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>

CT and MRI imaging features of peripheral primitive neuroectodermal tumors / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the CT and MRI features of peripheral primitive neuroectodermal tumors (pPNETs) and evaluate its diagnostic value.</p><p><b>METHODS</b>The clinicopathological data of 9 surgically treated patients with peripheral primitive neuroectodermal tumors confirmed by pathology were collected, spiral CT (4/9) and MRI (6/9) plain scanning and dynamic enhancement scanning were performed preoperatively. Both CT and MRI scannings were performed in 1 case. Those CT and MR images were retrospectively reviewed and analyzed together with clinicopathological findings.</p><p><b>RESULTS</b>The 9 lesions were located in skeletal muscles (n = 6), pelvic cavity (n = 2) and thoracic cavity (n = 1). The tumor size was 7.4-18.3 cm in diameter with a mean diameter of 11.6 cm. The shape of those lesions was round or ellipse (4 lesions) and irregular (5 lesions). The tumor usually presented as ill-defined masses, with homogeneous (n = 2) or inhomogeneous density (n = 7). Seven cases, including the 3 lesions located in the chest and pelvis, showed obvious necrosis and multilocular cyst formation. The tumors showed iso-density as that of the adjacent muscles on CT plain scans and moderate heterogeneous enhancement after intravenous injection of contrast agents. The features of the tumors on the MRI including slightly low signal intensity on SE T1-weighted imaging, iso-signal intensity or slightly high signal intensity on FSE T2-weighted imaging and heterogeneous dynamic delayed contrast-enhancement with obvious necrosis in most of them. Six cases had a lesion in the skeletal muscles, presented as a giant ill-defined masse surrounding bone and extended along neural route with bone destruction to varying degrees.</p><p><b>CONCLUSION</b>Primitive neuroectodermal tumor is a kind of malignant tumor with proliferation of small, undifferentiated neuroectodermal cells, usually occurring in children or adolescent and frequently located in the extremities, chest cavity, pelvic cavity and chest wall. It typically presents as a large, ill-defined masse extending along neural route with heterogeneous and obvious enhancement after intravenous injection of contrast agents. The tumors located in the chest and pelvic cavities and some in the extremities show obvious necrosis and multilocular cyst formation, while some of the tumors in the extremities appear as homogeneous solid masses.</p>

Evaluation of CT diagnostic criteria for peri-pancreatic artery and vein invasion in pancreatic carcinoma / 中华肿瘤杂志

<p><b>UNLABELLED</b>OBJECTIVE; To evaluate the clinical value of different CT diagnostic criteria for peripancreatic artery and vein invasion in pancreatic carcinoma through comparison with the findings on surgical exploration.</p><p><b>METHODS</b>Of 72 patients of having suspected pancreatic carcinoma were examined by multiplane spiral CT. Among 43 confirmed by surgical pathology; 15 underwent pancreaticoduodenectomy; 28 were found to have unresectable tumors. The peri-pancreatic major vessels including the superior mesenteric artery, celiac artery, hepatic artery, superior mesenteric vein and portal vein were explored carefully during surgical exploration.</p><p><b>RESULTS</b>The criteria for peri-pancreatic artery invasion was the presence of one of the following signs: artery embeded in tumor, or more than half of the artery circumference involved by tumor with wall irregularity or stenosis. The sensitivity of the above described criteria was 75.0% (12/16). If the criteria of tumor involvement exceeding half of the vessel circumference were adhered to, the sensitivity was 87.5% (14/16), which was high than the former, but the specificity was lower than that of the former one (90.2% versus 95.1%). The criteria for peri-pancreatic vein invasion was presence of any of the following signs: vein obliteration, more than half of the vein circumference involved by tumor, vein wall irregularity, vein stenosis, tear-drop sign of superior mesenteric artery. The sensitivity of the above described criteria was 92.9% (39/42), higher than that of the criteria that more than half of the vessel circumference was involved by the tumor (69.0%, 29/42), but the specificity of both criteria was the same (97.4%, 37/38).</p><p><b>CONCLUSION</b>For assessing peri-pancreatic artery and vein invasion, using the combination of different CT diagnostic criteria has higher accuracy than when using only criteria of more than half of vessel circumference involved by tumor.</p>

Multidetector CT and high magnetic field MRI in evaluation of small cystic-solid renal mass / 上海第二医科大学学报

Objective To evaluate the role of multidetector CT(MDCT) and high magnetic field MRI in diagnosis of small cystic-solid renal mass. Methods Fifty-two cases with small renal cystic-solid mass(≤3 cm) were consecutively collected,including small cystic-solid renal cell carcinoma(n=25),carcinoid(n=1),complex cysts(n=16),small angiomyolipoma(n=7) and benign cystic nephroma(n=3).All were examined by both 1.5T MRI and multidetector CT at intervals between 3 days and 2 months. Results All cases were proved by pathology.Multi-planar reconstruction techniques were useful for MDCT in differentiating small cystic-solid renal mass,with the sensitivity of 98.1%,which was as high as MRI.However,the accuracy for MDCT was 71.2%,significantly lower than that of MRI(90.4%)(P=0.001).MRI helped to identify the components and structure of renal masses,and behaved better in the detection of pseudo-capsule of renal cell carcinoma(57.7%).Conclusion High magnetic field MRI may play an important role in the diagnosis of small renal cystic-solid masses,and it may be feasible as a noninvasive examination when CT can not make the ultimate determination.

Evaluation of early stage diffused liver lesions with MR functional diffusion-weighted imaging--an experimental study / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the value of Diffusion-Weighted Imaging (DWI) in the diagnosis of early stage liver diffuse lesions.</p><p><b>METHODS</b>Diethylnitrosamine (DEN) was used to induce liver lesions in rats. Sequential DWI studies were performed on the livers from 1 to 14 weeks after DEN was administered through drinking water. Comparing studies with a blank control group was set and pathohistological examinations of the livers were performed.</p><p><b>RESULTS</b>No obvious routine MRI morphological change was found in either group during this period, but DWI demonstrated heterogeneous changes in the test group at the cirrhosis stage. There was no significant alteration of the apparent diffusion coefficient (ADC) value in the control group during this period (P > 0.05). The ADC values of the test group began to decline from the fifth week. Until the tenth week, the ADC value of the test group decreased drastically and when b = 300 s/mm2 statistic, the results showed an obvious difference between the two groups. There were also differences between the ADC values at the 10th, the 9th and the 1st weeks of the test group (P < 0.05). When b = 600 s/mm2 and 1000 s/mm2, significant differences were found after the sixth week between the two groups (P < 0.01). The main pathohistological liver change in the test group during the 1 to 4 week period after DEN was administered was swelling of hepatocytes; during the 5 to 8 week period it was fibrous tissues hyperplasia, and in the 9 to 14 week period it was cirrhotic nodule formation.</p><p><b>CONCLUSION</b>MR functional DWI could detect liver diffuse lesions earlier than conventional MR imaging. Measurement of ADC value may be of use in early diagnosis of liver diffuse diseases and for monitoring the changes of the lesions.</p>

Magnetic resonance diffusion-weighted imaging in the diagnosis of diffuse liver diseases in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The diagnosis of diffuse hepatic lesions in early stage is a tough task at any time for clinical conventional imaging. Magnetic resonance diffusion-weighted imaging (MR DWI) can detect the changes of tissue structure at molecular level. This study was designed to determine the value of DWI in the diagnosis of diffuse liver lesions in early stage.</p><p><b>METHODS</b>Diffuse liver lesions were induced by diethylnitrosamine in 42 rats of test group. Fourteen rats in control group were fed with pure water. Dynamic changes of MR DWI were observed every week in both groups during the early stage of diffuse liver lesions (1 to 12 weeks after drug administration in the test group). Apparent diffusion coefficient (ADC) values of liver parenchyma in different stages and pathologic changes were analyzed.</p><p><b>RESULTS</b>The process of diffuse hepatic lesions in the test group was classified into three stages according to pathological changes, namely hepatitis, hepatic fibrosis and cirrhosis. No obvious morphological changes were shown by conventional imaging in both groups during this stage. But MR DWI demonstrated heterogeneous signal changes in early stage of hepatic cirrhosis in the test group. No significant change of ADC values was found in the control group between different weeks (P > 0.05). The ADC values of the test group declined from the fifth week, and after the tenth week the ADC values were significantly different between the test and control groups at gradient factor (b) value 300 sec/mm(2) (P < 0.05). At b value 600 and 1000 sec/mm(2), significant difference was seen between the two groups from the sixth week onward. The range of ADC value of the groups was (1.7 - 0.9) +/- (0.40 - 0.04) mm(2)/sec (b = 600) and (1.38 - 0.75) +/- (0.07 - 0.35) mm(2)/sec (b = 1000), respectively. Dominant pathological changes included swelled hepatocytes within 1 to 4 weeks after the administration of diethylnitrosamine in the test group, hyperplasia of fibrous tissues in 5 - 8 weeks and formation of cirrhotic nodules in 9 - 12 weeks.</p><p><b>CONCLUSIONS</b>MR functional DWI could detect diffuse liver lesions earlier than conventional morphological imaging. ADC value as a marker for early diagnosis of diffuse liver lesions could also be used to inspect changes of the lesions.</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 multislice spiral computed tomography in demonstrating the relationship between bronchus and peripheral lung cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the value of multislice spiral computed tomography (MSCT) in demonstrating the relationship between bronchus and peripheral lung cancer.</p><p><b>METHODS</b>We prospectively performed volumetric targeted scans of 0.5 mm collimation with MSCT and reconstructed images of multiplanar reconstruction (MPR), curved multiplanar reformations (CMPR) and surface shaded display (SSD) in 53 peripheral lung cancers. The results were compared with macroscopic and microscopic specimens.</p><p><b>RESULTS</b>(1) The third- to seventh-order branches of the bronchi were clearly shown in all patients by the designed protocol. CT demonstrated the tumor-bronchus relationship in 29 (96.7%) adenocarcinomas and 13 (76.5%) squamous-cell carcinomas. Statistic analysis showed that there was no significant difference between the two groups (chi(2) = 2.8, P > 0.05). (2) The tumor-bronchus relationship was identified as four types with MSCT. Type I: bronchus was obstructed abruptly by the tumor, type II: bronchus penetrated into the tumor with tapered narrowing and interruption, type III: bronchus lumen shown within tumor was patent and intact, type IV: bronchus ran at the periphery of the tumor with intact or narrowed lumen. (3) Type I was shown in 31 of 53 (58.5%) tumors with squamous-cell carcinoma slightly more common than adenocarcinoma. Type II and type III were seen equally in 8 of 53 (15.1%) tumors which occurred only in adenocarcinomas. Type IV was seen in 15 of 53 (28.3%) tumors with adenocarcinoma being slightly more frequent than squamous cell carcinoma. (4) The tumor at the fourth-order bronchus was more common in squamous cell carcinoma, whereas that at the fixth-order bronchus was more likely in adenocarcinoma.</p><p><b>CONCLUSION</b>Volumetric targeted scan of ultra-thin section with MSCT and followed by MPR, CMPR and SSD reconstruction can greatly improve the manifestation of the bronchioles and accurately demonstrate the patterns of tumor-bronchus relationship, thereby reflecting pathologic changes to some extent.</p>

Small hepatocellular carcinoma: multiphase hepatic CT scan with a multidetector row helical CT scanner / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To evaluate multiphase hepatic CT scan using multidetector row helical CT (MDCT) in detecting hypervascular small hepatocellular carcinoma (SHCC).</p><p><b>METHODS</b>Multiphase hepatic CT scan in 75 patients with SHCC was carried out with Marconi MX8000 multidetector row helical CT scanner. The early arterial phase scan started at the 21th second after the injection of contrast medium, the late arterial phase scan started at the 34th second, and the portal venous phase started at the 80tieth second, six seconds every time.</p><p><b>RESULTS</b>The study showed that the density values of 71 lesions between liver and SHCC were different significantly among the early arterial phase, the late arterial phase and the portal venous phase (F=3.327, P<0.05). Among the 91 lesions, the detectable rates of the early arterial phase and the late arterial phase were 45.1% and 83.5%, respectively. The rate of double arterial phases was 92.3%. The rates increased to 94.5% and 97.8%, when the late arterial phase combined with the portal venous phase and the double arterial phase combined with the portal venous phase.</p><p><b>CONCLUSION</b>The utility of MDCT with faster speed, thinner slice and multiphases scanning has improved the opportunity of detecting hypervascular hepatocellular carcinoma.</p>

Preliminary clinical application of contrast-enhanced MR angiography using three-dimensional timeresolved imaging of contrast kinetics / 中华放射学杂志

Objective To assess the clinical application of contrast-enhanced MR angiography using three-dimensional(3D)time-resolved imaging of contrast kinetics(CE-MRA 3D-TRICKS).Methods TRICKS is a high temporal resolution(2—6s)MR angiographic technique using a short TR(2.8— 4.0 ms)and TE(0.9—1.3 ms),partial echo sampling and the central part of the k-space being updated more frequently than the peripheral part of the k-space.Pre-contrast mask 3D images are first acquired and 15--20 sequential 3D images following bolus injection of Gd-DTPA are then acquired.Results Thirty patients underwent contrast-enhanced MR angiography using TRICKS.Twelve vertebral arteries were well displayed on TRICKS.Seven of them showed normal,bilateral vertebral artery stenosis was shown in 1 case, and unilateral vertebral artery stenosis was shown in 4 wth aecompaning ipsilateral carotid artery bifurcation stenosis in one case.Bilateral renal artery showed normal in 4 cases,and the artery in transplanted kidney showed normal in one case and stenosis in another case.The cerebral artery showed normal in 2 cases, sagittal sinus thrombosis was detected in one case and intracranial arteriovenous malformation in one case. Pulmonary artery displayed normal in 3 cases,pulmonary artery thrombosis was seen in one case and pulmonary sequestration's abnormal feeding artery and draining vein was revealed in one case.The feeding artery in left lower limb fibrolipoma was showed in one case.The radial-ulnar artery artificial fistula stenosis was seen in one case,and left antebrachium hemangioma was showed in one case.Conclusion TRICKS can clearly delineate the whole body vascular system and can reveal any vascular abnormality.It is convenient and with high successful rate,which make it the first method of choice in displaying vascular abnormality.

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.

CT diagnostic value of adrenal ganglioneuroma / 中华放射学杂志

Objective To explore the dynamic spiral CT findings of adrenal ganglioneuromas and to evaluate its clinical value.Methods All 7 cases patients with adrenal ganglioneuromas confirmed by surgical pathology underwent spiral CT plain scanning and two phases dynamic enhancement scanning before operation.The CT images were reviewed and analysed retrospectively in comparison with surgical and pathological results.Results Six of 7 lesions were located in the right adrenal gland,1 in the left.The diameter of the tumors was 3.7—7.5cm,with a mean diameter of 4.6cm.The CT value of the plain scans, AP phases and PVP phases was 16.2—31.7 HU(with a mean value of 24.3 HU),20.9—36.6 HU(with a mean value of 30.2 HU),and 27.4—45.5 HU(with a mean value of 36.0 HU),respectively.The masses were well defined and showed a tendency of wedging into the space between the adjacent organs and structures and encasing the large vessels such as IV,but didn't compress or occlude them.Conclusion The dynamic SCT features of adrenal ganglioneuromas were obvious,dynamic SCT scans could suggest the diagnose.

Budd-Chiari syndrome:diagnosis with three-dimensional contrast-enhanced MR angiography / 中华放射学杂志

Objective To assess the various features of Budd-Chiari syndrome(BCS)on three- dimensional contrast-enhanced magnetic resonance angiography(3D CE MRA)and to evaluate the potential value of this new technique.Methods Thirty-three patients with BCS underwent 3D CE MRA examination. In 23 cases,BCS was secondary to hepatocellular carcinoma(21 patients)or right adrenal carcinoma (1 patient)or thrombophlebitis(1 patient).Ten patients had primary BCS.The patency of the hepatic veins,inferior vena cava(IVC)and portal veins were assessed.The presence of intra-and extrahepatic collaterals,liver parenchymal abnormalities and porto-systemic varices were evaluated.The diagnosis on 3D CE MRA was correlated with that on inferior vena cavography and right hepatic venography,which were available in 10 and 2 cases respectively.Results Various features of BCS were displayed on 3D CE MRA. Hepatic venous findings included tumor thrombosis(19 patients),tumor compression(2 patients), nonvisualization(4 patients)and focal stenosis(4 patients)of the hepatic veins.IVC findings were severe stenosis or occlusion(10 cases),tumor direct invasion(2 cases),tumor thrombosis(3 cases), thrombophlebitis(1 case)and web formation(3 cases).Intrahepatic collaterals were demonstrated in 9 patients including 2 with "spider web" sign.Detected extrahepatic collaterals included dilated azygos and hemiazygos veins(13 cases)and left renal-inferior phrenic-pericardiophrenic collaterals(2 cases).The occlusion of the left portal vein and the presence of porto-systemic varices were depicted in 2 and 10 patients respectively.Liver parenchymal abnormalities identified by 3D CE MRA consisted of caudate lobe enlargement(7 cases),heterogenous enhancement(18 cases)and associated tumors(18 cases). Compared with inferior vena cavography and hepatic venography,the accuracy of 3D CE MRA in the diagnosis of IVC obstruction or hepatic venous stenosis was 100%.Conclusion 3D CE MRA can display various features of BCS and has the potential to provide an accurate diagnosis.