Staged endovascular recanalization for symptomatic atherosclerotic non-acutely occluded internal carotid artery.

OBJECTIVE: Symptomatic "non-acutely" occluded internal carotid artery (NAOICA) results in stroke, cognitive impairment, and hemicerebral atrophy through cerebral hypoperfusion and artery-to-artery embolism. Atherosclerosis is the main cause of NAOICA. Conventional one-stage endovascular recanalization showed effectiveness but was plagued by many challenges. This retrospective analysis reports the technical feasibility and outcomes of the staged endovascular recanalization in patients with NAOICA. METHODS: Eight consecutive patients with atherosclerotic NAOICA and ipsilateral ischemic stroke within 3 months between January 2019 and March 2022 were retrospectively reviewed. The patients (all males, with a mean age of 64.6 years) underwent staged endovascular recanalization 13 to 56 days after documented occlusion by imaging techniques (mean 28.8 days); the mean follow-up period was 20 months (range: 6-28). The approach of the staged intervention was as follows. In the first stage, the occluded ICA was successfully recanalized using the simple small balloon dilation technique. In the second stage, angioplasty with a stent implant was performed with >50% residual stenosis in the initial segment or ≥70% residual stenosis in the C2-C5 segment. The technical success rate, the incidence of clinical adverse events (any stroke, death, cerebral hyperperfusion), and long-term in-stent stenosis (ISR) and reocclusion rates were evaluated. RESULTS: Technical success was achieved in seven patients, with early reocclusion occurring in one patient after the first-stage intervention. There were no adverse events observed within 30 days (0%), and long-term reocclusion and long-term ISR rates were both 14% (1/7). However, all patients developed iatrogenic arterial dissections during the first stage, indicating the challenge of reaching the true lumen through the occlusion site without damaging the intima. Based on the National Heart, Lung and Blood Institute (NHLBI) classification, there were two type A, four type B, three type C, and two type D dissections. The mean time interval between the two stages was 46.1 days (21-152 days). All type A and B dissections resolved spontaneously after ≥3 weeks of dual antiplatelet therapy, whereas most type C and all type D dissections did not heal spontaneously before the second stage. Also, one type C dissection led to reocclusion. This observation suggested that dissections without flow limit and persistent vessel staining or extravasation could be clinically observed, while severe dissections (characterized as type C or greater) required prompt stenting rather than conservative treatment. Performing high-resolution MRI preoperatively to exclude fresh thrombus in the occluded vessel segment is indispensable in selecting appropriate candidates for endovascular recanalization. This could avoid downstream embolism during the interventional procedure. CONCLUSIONS: This retrospective study found that staged endovascular recanalization for symptomatic atherosclerotic NAOICA may be feasible with an acceptable technical success rate and a low complication rate in the selected candidates.

Gorham-Stout disease affecting the spine with cerebrospinal fluid leakage and Chiari-like tonsillar herniation: a rare case report and review of literature.

BACKGROUND: Gorham-Stout disease (GSD) is a very rare disorder characterized by massive osteolysis of poorly understood aetiology. The association between GSD involving the skull base and cerebrospinal fluid (CSF) leakage has been reported in the literature. However, few cases of CSF leakage and Chiari-like tonsillar herniation in GSD involving the spine have been reported. CASE PRESENTATION: We present the case of a 20-year-old man with GSD involving the thoracic and lumbar spine, which caused CSF leakage and Chiari-like tonsillar herniation. The patient underwent four spinal surgeries for osteolytic lesions of the spine over a 10-year period. Here, we discuss the possible aetiology of the development of CSF leakage. Epidural blood patch (EBP) was performed at the T11-T12 level to repair the CSF leakage. After EBP treatment, rebound intracranial hypertension (RIH) developed, and tonsillar herniation disappeared 2 months later. CONCLUSIONS: GSD involving the spine with CSF leakage and Chiari-like tonsillar herniation is relatively rare. For patients who have undergone multiple spinal surgeries, minimally invasive treatment is an alternative treatment for CSF leakage. EBP can repair CSF leakage secondary to GSD and improve chronic brain sagging, with reversibility of Chiari-like malformations.

MTL-ABS3Net: Atlas-Based Semi-Supervised Organ Segmentation Network With Multi-Task Learning for Medical Images.

Organ segmentation is one of the most important step for various medical image analysis tasks. Recently, semi-supervised learning (SSL) has attracted much attentions by reducing labeling cost. However, most of the existing SSLs neglected the prior shape and position information specialized in the medical images, leading to unsatisfactory localization and non-smooth of objects. In this paper, we propose a novel atlas-based semi-supervised segmentation network with multi-task learning for medical organs, named MTL-ABS3Net, which incorporates the anatomical priors and makes full use of unlabeled data in a self-training and multi-task learning manner. The MTL-ABS3Net consists of two components: an Atlas-Based Semi-Supervised Segmentation Network (ABS3Net) and Reconstruction-Assisted Module (RAM). Specifically, the ABS3Net improves the existing SSLs by utilizing atlas prior, which generates credible pseudo labels in a self-training manner; while the RAM further assists the segmentation network by capturing the anatomical structures from the original images in a multi-task learning manner. Better reconstruction quality is achieved by using MS-SSIM loss function, which further improves the segmentation accuracy. Experimental results from the liver and spleen datasets demonstrated that the performance of our method was significantly improved compared to existing state-of-the-art methods.

Medical Image Segmentation With Deep Atlas Prior.

Organ segmentation from medical images is one of the most important pre-processing steps in computer-aided diagnosis, but it is a challenging task because of limited annotated data, low-contrast and non-homogenous textures. Compared with natural images, organs in the medical images have obvious anatomical prior knowledge (e.g., organ shape and position), which can be used to improve the segmentation accuracy. In this paper, we propose a novel segmentation framework which integrates the medical image anatomical prior through loss into the deep learning models. The proposed prior loss function is based on probabilistic atlas, which is called as deep atlas prior (DAP). It includes prior location and shape information of organs, which are important prior information for accurate organ segmentation. Further, we combine the proposed deep atlas prior loss with the conventional likelihood losses such as Dice loss and focal loss into an adaptive Bayesian loss in a Bayesian framework, which consists of a prior and a likelihood. The adaptive Bayesian loss dynamically adjusts the ratio of the DAP loss and the likelihood loss in the training epoch for better learning. The proposed loss function is universal and can be combined with a wide variety of existing deep segmentation models to further enhance their performance. We verify the significance of our proposed framework with some state-of-the-art models, including fully-supervised and semi-supervised segmentation models on a public dataset (ISBI LiTS 2017 Challenge) for liver segmentation and a private dataset for spleen segmentation.

PA-ResSeg: A phase attention residual network for liver tumor segmentation from multiphase CT images.

PURPOSE: Liver tumor segmentation is a crucial prerequisite for computer-aided diagnosis of liver tumors. In the clinical diagnosis of liver tumors, radiologists usually examine multiphase CT images as these images provide abundant and complementary information of tumors. However, most known automatic segmentation methods extract tumor features from CT images merely of a single phase, in which valuable multiphase information is ignored. Therefore, it is highly demanded to develop a method effectively incorporating multiphase information for automatic and accurate liver tumor segmentation. METHODS: In this paper, we propose a phase attention residual network (PA-ResSeg) to model multiphase features for accurate liver tumor segmentation. A phase attention (PA) is newly proposed to additionally exploit the images of arterial (ART) phase to facilitate the segmentation of portal venous (PV) phase. The PA block consists of an intraphase attention (intra-PA) module and an interphase attention (inter-PA) module to capture channel-wise self-dependencies and cross-phase interdependencies, respectively. Thus, it enables the network to learn more representative multiphase features by refining the PV features according to the channel dependencies and recalibrating the ART features based on the learned interdependencies between phases. We propose a PA-based multiscale fusion (MSF) architecture to embed the PA blocks in the network at multiple levels along the encoding path to fuse multiscale features from multiphase images. Moreover, a 3D boundary-enhanced loss (BE-loss) is proposed for training to make the network more sensitive to boundaries. RESULTS: To evaluate the performance of our proposed PA-ResSeg, we conducted experiments on a multiphase CT dataset of focal liver lesions (MPCT-FLLs). Experimental results show the effectiveness of the proposed method by achieving a dice per case (DPC) of 0.7787, a dice global (DG) of 0.8682, a volumetric overlap error (VOE) of 0.3328, and a relative volume difference (RVD) of 0.0443 on the MPCT-FLLs. Furthermore, to validate the effectiveness and robustness of PA-ResSeg, we conducted extra experiments on another multiphase liver tumor dataset and obtained a DPC of 0.8290, a DG of 0.9132, a VOE of 0.2637, and a RVD of 0.0163. The proposed method shows its robustness and generalization capability in different datasets and different backbones. CONCLUSIONS: The study demonstrates that our method can effectively model information from multiphase CT images to segment liver tumors and outperforms other state-of-the-art methods. The PA-based MSF method can learn more representative multiphase features at multiple scales and thereby improve the segmentation performance. Besides, the proposed 3D BE-loss is conducive to tumor boundary segmentation by enforcing the network focus on boundary regions and marginal slices. Experimental results evaluated by quantitative metrics demonstrate the superiority of our PA-ResSeg over the best-known methods.

Effect of Portland Cement versus Sulphoaluminate Cement on the Properties of Blended Lime-Based Mortars Prepared by Carbide Slag.

In order to improve the properties of lime-based mortars and promote the green development of the construction industry, blended lime-based mortars were prepared by using carbide slag instead of hydrated lime, and the additions of Portland cement and sulphoaluminate cement were studied in our work. The paper focused on mechanical properties, porosity, capillary water absorption and drying shrinkage of both types of blended mortars. The chemical composition and microstructure of hydration products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that sulphoaluminate cement provided more contributions to mechanical properties, capillary water absorption and early shrinkage compared to Portland cement.

Deep Learning-Based Radiomics Models for Early Recurrence Prediction of Hepatocellular Carcinoma with Multi-phase CT Images and Clinical Data.

Hepatocellular carcinoma (HCC) is the fifth most common malignancy in the world and the second most common cause of cancer-related death. By surgically removing hepatocellular carcinoma, the patients may have the early recurrence within one year. Recently, CT radiomics signatures have been demonstrated to be effective on predicting early recurrence of HCC. However, the radiomics signatures are based on hand-crafted low-level features, such as density and texture. In this paper, we propose a deep learning-based radiomics approach for predicting early recurrence of hepatocellular carcinoma with multi-phase computed tomography (CT) images. We also propose several models to combine the high-level radiomics features with clinical data to improve the prediction accuracy. The area under the curve (AUC) of receiver operating characteristic curve (ROC) is 0.825.

Cerebral Venous Thrombosis in Spontaneous Intracranial Hypotension: A Report on 4 Cases and a Review of the Literature.

OBJECTIVE: Spontaneous intracranial hypotension is a risk factor for cerebral venous thrombosis. The occurrence of cerebral venous thrombosis in patients with spontaneous intracranial hypotension raises difficult practical questions regarding the management of the 2 conditions. We reviewed our experience and the relevant literature to evaluate these related questions. METHODS: We retrospectively studied the medical records and imaging studies of patients with spontaneous intracranial hypotension at a tertiary center from January 2007 through January 2017. The main search strategy was a literature review of journal articles in PubMed (1966 to January 2017). RESULTS: Among 374 patients with spontaneous intracranial hypotension, 4 were also diagnosed with cerebral venous thrombosis. A literature review yielded an additional 31 cases, including 21 men and 14 women with a mean age of 40.6 years. Of the 35 patients, 8 (22.8%) patients received anticoagulation therapy and epidural blood patch. Nineteen (54.3%) patients were given anticoagulant only. Seven (20%) patients were treated with epidural blood patch only. One (2.9%) patient did not receive epidural blood patch or anticoagulation therapy. There is no difference in terms of age, sex, diagnosis interval, association with other complications, and prognosis between the first 3 groups. Of the 19 patients who received anticoagulation therapy, 4 patients (21.1%) had intracranial hemorrhage or hematoma enlargement after anticoagulation, and one of these 4 patients died following further intracranial hemorrhage. Of the 8 patients who received both anticoagulation and epidural blood patch, 1 patient (12.5%, P = 0.528) developed subdural hematoma after anticoagulation. Of the 5 cases had intracranial hemorrhage aggravation after anticoagulation, 4 were subdural hematoma occurrence or enlargement. CONCLUSION: Cerebral venous thrombosis is a rare but important complication of spontaneous intracranial hypotension. The primary focus of treatment should be the treatment of intracranial hypotension. It could be possible that anticoagulation might increase the risk of intracranial hemorrhage in patients with spontaneous intracranial hypotension, although a firm conclusion could not be drawn based on the limited number of patients currently available. The use of anticoagulation therapy should be prudent and should be monitored carefully if initiated.

Targeted Epidural Blood Patch Treatment for Refractory Spontaneous Intracranial Hypotension in China.

Objective An epidural blood patch (EBP) is the mainstay of treatment for refractory spontaneous intracranial hypotension (SIH). We evaluated the treatment efficacy of targeted EBP in refractory SIH. Methods All patients underwent brain magnetic resonance imaging (MRI) with contrast and heavily T2-weighted spine MRI. Whole spine computed tomography (CT) myelography with non-ionic contrast was performed in 46 patients, and whole spine MR myelography with intrathecal gadolinium was performed in 119 patients. Targeted EBPs were placed in the prone position one or two vertebral levels below the cerebrospinal fluid (CSF) leaks. Repeat EBPs were offered at 1-week intervals to patients with persistent symptoms, continued CSF leakage, or with multiple leakage sites. Results Brain MRIs showed pachymeningeal enhancement in 127 patients and subdural hematomas in 32 patients. One hundred fifty-two patients had CSF leakages on heavily T2-weighted spine MRIs. CSF leaks were also detected on CT and MR myelography in 43 and 111 patients, respectively. Good recovery was achieved in all patients after targeted EBP. No serious complications occurred in patients treated with targeted EBP during the 1 to 7 years of follow-up. Conclusions Targeted and repeat EBPs are rational choices for treatment of refractory SIH caused by CSF leakage.

Large-diameter compression arteries as a possible facilitating factor for trigeminal neuralgia: analysis of axial and radial diffusivity.

BACKGROUND: Neurovascular compression (NVC) of the trigeminal nerve is associated with trigeminal neuralgia (TN). Some arteries that compress the trigeminal nerve are large, while others are small. This study evaluated the influence of diameter of compression arteries (DCA) on NVC with and without TN using axial diffusivity (AD) and radial diffusivity (RD) of magnetic resonance (MR) imaging. METHODS: Fifty TN patients with unilateral NVC, 50 asymptomatic patients with unilateral NVC, and 50 healthy controls (HC) were divided into three groups (NVC with TN, NVC without TN, and HC). The three groups were imaged with a 3.0-T MR system using three-dimensional fast imaging employing steady-state acquisition (3D FIESTA) and diffusion tensor imaging (DTI). We compared the mean size of DCA between NVC with and without TN. The mean values of AD and RD at the site of NVC were compared between the three groups. Correlation analyses were performed between the DCA and the diffusion metrics (AD and RD) in NVC patients with and without TN. RESULTS: The mean DCA in NVC patients with TN (1.58 ± 0.34 mm) was larger than that without TN (0.89 ± 0.29 mm). Compared with NVC without TN and HC, the mean values of RD at the site of NVC with TN were significantly increased; however, no significant changes of AD were found between the groups. Correlation analysis showed that DCA positively correlated with RD in NVC patients with and without TN (r = 0.830, p = 0.000). No significant correlation was found between DCA and AD (r = 0.178, p = 0.077). CONCLUSIONS: Larger-diameter compression arteries may increase the chances of TN, and may be a possible facilitating factor for TN.

Optimal Contrast of Cerebral Dual-Energy Computed Tomography Angiography in Patients With Spontaneous Subarachnoid Hemorrhage.

OBJECTIVE: The aim of this study was to investigate the image quality of cerebral dual-energy computed tomography (CT) angiography using a nonlinear image blending technique as compared with the conventional linear blending method in patients with spontaneous subarachnoid hemorrhage (SAH). METHODS: A retrospective review of 30 consecutive spontaneous SAH patients who underwent a dual-source, dual-energy (80 kV and Sn140 kV mode) cerebral CT angiography was performed with permission from hospital ethical committee. Optimized images using nonlinear blending method were generated and compared with the 0.6 linear blending images by evaluating cerebral artery enhancement, attenuation of SAH, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR), respectively. Two neuroradiologists independently assessed subjective vessel visualization per segment using a 5-point scale. RESULTS: The nonlinear blending images showed higher cerebral artery enhancement (307.24 ± 58.04 Hounsfield unit [HU]), lower attenuation of SAH (67.07 ± 6.79 HU), and image noise (7.18 ± 1.20 HU), thus achieving better SNR (43.92 ± 11.14) and CNR (34.34 ± 10.25), compared with those of linear blending images (235.47 ± 46.45 HU for cerebral artery enhancement, 70.00 ± 6.41 HU for attenuation of SAH, 8.39 ± 1.25 HU for image noise, 28.86 ± 8.43 for SNR, and 20.37 ± 7.74 for CNR) (all P < 0.01). The segmental scorings of the nonlinear blending image (31.6% segments with a score of 5, 57.4% segments with a score of 4, 11% segments with a score of 3) ranged significantly higher than those of linear blending images (11.5% segments with a score of 5, 77.5% segments with a score of 4, 11% segments with a score of 3) (P < 0.01). The interobserver agreement was good (κ = 0.762), and intraobserver agreement was excellent for both observers (κ = 0.844 and 0.858, respectively). CONCLUSIONS: The nonlinear image blending technique improved vessel visualization of cerebral dual-energy CT angiography by optimizing contrast enhancement in spontaneous SAH patients.

[Clinical characteristics of 42 cases of spontaneous intracranial hypotension with cerebrospinal leakage].

OBJECTIVE: To review the clinical characteristics of spontaneous intracranial hypotension (SIH) with cerebrospinal fluid (CSF) leakage. METHODS: Clinical data of 42 SIH patients with cerebrospinal leakage, whose diagnosis met the criteria of the International Headache Classification, were retrospectively reviewed. The patients were divided into short (n=27) and long (n=15) course groups. The clinical data and imaging features were compared between two groups. RESULTS: Thirty-nine patients (92.9%) had orthostatic headache. Compared with the short course group, the frequency of headache were significantly lower in patients with long disease duration (80% vs 100%, P =0.040); the ratio of high CSF opening pressure (>=60.0 mm H2O), the average CSF opening pressure, and the frequencies of subdural hematoma were higher in long course group than those in short course group [60.0% vs 20.8%, (64.7±42.1) vs (40.0±33.8)mm H2O, and 50.0% vs 11.6%; P=0.019, 0.038 and 0.018, respectively]. Forty-two patients underwent CT myelography;definite focal CSF leakage sites were found in all patients and multiple sites of CSF leakage in 38 patients. CONCLUSION: All SIH do not necessarily show the typical clinical manifestations, and cranial MRI and CT myelography are helpful in the diagnosis. Because of higher risk of subdural hemorrhage, patients with long disease duration require active intervention.

Vascular compression of the trigeminal nerve in asymptomatic individuals: a voxel-wise analysis of axial and radial diffusivity.

BACKGROUND: Neurovascular compression (NVC) of the trigeminal nerve is associated with trigeminal neuralgia (TN), but also occurs in many asymptomatic individuals. The purpose of this study was to investigate the possible microstructural tissue changes of trigeminal nerves (TGN) in asymptomatic individuals with NVC by using axial diffusivity (AD) and radial diffusivity (RD) of MR imaging and to discuss its underlying mechanisms. METHODS: Twenty asymptomatic individuals with unilateral NVC and 18 healthy controls (HCs) were divided into three groups (compressed, uncompressed side in asymptomatic individuals and HCs). Three groups were imaged with a 3.0-T MR system using three-dimensional fast imaging employing steady-state acquisition (3D FIESTA) and diffusion tensor imaging (DTI). We placed a region of interest over the root entry zone of the TGN and measured fractional anisotropy (FA), AD and RD. The mean values of FA, AD and RD were compared among the three groups. RESULTS: No significant changes in any of the diffusion metrics (FA, RD and AD) were found among the three groups (compressed, uncompressed side in asymptomatic individuals and HCs). CONCLUSIONS: Our study demonstrated that neither demyelination nor axonal injury is found in asymptomatic individuals with NVC.

Metal artifact reduction by dual-energy computed tomography using energetic extrapolation: a systematically optimized protocol.

OBJECTIVES: Energetic extrapolation is a promising strategy to reduce metal artifacts in dual-source computed tomography (DSCT). We performed this study to systematically optimize image acquisition parameters for this approach in a hip phantom and assess its value in a clinical study. MATERIALS AND METHODS: Titanium and steel hip prostheses were placed in a standard hip phantom and a water tank and scanned on a DSCT scanner. Tube spectra, tube current ratio, collimation, pitch, and rotation time were optimized in a stepwise process. Artifacts were quantified by measuring the standard deviation of the computed tomography density in a doughnut-shaped region of interest placed around the prosthesis. A total of 22 adult individuals with metallic implants referred for computed tomography for a musculoskeletal indication were scanned using the optimized protocol. Degree of artifacts and diagnostic image quality were rated visually (0-10) and maximum streak intensity was measured. RESULTS: Sn140/100 kVp proved superior to Sn140/80 kVp. There was a benefit for increasing tube current ratio from 1:1 to 3:1, but not beyond, in favor of the Sn140 kVp spectrum. Artifacts were less severe for a collimation of 32 × 0.6 mm as compared with 40 × 0.6 mm. A pitch of 0.5 at a rotation time of 0.5 seconds per rotation was preferable to other combinations with comparable scanning times. In the clinical study, increasing the extrapolated photon energy from 64 to 120 keV decreased the severity of artifacts from 8.0 to 2.0 (P < 0.001) and decreased streak intensity from 871 to 153 HU (P < 0.001). The median diagnostic image quality rating improved from 2.5 to 8.0 (P < 0.001). The median energy level visually perceived as optimal for diagnostic evaluation was 113 keV (range, 100-130 keV). CONCLUSIONS: Sn140/100 kVp with a tube current ratio of 3:1, a collimation of 32 × 0.6 mm, and extrapolated energies of 105 to 120 keV are optimal parameters for a dedicated DSCT protocol that effectively reduces metal artifacts by energetic extrapolation. The protocol effectively reduces metal artifacts in all types of metal implants. The optimized reconstructions yielded relevant additional findings.

Image quality and dose performance of 80 kV low dose scan protocol in high-pitch spiral coronary CT angiography: feasibility study.

To investigate the image quality and dose performance of 80 kV high-pitch spiral (HPS) coronary CT angiography (CCTA). 106 patients consecutively enrolled into prospectively ECG-triggering HPS CCTA (pitch = 3.4) exam using kV/ref. mAs = 80/400, 100/370, and 120/370 when patient BMI was ≤22.5 (n = 40), between 22.5 and 27.5 (n = 53) and >27.5 kg/m² (n = 13). Image quality was assessed per-segment by two observers independently using a 4-point scale (1-excellent, 4-non-diagnosable). Image noise and signal-to-noise ratio (SNR), contrast-to-noise ratio were measured. Diagnostic image quality was obtained in 503 of 507, 687 of 693, 164 of 167 coronary segments in 80, 100, 120 kV groups without significant difference (P = 0.482). The proportions of segments with score 1-4 were not significantly different among three kV groups (all P > 0.05). Image noise were significantly higher in 80 kV group than 100 and 120 groups (P < 0.001), while SNR was not (P = 0.097). The effective dose of 80 kV group (0.36 ± 0.03 mSv) was significantly lower than that of 100 kV group (0.86 ± 0.08 mSv) and 120 kV group (1.77 ± 0.18 mSv). The mean ± SD of HR in all patients was 54.8 ± 5.1 bpm. 80 kV HPS CCTA is feasible for patient with BMI ≤ 22.5 kg/m² which can save 58% dose than 100 kV group, while maintain diagnosable image quality.

[Researching the character and stenosis of coronary calcified plaques by using 16-slice spiral CT].

OBJECTIVE: To explore the characters of coronary calcified plaques by using 16-slice spiral CT and determine their stenosis degree according to the results of catheter coronary angiography. METHODS: Twenty patients who had received 16-slice spiral CT coronary angiography and conventional coronary angiography (CAG) were found to be with calcified plaques. The characters of these plaques, including the diameter of calcified plaques and lumen diameter of the exact artery segment, were retrospectively analyzed. The stenosis degree of the corresponding segment was judged in accordance with the results of CAG. RESULTS: Totally 84 calcified plaques were observed in 16-slice spiral CT images in these 20 patients. Among them there were 16 small nodules (diameter: < 0.15 cm), 56 purely calcified plaques (diameter: > or = 0. 15 cm), and 12 complex plaques with calcify component. There was no obvious stenosis in artery segments with little calcified nodules. The stenosis degree of most segments with purely calcified plaques (75%) was less than 50%. The stenosis degree had no significant correlation with the size of plaques (P > 0.05). However, the stenosis degree of complex plaques had much closer relationship with the characters of mixed plaques. CONCLUSIONS: Most coronary segments with calcified plaques have slight stenosis. Their stenosis degree is not related with the size of plaques. The stenosis degree of complex plaques has a closer relationship with the characters of mixed plaques.

[Functional MRI of human brain in musicians and non-musicians].

OBJECTIVE: To explore the differences in brain activation between musicians and non-musicians by use of functional MRI. METHODS: Twelve right-handed musicians and twelve right-handed non-musicians were recruited in the study. During a listening task, they were scanned on the Sigma 1.5T scanner (GE) while they were passively listening to several segments of music of "the Butterfly Love" and the white noise with same physical energy. RESULT: Both musicians and non-musicians demonstrated bilateral transverse gyrus weak activated while listening to the white noise. But when listening to music, they showed bilateral temporal areas strongly activated including superior temporal gyrus, transverse gyrus and some middle temporal areas. Moreover, musicians showed relative left dominance (10/12), whereas non-musicians demonstrated right dominance(11/12). Furthermore,besides bilateral temporal areas, more and stronger activated areas were found in musicians such as cuneus, precuneus,medial frontal and left middle occipital gyrus. CONCLUSION: There are different neuro-patterns between musicians and non-musicians.

Multi-detector CT enterography with iso-osmotic mannitol as oral contrast for detecting small bowel disease.

AIM: To assess the feasibility and usefulness of multi-detector CT enterography with orally administered iso-osmotic mannitol as negative contrast in demonstrating small bowel disease. METHODS: Thirteen volunteers and 38 patients with various kinds of small bowel disease were examined. We administered about 1 500 mL iso-osmotic mannitol as negative contrast agent and then proceeded with helical CT scanning on a Siemens Sensation 16 scanner. All volunteers and patients were interviewed about their tolerance of the procedure. Two radiologists post-processed imaging data with MPR, thin MIP, VRT and INSPACE when necessary and then interpreted the scans, and adequacy of luminal distention was evaluated on a four-point scale. Demonstration of features of various kinds of small bowel disease was analyzed. RESULTS: The taste of iso-osmotic mannitol is good (slightly sweet) and acceptable by all. Small bowel distention was excellent and moderate in most volunteers and patients. CT features of many kinds of diseases such as tumors, Crohn's disease,and small bowel obstruction, etc. were clearly displayed. CONCLUSION: Multi-detector CT enterography with iso-osmotic mannitol as negative contrast to distend the small bowel is a simple, rapid, noninvasive and effective method of evaluating small bowel disease.