave the most likely diagnosis along with their degree of diagnostic confidence. The correct diagnosis, irrespective of confidence level, was reached with 71% of the HRCT scans and with 72% of both the corresponding 10-mm and complete conventional CT scans. Confidence level 1 (definite) was reached with 49% of HRCT scans, 31% of corresponding 10-mm scans, and 43% of complete conventional CT examinations; the correct diagnosis was made in 92%, 96%, and 94% of those examinations, respectively. In none of the patients were findings on the limited HRCT scan normal when findings on the conventional CT scan were abnormal. We conclude that in most patients with chronic infiltrative lung disease a specific diagnosis can be made by obtaining a limited number of HRCT scans.     

多层面螺旋CT胆道成像技术的临床应用

目的 探讨多层面螺旋CT胆道成像技术（MSCTC）要点及其临床应用价值。材料与方法 19例怀疑胆道梗阻患者,从周围静脉滴注10%胆影葡胺100ml后,60-90分钟行上腹部快速容积扫描,利用图形工作站的后处理功能行胆道系统的三维重建,并将观察结果与原始横断面图像和临床病理进行对照,结果 （1）15例血清胆红素低于2mg/dl(34umol/L)的病 列中14例胆道强化效果良好,而4例血清胆红素高于2mg/dl的病例中3例强化效果较差,（2）与横断面图像相比,三维图像显示胆道梗阻的部位与病因更直观、准确,无假阳性和假阴性发生。（3）Raysum技术能去除强化胆汁的掩盖,更清楚地显示胆道系统的细小病变。结论 MSCTC是一种安全可靠、简便易行的胆道系统无创伤检查技术,尤其对血清胆红素低于2mg/dl的病例有很高的临床应用价值。     

Multislice CT cholangiography without biliary contrast agent: technique and initial clinical results in the assessment of patients with biliary obstruction

Our objective was to describe our technique for multislice CT cholangiography without cholangiographic contrast agent, and to present our preliminary clinical results. Thirty-seven patients with suspected biliary obstruction were studied. A multislice CT unit was used with the following technical parameters: 2.5-mm collimation; 7.5-mm/s table speed; pitch 6; 0.8-s rotation time; 300 mA; 120 kVp; 18- to 24-s scan time; scan volume ranging from the hepatic dome to below the pancreatic head; 70-s delay after injection of 150 ml of iodinated contrast agent at 4 ml/s. No biliary contrast material was given; oral iodinated contrast agent was administered to opacify bowel loops. Axial, multiplanar reformatted, and minimum intensity projection images were evaluated. The CT findings were compared with the gold standard techniques: endoscopic retrograde cholangiography (ERCP) in 30 patients, percutaneous transhepatic cholangiography in 5, and intraoperative cholangiography in 2. In 5 patients with ampullary lesions biopsy was made during ERCP, 9 underwent surgery, and 11 US-guided fine-needle aspiration. Bile ducts appeared hypodense within the surrounding enhanced structures. Regarding the site of obstruction, agreement between multislice CT and conventional cholangiography was observed in all cases. One patient presented negative findings on both CT and ERCP. In 31 of 36 (86%) patients, multislice CT cholangiography without cholangiographic contrast agent correctly assessed the cause of bile duct obstruction. Multislice CT cholangiography without cholangiographic contrast agent seems to be a promising diagnostic tool in the assessment of patients with bile duct obstruction. Electronic Publication     

多层螺旋CT阴性法胰胆管造影在肝外胆管梗阻诊断中的应用(附40例报告)

目的　评价多层螺旋CT(MSCT)阴性法胰胆管造影 (N -CTCP)对肝外胆管梗阻性疾病的诊断价值。方法　对 40例肝外胆管梗阻性疾病 (肝外胆管结石 19例 ,恶性胆管梗阻 2 1例 )进行N -CTCP成像 ,将扫描重建数据行编辑处理 ,获得最小强度投影(MinIP)图像 ,结合CT轴面源像 (ASI) ,并与临床诊断或手术病理结果对照。结果　 40例均 1次屏气完成扫描 ,N -CTCP成像显示胆管树满意 ,MinIP对判断肝外胆管梗阻和定位诊断准确率为 10 0 % ,定性诊断准确率为 85 %。结论　N -CTCP对肝外胆管梗阻定位准确 ,结合轴面源像 (ASI) ,对肝外胆管结石及恶性胆管梗阻的判断有较高的准确性。     

螺旋CT在小肠梗阻诊断中的价值

目的:探讨螺旋CT在小肠梗阻诊断中的价值。方法:对64例小肠梗阻患者肌注低张剂、口服对比剂后行螺旋CT平扫和增强扫描,并与手术病理结果对照。结果:机械性小肠梗阻59例(其中肠肿瘤17例,炎性病变7例,腹外疝8例,腹内疝5例,肠粘连8例,腹茧症5例,胆石3例,肠套叠3例,肠扭转2例,粪块1例),CT诊断正确55例,诊断符合率93%。麻痹性肠梗阻5例,CT诊断正确3例,诊断符合率为60%。8例绞窄性肠梗阻,7例CT诊断正确,诊断符合率88%。结论:CT判断小肠梗阻的有无以及明确梗阻的部位、原因、程度和肠管缺血具有较高的准确性,是诊断小肠梗阻的可靠方法。     

高位胆道梗阻的CT与MRI、MRCP诊断价值

目的　探讨CT、MRI和MRCP对高位胆道梗阻的临床诊断价值。方法　对 12例高位梗阻 (恶性 11例 ,良性 1例 )进行了常规MRI、2DFSE序列MRCP检查 ,其中 10例恶性病变进行了CT检查 (平扫 7例 ,增强 3例 )。结果　CT、MRI和MRCP对高位梗阻定位诊断准确率分别为 90 %、92 %和 10 0 % ,定性诊断准确率分别为 80 %、83%和 6 7% ,MRI +MRCP定性诊断准确率提高到 92 %。10例恶性梗阻CT检查显示肿物 5例 ,胆总管环形增厚 3例。 12例MRI扫描显示肿物 8例 ,肝内转移 2例。MRCP显示梗阻近端形态较为特征 ,截断状以肝癌多见 ,锥状以胆管癌和转移癌多见 ,漏斗状见于良性病变。MRCP显示多发狭窄的长度和范围。结论　CT和MRI对高位梗阻具有同样重要的定性诊断价值。MRCP确定病变部位和范围具有独特的价值。MRI和MRCP结合可提高定位和定性诊断正确率     

应用螺旋CT胆道造影诊断胆管阻塞的可靠性研究

目的　研究螺旋CT胆管造影 (SCTC)诊断胆管阻塞可靠性及应用价值。方法　回顾分析经手术病理及ERC证实的 65例胆系疾病患者SCTC结果 ,以手术病理或 /和ERC为金标准 ,据临床流行病学诊断试验研究方法 ,分析SCTC诊断胆系阻塞的可靠性及应用价值。结果　胆管显影率 89% ,诊断胆管阻塞部位及原因准确率 89% ,肝外主胆管阻塞部位、原因准确率 97% ,灵敏度92 % ,特异度 95 % ,观察者间观察符合率 93 % ,卡帕值 0 .71。结论　SCTC 3D图像结合轴位像能准确显示阻塞部位和原因 ,为胆管复合结石的术前诊断及胆系术后随访提供了新的检查方法     

ERCP与MRCP对胆道恶性梗阻诊断价值的分析比较

目的比较内镜逆行胰胆管造影(ERCP)和磁共振胰胆管造影(MRCP)对胆道恶性梗阻性疾病的诊断价值。方法对383例胆道梗阻,经手术和(或)ERCP病理证实的142例恶性胆道梗阻患者ERCP和MRCP影像资料进行对比分析。结果MRCP和ERCP总确诊137例恶性梗阻,占96.4%;两种方法定位诊断率分别为92.3%和87.3%;定性诊断率为78.5%和89.8%。结论MRCP在诊断胆道恶性梗阻性疾病方面具有简便安全以及漏诊率低等优点,但误诊率较ERCP高;而ERCP如在诊治过程中与MRCP相结合注重影像学的诊断分析,则可以提高阳性检出率。两者结合使用可起互补作用。