Preliminary study on MR colonography with air enema in detection of colorectal neoplasms / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The few studies on MR colonography with air enema involved feasibility of bowel distention and imaging quality and lacked detection sensitivity of colorectal neoplasms. The purpose of this prospective study was to assess the detection sensitivity of colorectal neoplasms with the three-dimensional Fourier transform fast spoiled gradient-recalled MR colonography with air enema.</p><p><b>METHODS</b>A total of 30 patients scheduled for optical colonoscopy due to rectal bleeding, positive fecal occult blood test results or altered bowel habits were recruited and successfully underwent entire colorectal examinations with three-dimensional Fourier transform fast spoiled gradient-recalled MR colonography and subsequent optical colonoscopy on the same day. Detection sensitivity of colorectal neoplasms with MR colonography was statistically analyzed on a per-neoplasm size basis by using findings from optical colonoscopy and histopathological examinations as the reference standards.</p><p><b>RESULTS</b>Seventy-six neoplasms were detected with optical colonoscopy, consisting of 1 mm-5 mm (n = 11), 6 mm-9 mm (n = 29) and ≥ 10 mm (n = 36) in diameter. Detection sensitivities of 1 mm-5 mm, 6 mm-9 mm, ≥ 10 mm and ≥ 6 mm colorectal neoplasms with MR colonography were 9.1%, 75.9%, 100% and 89.2%, respectively; overall detection sensitivity for all sizes colorectal neoplasms was 77.6%.</p><p><b>CONCLUSIONS</b>Detection sensitivity of three-dimensional Fourier transform fast spoiled gradient-recalled MR colonography with air enema is low for 1 mm-5 mm colorectal neoplasms, but the detection sensitivity is 89.2% for ≥ 6 mm neoplasms, and all ≥ 10 mm neoplasms could be detected.</p>

Comparison of MRI manifestations and histopathologic findings in pancreatic head carcinoma in vivo ex vivo / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To prospectively analyze the correlation of MRI image characteristics with histopathological findings in pancreatic head carcinoma in vivo and ex vivo.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

A comparative study of MRI manifestations and pathological changes in hepatocellular carcinoma treated by transcatheter arterial chemoembolization with lipiodol / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To analyze the MRI manifestations and pathological changes of hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE) with lipiodol.</p><p><b>METHODS</b>23 patients with 31 HCC lesions treated by TACE underwent MRI examination within 1 week before their surgical resections. MRI was performed with SE sequence (T1WI and FSE T2WI) and FMPSPGR sequence dynamic multi-phase contrast scans. All resected specimens were cut into 5-10mm thick slices, corresponding to the same plane as that of MRI scans. The specimens were wholly embedded in paraffin, serial sections made and stained with hematoxylin and eosin. The MRI findings were thus compared with the pathology of the specimen sections.</p><p><b>RESULTS</b>(1) MRI findings: In all 31 lesions, the signal intensity of lesions varied and was mostly heterogeneous on SE T1WI and T2WI images. Three lesions were inhomogeneous hyper-intensity and the other 28 lesions were iso- or hypo-intensity on FMPSPGR plain scannings. Twenty-two lesions were enhanced on early-phase dynamic scanning, and no enhancement was found in the other 9 lesions. Partial enhancement was also seen in 6 lesions on delay-phase dynamic scanning. (2) Pathologically, no coagulation necrosis was found in 2 specimens, but 6 lesions showed complete coagulation necrosis and 23 showed various degrees of it. The other pathological changes found included intra-tumoral hemorrhage (n=10), intra-lesional fibrotic septa formation (n=5), capsule-like fibrotic tissue proliferation around the lesions (n=12), inflammatory infiltration (n=28), focal mucoid degeneration (n=2), focal hyaline degeneration (n=2), and lipiodol retention (n=6). (3) Radiological-pathological correlation study: hyper-intense areas on T1WI corresponded to areas of coagulation necrosis with or without hemorrhage and of residual viable tumor; iso- and hypo-intense corresponded to areas of coagulation necrosis or residual viable tumor. Hyper-intense areas on T2WI corresponded to those of residual viable tumor or coagulation necrosis with hemorrhage, and iso-intense areas corresponded to those of coagulation necrosis, small residual viable tumor or intra-lesional fibrotic septa formation, and hypo-intense areas corresponded to those of coagulation necrosis or intra-lesional fibrotic septa formation. Areas of enhancement within the lesions on the early-phase dynamic-contrast images corresponded to areas of residual viable tumors, while areas of no enhancement were those of coagulation necrosis, hemorrhage, intra-lesional fibrotic septa formation or small residual viable tumors. Areas of enhancement on the delay-phase dynamic scanning were those of residual viable tumors or intra-lesional fibrotic septa formation, while no enhancement corresponded to the areas of residual viable tumors, coagulation necrosis, and hemorrhage. Areas of enhancement on the delay-phase dynamic scanning corresponded to those areas of fibrosis tissue or residual viable tumors. Inflammatory infiltration was found in areas of different signal intensity on MRI images.</p><p><b>CONCLUSIONS</b>(1) Different pathological changes in HCCs after TACE are represented by various signal intensities on SE sequence images. The only area of hypo-intensity on T2WI has a specificity in representing coagulation necrosis. (2) FMPSPGR sequence dynamic MRI is superior to SE sequence in demonstrating and determining the necrosis and residual viable tumor. Enhanced areas within the lesions on the early-phase dynamic-contrast images represent residual viable tumors and the enhancement of capsule on early-phase dynamic-contrast images also represent subcapsular residual viable tumors. (3) MRI can demonstrate accurately the areas of necrosis and residual viable HCC tissues after TACE and evaluate the effect of TACE.</p>

The value of high-resolution contrast-enhanced three-dimensional magnetic resonance angiography in the evaluation of hepatic arterial anatomy / 中华放射学杂志

Objective Compared with digital subtraction angiography(DSA),to evaluate the value of high-resolution contrast-enhanced three-dimensional magnetic resonance angiography(3D MRA) in defining hepatic arterial anatomy.Methods The data about abdominal high-resolution contrast-enhanced 3D MRA and DSA of 26 patients (24 patients with primary liver cancer,2 patients with metastatic liver tumor) was retrospectively analyzed.The display quality of different segmental hepatic artery was scored with 4 grades and the agreement between high-resolution 3D MRA and DSA was determined with the weighted Kappa statistic.The depiction of hepatic arterial anatomy/anomalies and vascular pathology on high- resolution 3D MRA was assessed and compared with DSA.Results With respect to display quality,there was good or fair correlation between high-resolution 3D MRA and DSA for the common hepatic artery (the mean score respectively was 3.96,3.96 and Kappa value 0.99),gastroduodenal artery (the mean score respectively 3.85,3.88 and Kappa value 0.85 ),right hepatic artery(the mean score respectively 3.92, 3.96 and Kappa value 0.65 ),left hepatic artery (the mean score respectively 3.77,3.92 and Kappa value 0.43 ),left gastric artery(the mean score respectively 3.73,3.85 and Kappa value 0.43 ),right anterior artery (the mean score respectively 3.35,3.70 and Kappa value 0.53),right posterior artery (the mean score respectively 3.31,3.73 and Kappa value 0.46)and 1V segment artery (the mean score respectively 2.92,3.46 and Kappa value 0.51 );Poor correlation was found for the Ⅱsegment artery (the mean score respectively 2.15,3.35 and Kappa value 0.18)and Ⅲsegment artery (the mean score respectively 2.19, 3.35 and Kappa value 0.21 ).Compared with DSA,18 normal hepatic arterial anatomy and 7 arterial anomalies were accurately demonstrated(accuracy ratio 96.1% (25/26)),the obliteration of gastroduodenal artery correctly depicted in 1 patient on high-resolution 3D MRA image.Conclusions High-resolution 3D MRA can provide accurate evaluation of hepatic artery and has the capacity of depicting hepatic segment artery.

The comparative study of diffusion-weighted MR imaging with modified sensitivity encoding technique for small hepatocellular carcinoma lesions / 中华放射学杂志

Objective To prospectively evaluate whether DWI with mSENSE(mSENSE-DW1)can help to improve image quality and affect the calculation of lesion's ADC,compared with DWI with conventional phase encoding(conventional DWI)in patients with small HCC lesions.Methods Thirty-two patients with 47 small HCC lesions underwent single-shot spin-echo echo-planar.(SE-EPI)DWI with conventional phase encoding and mSENSE.Three b values of 300,500 and 800 s/mm~2 were used.Image quality and CNR between conventional DWI and mSENSE-DWI group were compared with different b value. Lesion's ADC were also calculated and compared.Matched-pairs Wilcoxon signed rank test and Friedman test were used to test statistical significance.Results The image quality was assessed with a five-point scale.For conventional DWI group,image quality score of 2 was assigned in 5 cases,score of 3 in 24 cases, score of 4 in remaining 3 eases with b=300 s/mm~2,score of 2 in 9 eases,score of 3 in 22 cases,score of 4 in remainingl cases with b=500 s/mm~2,score of 1 in 2 cases,score of 2 in 24 cases,score of 3 in remaining 6 cases with b=800 s/mm~2.For mSENSE-DWI group,image quality score of 3 was assigned in 4 cases,score of 4 in 25 cases,score of 5 in 3 eases with b=300 s/mm~2,score of 3 in 10 cases,score of 4 in 20 cases,score of 5 in remaining 2 cases with b=500 s/mm~2,score of 2 in 7 cases,score of 3 in 23 eases, score of 4 in remaining 2 cases with b=800 s/mm~2.Higher image quality scores were achieved at mSENSE- DWI group than conventional DWI group(Z=-5.578,-5.488,-4.796 respectively,P

Imaging diagnosis of solid psedopapillary tumor of pancreas / 中华放射学杂志

Objective To retrospectively analyze and conclude the characteristics of imaging appearances of solid psedopapillary tumor of pancreas.Methods Among 7 cases with pathologically proved solid psedopapillary tumor of pancreas,6 cases underwent CT examinations of upper abdomen preoperatively,and the rest One had MRI examination.The mean age of these 7 cases(all female)was 30.7 years(range,14—44 years).Results The tumors were usually quite large in the largest diameter ranged from 2.8 to 15.9cm(mean largest diameter,7.9 cm);Tumors were all well demarcated,and 5 of them were of capsule on CT or MR imaging.All tumors were well-encapsulated on pathologic specimens, except for the capsule of 1 tumor was partially invaded;In 6 cases underwent CT examination,scattered, punctate and linear calcification were noted in the capsule of 2 tumors and the rim of another one;Except for 1 tumor was almost solid,the other 6 tumors contained both solid and cystic components;Scattered sheets of high attenuation shown in the cystic or solid parts on CT imaging in several cases and the high signal intensity on T_1-weighted MR imaging signified the possibility of bleeding in tumors,which then was testified by pathologic evaluation.Conclusion The solid psedopapillary tumor of pancreas has comparatively characteristic clinical and imaging features.

Initial experience of demonstrating hepatic artery in orthotopic liver transplanation candidates using high resolution contrast-enhanced MR angiography accelearated by generalized autocalibrating partial parallel acquisition / 中华放射学杂志

0.75).The distal branch of hepatic right/left artery were well delineated in 39 patients(scored 4),hepatic right/left artery in 23 patients(scored 3),proper hepatic artery in 4 patients(scored 2)and hepatic common artery in 1 patients(scored 1).The average score was 3.49.Fifty three cases with normal hepatic arterial anatomy and 14 cases with anomalies were accurately detected on high-resolution MRA images.Conclusion High- resolution contrast-enhanced MRA accelerated by GRAPPA could delineate the hepatic artery accurately.