Wandering liver: multidetector CT features and the importance of multiplanar reformations

The terms wandering liver, hepatic torsion, and hepatic vagrancy have been applied to cases in which hepatic hypermobility results in displacement of the liver from its normal position within the right upper quadrant of the abdomen. This is thought to result from multiple factors, including the lack of normal hepatic suspensory ligaments, persistence of the ventral mesentery, and lack of inferior vena cava tethering Siddins and Cade (Aust N Z J Surg 60:400–403, 1990). A wandering liver has been described in both adults Siddins and Cade (Aust N Z J Surg 60:400–403, 1990), Tate (Am Surg 59:455–458, 1993), Chiavarini and Chang (Radiology 115:47–48, 1974), Cope and Levy (South Afr Med J 40:366–369, 1966), Sharov (Vestn Roentgenol Radiol 35:63–64, 1960), Puthenpurayil et al. (AJR 177:1113–1115, 2001), Fuentes et al. (AJR 188:331–333, 2007) and children Feins and Borger (AJR 188:331–333, 2007), Al-Ali et al. (Pediatr Radiol 27:287, 1997), and it is usually associated with bowel obstruction Siddins and Cade (Aust N Z J Surg 60:400–403, 1990), Tate (Am Surg 59:455–458, 1993), Chiavarini and Chang (Radiology 115:47–48, 1974), Cope and Levy (South Afr Med J 40:366–369, 1966), Sharov (Vestn Roentgenol Radiol 35:63–64, 1960), Fuentes et al. (AJR 188:331–333, 2007), Feins and Borger (AJR 188:331–333, 2007). We report a case of an incidental wandering liver in an adult without associated obstruction, diagnosed by multidetector computed tomography with multiplanar reformations.     

Evaluation of subsubsegmental pulmonary arteries of the posterior and anterior segments of the right upper lobe using multidetector row computed tomography with multiplanar reconstruction images

Purpose  We evaluated the patterns of subsubsegmental pulmonary arteries of the right upper lobe (posterior segment: S2; anterior segment: S3) with multiplanar reconstruction (MPR) images by multidetector row computed tomography (MDCT). Materials and methods  A total of 64 patients who had undergone MDCT scans were included in the study. The subsubsegmental arteries were named by adding “i” or “ii” as the superior or the inferior branch, respectively, of the subsegmental arteries. The subsubsegmental arteries of S2 (A2ai, A2aii, A2bi, A2bii) and S3 (A3ai, A3aii, A3bi, A3bii) were evaluated as arising from either the recurrent artery (RA) or the ascending artery (AA). Results  A2ai originated from the RA and AA in 43 and 21 patients, respectively. The corresponding numbers were 32 each for A2aii; 28 and 36 for A2bi; 23 and 41 for A2bii; 60 and 4 for A3ai; 43 and 21 for A3aii; 59 and 5 for A3bi; and 54 and 10 for A3bii. Conclusion  The branching pattern of the subsubsegmental pulmonary arteries in the right upper lobe (S2 and S3) could be visualized using MDCT with MPR images.     

Preoperative assessment of longitudinal extent of bile duct cancers using MDCT with multiplanar reconstruction and minimum intensity projections: comparison with MR cholangiography

Objective

To compare the performance of MDCT, including multiplanar reformation (MPR) and minimum intensity projection (MinIP) images, with that of transaxial MDCT with MR cholangiography (MRC) in the preoperative evaluation of the longitudinal extent of bile duct cancer.

Methods

Twenty-seven patients with surgically proven bile duct cancer, who had undergone preoperative multiphasic MDCT and MRC, were included. Two radiologists evaluated the MDCT set with MPR and MinIP images and the image set of transaxial MDCT with MRC, regarding the longitudinal extent of bile duct cancer. The results were compared with the surgical and pathology findings.

Results

The area under the receiver operating characteristic curves of the MDCT set with MPR and MinIP images and the image set of transaxial MDCT with MRC for predicting the longitudinal extent of bile duct cancer, were 0.938, 0.923 and 0.839, 0.836 for both reviewers. The differences were not statistically significant for either image set or either reviewer. The sensitivity and specificity of the MDCT image set for detecting tumor involvement of the biliary second confluences or intrapancreatic segment were similar for both reviewers to those of transaxial MDCT with MRC.

Conclusions

MDCT with MPR and MinIP images showed comparable diagnostic performance to that of transaxial MDCT with MRC for predicting the longitudinal extent of bile duct cancer.     

Assessment of vascular invasion in pancreatic head cancer with multislice spiral CT: value of multiplanar reconstructions

The use of multiplanar reconstructions (MPRs) generated from multislice spiral CT (MSCT) data sets in the preoperative assessment of vascular invasion in pancreatic cancer was evaluated. Forty patients underwent biphasic high-resolution MSCT prior to surgery for pancreatic head cancer. Image reconstruction included thin-slice axial, sagittal and coronal MPRs as well as an MPR perpendicular to the course of a major peripancreatic vessel in proximity to the tumor. CT criteria for vascular invasion were: (1) circumferential involvement >180° and (2) vessel narrowing. Imaging findings of 52 vessels were correlated with surgical and histopathological reports. Regarding the CT criterion circumferential involvement, vascular invasion was demonstrated on axial MPRs with a sensitivity and specificity of 58 and 97%. For the assessment with coronal and sagittal MPRs sensitivity was only 47%. Vascular invasion was recognized best on perpendicular MPRs with a sensitivity, specificity and accuracy of 74, 97 and 88%, respectively. Vessel narrowing was a less reliable CT criterion for vascular invasion, mainly due to the lower specificity of 91% obtained with each available MPR. Thin-slice MPRs oriented perpendicularly to a possibly invaded vessel exactly depict the grade of circumferential involvement and thus have the capability to improve the assessment of vascular invasion in pancreatic cancer.     

Obstructive lesions of the central airways: evaluation by using spiral CT with multiplanar and three-dimensional reformations

The purpose of this study was to assess the accuracy of transverse CT scans as well as multiplanar (MPR) and three-dimensional (3D) reconstructions in the evaluation of obstructive lesions of the central airways. A total of 64 patients were evaluated for the presence of obstructive lesions of the central tracheobronchial tree with transverse spiral CT scans, multiplanar reformations (MPRs), 3D shaded surface displays (3D SSDs) and minimum intensity projections (MIPs). The findings of these modalities were then compared with those obtained at bronchoscopy. The severity, length, and shape of airway narrowing were analyzed comparatively on the four sets of images. Transverse CT scans and MPRs had a similar accuracy (99%) in detecting obstructive airway lesions. The accuracy of both was significantly higher than that of 3DSSDs (90%, p <0.05) and MIPs (81%; p < 0.01). There was no statistically significant difference between the four imaging modalities in the analysis of the morphology of airway stenoses. Symmetric stenoses were similarly analyzed on the four sets of images, whereas MPRs and MIPs failed to depict accurately simple and complex asymmetric stenoses. Transverse CT scans are accurate in the depiction of obstructive lesions of the central airways and may be complemented by MPRs and/or 3DSSDs in their morphologic evaluation.Correspondence to: M. Remy-Jardin     

胆管癌的18F-FDG PET/CT诊断价值

目的 总结胆管癌18F-FDG PET/CT显像表现,提高胆管癌的诊断准确性.方法 回顾经病理或临床综合手段证实的53例胆道疾病的18F-FDG PET/CT表现,分析PET/CT诊断胆管癌的敏感性、特异性和准确性.结果 肝内胆管癌14例、近段胆管癌18例、中远段胆总管癌15例、胆管炎性病变或伴结石6例.肝内转移9例,腹腔及腹膜后淋巴结转移15例,椎体等远处转移3例.PET/CT诊断胆管癌的敏感性为95.7％、特异性为83.3％、准确性为94.3％.结论 18F-FDG PET/CT在胆管癌的诊断与鉴别诊断、分期、检测疗效及预后等具有独特的应用价值.     

Preoperative assessment of hilar cholangiocarcinoma using multidetector-row CT: correlation with histopathological findings

PURPOSE: Our aim was to investigate the diagnostic reliability of multidetector-row computed tomography (MDCT) for preoperative assessment of local tumoral spread in hilar cholangiocarcinoma. MATEIRALS AND METHODS: Thirteen of 30 consecutive patients with hilar cholangiocarcinoma who underwent surgery, excluding 17 patients who underwent biliary drainage or preoperative portal embolization, were retrospectively evaluated. Using MDCT systems of 4 detector rows or 16 detector rows, plain and dynamic contrast-enhanced images of three phases were obtained. Extent of tumor spread and lymph node metastasis were assessed with MDCT and compared with histopathological findings. RESULTS: The Bismuth-Corlette classification of hilar cholangiocarcinoma with MDCT were type I, 1 patient; type IIIa, 3 patients; type IIIb, 4 patients; and type IV, 5 patients; those with histopathological findings were type I, 1 patient; type IIIa, 2 patients; type IIIb, 4 patients; and type IV, 6 patients. One patient diagnosed as type IIIa with MDCT was pathologically diagnosed as type IV. Accuracy of MDCT in tumoral spread was 92.3%, although that of lymph node metastasis was 54%. CONCLUSION: MDCT is likely to play an important role in evaluation of focal lesion spread especially in intrapancreatic tumor invasion, although a greater number of cohort cases are necessary to clearly define its role.     

Usefulness of the long-axis and short-axis reformatted images of multidetector-row CT in evaluating T-factor of the surgically resected pancreaticobiliary malignancies

PURPOSE: To evaluate the diagnostic efficacy of curved planar reformations along the duct (long-axis CPR) and series of reformations perpendicular to the duct (short-axis MPR) in evaluating T-factors of pancreaticobiliary malignancy. MATERIALS AND METHODS: Twenty-five patients with surgically proven pancreaticobiliary malignancy (12 bile duct cancers and 13 pancreas cancers) were evaluated. A dynamic study was performed with multidetector-row CT with four detectors, and reconstructed with 1mm thickness and intervals. Tracing the center of the duct system on axial images, long-axis CPR images and serial short-axis MPR images were obtained. Two radiologists interpreted the T factor of the diseases three times: session (1), axial images only; session (2), axial, coronal and sagittal multiplanar reformation images; and session (3), axial, long-axis CPR, and short-axis MPR images. Receiver operating characteristic curves were analyzed. RESULTS: In evaluations of bile duct cancer, Az values of (3) (0.95, 0.92) were higher than those of (1) (0.89, 0.88) and (2) (0.92, 0.89), with some significant differences. In evaluations of pancreas cancer, Az values of all interpretations were almost equal. CONCLUSION: Long-axis CPR and short-axis MPR images were suggested to be useful as additional images to the original axial images in evaluating the local extension of bile duct carcinomas.     

MDCT diagnosis of ileocolic intussusception secondary to an appendiceal mucocele: value of multiplanar reformation

We describe an extremely rare case of an ileocolic intussusception with an appendiceal mucocele as the lead-point and cause of acute right lower quadrant pain in an adult patient. There are only few reported cases of this entity in the radiologic literature. We describe the multislice (computed tomography) CT features and emphasize the value of multiplanar reformations. We also discuss how specific findings on CT should allow for a correct preoperative diagnosis. This case report has not been presented previously at any Radiology meeting. No grants were received for this case report. The authors disclose no potential conflict of interest.     

Multiple bile duct hamartomas simulating liver metastases on US and CT: case report

The radiological findings in multiple bile duct hamartomas (MBDH) are rare macroscopic manifestations of a more common microscopic entity. We present a patient in which the US and CT appearance simulated liver metastases. Final diagnosis was made by liver biopsy. Correspondence to: T. Sainte     

Diagnostic value of multidetector row CT in rectal cancer staging: comparison of multiplanar and axial images with histopathology

AIM: Although magnetic resonance (MR) imaging is widely used for rectal cancer staging, many centres in the UK perform computed tomography (CT) for staging rectal cancer at present. Furthermore in a small proportion of cases contraindications to MR imaging may lead to staging using CT. The purpose of this study was to evaluate the accuracy of current generation multidetector row CT (MDCT) in local staging of rectal cancer. In particular the accuracy of multiplanar (MPR) versus axial images in the staging of rectal cancer was assessed. MATERIAL AND METHODS: Sixty-nine consecutive patients were identified who had undergone staging of rectal cancer on CT. The imaging data were reviewed as axial images and then as MPR images (coronal and sagittal) perpendicular and parallel to the tumour axis. CT staging on axial and MPR images was then compared to histopathological staging. RESULTS: MPR images detected more T4 and T3 stage tumours than axial images alone. The overall accuracy of T-staging on MPR images was 87.1% versus 73.0% for axial images alone. The overall accuracy of N staging on MPR versus axial images was 84.8% versus 70.7%. There was a statistically significant difference in the staging of T3 tumours between MPR and axial images (p<0.001). CONCLUSION: Multidetector row CT has high accuracy for local staging of rectal cancer. Addition of MPR images to standard axial images provides higher accuracy rates for T and N staging of rectal cancer than axial images alone.     

Assessment of the pancreatic and intrapancreatic bile ducts using 0.5-mm collimation and multiplanar reformatted images in multislice CT

Our objective was to evaluate the ability of multiplanar reformatted (MPR) images combined with 0.5-mm axial images to depict the pancreatic and intrapancreatic bile ducts and compare the results with those of 0.5-mm axial, 2-mm axial, and 6-mm axial images alone. Seventy-seven patients without obstruction of the main pancreatic ducts (MPD) underwent dual-phase helical scanning of the pancreas using multislice computed tomography (MSCT). The MPR images were generated from 0.5-mm-thick images. Visualization of the pancreatic and intrapancreatic bile ducts and their confluence was graded on a four-point scale by a consensus of two radiologists. The results for 0.5-mm axial images in early-phase CT, 2-mm axial images in early-phase CT, MPR images combined with 0.5-mm axial images in early-phase CT, and 6-mm axial images in late-phase CT were then compared. The relationships of the focal pancreatic lesions with the pancreatic ducts were analyzed. The MPR images combined with 0.5-mm axial images were significantly superior to the other three types of images for the visualization of the pancreatic and intrapancreatic bile ducts and their confluence (p<0.01). The depiction rate of the MPD using MPR images combined with 0.5-mm axial images was 94, 94, 95, and 75%, respectively in the head, neck, body, and tail of the pancreas. Accessory pancreatic ducts, intrapancreatic bile ducts, and duct confluence were depicted in 48, 99, and 92%, respectively. In comparison with evaluation based on axial images alone, the use of MPR images more clearly demonstrated the relationship between the lesions and the pancreatic ducts in 14 of 19 lesions. The MPR images combined with 0.5-mm axial images improve the CT depiction of the pancreatic and intrapancreatic bile ducts in comparison with 0.5-mm axial, 2-mm axial, and 6-mm axial images alone. Electronic Publication     

MR imaging and MR cholangiopancreatography in the preoperative evaluation of hilar cholangiocarcinoma: correlation with surgical and pathologic findings

The primary aim was to evaluate delayed contrast-enhanced MRI in depicting perineural spread of hilar cholangiocarcinoma (CCC) and consequently to determine the capability of MRI/MRCP for staging CCC. Fifteen patients that underwent MRI/MRCP and surgical treatment were retrospectively included. Two radiologists evaluated MR images to assess delayed periductal enhancement, extent of bile duct stenosis, liver parenchymal and vascular involvement and presence of liver atrophy. An agreement between delayed enhancement of the bile duct walls and perineural neoplastic spread showed a very good correlation factor (0.93). The overall accuracy in detecting biliary neoplastic invasion was higher for delayed T1-weighted images (93.3%) than for the MRCP images (80%), and T1-delayed image increased the MR accuracy in assessing the neoplastic resectability (p < 0.05). MRI correctly predicted vascular involvement in 73% and liver involvement in 80% of the cases. The number of overall correctly assessed patients with regard to resectability was 11 true positive, 1 false positive and 3 true negative. The combination of MRI/MRCP is a reliable diagnostic method for staging hilar cholangiocarcinomas. Delayed periductal enhancement is accurate in the evaluation of neoplastic perineural spread, and it can improve diagnostic accuracy to identify resectable and unresectable tumours.     

磁共振扩散加权成像在胆管癌及肝占位性病变鉴别诊断中的应用价值

目的 探讨磁共振扩散加权成像在胆管癌及肝良、恶性占位性病变鉴别诊断中的应用价值。方法 采用DWI技术对胆管癌患者及肝良、恶性占位性病变患者进行了鉴别和诊断,探讨DWI对胆管癌定性诊断中的作用,及其与肝其他占位性病变进行鉴别比较研究过程中的特点。结果 肝细胞癌组、肝转移瘤组的ADC值与胆管癌组比较无明显差异。肝血管瘤组、肝囊肿组及正常肝组织的ADC值则明显高于胆管癌组,且差异具有统计学意义。胆管癌组的ADC值与与肝恶性病变比较无明显差异;但是胆管癌组的ADC值明显低于肝良性病变组,且差异具有统计学意义。结论 DWI序列速度快,通过DWI图像特点及量化分析ADC值,对胆管癌及肝良、恶性占位性病变可提供定量的诊断信息,可作为上腹部平扫的补充检查序列,应列为MRI常规序列之一。     

Diameters of the common bile duct in adults and postcholecystectomy patients: a study with 64-slice CT

This study aims to collect data by multidetector computed tomography (MDCT) on the diameter of the normal common bile duct (CBD) and the diameter of CBD after cholecystectomy. In this retrospective study, CBD measurements were performed on axial oblique images, perpendicular to the long axis of the distal CBD. The mean diameter of the normal CBD was measured in 604 patients without cholecystectomy. The patients were divided into 6 groups according to their age. Analysis of variance (ANOVA) was used to compare data obtained from the six age groups. The mean diameter of the CBD of 46 patients who had cholecystectomy was calculated. The results were compared with age matched control group by Student's t test. The largest diameter of CBD ranged from 1.8 to 11.8mm. The mean of the largest diameter of 604 subjects was 4.77 ± 1.81. The diameter of the CBD significantly increased with age. Mean largest CBD diameters of postcholecystectomy subjects (7.28 ± 2.37) were significantly greater than age matched control group. In conclusion the diameter of CBD shows a considerable increase with age. The largest diameter of the CBD is up to 6mm in most of the subjects. An upper limit of 8mm appears reasonable after the age of 50; and an upper limit of 10mm seems appropriate for cholescystectomized subjects.     

The local spread of lower bile duct cancer: evaluation by thin-section helical CT

This study illustrates the local spread of lower bile duct cancer with thin-section helical CT in correlation with the surgical and pathological findings. Pathologically, 16 patients had pancreatic invasion, 4 had small bowel mesentery invasion, 7 had extrapancreatic nerve plexus invasion, and 3 patients had vascular invasion. On thin-section helical CT, pancreatic invasion was correlated to the clarity or non-clarity of the bile duct mass-pancreas border and the presence of an intrapancreatic mass. Cases with small bowel mesentery and extrapancreatic nerve plexus invasion showed mass or stranding around the superior mesenteric artery and/or inferior pancreatoduodenal artery. Vascular invasion was seen as tumor contiguity to these vessels. Received: 28 September 1998; Revised: 30 December 1998; Accepted: 2 April 1999     

64层螺旋CT结合多平面重建诊断早期胃癌的价值

目的探讨64层螺旋CT横断位结合多平面重建（MPR）对早期胃癌的检出价值。方法回顾性分析30例经病理证实的早期胃癌的CT影像特征,由2名有经验的放射诊断医师分别评估轴位及MPR重建图像对早期胃癌的检出率,意见不同时通过协商达成一致。结果30例患者中,轴位图像检出18例,其检出率18／30;结合MPR图像检出26例,检出率26／30,两者之间的检出率差异有统计学意义（P=0．020）;单纯CT横断位图像T分期准确性为26．67％（8／30）,结合MPR图像T分期准确性为63％（19／30）,两者比较差异有统计学意义（χ2=8．148,P=0．004）。结论64层螺旋CT横断位结合MPR图像能提高早期胃癌的检出率及术前分期的准确性。     

Evaluation of the longitudinal tumor extent of bile duct cancer: value of adding gadolinium-enhanced dynamic imaging to unenhanced images and magnetic resonance cholangiography

OBJECTIVE: To determine the added value of gadolinium-enhanced dynamic magnetic resonance (MR) images compared with unenhanced and MR cholangiography (MRC) images, to evaluate the longitudinal extension of bile duct cancer. MATERIALS AND METHOD: Thirty-three patients with hilar cholangiocarcinoma or common duct cancer who had undergone MRC, unenhanced, and gadolinium-enhanced dynamic MR images and surgery were included in this study. Two experienced radiologists independently reviewed 2 image sets in 2 steps, that is, the MRC set (unenhanced and MRC) and the combined image set (MRC set with dynamic images). At each step, the readers determined the tumor status according to the Bismuth-Corlette classification. The readers assigned their confidence levels on a 5-point scale regarding whether the tumor involved the secondary confluence of the bile duct and the intrapancreatic common bile duct. The radiologists' diagnostic confidence of the 2 image sets was analyzed using receiver operating characteristic analysis. RESULTS: Receiver operating characteristic analysis showed higher areas under the curve values when the combined image set was interpreted (0.990 +/- 0.017 for reader 1 and 0.951 +/- 0.027 for reader 2) than when the MRC set was interpreted (0.982 +/- 0.017 for reader 1 and 0.902 +/- 0.038 for reader 2); however, the difference was not statistically significant for either reader (P > 0.05). In addition, regarding evaluation of the tumor status according to the Bismuth-Corlette classification, the overall accuracy was higher for the combined image set than for the MRC set alone, but the difference was not significant (P > 0.05). When dynamic images were added to the MRC images, interobserver agreement improved from 0.72 to 0.84. CONCLUSIONS: The addition of contrast-enhanced dynamic images to unenhanced and MRC images did not significantly improve the diagnostic accuracy for assessment of the longitudinal extent of bile duct cancer.     

Identification and characterization of focal ground-glass opacity in the lungs by high-resolution CT using thin-section multidetector helical CT: experimental study using a chest CT phantom

Purpose The aim of this study was to investigate how much the radiation dose can be reduced for the identification and characterization of focal ground-glass opacities (GGOs) by high resolution computed tomography (HRCT). Materials and methods A chest CT phantom including GGO nodules was scanned with a 40-detector CT scanner. The scanning parameters were as follows: tube voltage 120 kVp; beam collimation 32 × 1.25 mm; thickness and intervals 1.25 mm; tube current and rotation time 180, 150, 120, 90, 60, and 30 mA. 180 mA was the standard. Using a three-point scale at different currents, we visually evaluated image quality. Furthermore, we carried out observer performance tests using receiver operating characteristic (ROC) analysis to evaluate the ability to identify GGO nodules at each current. Results By visual analysis, the scores for all particulars were significantly lower on images obtained at less than 120 mA than at 180 mA (Steel’s test, P < 0.05). There was no statistically significant difference in any particulars other than artifact on images obtained at 180, 150, and 120 mA. By ROC analysis there was no statistical difference in the Az value to identify GGO nodules on images obtained at 180, 150, 120, 90, or 60 mA. However, the Az value at 30 mA was significantly lower than at 180 mA (Dunnett’s test, P < 0.01). Conclusion The minimum current necessary for the characterization of GGO nodules on HRCT was 120 mA, although their identification was possible at currents of >30 mA.