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Purpose: To determine the feasibility of pre-TACE IVIM imaging based on histogram analysis for predicting prognosis in the treatment of unresectable hepatocellular carcinoma (HCC).Materials and Methods: Fifty-five patients prospectively underwent 1.5T MRI 1 week before TACE. Histogram metrics for IVIM parameters and ADCs maps between responders and non-responders with mRECIST assessment were compared. Kaplan-Meier, log-rank tests and Cox proportional hazard regression model were used to correlate variables with time to progression (TTP).Results: Mean (p = 0.022), median (p = 0.043), and 25th percentile (p < 0.001) of perfusion fraction (PF), mean (p < 0.001), median (p < 0.001), 25th percentile (p < 0.001) and 75th percentile (p = 0.001) of ADC(0,500), mean (p = 0.005), median (p = 0.008) and 25th percentile (p = 0.039) of ADCtotal were higher, while skewness and kurtosis of PF (p = 0.001, p = 0.005, respectively), kurtosis of ADC(0,500) and ADCtotal (p = 0.005, p = 0.001, respectively) were lower in responders compared to non-responders. Multivariable analysis demonstrated that mRECIST was associated with TTP independently, and kurtosis of ADCtotal had the best predictive performance for disease progression.Conclusion: Pre-TACE kurtosis of ADCtotal is the best independent predictor for TTP.Key Points: • mRECIST was associated with TTP independently. • Lower kurtosis and higher mean for ADCs tend to have good response. • Pre-TACE kurtosis of ADC total is the best independent predictor for TTP. [ABSTRACT FROM AUTHOR]

Background: Three-dimensional (3D) whole-liver perfusion magnetic resonance (MR) imaging with parallel imaging, a novel imaging method to characterize tumor vascularization in vivo, has recently been applied to comprehensively image perfusion changes in large tumors. Coupled with new perfusion software, this technique enables motion correction, registration, and evaluation of perfusion MR parameters. The purpose of this study was to assess the feasibility of 3D whole-liver perfusion MR, for imaging hepatocellular carcinoma (HCC) and colorectal hepatic metastases (CRHM).Methods: 26 patients with hepatic tumors (10 HCC; 16 CRHM) were subjected to 3D whole-liver perfusion MR with a temporal resolution of 3.7 seconds. The following estimated perfusion parameters were measured: the volume transfer constant K(trans) (min(-1)); the volume (V(e)) of extravascular extracellular space (EES) per volume unit of tissue; and the flux rate constant between EES and plasma K(ep) (min(-1)). Statistical analysis was conducted to investigate inter-observer characteristics and significance of the measured parameters.Results: Inter-observer agreement analysis (95% limits of agreement) yielded a mean difference of -0.0048 min(-1) (-0.0598 ~ 0.0502) for K(trans), -0.0630 ml (-0.5405 ~ 0.4145) for V(e), and -0.0031 min(-1) (-0.0771 ~ 0.0709) for K(ep) respectively. When comparing images from patients with HCC vs. CRHM, significant differences were seen for the mean K(trans) (p = 0.017), but not for V(e) (p = 0.117) or K(ep) (p = 0.595).Conclusion: Herein we show that 3D whole-liver MR perfusion imaging with semi-automatic data analysis is feasible and enables the reliable quantitative evaluation of the perfusion parameters for HCCs and CRHMs. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To evaluate the clinical value of diffusion-weighted imaging (DWI) in combination with T2-weighted imaging (T2WI) for the detection of rectal cancer as compared with T2WI alone. Materials and methods: Forty-five patients with rectal cancer and 20 without rectal cancer underwent DWI with parallel imaging and T2WI on a 1.5T scanner. Images were independently reviewed by two readers blinded to the results to determine the detectability of rectal cancer. The detectability of T2W imaging without and with DW imaging was assessed by means of receiver operating characteristic analysis. The interobserver agreement between the two readers was calculated with kappa statistics. Results: The ROC analysis showed that each of two readers achieved more accurate results with T2W imaging combined with DW imaging than with T2W imaging alone significantly. The A z values for the two readers for each T2WI and T2WI combined with DWI were 0.918 versus 0.991 (p =0.0494), 0.934 versus 0.997 (p =0.0475), respectively. The values of kappa were 0.934 for T2WI and 0.948 for T2WI combined with DWI between the two readers. Conclusion: The addition of DW imaging to conventional T2W imaging provides better detection of rectal cancer. [Copyright &y& Elsevier]

Purpose: Our purpose was to demonstrate the prognostic significance of T1 mapping on gadoxetic acid-enhanced MR imaging in prediction of recurrence of single HCC after hepatectomy.Materials and Methods: One hundred and seven patients with single nodular HCC (≤3 cm) who underwent preoperative gadoxetic acid-enhanced MRI were included in the study. T1 mapping with syngo MapIt was obtained on a 1.5 T scanner. Radiological features and reduction rate of T1 relaxation time (Δ%) of tumors were assessed by two radiologists. Cumulative recurrence rates were compared between groups of low and high reduction rate of T1 relaxation time. A further classified cumulative recurrence rate of the overall cohort was based on the numbers of independent predictive factors.Results: Reduction rate of T1 relaxation time (P = 0.001) and non-hypervascular hypointense nodules (P = 0.042) in preoperative gadoxetic acid-enhanced MRI were independently related to recurrence of HCC after hepatectomy. Patients of lower reduction rates group had higher cumulative recurrence rates (P < 0.0001) than patients of higher reduction rates group. A combination of the two risk factors in patients with single HCC had significantly higher recurrence rates compared to those with either or none of the two risk factors.Conclusions: Reduction rate of T1 relaxation time combined with non-hypervascular hypointense nodules can be reliable biomarkers in the preoperative prediction of recurrence of HCC after hepatectomy. [ABSTRACT FROM AUTHOR]

Purpose: To determine the feasibility of pre-TACE IVIM imaging based on histogram analysis for predicting prognosis in the treatment of unresectable hepatocellular carcinoma (HCC)., Materials and Methods: Fifty-five patients prospectively underwent 1.5T MRI 1 week before TACE. Histogram metrics for IVIM parameters and ADCs maps between responders and non-responders with mRECIST assessment were compared. Kaplan-Meier, log-rank tests and Cox proportional hazard regression model were used to correlate variables with time to progression (TTP)., Results: Mean (p = 0.022), median (p = 0.043), and 25 th percentile (p < 0.001) of perfusion fraction (PF), mean (p < 0.001), median (p < 0.001), 25 th percentile (p < 0.001) and 75 th percentile (p = 0.001) of ADC (0,500) , mean (p = 0.005), median (p = 0.008) and 25 th percentile (p = 0.039) of ADC total were higher, while skewness and kurtosis of PF (p = 0.001, p = 0.005, respectively), kurtosis of ADC (0,500) and ADC total (p = 0.005, p = 0.001, respectively) were lower in responders compared to non-responders. Multivariable analysis demonstrated that mRECIST was associated with TTP independently, and kurtosis of ADC total had the best predictive performance for disease progression., Conclusion: Pre-TACE kurtosis of ADC total is the best independent predictor for TTP., Key Points: • mRECIST was associated with TTP independently. • Lower kurtosis and higher mean for ADCs tend to have good response. • Pre-TACE kurtosis of ADC total is the best independent predictor for TTP.

Aim: To compare differences between volumetric interpolated breath-hold examination (VIBE) using two-point Dixon fat-water separation (Dixon-VIBE) and chemically selective fat saturation (FS-VIBE) with magnetic resonance imaging examination., Methods: Forty-nine patients were included, who were scanned with two VIBE sequences (Dixon-VIBE and FS-VIBE) in hepatobiliary phase after gadoxetic acid administration. Subjective evaluations including sharpness of tumor, sharpness of vessels, strength and homogeneity of fat suppression, and artifacts that were scored using a 4-point scale. The liver-to-lesion contrast was also calculated and compared., Results: Dixon-VIBE with water reconstruction had significantly higher subjective scores than FS-VIBE in strength and homogeneity of fat suppression (< 0.0001) but lower scores in sharpness of tumor (P < 0.0001), sharpness of vessels (P = 0.0001), and artifacts (P = 0.034). The liver-to-lesion contrast on Dixon-VIBE images was significantly lower than that on FS-VIBE (16.6% ± 9.4% vs 23.9% ± 12.1%, P = 0.0001)., Conclusion: Dixon-VIBE provides stronger and more homogenous fat suppression than FS-VIBE, while has lower clarity of focal liver lesions in hepatobiliary phase after gadoxetic acid administration.

Objective: The purpose of our study was to assess the impact of sublingual nitroglycerin (NTG) spray on free-breathing 3D whole-heart coronary MR angiography (MRA)., Subjects and Methods: We compared the timing parameters; measured the lumen diameter of the major coronary arteries; calculated coronary vasodilation, apparent signal-to-noise ratio (SNR), and apparent contrast-to-noise ratio (CNR); and evaluated the image quality on pre- and post-NTG coronary MRA in 15 volunteers. Statistical analysis was performed with p value less than 0.05 considered significant., Results: The mean trigger delay and optimal acquisition window were shortened significantly and the mean scanning time was prolonged statistically after NTG administration. There was no significant alteration in terms of apparent SNR and apparent CNR. The lumen diameters were significantly larger in coronary MRA post-NTG than in that of pre-NTG, with an average 25.35% +/- 6.51% (SD) increase, and the left circumflex coronary artery (LCX) had slightly lower vasodilation in comparison with the right coronary artery. Image quality scores of 53 (39.3%, 53/135) segments were increased and 15 segments (11.1%, 15/135) decreased after NTG administration, and the remaining 67 segments (49.6%, 67/135) were unchanged., Conclusion: In general, sublingual NTG is useful for improving visualization of the coronary artery lumen and alleviating the impact of artifact. However, several alterations and disadvantages should be taken into consideration in view of the disturbed assessment of vasodilatory response in the LCX and the impaired quality in a minority of segments after NTG administration. Further studies are needed to evaluate the effect of beta-blockade on eliminating the disadvantages of sublingual NTG.

Objective: To evaluate the clinical practical value of apparent diffusion coefficient (ADC) measurements based on diffusion-weighted MR imaging (DWI) for quantification of liver fibrosis and inflammation for hepatitis viral infection., Methods: Diffusion-weighted MRI with parallel imaging was prospectively performed on 85 patients with chronic hepatitis and on 22 healthy volunteers within a single breath-hold using a single-shot spin-echo echo-planar sequence at b values of 100, 300, 500, 800 and 1000 s/mm2 respectively. ADC values of liver were measured with five different b values. The inflammation grades and fibrosis stages were evaluated histologically by biopsy. One-way analysis of variance and Spearman' s rank correlation test were used for statistical analysis. Receiver operating characteristics analysis was used to assess the performance of ADC in predicting the presence of stage > or = 2 and stage > or = 3 hepatic fibrosis, and grade > or = 1 hepatic inflammation., Results: There was moderate negative correlation between hepatic ADC values and fibrosis stage. And the best correlation was obtained for a b value of 800 s/mm2 (r = -0.697, P = 0. 000). At all b values there was a significant decrease in hepatic ADC in patients with stage < or = 1 versus stage > or = 2 fibrosis and stage < or = 2 versus stage > or = 3 fibrosis (P < 0.05). Hepatic ADC was a significant predictor of stage > or = 2 and > or = 3 fibrosis. The areas under the curve were 0.909 vs 0.917, sensitivity 76.6% vs 80.0% and specificity 88.3% vs 91.5% (ADC with a b value of 800 s/mm2, 1.26 x 10(-3) mm2/s or less and 1.19 x 10(-3) mm2/s or less). There was weak to moderate negative correlation between ADCs and inflammation grade. Hepatic ADC was a significant predictor of grade > 1 inflammation with an area under the curve of 0.781, sensitivity of 60.0% and specificity of 86.4% (ADC with a b value of 500 s/mm2, 1.54 x 10(-3) mm2/s or less)., Conclusion: The DWI measurement of hepatic ADC can be used to quantify liver fibrosis and inflammation. It will be a new approach for early diagnosis and therapeutic follow-up of hepatic fibrosis.

Objective: To evaluate the added value of single breath-hold diffusion-weighted imaging (DWI) in detection of small HCC lesions (

Objective: To prospectively analyze the correlation of MRI image characteristics with histopathological findings in pancreatic head carcinoma in vivo and ex vivo., Methods: Sixteen patients with pancreatic head carcinoma were examined by 1.5T MRI. MR sequences included pre-and post-contrast dynamic 2D FLASH T1WI, TSE T2WI + fat suppressed (FS). All fresh specimens were scanned again within an hour after resection during the Whipple procedure, and were then cut into slices along the direction of MRI scan. The MRI image characteristics were compared with gross and histopathologic findings of the specimens., Results: The tumor size ranged from 1.5 cm x 2.0 cm to 4.8 cm x 4.2 cm with a mean value of 3.6 cm x 3.1 cm. The MRI findings in vivo showed hypointensity in 14 lesions and isointensity in 2, and on 2D FLASH T1WI and TSE T2WI, all lesions displayed mixed intensity except 3 lesions with iso-intensity. During post-contrast dynamic pancreatic parenchymal phase, 15 lesions showed mild enhancement and 11 lesions had ring enhancement sign. Nine lesions displayed progressive irregular moderate enhancement during post-contrast dynamic hepatic phase. Four lesions showed enhancement with iso- and hyperintensity in post-contrast dynamic delayed phase. The MRI findings demonstrated that all lesions ex vivo had hypointensity on 2D FLASH T1 WI and mixed intensity on TSE T2WI + FS. Tumor tissues mainly displayed hypointensity, and the area containing tumor and inflammatory tissue showed iso-intensity on 2D FLASH T1WI. On T2WI + FS, the fibrosis proportion displayed hypo or isointensity, while the tumor and chronic inflammatory tissue demonstrated slight hyperintensity, and the zones of mucous degeneration or pancreatic ductal dilatation displayed hyper-intensity. The ring enhancement of tumor was caused by multiple factors and no obvious enhancement within tumor and fibrosis area were observed during post-contrast dynamic pancreatic parenchymal phase. Progressive irregular enhancement originated from desmoplastic reaction within the tumor during post-contrast dynamic hepatic phase and delayed phase, respectively., Conclusion: Pancreatic head carcinomas contain various kinds of tissues. MRI can reveal these pathologic characteristics. No obvious hemorrhage and necrosis within the tumor were observed in this series.

Objective: To investigate the role of MRI in evaluating the peripancreatic vessel invasion and resectability of pancreatic carcinoma based on the comparison of MRI image with surgical exploration, and try to establish the criteria for assessment of the sensitivity, specificity and accuracy of resectability., Methods: Forty-one pancreatic carcinoma patients confirmed by pathology received preoperative plain and contrast enhanced MRI scan, and 37 of them had additional coronal MRA scan. Peripancreatic vessel invasion was preoperatively assessed based on MRI features, and the vessel invasion degree from the uninvolved to the severely involved was divided into 6 grades represented by 1, 2a, 2b, 3a, 3b and 4, respectively. Compared with the findings during the surgery, the sensitivity and specificity of each vessel invasion grade were studied and the receiver operator characteristic curve (ROC) was drawn. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of resectability evaluation based on 2 and 2a degree were calculated respectively. The resectability of involved arteries and veins of grade 2 were also analyzed., Results: Of the 41 patients, 22 had resectable tumor, with 20 curative resection and 2 palliative. Compared with the findings during surgery, seven vessels including three arteries and four veins were not correctly interpreted by MRI. If grade 1,2a,2b,3a and 3b was used as the resectable standard,respectively, the sensitivity to predict the unresectbility was 78.3%, 84.8%, 67.4%, 56.5% and 47.8%, respectively. Receiver operator characteristic curve demonstrated that grade 2a was the optimal critical point. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of grade 2a in predicting the unresectbility were 84.8%, 98.5%, 92.9%, 96.6% and 95.9%., Conclusion: Our data showed that grade 2a (tumor involvement < 2 cm long and < 1/2 circumference of the vessel) may be more sensitive and accurate in predicting the resectability, which may be considered as the line of demarcation between the respectable and unresectable cases in clinical practice.

Aim: To evaluate the efficacy of ferucarbotran-enhanced MR imaging in the detection of focal hepatic lesions compared to plain and Gd-DTPA-enhanced MR imaging., Methods: Fifty-nine patients with suspected focal hepatic lesions were admitted to the study. Plain MR imaging (FSE T(2)WI with fat suppression and GRE T(1)WI sequences) and Gd-DTPA dynamic enhanced MR of the liver were initially performed followed by ferucarbotran-enhanced MR imaging 48 h later (including GRE T(1)WI, FSE T(2)WI with fat suppression, and GRE T(2)WI sequences). Images were reviewed independently by three observers. Results were correlated with surgery and pathologic examination or reference examination, and sensitivity was statistically calculated for the different MR imaging sequences., Results: Among all confirmed lesions (n = 133), ferucarbotran-enhanced MR imaging revealed 130 lesions on FSE T(2)WI with fat suppression, 115 lesions on dynamic T(1)WI GRE, and 127 lesions on GRE T(2)WI. Pre-contrast MR imaging revealed only 84 lesions on GRE T(1)WI and 106 lesions on FSE T(2)WI with fat suppression, while Gd-DTPA dynamic enhanced GRE T(1)WI revealed 123 lesions. For 44 micro-lesions (< 1.0 cm) in all patients the detection rates were as follows: ferucarbotran-enhanced FSE T(2)WI with fat suppression, 93.2% (41/44); ferucarbotran-enhanced GRE T(2)WI, 88.6% (39/44); Gd-DTPA dynamic-enhanced GRE T(1)WI, 79.5% (35/44); pre-contrast FSE T(2)WI with fat suppression, 54.5% (24/44); and pre-contrast GRE T(1)WI, 34.1% (15/44). In detecting micro-lesions, statistically significant difference was found for Ferucarbotran-enhanced FSE T(2)WI with fat suppression and GRE T(2)WI sequences compared to the other sequences (P < 0.05)., Conclusion: Ferucarbotran-enhanced FSE T(2)WI with fat suppression and GRE T(2)WI sequences are superior in detecting micro-lesions (< 1 cm) in comparison with plain and Gd-DTPA dynamic-enhanced MR imaging.

Aim: To determine the accuracy of high-resolution magnetic resonance imaging (MRI) using phased-array coil for preoperative assessment of T staging and mesorectal fascia infiltration in rectal cancer with rectal distention., Methods: In a prospective study of 67 patients with primary rectal cancer, high-resolution magnetic resonance imaging (in-plane resolution, 0.66 multiply 0.56) with phased-array coil were performed for T-staging and measurement of distance between the tumor and the mesorectal fascia. The assessment of MRI was compared with postoperative histopathologic findings. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were evaluated., Results: The overall magnetic resonance accuracy was 85.1% for T staging and 88% for predicting mesorectal fascia involvement. Magnetic resonance sensitivity, specificity, accuracy, positive predictive value, and negative predictive value was 70%, 97.9%, 89.6%, 93.3% and 88.5% for

Objective: To evaluate various kinds of sequences and modified dynamic contrast-enhanced MRI methods in the diagnosis of pancreatic carcinoma., Methods: Forty-nine pancreatic carcinoma patients proved by histopathology or clinical examination and follow-up underwent MR examination. Plain MR sequences included: T1-weighted 2D FLASH, T1 WI 3D VIBE, TSE T2 WI and HASTE with FS. Modified dynamic contrast-enhanced scanning procedures were coronal scaning with 3D FLASH and axial scaning using T1 WI 3D VIBE sequences in turn for the upper abdominal area and pancreatic area. The coronal imaging were used to obtain 3D peripancreatic vessels during arterial phase and portal vein phase scanning, respectively. The axial imaging were used to detect the tumor in pancreatic parenchymal phase and delayed phase scanning, respectively. Final scanning for the whole upper abdomen was performed using T1 WI 2D FLASH axial sequence., Results: (1) Of 49 lesions in these patients, 45 showed hypo-intensity and 4 iso-intensity on 3D VIBE. Forty-six lesions showed hypo-intensity and 3 isointensity on 2D FLASH. On TSE T2 + FS, lesion contour was not clear enough; 3 of them displayed isointensity, the other showed iso- or hyper-intensity. (2) During pancreatic parenchymal phase, 48 lesions showed hypo-intensity and 39 ring enhancement. Twenty-four lesions displayed marginal tubercle and inner compartment enhancement during portal vein and delayed phase. Six lesions showed iso- or hyper-intensity in delayed phase. (3) Thirty-seven patients underwent surgical exploration. MRI and MRA had a good correlation with surgical findings for peripancreatic vessels which were diagnosed as being invasive or noninvasive by tumors except three superior mesenteric arteries and four superior mesenteric veins being misdiagnosed., Conclusion: As"one-stop-shop" MRI examination, modified MRI sequences consisting of dynamic coronal and axial contrast-enhanced scanning is feasible and helpful in diagnosing, staging and assessing the resectability for pancreatic carcinoma.

Objective: To evaluate the value of MR dynamic Gadolinium-enhanced fast multiplanar spoiled gradient-echo (FMPSPGR) and spin-echo (SE) T1-weighted fat-suppressed techniques in the diagnosis of pancreatic carcinoma., Methods: Eighteen cases of pancreatic carcinoma verified by surgical and pathologic results were examined by MR, and the MR sequences included SE T1WI, FSE T2WI, SE T1-weighted fat-suppressed and dynamic Gadolinium-enhanced FMPSPGR., Results: Of 18 pancreatic carcinomas, 10, 6, and 2 tumors showed respectively hypo-intensity, iso-intensity and hyper-intensity on SE T1WI, meanwhile, 8, 6, and 4 tumors displayed hyper-intensity, iso-intensity and hypo-intensity on FSE T2WI in comparison with the normal pancreatic tissue. All of the tumors showed hypo-intensity on SE T1-weighted fat-suppressed and also obvious non-enhancement or slight enhancement on MR dynamic Gadolinium-enhanced FMPSPGR images during the arterial dominant phase scanning., Conclusion: SE T1-weighted fat-suppressed and MR dynamic Gadolinium-enhanced FMPSPGR sequences could evidently improve the sensitivity and specificity in the diagnosis of pancreatic carcinoma.

Aim: To evaluate the value of superparamagnetic iron oxide (SPIO) enhanced MRI in characterizing focal hepatic lesions., Methods: Forty-three patients (32 men,11 women, mean age 51 years, age range 25-74 years) with previously identified focal hepatic lesions were enrolled into this study. All the patients underwent plain, Gd-DTPA enhanced MRI and the SPIO enhanced MRI 1-7 d later. The surgico-pathologic diagnosis was aestablished in 31 cases and the diagnosis in other 12 cases was made on the basis of clinical findings and biochemical tests. The signal changes of lesions were analyzed and the CNRs of lesion-to-liver were measured before and after SPIO enhancement. The data were analyzed by paired t test., Results: Focal hepatic lesions included primary hepatocellular carcinoma (HCC,n=22), hemangioma (n=5), cyst (n=4), metastases (n=5), cirrhotic nodule (n=4), focal nodular hyperplasia (FNH, n=5) and other miscellaneous lesions (n=6). After SPIO enhancement HCC demonstrated iso- or slight hyperintensity on T1WI and moderate hyperintersity on T2WI, hemangioma showed moderate hyperintensity on T1WI and obvious hyperintensity on T2WI, the SI of cyst had no change either on T1WI or on T2WI, cirrhotic nodules revealed iso-intensity on T2WI, and the SI of FNH decreased significantly on T2WI. No specific manifestations were found in the other 6 miscellaneous lesions after SPIO enhancement., Conclusion: SPIO enhanced-MRI can improve the characterization confidence for diagnosis of focal hepatic lesions.