Dual-energy computed tomography angiography for evaluating the renal vascular variants / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Recognizing renal vascular variants preoperatively is important in order to avoid vascular complications during surgery. This study aimed to investigate the renal vascular variants with dual-energy computed tomography (DECT) angiography to provide valuable information for surgery.</p><p><b>METHODS</b>A total of 378 patients underwent DECT. The number, size, course and relationships of the renal vessels were retrospectively observed from the scans. Anomalies of renal arteries and veins were recorded and classified. Multiplanar reformations (MPR), maximum intensity projections (MIP), and volume renderings (VR) were used for analysis.</p><p><b>RESULTS</b>In 378 patients (756 kidneys), renal artery variations were discovered and recorded in 123 kidneys (16.3%, 123/756) of 106 patients (28.0%, 106/378). Type IB (early branches of the only one main renal artery) and IC (accessory renal artery with only one main renal artery) were found most frequently with an incidence of 11.4% (43/378) and 14.5% (55/378). The incidence of renal artery variations in the left kidney was not statistically different than in the right kidney (12.4% vs. 11.1%). The incidence of renal vein variations was detected in 104 patients (27.5%, 104/378). The incidence of venous variants in the right kidney was higher than in the left kidney (20.1% vs. 7.4%), but left renal vein variations were more complex. Variants of the left renal vein were detected in 28 patients including type 1 (circumaortic left renal vein) in eight cases, type 2 (retroaortic left renal vein) in seven cases, type 3 (abnormal reflux) in six cases, type 4 (late venous confluence of left renal vein) in five cases, and type 5 (rare type) in two cases. The frequency of left renal vein variation associated with the left renal accessory artery was significantly higher than with early branches of the left renal artery (P = 0.037).</p><p><b>CONCLUSIONS</b>The renal vascular variants are rather common and complex. DECT angiography can demonstrate the precise anatomy of the renal vessels, which is a benefit for renal transplantation or other renal operations.</p>

Assessment of bone marrow changes in postmenopausal women with varying bone densities: magnetic resonance spectroscopy and diffusion magnetic resonance imaging / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Recent studies suggest that bone marrow adipose tissue might play a role in the pathogenesis of osteoporosis. There are inconsistent findings on the relationship among marrow fat content, bone mineral density and apparent diffusion coefficient (ADC). This study aimed to prospectively explore the efficacy of MR spectroscopy (MRS) and diffusion-weighted MR imaging (DWI) in detecting vertebral marrow changes in postmenopausal women with varying bone densities.</p><p><b>METHODS</b>Both MRS and DWI of the lumber spine were performed in 102 postmenopausal women (mean age, (67.3 +/- 6.5) years; range, 55 - 83 years), who underwent dual X-ray absorptiometry. Marrow fat content and ADC were compared and correlated among three groups: 24 with normal bone density, 31 with osteopenia and 47 with osteoporosis.</p><p><b>RESULTS</b>Vertebral marrow fat content was significantly increased in the osteoporotic group ((65.60 +/- 7.68)%, P < 0.001) and the osteopenic group ((57.68 +/- 6.45)%, P < 0.001), when compared with the normal bone density group ((51.67 +/- 3.27)%). ADC values were significantly decreased in the osteoporotic group ((0.39 +/- 0.03) x 10(-3)mm(2)/s, P < 0.001) and in the osteopenic group ((0.42 +/- 0.02) x 10(-3)mm(2)/s, P < 0.001), when compared with the normal bone density group ((0.47 +/- 0.03) x 10(-3)mm(2)/s). The marrow fat content negatively correlated with both bone density (r = -0.731, P < 0.001) and marrow ADC (r = -0.572, P < 0.001). The bone density positively correlated with the ADC values (r = 0.802, P < 0.001).</p><p><b>CONCLUSIONS</b>Postmenopausal women experience a corresponding increase in vertebral marrow fat content as the bone density decreases. Marrow fat content and ADC correlate to the bone density. MRS and DWI may indirectly assess the early bone marrow changes in postmenopausal women.</p>

Value of fast dynamic contrast enhanced MRI in the diagnosis of orbital lesions / 眼科

Objective To study the value of fast dynamic contrast enhanced MRI in the diagnosis of orbital occupying lesions. Design Retrospective ease series.Participants 21 patients with orbital occupying lesions.Methods All the 21 patients were performed on fast dynamic contrast enhanced MRI and were verified by pathology.The raw datum were processed by the software of GE Functool. Parameters such as time-intensity curve(TIC),time to peak(Tpeak),1 minute enhancement ratio(ERlmin)and maximum enhancement ratio(ERmax)were analyzed to study the characteristics of orbital diseases on fast dynamic contrast-enhanced MRI.Main Outcome Measures TIC,ERlmin,and ERmax.Results The characteristics of TIC between benign diseases and malignant tumors were different. Of the 16 cases of benign lesions,12 demonstrated as continuous increasing type,and of 5 cases of malignant lesions,3 cases of lym- phoma were all platform type.The ER1min of the malignant tumors(150.47?42.18)was higher than that of the benign lesions (101.37?43.02)(P=0.021).Cavernous hemangiomas had special progressing enhancing model.Conclusions Fast dynamic contrast enhanced MRI is valuable to distinguish malignant tumors from benign occupying lesions.(Ophthalmol CHN,2007,16:305-308)