Study of brain perfusion with IVIM-DWI in early hypertension / 医疗卫生装备

Objective To explore the value of intra-voxel incoherent motion diffusion weighted imaging(IVIM-DWI)in brain perfusion of early hypertensive patients. Methods Totally 36 hypertensive patients and 14 volunteers were recruited and scanned using routine MRI sequences including axial T2WI, T1WI, T2FLAIR, TOF-MRA and IVIM-DWI sequence. Perfusion-related diffusion coefficient (D*) values and perfusion fraction (f) values in various regions were measured separately.The independent sample t test was used to analyze the data.Results Compared with the volunteers,both D*values and f values in lenticular nucleus,thalamus,superior frontal gyrus,occipital lobe,genu of corpus callosum(CC)and posterior horns of periventricular WM, were found to be lower (P<0.05) in hypertensive patients. For other regions, there were no significant difference(P>0.05).Conclusion IVIM-DWI has the ability to detect subtle brain perfusion abnormalities at early stages of hypertension.It has an important value to the prevention and treatment of hypertensive encephalopathy.

Imagings of coronary total occlusion using dual-source computed tomography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To analyze the imaging characteristics of coronary arteries with total occlusion (TO) lesions shown by dual-source computed tomography CT (DSCT) coronary angiography.</p><p><b>METHOD</b>The clinical data of patients who were diagnosed as coronary heart disease together with total occlusion lesions between March 2008 and March 2010 were retrospectively analyzed.</p><p><b>RESULTS</b>In a cohort of 140 patients with 152 TO lesions, TO vessels in right coronary artery, left anterior descending artery, left circumflex coronary artery, or left main coronary artery were 68, 48, 20, and 1, respectively. Side branch TO were found in 15 vessels, in which 13 cases were found to be with TO in two coronary arteries. The length of TO was 5-58 mm, mean (16.8 ± 3.9) mm. TO lesions with a length ≥ 1 cm accounted for 91.4%. The appearance of stump in TO were abrupt occlusion (n=68) , blunt occlusion (n=64) , and mouse-tail occlusion (n=20) . Among all the TO lesions, 73% were soft plaque or mainly soft plaque together with minimal calcification. Mixed plaque and calcified plaque were less seen. Ten TO segments presented with dilated lumens were thrombogenesis. There were 25 TO segments angulated or tortuosity, which were most frequently shown in right coronary artery. DSCT only presented 3 TO with clear collateral vessels and no TO with bridge collateral vessels was shown.</p><p><b>CONCLUSIONS</b>DSCT can provide most necessary information of coronary TO lesions. Therefore, it can be used to guide surgeries on TO lesions and improve the success rates of surgeries.</p>

Diagnosis of aortic intramural hematoma by electron beam CT / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the value of electron beam CT (EBCT) in the diagnosis of aortic intramural hematoma (AIH).</p><p><b>METHODS</b>Twenty-five patients who complained of acute chest and back pain were scanned with an EBCT scanner (Imatron C-150) using contrast-enhanced continuous volume scanning (CVS) for establish the diagnosis of AIH.</p><p><b>RESULTS</b>Seven patients were diagnosed as having Stanford type A, and the others as type B AIH. The direct features of AIH in EBCT included crescent or circular thickening (>5 mm) of the aortic wall without signs of lumen formation resulting from intimal rupture. The indirect features included calcification ingression (7 cases), penetrating ulcer (12 cases), atherosclerosis (18 cases) and leakages (5 cases). The complicating features included pericardial effusion (5 cases), pleural effusion (14 cases), involvement of the large branches (5 cases), aortic dissection (3 cases) and aneurysms (4 cases).</p><p><b>CONCLUSION</b>EBCT can provide important information for the diagnosis and treatment of AIH, and can be useful for follow-up observation of the patients.</p>

Experimental study of evaluation on neuroprotective effect for tetramethylpyrazine against focal cerebral ischemic injury with diffusion-weighted magnetic resonance imaging / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To evaluate the neuroprotective effect of tetramethylpyrazine (TMP) against focal cerebral ischemic injury in rats with diffusion-weighted magnetic resonance imaging (DWMRI).</p><p><b>METHODS</b>Rat models of focal cerebral ischemic injury were established in 16 male SD rats. They were randomly divided into the TMP group and the control group, eight in each group, and pretreated with TMP and normal saline respectively before modeling. Change of infarcted cerebral focus was observed with DWMRI at 1, 2, 6, 12 and 24 hrs after infarction, and the infarction volume (IV) at 24 hrs after modeling was estimated by triphenyltetrazolium chloride (TTC) stain.</p><p><b>RESULTS</b>The IV in all time points observed in the TMP group with DWMRI was significantly smaller than that in the control group (P<0.01). Compared with that at 1 hr after infarction, in the control group at 2, 6, 12 and 24 hrs after modeling, the IV enlarged by 13.3%, 29.7%, 50.3% and 57.3% respectively, while that in the TMP group 9.9%, 21.3%, 37.1% and 40.5% respectively. The cerebral IV estimated by TTC stain 24 hrs after modeling was larger than that estimated by DWMRI.</p><p><b>CONCLUSION</b>TMP pretreatment before modeling was effective in protecting brain against cerebral ischemic damage in rats. DWMRI dynamic scanning observation has important significance in observing the cerebral ischemic developing process and evaluating the effectiveness of brain protective measures.</p>