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PURPOSE: Imaging plays a significant role in diagnosing leptomeningeal metastases. However, the most appropriate sequence for the detection of leptomeningeal metastases has yet to be determined. This study compares the efficacies of contrast-enhanced T2 fluid attenuated inversion recovery (FLAIR) and contrast-enhanced 3D T1 black-blood fast spin echo (FSE) imaging for the detection of leptomeningeal metastases. MATERIALS AND METHODS: Tube phantoms containing varying concentrations of gadobutrol solution were scanned using T2 FLAIR and 3D T1 black-blood FSE. Additionally, 30 patients with leptomeningeal metastases were retrospectively evaluated to compare conspicuous lesions and the extent of leptomeningeal metastases detected by T2 FLAIR and 3D T1 black-blood FSE. RESULTS: The signal intensities of low-concentration gadobutrol solutions (< 0.5 mmol/L) on T2 FLAIR images were higher than in 3D T1 black-blood FSE. The T2 FLAIR sequences exhibited significantly greater visual conspicuity scores than the 3D T1 black-blood sequence in leptomeningeal metastases of the pial membrane of cistern (P = 0.014). T2 FLAIR images exhibited a greater or equal extent (96.7%) of leptomeningeal metastases than 3D T1 black-blood FSE images. CONCLUSION: Because of its high sensitivity even at low gadolinium concentrations, contrast-enhanced T2 FLAIR images delineated leptomeningeal metastases in a wider territory than 3D T1 black-blood FSE.
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Humanos , Gadolínio , Membranas , Metástase Neoplásica , Estudos RetrospectivosRESUMO
Objective To investigate the application value of time-spatial labeling inversion pulse (T-SLIP) in renal corticomedullary differentiaton and the best black blood inversion time (BBTI) value.Methods Totally 60 volunteers were included,who underwent abdominal MR scan with noncontrast-enhanced SSFP sequence combined with T-SLIP.All subjects were scanned with different BBTI (800,1 000,1 200,1 400,1 600,1 800 ms) using coronary T-SLIP SSFP sequence.The images quality was evaluated using a four-point scale method.The region of renal cortex and medulla was devised automatically based on the image training algorithm.The signal intensity ratio with the different BBTI was calculated through measuring the signal intensity of the renal cortex and medulla.And the best BBTI values were analyzed.Results When BBTI was 1 200 ms,the image score was the highest.The signal intensity ratio (SIR) had statistical difference among different BBTI groups (all P＜0.05),when BBTI was 1 200 ms,the SIR was the highest,and the contrast between the renal cortex and medulla was obvious.Conclusion T-SLIP technology can improve the visibility of renal corticomedullary without contrast agents.The optimal BBTI for the best corticomedullary differentiation is 1 200 ms.
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Objective To evaluate the value of magnetic resonance black-blood thrombus imaging (BTI) of the stage of disease in intracranial venous and sinus thrombosis(CVT).Methods From June 2015 to October 2016,37 patients with CVT diagnosed with routine imaging examinations in Beijing Xuanwu Hospital,Capital Medical University were enrolled prospectively,and they also underwent BTI examination.The patients were randomly divided into either a acute group (≤14 d,n=23) or a chronic group (>15 d,n=14) according to the time from the onset of symptoms to BTI.Signal to noise ratio(SNR) and contrast to noise ratio(CNR) difference between acute and chronic CVT groups were compared.The magnetic resonance venography (MRV) examination was used as a reference to calculate the accuracy of BTI on per-segment level.Results (1) The SNR and CNR of thrombosis in the acute group and chronic group were 206±97 and 94±41,201±96 and 86±40,respectively.There was significant difference between two groups (t=4.9 and 5.0 respectively;all P<0.01).(2) In 37 patients with CVT,the thrombi in 159 cerebral veins and venous sinus segments were detected with MRV.BTI identified the thrombi accurately in 152 vascular segments,and the thrombi in 352 vascular segments were eliminated.The diagnostic sensitivity and specificity were 95.6% (152/159) and 98.0% (352/359) respectively.Conclusion Achieving direct angiography of cerebral venous thrombosis,BTI technique can accurately differentiate acute or chronic thrombus.It has higher accuracy.