Scan time reduction with a small field-of-view quadruple inversion-recovery high-resolution contrast-enhanced MRI for carotid atherosclerosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To reduce the acquisition time of carotid high-resolution contrast-enhanced magnetic resonance imaging (CEMRI), we designed a small field-of-view (FOV) quadruple-inversion-recovery (SF-QIR) T1WI and evaluated the image quality.</p><p><b>METHODS</b>Twenty-four subjects with carotid plaque were enrolled in our study. All the subjects were imaged using the same 3.0T MRI by SF-QIR and standard rectangular FOV QIR (SrF-QIR) with identical parameters except for the phase-encoding step numbers and the RF excitation methods. Three independent readers qualitatively evaluated the differences between the two sequences in regard of the carotid outer wall border delineation, fibrous cap and lipid-rich necrotic core (LR-NC) border delineation, and diagnostic confidence. The quantitative measurements included maximal stenosis, wall area, LR-NC area, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). The inter-reader variability was assessed.</p><p><b>RESULTS</b>The application of SF-QIR combined with orthogonal radio frequency excitation resulted in nearly half of the scan time with the SrF-QIR. Both qualitative and quantitative assessment by the readers revealed no significant differences between the two sequences except for SNR and CNR (Pgt;0.05). Since the mean loss of SNR with SF-QIR was 37.7%, SrF-QIR demonstrated a superior performance in SNR (P<0.001).</p><p><b>CONCLUSION</b>The small FOV QIR sequence is effective in high-resolution CEMRI for evaluating carotid plaques and can effectively reduce the scan time and eliminate motion artifacts.</p>

Quantitative measurement of carotid atherosclerotic plaque by high-resolution three- dimensional black-blood magnetic resonance imaging / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the value of high-resolution three-dimensional black-blood magnetic resonance imaging (3D-BB-MRI) in quantitative measurement of carotid atherosclerotic plaque by comparison with two-dimensional black-blood magnetic resonance imaging (2D-BB-MRI).</p><p><b>METHODS</b>Forty patients were scanned with routine 2D and oblique-sagittal 3D-BB-MRI. The original oblique-sagittal 3D images were reformatted to an axial 2D-like dataset. Two experienced radiologists identified the interested slice in consensus for every patient (unilateral carotid artery) in 2D-BB-MRI images and matched the axial reformatted 3D images with 2D black-blood images. Plaque thickness (PT), lumen area (LA) and total vessel area (TVA) were measured, and lumen stenosis (LS) and normalized wall index (NWI) were calculated.</p><p><b>RESULTS</b>There was no measurement difference between 2D-BB-MRI and reformatted 3D-BB-MRI (P>0.05), and these two methods had a good correlation (r<0.9). The Bland-Altman chart showed that 2D-BB-MRI and 3D-BB-MRI were in good agreement in the measurement of PT, LA and TVA.</p><p><b>CONCLUSION</b>3D-BB-MRI and 2D-BB-MRI have no obvious difference in quantitative measurement of the carotid plaques. 3D-BB-MRI can demonstrate the vessels and plaques by multiplanar reconstruction and thus have better performance in evaluating carotid atherosclerosis compared with 2D-BB-MRI.</p>

Whole Body Diffusion-weighted MR Imaging Study of Bone Marrow in Healthy Adults / 中国医学影像学杂志

Purpose To explore the correlation between whole body magnetic resonance diffusion-weighted imaging (WB-DWI) quantitative parameters of healthy adults' bone marrow with gender, age, height, weight, body mass index, and sex hormone levels. Materials and Methods 108 healthy adult subjects in different age groups underwent WB-DWI scan using GE 1.5T MR scanner, among them estradiol and progesterone levels were measured in 60 subjects within 48 hours before or after the scan. Apparent diffusion coefficient (ADC) values of bone marrow and the signal to noise ratio (SNR) were compared among different gender and age groups. Partial correlation analysis was used to evaluate the correlation of skeletal system ADC values and SNR with sex, age, height, weight, body mass index, estradiol and progesterone levels in 60 subjects. Results ADC values and SNR of the female subjects were significantly higher than males (P<0.01);there were significantly differences for skeletal system ADC values and SNR in different age groups (P<0.01). Skeletal system ADC values was significantly negatively correlated (r=-0.642, P<0.01) with age, and were mildly positively correlated (r=0.278, 0.271, P<0.05) with estradiol and progesterone levels;SNR was significantly negatively correlated (r=-0.709, P<0.01) with age, and was mildly positively correlated (r=0.293, P<0.05) with estradiol levels;ADC values and SNR had no significant correlation with height, weight and body mass index. Conclusion Skeletal system ADC values are effected by gender, age and sex hormone levels, the skeletal system WB-DWI manifestations are different in different gender and age groups.

A finger-taping switch task functional magnetic resonances imaging study in the patients with Tourette's syndrome / 中华神经科杂志

ObjectiveTo investigate the central nervous system mechanisms of active of movement switch in the patients with Tourette' s syndrome( TS),and to explore the possible underlying distinct neural networks for tic trigger and generation. Methods Participants were 14 patients with TS and 14 age- and gender-matched healthy volunteers with no history of physical,psychiatric or neurological disease: All patients were assessed with functional magnetic resonances imaging (fMRI)of the brain during the intermittent performance of finger-tapping switch tasks,Blood-oxygen-level dependent-fMRI was performed using a 3.0 Tesla MR.The area over which the activation was distributed was calculated,and the activation volumes were also compared between the patients with TS and the control subjects.ResultsThe regions activated in the patients with TS and in the volunteers were similar in several brain regions,including contralateral precentral and postcentral gyrus,contralateral mesia pre-front gyrus,contralateral cingulate gyrus,contralateral insula and ipsilataral cerebellum. There were also many different activation areas between the patients and the control subjects. The patients with TS demonstrated more significant and extended activation in the contralateral pre- and postcentral gyrus than the healthy volunteers.The volume of the left pre- and postcentral gyrus of the TS patients was (8.024 ±0.071 ) cm3,while the volume of the left pre-and postcentral gyrus of the control subjects was ( 6.480 ± 0.026) cm3 ( t =3.026,P ＜ 0.01 ) ; The volume of the right pre- and postcentral gyrus was (6.192 ± 0.019) cm3 in the TS cases,while there was (5.608 ±0.037) cm3 in the control subjects (t =2.752,P ＜0.05).There were significant differences in the volumes of bilateral pre- and postcetral gyrus between the TS and control subjects. The activations of conralateral thalamus without contralateral insula were found in the patients with TS. Conversely, the contralateral insula activation without thalamus activation could be found in the healthy volunteers.ConclusionThe thalamus might play an important role in the aetiological and physiopathologic mechanisms of the TS. The thalamus along with the parietal cortex,cingulate cortex and insular cortex appear to constitute a distinct neural network for tic trigger and generation.

H-magnetic resonance spectrum of putaman of Tourette' s syndrome / 中华神经科杂志

Objective To study the changes of the putamen metabolites with magnetic resonance spectrum(MRS),and to explore possible underlying unrecongnised aetiological factor and pathophysiology mechanism in the central nervous system of the patients with Tourette' s syndrome.Methods Twenty-two cases of Tourette' s syndrome,and twenty-two gender and age-matched subjects ( the control subjects ) were performed on a clinical 3.0 T MRI system.Proton prob-voxel spectroscopy imaging (1H-MRS) was obtained from two sides of the putamen.The metabolites included N-acetylaspartate (NAA),creatine and phosphocreatine ( Cr),choline-containing compounds (Cho),and myoinositol ( MI ).The value of the NAA,Cr,Cho,and MI were calculated by integration of their peaks.The ratios of NAA/Cr,Cho/Cr,ML/Cr were calculated respectively.Repeated measures analysis of variance ( ANOVA ) was used to test both the value of NAA/Cr,Cho/Cr,MI/Cr of the putamen for group difference,with group as between-subjects factor and side as within-subjects factor.Results The NAA/Cr ratio in patients ( left:1.29 ± 0.13 ; right:1.34 + 0.15 ) was significantly lower than that in the control subjects ( left:1.50 ± 0.08,T =1.962,P ＜0.05 ; right:1.52 ± 0.11,T =1.865,P ＜ 0.05 ).There was no significant difference in the Cho/Cr and MI/Cr ratio between both groups.Conclusion The abnormalities of the structure and(or) function in the putamens of patients may be the one of the underlying anaetiological factors and pathophysiology mechanisms of the Tourette' s syndrome.

Optimization of b-value in breast diffusion-weighted 1.5 T MR imaging ZHANG Jing / 中华放射学杂志

ObjectiveTo optimize the b-value of breast diffusion-weighted MRI (DW-MRI) at 1.5T by applying a range of b values and comparing the apparent diffusion coefficient (ADC) and signal-to-noise ratio (SNR) on a phantom,disease-free breast tissues,and benign and malignant lesions.Methods A phantom and 32 women with pathologically confirmed malignant ( 18 ) and benign ( 14 ) lesions were examined using EPI-DWI with different b values on a 1.5 T MR scanner.The b-value of EPI-DWI was 0,50,100,200,400,600,800,1000,1200,1400,1600,1800,2000,2200,2400,and 2600 s/mm2,respectively.The SNR and ADC values of the phantom,disease-free breast tissues,and benign and malignant lesions were measured.The correlation between the b-value and ADC or SNR of each image was analyzed.ResultsThe SNR of DWIdecreased as the b-valueincreased,showing aninversecorrelation (r =-0.802,P ＜0.01 ).The ADC values of benign and malignant lesion decreased as the b-value increased (r =-0.923 and -0.855,P ＜0.01 ).The maximum difference in ADC between malignant and benign lesions was observed when the b-value is between 800 and 1000 s/mm2 and diminished when the b-value was greater than 1400 s/mm2.ConclusionFor good image quality and valid differentiation between malignant and benign lesions,the optimized b-value of DWI at 1.5 T is between 800 s/mm2 and 1000 s/mm2.

MRI abnormalities and related risk factors of the brain in patients with neuromyelitis optica / 中华放射学杂志

Objective To investigate the MRI features of the brain in patients with neuromyelitis optica (NMO), and to evaluate the correlation between the brain abnormalities and related risk factors.Methods Fifty-four patients with definite NMO according to 2006 Wingerchuk diagnosis criteria were enrolled in this study. MRI scanning of the brain was performed in these patients. Distribution and signalfeatures of all the lesions were analyzed. A Logistic regression analysis was used to evaluate the risk factors of brain abnormalities. Results Twenty-four NMO patients (44. 4%) showed unremarkable findings and thirty (55.6%) showed abnormalities on brain MRI. Multiple and non-specific small lesions in the subcortical white matter and grey-white matter junction were the most frequent abnormalities on brain MRI (13/30, 43. 3%). Typical lesion locations included corpus callosum, subependyma of ventricles,hypothalamus and brain stem. The lesions showed punctate, patchy and linear abnormal signals. Postcontrast MRI showed no abnormal enhancement in 16 cases. Logistic regression analysis showed that coexisting anto-immune disease or infection history had correlations with abnormalities of the brain on MRI (OR=3.519,P ＜0.05). Conclusions There was a high incidence of brain abnormalities in NMO.Subependymal white matter, corpus callosum, hypothalamus and brain stem were often involved in NMO.NMO patients with coexisting anto-immune disease and infection history had higher risk of brain abnormalities.

Preliminary study on predicting the response of breast carcinoma to neoadjuvant chemotherapy using apparent diffusion coefficient / 中华放射学杂志

Objective To investigate the value of apparent diffusion coefficient(ADC)of breast carcinoma before and one course after neoadjuvant chemotherapy,and to predict the response of breast carcinoma to neoadjuvant chemotherapy.Methods Twenty female patients with 21 breast carcinoma lesions were examined with diffusion weighted imaging(DWI)and contrast-enhanced MRI within 7 days prior to neoadjuvant chemotherapy(adriamycin + taxinol),during 18-21 days after the first couse of therapy and within 7 days prior to the surgery resection.The tumors were divided into response group and relative nonresponse group by change of the tumor.The difference of ADC between the two groups before and after 1st course of chemotherapy was compared.Results In chemotherapy response group with 15 lesions,the mean ADC was(0.98±0.15)×10-3 mm2/s before chemotherapy and increased to(1.22±0.23)×10-3 mm2/s after 1 st course of chemotherapy(P＜0.05),while in nonresponse group with 6 lesions,the mean ADC before and after chemocherapy was(1.09±0.08)×10-3 mm2/s and(1.11±0.07)×10-3 mm2/s,respectively,with no statistical difference(P>0.05).The mean ADC of response group prior to chemotherapy was significantly lower than that of nonresponse group(P＜0.05).A significant negative correlation(r=-0.51,P＜0.05)was observed between the ADC prior to treatment and change of ADC after the first couse therapy.Conclusion Preliminary results revealed the initial ADC of the tumor in patient with breast carcinoma and the changes of ADC after 1 st couse treatment may predict response to neoadjuvant chemotherapy.

Comparison of whole body MR diffusion weighted imaging and skeletal scintigraphy In detecting bone metastasis / 中华放射学杂志

0bjective To evaluate the application of whole body MR diffusion weighted imaging (DWI)in the detection of bone metastasis using skeletal scintigraphy as the referenee.Methods Fonv.two healthy volunteers and 38 patients with malignant tumors were enrolled in our studv.A11 the patients received MR examination and skeletal scintigraphy within one week.MR examination was performed on GE signa 3.0T MR scanner using a build.in body coil.The skeletal system Was divided into eight regons and the images of the whole body MR DWI and skeletal seintigraphy were reviewed to compare the two modalities patient by patient and region by region.The images were reviewed separately by two radiologists and two nuclear medicine physicians,who were blinded to the results of another imaging modality.Results A total of 169 metastatic lesions in 69 regions of 30 patients were detected by whole body MR DWI while 156 lesions in 68 regions of 29 patients were identified by skeletal seintigraphy.There were two cases negative in scintigraphy but positive in whole body MR DWI and one case positive in scintigraphy only.There were eight lesions negative in scintigraphy but positive in whole body MR DWI,mainly located in the spine.pelvis and femur.Seven 1esions were only detected by scintigraphy,mainly located in the skull.sternum.clavicle and scapula.Conclusion The whole body MR DWI reveals excellent consistency with skeletal scintigraphy regarding bone metastasis.and the two modalities are complementary for each Other.

Comparison of 16 slice multi-detector computed tomography and breath hold 3D magnetic resonance angiography in the detection of coronary stenosis / 老年心脏病学杂志（英文版）

Objective To compare 16-slice multi-detector spiral computed tomography (MDCT) and breathhold 3D magnetic resonance (MR) coronary angiography in the visualization of coronary arteries and the accuracy of detecting significant (＞ 50%) coronary stenoses in patients with suspected coronary artery disease. Methods Forty patients were examined by 16-slice CT (GE, Lightspeedl6)and MR (GE,Twinspeed) within 3 days; 31 of them underwent conventional coronary angiography (CAG) within 2 weeks after CT and MR scan. CT was performed with 16× 1.25 mm detector collimation, 0.5 s rotation time and images were reconstructed at 60%-75% of the cardiac cycle. MR was performed with breath hold 3D FIESTA (TR4.0 ms, TE1.7 ms, flip angle 65, slice thickness 3 mm, FOV 280 mm, matrix 256× 192). Mean heart rate was 63 ± 5.8 bpm and β-blocker was used in 24 patients. MR and CT image quality was evaluated in 9 coronary segments (RCA1, RCA2, RCA3, LM, LAD1, LAD2, LAD3, LCX1, LCX2) using a four-point grading scale.Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated for detection of significant stenosis using CAG as the gold standard. Results 16-slice CT showed higher image quality in most coronary segments except RCA2.Forty-three segments were diagnosed as significant stenosis by CAG, 36 and 27 of these were correctly detected by CT and MR respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of 16-slice CT and MR for detecting significant stenosis were 83 %, 84 %, 49 %, 97 % and 63 %, 90 %, 55 %, 93 %, respectively. Conclusion Sixteen-slice CT showed higher image quality in most coronary segments excepted for middle RCA. 16-slice CT had higher sensitivity than MR for detection of coronary significant stenosis, whereas MR had higher specificity than CT. Both CT and MR showed high negative predictive value,which is useful for excluding coronary stenosis in symptomatic patients.

MR imaging of meningeal carcinomatosis by systemic malignancy / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the magnetic resonance (MR) features of meningeal carcinomatosis, and to improve the ability in understanding and diagnosing meningeal carcinomatosis by MR findings.</p><p><b>METHODS</b>Eleven cases with proven meningeal carcinomatosis were studied by conventional and Gd-DTPA enhanced MR imaging. The enhancement patterns and features, as well as the types of meningeal involvement, were retrospectively analyzed.</p><p><b>RESULTS</b>Conventional MR imaging showed no evident meningeal abnormalities. After the administration of Gd-DTPA, abnormal pia mater enhancement was detected in 9 cases, demonstrating as the continuous, thin, and lineal high signal intensity on the brain surface that could descend into the sulci. The abnormal pial enhancement occurred on the cortical surfaces of cerebellum, brainstem, and cerebrum. No abnormal enhancement in the subarachnoid space was found. Abnormal dura-arachnoid enhancement was seen in 3 cases, showing as the continuous, thick, and curvilineal high signal intensity over the convexities or in the tentorium without extension into the cortical sulci. Cerebral dura-arachnoid involvement was found in all 3 cases and one of them also showed abnormal enhancement in cerebellar dura-arachnoid and tentorium. Of the 11 cases, 9 with pial involvement had abnormal cerebrospinal fluid (CSF) results, 2 involving only the dura-arachnoid had normal CSF results.</p><p><b>CONCLUSION</b>Meningeal carcinomatosis could be well demonstrated by Gd-DTPA enhanced MR imaging, and its type could be differentiated by the enhancement features. Combined with the clinical information, Gd-enhanced MR imaging may lead to the diagnosis and guide the therapy of meningeal carcinomatosis.</p>

MRI of demyelinating pseudotumor of the central nervous system / 中华放射学杂志

Objective To describe the MR manifestations of demyelinating pseudotumor of the central nervous system (CNS), and to discuss the pathologic features and MR diagnostic value and limit in this disease entity. Methods Seven pathologically proved and one clinically proved cases of demyelinating pseudotumor of CNS were studied with MR imaging, and the MR imaging features were retrospectively analyzed. Results MR imaging demonstrated localized mass without adjacent multiple accompanying lesions in all 8 cases. On T 1WI, the lesions showed homogenous low signal in 5 cases, inhomogenous low signal in 2 cases, and mixed high and low signal in 1 case. On T 2WI, the lesions presented as homogenous high signal in 5 cases and inhomogenous high signal in 3 cases. Of the 7 cases with Gd DTPA administration, marked enhancement was seen in each case. The enhancement pattern of vertical distribution to the lateral ventricle was demonstrated in left frontoparietal lobe in one case, and predominant dorsal white matter enhancement of the cervical spinal cord was revealed in another case. Follow up MR imaging showed no lesion recurrence, and gradual shrinkage of the lesion after steroid therapy was demonstrated in one case. Conclusion It is a difficult task to make the correct diagnosis of CNS demyelinating pseudotumor based on the clinical information and imaging findings, and this disease entity is often misdiagnosed as tumor by MR imaging. Thorough analysis of the clinical history and careful observation of MR manifestations (especially contrast enhanced MR findings) would be helpful in diagnosing the demyelinating pseudotumor and, in such circumstances, providing test steroid therapy, thus avoiding the devastating injury caused by surgery or radiation therapy.

A prospective study of 3D dynamic MRI on differential diagnosis of breast lesions / 中华放射学杂志

Objective To prospectively evaluate the diagnostic ability of the lesions′ morphology, signal intensity time course, and early phase enhancement rate in dynamic MRI of the breast. Methods Forty cases with breast lesions were examined with a new Efgre 3D dynamic MR imaging series. Time signal intensity curves of the lesions were obtained and classified according to their shapes as monophasic, biphasic, or washout. Early phase enhancement rates of the lesions were calculated. The diagnostic indices were got by lesions′ morphology criterion, the time signal intensity curves criterion, and the enhancement rate criterion. Results There were 23 malignant and 18 benign lesions. The distribution of curve types for malignant lesions was monophasic (5%), biphasic (18%), and washout (77%). The distribution of curve types for benign lesions was monophasic (72%), biphasic (11%), and washout (17%). The distribution proved significantly difference (? 2=20.68, P

MR angiography of internal carotid artery stenosis: contrast enhanced MRA versus gated 2D TOF MRA / 中华放射学杂志

Objective To compare the accuracy of CE MRA and Gated 2D TOF MRA in evaluation of internal carotid artery stenosis. Methods 34 patients (male 27, female 7, age range 45-78 years) were evaluated with contrast enhanced three dimensional magnetic resonance angiography (CE MRA) and unenhanced ECG gated two dimensional time of flight MRA (Gated 2D TOF MRA). Digital subtraction angiography (DSA) was used as the “gold standard”. The MRA images were reprojected with maximum intensity projection (MIP) algorithm. Sensitivity, specificity, diagnositic accuracy,overestimation and underestimation were assessed. Results (1) DSA provided 68 diagnostic judgments: 23 were negatives and 45 were positives (mild stenosis 10, moderate stenosis 14, severe stenosis 17, occlusion 4). CE MRA was in agreement with angiography in 66 (97%), but overestimation resulted in 2 cases. Gated 2D TOF MRA was in agreement with angiography in 56 (82%), with 9 overestimation and 3 underestimation. (2) Taking negative and positive cases as judgement, CE MRA showed higher sensitivity, specificity, and diagnostic accuracy than Gated 2D TOF MRA (100% versus 95 6%, 100% versus 78.3%, 100% versus 89.4%, respectively). (3) Taking 70% stenosis as judgement, CE MRA also showed higher sensitivity, specificity, and diagnostic accuracy than Gated 2D TOF MRA (100% versus 95 2%, 97.8% versus 93.6%, 98.5% versus 94.1%, respectively). Gated 2D TOF MRA vs DSA, CE MRA vs DSA and Gated 2D TOF MRA vs CE MRA all had no significant difference (? 2=3.000 with P =0.083, ? 2=2.000 with P =0.157, and ? 2=1.600 with P =0.206 respectively) Conclusion Compared with Gated 2D TOF MRA,CE MRA is more accurate in evaluation of carotid artery stenosis.

MR imaging findings of osteosarcomas treated with high intensity focused ultrasound / 中华放射学杂志

Objective To evaluate the usefulness of MR imaging in follow-up of osteosarcomas treated with high intensity focused ultrasound (HIFU). Methods The images of nonenhanced and multiphase gadolinium-enhanced MR imaging before and after HIFU treatment in 16 patients with osteosarcomas pathologically confirmed were interpreted prospectively and correlated with the results of ~ 99mTc-MDP bone scan. Results The results of HIFU in 14 osteosarcomas were evaluated correctly. Before HIFU, 16 osteosarcomas demonstrated hypointensity on T1WI and heterogenous hyperintensity on T2WI and obvious enhancement during capillary and delayed phases and abnormal radioactivity accumulation were detected.One to Four weeks after HIFU treatment, the osteosarcomas became slightly hyperintense on T1WI and heterogenously hyperintense on T2WI, and no enhancement during capillary and delayed phase was noted. There was a clear boundary presenting between the targeted and untreated areas, and abnormal radioactivity accumulation disappeared. Both the signal intensity on T2WI and the tumor size reduced gradually after HIFU treatment 3 to 25 months. Conclusion HIFU is an effective local therapy for osteosarcomas, and MRI can accurately evaluate the efficacy of HIFU.

Efficiency of breath-hold three-dimensional fast imaging employing steady state acquisition sequence for coronary stenoses detection / 中华放射学杂志

Objective To evaluate the efficiency of coronary magnetic resonance angiography (CMRA) for stenoses detection by using breath-hold three-dimensional fast imaging employing steady state acquisition (FIESTA) sequence with the reference of conventional coronary catheter angiography. Methods~Consecutive 33 patients accepted CMRA examination within 3 weeks after the catheter angiography. Coronary stenoses was graded in 5 levels as 0%, 0%-25%, 25%-50%, 50%-75%, and 75%-100%, respectively, and CMRA and catheter angiogram were compared segment by segment. Results For the differentiation of the stenoses 50%, the accuracy, sensitivity, and specificity of CMRA was 84.3%, 84.8%, and 84.1%, respectively, and the negative prediction value was 92.3%. The accuracy, sensitivity, and specificity for the differentiation of stenoses between 50%-75% and 75%-100% were all 61.5%. Conclusion The breath-holding three-dimensional FIESTA sequence for CMRA was practical to exclude hemodynamic significant coronary stenoses but limited in detail grading.

Primary ureteral carcinoma: MRI diagnosis and comparison with other diagnostic imaging facilities / 中华放射学杂志

Objective To investigate MRI examination methods and imaging manifestations of primary ureteral carcinoma, and to evaluate its clinical values when comparing with other diagnostic imaging facilities. Methods Eighty-seven cases of primary ureteral carcinoma who were operated within recent 8 years came into the study, among which, 35 cases had MRI examinations. For MRI examination, coronal heavy T2WI (water imaging) was performed to show the dilated ureter, then axial T2WI and T1WI were scanned at the obstruction level. 11 cases underwent additional Gd-DTPA dynamic contrast enhanced scans. The original pre-operative diagnostic reports of various imaging facilities were analyzed comparing with the results of operation and pathology. Results MRI showed ureteral dilatation in 33 of 35 cases, no abnormal appearance in 1 case, and only primary kidney atrophy post renal transplantation in 1 case. Among the 33 cases with ureteral obstruction, soft mass at the obstruction level was detected on axial scans in 32 cases. The lesions showed gradual and homogeneous mild to moderate enhancement on contrast MRI. The overall employment rate of imaging facilities was as follows: ultrasound (94. 3% ) , IVU (59. 8% ) , CT (52. 9% ) , MRI (40. 2% ) , and RUP (35. 6% ). The accurate diagnostic rate was as follows: MRI (91. 4% ) , RUP (80. 6% ) , CT (63. 0% ) , ultrasound (47. 6% ) , and IVU (11. 5% ). Conclusion Combination of MR water imaging and conventional sequences can demonstrate most primary ureteral carcinoma lesions and has a highest diagnostic accuracy among the current diagnostic imaging facilities. It should be taken as the first diagnostic imaging method of choice when primary ureteral carcinoma is suspected after ultrasound screening.

Changes on cognitive function, brain magnetic resonance imaging and diffusion tensor imaging in patients with multiple sclerosis / 中华神经科杂志

Objective To investigate the association of cognitive impairment with the brain structure changes in multiple sclerosis (MS). Methods 70 patients with MS were tested with the Wechsler Intelligence Scale and brain MRI. Analysis was performed to the brain MRI in 50 patients and diffusion tensor imaging (DTI) in 7 patients. Results The rate of the patients whose full intelligence quotient (FIQ) were less than 90 scores was 40% (28/70), which were higher than that of the normal group (P

High resolution MR imaging in measurement of vascular wall area in atherosclerotic carotid artery: assessment of reproducibility / 第二军医大学学报

Objective: To assess the reproducibility of high resolution MR imaging(MRI) in measuring the vascular wall area in atherosclerotic carotid artery. Methods: Twenty four subjects (male 18, female 6, aged 60 78 years) with 50% 79% stenosis (confirmed by Doppler ultrasound) were recruited for the study. Two independent MRI examination were conducted within 2 weeks using high resolution imaging on a 1.5 T scanner (Signa, GE Medical Systems). Three slices were selected (4 mm distal to the bifurcation, just under the bifurcation and 4 mm proximal to the bifurcation) from the bilateral carotid artery to measure the luminal, outer wall boundary and wall area. The above process was done by 2 observers blinded to each other's results. The Interscan and Interobserver variations were assessed by paired Student's t test. Results: There was no significant difference in lumen, outer wall boundary and wall area measurement for both Interscan and Interobserver comparison. Conclusion: High resolution MRI of the human carotid artery in measuring the vessel lumen and wall areas has high reproducibility. MRI can also be used to monitor the progression of atherosclerotic plaque of carotid artery.

Localization strategy for magnetic resonance coronary angiography / 中华放射学杂志

Objective To develop a localization strategy for magnetic resonance coronary angiography (MRCA). Methods In 89 subjects, the standard 4-chamber view and long-axis view of left and right ventricle were acquired using Fast-Imaging-Employing-Steady-State-Acquisition (FIESTA) sequence in CINE mode, and the trigger-delay time for mid-diastolic phase was determined. Coronary vessels including right coronary artery (RCA), left main (LM), left anterior descending (LAD), and left circumflex (LCX) were localized and imaged using 3-dimensional fat-suppressed FIESTA sequence during end-expiration. The reproducibility of the localization strategy was evaluated by taking the standard of coronary segmentation system recommended by American Heart Association. Results Eighty-six subjects completed the examination with full respiratory co-operation and the indication ratio was 96.63%. Nine planes were optimized as the standard to target the main branches of coronary arteries, and a comprehensive reproducibility reached 100% in demonstrating the proximal and middle segment of RCA (AHA-18, 19), LM (AHA-1, 2), proximal and middle segment of LAD (AHA-3, 5, 7), and proximal LCX (AHA-10). The reproducibility for the demonstration of distal segments of LAD, LCX, and RCA (AHA-9, 14, 21) was 94.19%, 72.09%, and 96.51%, respectively. Conclusion This is a simple and practical localization strategy for MRCA. It could image the proximal and middle segments of the coronary arteries with good reproducibility, which indicates the potential for clinical application.