A magnetization transfer imaging study of bilateral optic radiation and visual cortex in patients with primary glaucom / 中华放射学杂志

Objective To analyse the changes in bilateral optic radiation and visual cortex in patients with primary glaucoma detected by magnetization transfer imaging ( MTI ),and try to explore the influence of the disease on posterior visual pathway.Methods MTI was performed in 20 patients with primary glaucoma with normal signal on conventional magnetic resonance imaging (MRI).The same scanning was performed in 31matched healthy controls.MTI was obtained using spoiled gradient recalled acquisition sequence (SPGR).Magnetization transfer ratio ( MTR ) of bilateral optic radiation and visual cortex was measured after post-processing.The MTR value differences of the same area between two groups were compared by independent-sample t test or Satterthwaite t test if variances were not equality.Result The MTR value in the left and right optic radiation were ( 32.8 ± 2.2 ) ％ and ( 32.7 ± 2.0 ) ％ in the glaucoma group,(34.6 ± 1.4 )％ and (34.8 ± 1.3 )％ in the control group.There was a statistically significant difference between the two groups (left t =3.284,right t =4.040 ;P ＜ 0.01).The MTR value of the left and right visual cortex were ( 30.1± 2.0 ) ％ and ( 30.8 ± 1.8 ) ％ in the glaucoma goup,and (32.3 ± 1.2 )％ and (32.4 ± 1.2 )％ in the control group.Statistically significant difference was found between the two groups ( left t =4.319,right t =3.445 ;P ＜ 0.01).Conclusions Potential neuropathology changes occurring in the posterior visual pathway of patients with glaucoma indicate that the whole visual pathway may be involved by glaucoma.The micro physiological changes can be detected by MTI which can not be found by conventional MRI.It is a useful method of studying trans-synaptic damage of visual pathway n vivo glaucoma which provides more information for guiding the clinic diagnosis,cure and prognosis of glaucoma.

Diameter measurements of cerebral arteries on three-dimensional time-of-flight MR angiograms / 中华放射学杂志

14 years) in female. ICA-C4: (4.3?0.6) mm in male, (3.9?0.6) mm in female. A1 segment of anterior cerebral artery (ACA-A1): (2.1?0.4) mm in male, (2.1?0.4) mm in female. Anterior communicating artery (ACoA): (1.4?0.4) mm in male, (1.3?0.4) mm in female. M1 segment of middle cerebral artery (MCA-M1): (2.7?0.4) mm in male, (2.6?0.4) mm in female. Basilar artery (BA): (2.9?0.5) mm in male, (2.8?0.4) mm in female. P1 segment of posterior cerebral artery (PCA-P1): (2.1?0.5) mm on the left and (2.0?0.5) mm on the right in male, (2.0?0.3) mm on the left and (1.9?0.3) mm on the right in female. PCA-P2: (1.8?0.4) mm in male, (1.7?0.3) mm in female. Posterior communicating artery (PCoA): (1.1?0.3) mm in male, (1.2?0.4) mm in female. Among various diameters, only PCA-P1 had significant difference between the left and the right (P=0.003); only MCA-M1 (P=0.048), PCA-P1 (P=0.012), ICA-C2 (P=0.000) and C4 segments (P=0.000) had significant differences in gender, respectively; and only ICA-C2 had significant difference in age (P=0.001). Of these significantly different diameters, the diameters in male were larger than those in female. There were significant correlation between PCA-P1 and PCA-P2 (r=0.652,P=0.000), and between ICA-C2 and ICA-C4 in female group (r=0.550,P=0.000), respectively. Conclusions The normal values of diameter of cerebral arteries on MR angiograms may play a reference role in diagnosing cerebral vascular diseases.

The Role of MR Angiography in Diagnosing Cerebral Arteriovenous Malformation / 实用放射学杂志

Objective To summarize MR manifestations of cerebral arteriovenous malformations (AVMs), and to evaluate the accuracy of MR angiography in determining cerebral AVMs’ aspects. Methods Thirty-six cases of cerebral AVMs were analyzed comparatively between MRA and DSA in sizes, feeding arteries and draining veins. Results Cerebral AVMs were appeared in every part of brain. MRI showed honeycombed and linear flow-void low intensity signal in lesion area, showed flow-void signal of expanded thickening vessels, and showed cerebral atrophy or fraction surrounding the lesions. MRA showed that the sizes of most AVMs were 2～5 cm, that the feeding arteries originate from the expansion of original feeding arteries of these areas, that the draining veins drain from the lesions into the surrounding veins or sinuses. The numbers of these vessels were related positively to the sizes of lesions. The differences in showing AVMs between MRA and DSA were that the sizes of lesions on MRA were more than those on DSA, and the numbers of draining veins on MRA were more than those on DSA. Conclusion MRA may show all signs of AVMs, and is not less than, or superior to DSA in their diagnosis. MRI may play important roles in the examination and the diagnosis of cerebral AVMs.

MRI and Ultrastructural Pathology on Acute Myocardial Infarction / 实用放射学杂志

Objective To study the MRI features and its ultrastructural pathology basis in different myocardial injury areas after acute infarction.Methods 10 rabbits were given ligation of left anterior descending branch 24 hours to make pathologic models.All animals underwent conventional MRI,contrast media dynamic enhancement MRI,cine-MRI and dobutamine stress test.Myocardial blood flow was measured with radioactive micropheres to define risk regions.Ischemic and infarcted regions were defined as Even's blue and 2,3,5triphenyltetrazolium chloride(TTC)negative regions respectively,and made electron microscopy specimens to observe the changes of mitochondria and myofibril.The myocardial ultrastructural injury was scored and graded.Results There were no significant change on T 1WI,but the signal intensity on T 2WI increased significantly after AMI.The diseased myocardium became thinning were seen in 40% cases,and the abnormal flowing high signal were seen in 60% cases.The dynamic enhancement time-signal intensity curves were different in normal,ischemic and infarcted regions.Cine-MRI showed the cardiac wall movement impairing and the wall thick thinning,but the wall movement reinforcing and the wall thick thickening after dobutamine stress.The water content of ischemic and infracted myocardium were marked higher than normal myocardium.The myocardial blood flow in diseased regions were decreased significantly than that in normal regions.The volume density and numerical density of mitochondria in different injury regions showed significant differences.Conclusion MRI appearances of AMI were associated with the injury degree of myocardial ultrastructure and the residual myocardial blood flow.

MRI Diagnosis of Primary Intracranial Teratoma / 实用放射学杂志

Objective To investigate the role of MRI in diagnosis of primary intracranial teratoma.Methods Nine cases of primary intracranial teratoma proved by operation and pathology were examined by MRI before operation.MRI features were analysed retrospectively.Results The localized and qualitative rates were 100% and 88.8% respectively.The characteristic MRI appearances of primary intracranial teratoma were as follows:(1)The tumor was lobular in shape with clear margin;(2)The tumor had heterogeneous signal intensity ;(3)Inhomogeneous Gd-DTPA enhancement in most of the tumors.Conclusion Multiplanar imaging and Gd-DTPA enhancement in MRI are helpful in diagnosis and differential diagnosis of teratoma.

Consecutive Three-dimensional Time-of-Flight MRA:Its Capacity in Determining Cerebral Arteries / 实用放射学杂志

Objective To evaluate the capacity of consecutive three-dimensional time of flight(3D-TOF)MRA and velocity-encoding(Venc)three-dimensional phase-contrast MRA(3D-PC MRA)in determining cerebral arteries.Methods 15 persons being normal on MR images,consecutive 3D-TOF and 3D-PC MR angiograms were selected prospectively to evaluate the difference between two MRA techniques in determining cerebral arteries.The 38 normal sides of 43 cerebral arteriographic cases undergone MRA and DSA were selected retrospectively to evaluate the capacity of MRA technique in determining cerebral arteries with DSA criterion.Results The branch grades of ACA,MCA or PCA demonstrated by 3D-TOF technique were not respectively different from that by 3D-PC.But the former imaging quality was much better than that of the later.The branch grades of ACA,MCA or PCA shown by MRA were respectively different from those by DSA.These grades of ACA,MCA shown by MRA were one less than those by DSA,and that of PCA shown by MRA was a few different from that by DSA.Conclusion The capacity of consecutive 3D-TOF MRA in demonstrating cerebral arteries is less than that of DSA,but it is enough to most cerebral vascular diseases.

Value of HASTE MR Cholangiopancreatography in the Diagnosis of the Biliary Obstructive Diseases / 实用放射学杂志

Objective The aim of this study was to evaluate magnetic resonance cholangiopancreatography(MRCP)using half-Fourier acquisition single-shot fast spin-echo(HASTE)sequence in the diagnosis of biliary obstructions.Methods Forty-five patients with pancreaticobiliary duct diseases underwent MRCP on 1.5 T scanner,a heavily T 2-weighted HASTE was used during a breath-hold.The source images were three-dimensional reconstructed postprocessed on workstation.The findings of MRCP images were analyzed and compared with US,CT,ERCP or PTC.Results The diagnostic accuracy of MRCP was 94%,the same as ERCP(92%),but it was superior to US and CT(?