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Objective: To explore the application value of free-breathing Star volumetric interpolated breath-hold examination (StarVIBE) sequence for acquisition of chest T1WI. Methods: Data of 37 patients with chest lesions detected with CT were collected. The patients were divided into unable-to-hold-breath group (n=17) and able-to-hold-breath group(n=20) according to whether they could hold breath for 20 s or not. Then all patients underwent plain and delayed phase enhanced StarVIBE sequence and conventional VIBE sequence MR examinations. Imaging qualities were evaluated using "5-point scale" in terms of lesion conspicuity, artifact, pulmonary vessels sharpness, mediastinal structures conspicuity and overall quality, and then were compared between sequences and groups, respectively. Results: In unable-to-hold-breath group, the scores of StarVIBE sequence were higher than those of conventional VIBE sequence on both plain and enhanced images (all P0.05), and the scores of artifact and the overall image quality were not statistically different between two sequences (all P>0.05). However, in able-to-hold-breath group, StarVIBE sequence demonstrated higher score of pulmonary vessels sharpness on both plain and enhanced images (P<0.05). Conclusion: For acquisition of chest T1WI, using free-breathing StarVIBE sequence can achieve similar image quality to conventional VIBE sequence patients being able to breath-holding. For patients being unable to hold breath, relative good image quality could be obtained using free-breathing StarVIBE sequence.
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Objective: To investigate the value of CT radiomics for preoperative prediction of gastric cancer lymphovascular invasion. Methods: Totally 181 patients with gastric cancer confirmed by surgical pathology were retrospectively collected and randomly divided into training set (n=120) and verification set (n=61). Firstly, the tumor area was delineated and segmented, and the radiomics features were extracted based on enhanced CT venous phase images. Then, the training set was used to screen features associated with lymphovascular invasion, and a radiomics signature was built. Finally, the model was validated based on the verification set, and ROC curve and calibration curve were used to assess the model's predictive power and fit assessment. Results: Seven radiomics features most relevant to lymphovascular invasion of gastric cancer were extracted and used to build the radiomics signature. The AUC of the training set was 0.742 (P=0.001, 95%CI [0.652, 0.831]), of the verification set was 0.727 (P=0.002, 95%CI [0.593, 0.853]). The optimal threshold based on the training set was 0.422. The accuracy, sensitivity and specificity of the model in the training set was 0.708, 0.586 and 0.806, respectively. This threshold was used for the verification set with accuracy, sensitivity, and specificity of 0.689, 0.519 and 0.824, respectively. The calibration curve showed that the radiomics signature had a good fit in both the training set and the verification set (both P>0.05). Conclusion: CT radiomics can be used as a novel non-invasive imaging method for preoperatively predicting lymphovascular invasion in gastric cancer.
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Objective The aim of this study was to investi-gate the changes of brain function in patients with drug-naive idiopath-ic epilepsy ( DNIE ) using resting-state functional MRI ( rs-fMRI ) amplitude of low-frequency fluctuation ( ALFF) , analyze the correlation of abnormal brain regions with the clinical variable ( disease course) , and gain a deeper insight into the pathophysiological mechanisms of idiopathic epilepsy. Methods This study included 25 cases of DNIE (15 males and 10 females) and 34 cases of drug idiopathic epilepsy (DIE, 22 males and 12 females).Another 25 healthy volunteers matched with the DNIE patients in sex, age, education and handedness were recruited as normal controls.The rs-fMRI data obtained from all the subjects were processed, subjected to ALFF analysis, and compared among the DNIE, DIE, and nor-mal control groups.The correlation was evaluated between the ALFF statistical brain mapping and the course of disease. Results Obvious differences were found in ALFF among the DNIE, DIE and control subjects.Compared with the normal controls, the DNIE pa-tients showed increased ALFF in the right inferior temporal gyrus, right lingual gyrus and right cuneus, but decreased ALFF in the right insula, left hippocampus, right midbrain, right middle frontal gyrus, left anterior cingulated gyrus, left middle cingulate gyrus and right inferior parietal lobule.In comparison with the DIE patients, those of the DNIE group exhibited increased ALFF in the left inferior occipital gyrus, right middle occipital gyrus and left middle occipital gyrus, but decreased ALFF in the right inferior frontal gyrus, left insula, right superior temporal gyrus and right middle frontal gyrus.In the DNIE patients, the disease course was found to be correlated positively with ALFF in the right cerebellum posterior lobe, left cerebellar tonsil, right lingual gyrus, left orbital gyrus, left middle oc-cipital gyrus, left corpus callosum, left caudate nuclear, left superior frontal gyrus, left medial frontal gyrus, right precuneus and left middle frontal gyrus, but negatively with ALFF in the right parahippocampal, right superior temporal gyrus, left superior temporal gyrus and right post-central gyrus. Conclusion The ALFF of resting-state cerebral function is abnormal in DNIE patients.The correlation between ALFF and the clinical variable ( disease course) provides a new insight into the pathophysiological mechanisms of epilepsy.