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OBJECTIVE. The purpose of this study was to assess whether MR volumetric data on DW and T2-weighted MR images are correlated with lymphovascular invasion and lymph node metastases in resectable rectal cancer. MATERIALS AND METHODS. This retrospective study consisted of 50 consecutive patients with rectal cancer who underwent radical surgery within 1 week of MRI. The gross tumor volume was determined on both diffusion-weighted and T2-weighted MR images and correlated with pathologic lymphovascular invasion and lymph node metastases using univariate, multivariate, and ROC curve analyses. RESULTS. Both gross tumor volume values showed correlations with lymphovascular invasion ( r = 0.750 vs r = 0.710; p < 0.0001) and lymph node metastases ( r = 0.780 vs r = 0.755; p < 0.0001). Both values were associated with lymphovascular invasion and lymph node metastases in univariate analysis (all p < 0.0001), whereas only the DWI-based value was an independent risk factor for lymphovascular invasion (odds ratio = 1.207; p = 0.005) and lymph node metastases (odds ratio = 1.420; p = 0.005) in multivariate analysis. Both values could distinguish between N0 and N1, N0 and N1-N2, and N0-N1 and N2 disease (all p < 0.0001) in the Mann-Whitney U test. The area under the ROC curve was higher for the DWI-based value in lymphovascular invasion (0.899 vs 0.877), N0 vs N1 (0.865 vs 0.827), N0 vs N1-N2 (0.934 vs 0.911), and N0-N1 vs N2 (0.932 vs 0.927). CONCLUSION. Tumor volumetry data correlated with both lymphovascular invasion and lymph node metastases in resectable rectal cancer. In particular, the DWI-based gross tumor volume showed the most potential for noninvasive preoperative evaluation of lymphovascular invasion and lymph node metastases.

Kidney transplantation has emerged as the treatment of choice for many patients with end-stage renal disease, which is a significant cause of morbidity and mortality. Given the shortage of clinically available donor kidneys and the significant incidence of allograft dysfunction, a noninvasive and accurate assessment of the allograft renal function is critical for postoperative management. Prompt diagnosis of graft dysfunction facilitates clinical intervention of kidneys with salvageable function. New advances in magnetic resonance imaging (MRI) technology have enabled the calculation of various renal parameters that were previously not feasible to measure noninvasively. Diffusion-weighted imaging provides information on renal diffusion and perfusion simultaneously, with quantification by the apparent diffusion coefficient, the decrease of which reflects renal function impairment. Diffusion-tensor imaging accounts for the directionality of molecular motion and measures fractional anisotropy of the kidneys. Blood oxygen level-dependent MR evaluates intrarenal oxygen bioavailability, generating the parameter of R2* (reflecting the concentration of deoxyhemoglobin). A decrease in R2* could happen during acute rejection. MR nephro-urography/renography demonstrates structural data depicting urinary tract obstructions and functional data regarding the glomerular filtration and blood flow. MR angiography details the transplant vasculature and is particularly suitable for detecting vascular complications, with good correlation with digital subtraction angiography. Other functional MRI technologies, such as arterial spin labeling and MR spectroscopy, are showing additional promise. This review highlights MRI as a comprehensive modality to diagnose a variety of etiologies of graft dysfunction, including prerenal (e.g., renal vasculature), renal (intrinsic causes) and postrenal (e.g., obstruction of the collecting system) etiologies.

Objective: To investigate MRI features and associated histological and pathological changes of hilar and extrahepatic big bile duct cholangiocarcinoma with different morphological sub-types, and its value in differentiating between nodular cholangiocarcinoma (NCC) and intraductal growing cholangiocarcinoma (IDCC)., Methods: Imaging data of 152 patients with pathologically confirmed hilar and extrahepatic big bile duct cholangiocarcinoma were reviewed, which included 86 periductal infiltrating cholangiocarcinoma (PDCC), 55 NCC, and 11 IDCC. Imaging features of the three morphological sub-types were compared., Results: Each of the subtypes demonstrated its unique imaging features. Significant differences (P < 0.05) were found between NCC and IDCC in tumor shape, dynamic enhanced pattern, enhancement degree during equilibrium phase, multiplicity or singleness of tumor, changes in wall and lumen of bile duct at the tumor-bearing segment, dilatation of tumor upstream or downstream bile duct, and invasion of adjacent organs., Conclusion: Imaging features reveal tumor growth patterns of hilar and extrahepatic big bile duct cholangiocarcinoma. MRI united-sequences examination can accurately describe those imaging features for differentiation diagnosis.

Objective: To determine the clinical value of dual-source CT angiography (DSCTA) in the diagnosis of postoperative aortic intramural hematoma (AIMH) in patients with endovascular stent-graft exclusion (EVE) surgery., Methods: Between Oct 2008 and May 2013, thirty-six patients were diagnosed with AIMH by DSCTA, and 12 of these patients with type B underwent EVE. The 12 patients were followed up with DSCTA, which included imaging reconstruction (multi-plane reconstruction, MPR), maximum intensity projection (MIP) and volume rendering technique (VRT). The extent and type of AIMH, aortic ulcers and the outcomes and complications of AIMH were observed., Results: The 36 cases of AIMH included 11 Stanford type A and 25 type B. No tearing intimal flap or contrast materials within the hematoma were observed. The maximum aortic diameter of the hematoma areas varied from 3.8 to 5.4 cm (average 4.3 cm) and the maximum thickness of the hematoma ranged from 0.5 cm to 1.3 cm (average 0.9 cm). The ratio between the minimum and the maximum diameter of the aortic lumen in the hematoma areas ranged from 0. 74 to 0. 98 (average 0.85). Aortic ulcers were revealed in 3 patients with type A AIMH and 8 patients with type B AIMH. Intimal tearing of distal abdominal aorta was found in 3 patients with type B AIMH. In the 12 patients underwent EVE surgery, hematoma shrank in all cases with 4 cases almost resolving and aortic ulcers in the area of stent-graft exclusion disappeared in 3 cases. The form of stent-graft appeared normal in 9 cases and slightly abnormal in 3 cases. Fluent main branches of aortic arch and none existence of stent endoleaking were observed., Conclusion: DSCTA with handy, effective and non-invasive advantages is one of the important imaging methods in the diagnosis of AIMH in patients with EVE surgery.

Objective: To assess the value of sixty-four slice spiral CT angiography (CTA) in diagnosing and evaluating abdominal aortic aneurysm (AAA) before operations., Methods: Between Oct 2006 and Jan 2008, forty-three consecutive patients with suspected AAA underwent examinations by the sixty-four slice spiral CT angiography with 370 mg I/mL contrast material. Of these patients, 38 patients whose AAA imaging quality met the diagnostic criteria were enrolled in the study. Imaging reconstruction were made at the workstation, which included multi-plane reconstruction (MPR), maximum intensity projection (MIP) and volume rendering technique (VRT). The comprehensive observation and analysis focused on the type, location, size and extension of AAA. The classification of AAA was based on the relevant parameters that satisfied the requirement of endovascular stent-graft exclusion., Results: (1) The aneurysms of all of the 38 patients were located at under the level of renal arteries, including six that were adjacent to renal arteries and 32 under renal arteries. (2) Among the 38 patients with AAA, 4 were type I , 3 were type II A, 4 were type II B, 21 were type II C, and 6 were type III. (3) The sixty-four slice spiral CT angiography clearly displayed the shape, locality and size of the aneurysms, the anatomic relations between the aneurismal bodies and the adjacent main branches of aorta, and the mural thrombus in all of the patients. Relevant parameters of AAA could be accurately measured by the CTA images., Conclusion: Sixty-four slice spiral CT angiography is a fast, non-invasive and effective instrument for diagnosing and evaluating AAA before operations.

Objective: To investigate the clinical application of first-pass perfusion MDCT in the assessment of tumor angiogenesis in carcinoma of esophagus and cardia., Methods: CT perfusion was performed with multi-detector row CT (MDCT) in 44 patients with carcinoma of esophagus and esophagogastric junction, who was diagnosed with pathological results and did not received any anti-tumor therapy. Twenty-one patients with peripheral lung cancer but normal esophagus were served as controls. Perfusion parameters were compared between normal and malignant esophagus, between adenocarcinoma and squamous cell carcinoma, as well as between tumors with metastases and those without metastases., Results: Carcinoma of esophagus and esophagogastric junction showed higher blood flow, peak enhancement index, blood volume, and shorter time to peak compared with normal esophagus (P < 0.05). There were no statistically significant differences in perfusion parameters between adenocarcinoma and squamous cell carcinoma (P > 0.05), whereas tumors with metastases showed higher blood flow and shorter time to peak compared with those without metastases (P < 0.05)., Conclusion: MDCT perfusion could assess tumor vascularity in carcinoma of esophagus and esophagogastric junction, and tumor vascularity or angiogenesis was not influenced by its histological type. However, high blood flow and short time-to-peak may be helpful to predict tumor metastases.

Objective: To explore the diagnostic value of the system serial of three-dimensional spoiled gradient-echo T1-weighted MR imaging (three-dimensional volumetric interpolated breath-hold examination, 3D-VIBE) used to the preoperative assessment of hepatic portal cholangiocarcinoma., Methods: 31 surgically confirmed patients with hepatic portal cholangiocarcinoma underwent the preoperative examination through MR imaging system serial that was including T2W, two dimension (2D) T1W plain scan, 2D magnetic resonance cholangiopancreatography (MRCP), and Gadolinium-enhanced 3D-VIBE triple-phase dynamic acquisitions followed by 2D T1W scanning at the equilibrium phase. Meanwhile, it was performed for focusing on assessing or judging the tumor morphological type, the longitudinal infiltration extent of the bile duct and the involvement of neighbor blood vessels. And the 3D-VIBE was compared with 2D T1W systems for assessing or judging the tumor resectability., Results: (1) (3D-VIBE directly displayed the hepatic portal tumors and correctly classified the tumor morphological types in all patients, but 2D T1W systems missed to show 8 hepatic portal cholangiocarcinoma of periductal-infiltrating type (25. 8%); (2) According to Bismuth-Corlette classification, 3D-VIBE was closed to MRCP in accuracy (93.5%) for showing the longitudinal infiltration extent of tumor, but 2D T1W system serial underestimated (32.3%) the extent. (3) 3D-VIBE showed more involvement of the main trunk of hepatic artery, portal vein and their branches than 2D T1W systems did. (4) The positive predicting value and accuracy for assessing tumor resectability were 84.0% and 90.0% for 3D-VIBE system, as 64.0% and 71.0% for 2D T1W systems., Conclusion: 3D-VIBE system is superior to other MR imaging system serial in the preoperative assessment of the morphological type, the longitudinal infiltration extent and the tumor resectability of hepatic portal cholangiocarcinoma.