Yi Sheng Liu

Carpal tunnel syndrome assessed with diffusion tensor imaging: Comparison with electrophysiological studies of patients and healthy volunteers

The main goal of this study was to investigate the applicability of parameters derived from diffusion tension imaging (DTI) in diagnosing carpal tunnel syndrome (CTS). Forty subjects were recruited, of which 19 were normal controls and 21 belonged to the CTS group. DTI of median nerves evaluated at 4 levels of the wrist (distal radius, pisiform bone, middle portion of the carpal tunnel, and hamate bone) and conventional MRI of the wrist was performed in normal and CTS subjects in two finger postures (extension and flexion). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were derived from DTI, and parameters related to abnormal hyperintensity of the median nerve were derived from conventional MRI. Electrophysiological tests, including nerve conduction velocity and F wave were also performed for comparison. The results of FA and ADC measurements did not depend on the measuring location and finger posture. Mean FA was decreased while mean ADC was increased by CTS. FA and ADC at the middle portion of the carpal tunnel was 0.47±0.05 and 1.37±0.12 (×10(-3) mm2/s) for the control group and 0.42±0.04 and 1.50±0.15 (×10(-3) mm2/s) for the CTS group, respectively. The linear correlations of FA and ADC versus electrophysiological indicators of CTS were significant (R2 ranged from 0.09 to 0.36), indicating FA and ADC from DTI had significant correlation with the existence and severity of CTS.

MR grading system of osteochondritis dissecans lesions: Comparison with arthroscopy

OBJECTIVE To assess the diagnostic performance of combined three-dimensional (3D) gradient-echo (GRE) T1-weighted and routine MR imaging protocol for the evaluation of osteochondritis dissecans (OCD). MATERIALS AND METHODS This prospective study was approved by our institutional review board and all patients gave informed consent. Three-dimensional GRE MR sequence was added to the routine protocol performed on 40 consecutive patients (35 men, 5 women; age range, 12-57 years; mean age, 20 years) with 17 juvenile and 24 adult OCD lesions (27 in knees; 14 in elbows) which were confirmed by arthroscopy. Two independent musculoskeletal radiologists reviewed all MR images. The OCD lesions were classified into five stages by assessing the signal intensity of fragment-bone interface and the integrity of articular cartilage on MR images. Stage-IV and -V lesions were considered as unstable. The sensitivity, specificity, accuracy, and interobserver agreement (κ statistics) were calculated. RESULTS The sensitivity, specificity, and accuracy for detection of OCD instability were 100% (11 of 11), 100% (6 of 6), and 100% (17 of 17) in juvenile lesions; and 93% (14 of 15), 100% (9 of 9), and 96% (23 of 24) in adult lesions. The overall accuracy of MR findings in determining the staging was 90% (37 of 41) for reader 1 and 83% (34 of 41) for reader 2. Agreement between readers was substantial with a κ value of 0.75 for MR staging of OCD lesions. CONCLUSIONS Three-dimensional GRE T1-weighted MR imaging combined with the routine sequences demonstrates excellent diagnostic capabilities in detecting unstable OCD lesions.

Differentiating Radiation-Induced Necrosis from Recurrent Brain Tumor Using MR Perfusion and Spectroscopy: A Meta-Analysis.

Purpose This meta-analysis examined roles of several metabolites in differentiating recurrent tumor from necrosis in patients with brain tumors using MR perfusion and spectroscopy. Methods Medline, Cochrane, EMBASE, and Google Scholar were searched for studies using perfusion MRI and/or MR spectroscopy published up to March 4, 2015 which differentiated between recurrent tumor vs. necrosis in patients with primary brain tumors or brain metastasis. Only two-armed, prospective or retrospective studies were included. A meta-analysis was performed on the difference in relative cerebral blood volume (rCBV), ratios of choline/creatine (Cho/Cr) and/or choline/N-acetyl aspartate (Cho/NAA) between participants undergoing MRI evaluation. A χ2-based test of homogeneity was performed using Cochran’s Q statistic and I2. Results Of 397 patients in 13 studies who were analyzed, the majority had tumor recurrence. As there was evidence of heterogeneity among 10 of the studies which used rCBV for evaluation (Q statistic = 31.634, I2 = 97.11%, P < 0.0001) a random-effects analysis was applied. The pooled difference in means (2.18, 95%CI = 0.85 to 3.50) indicated that the average rCBV in a contrast-enhancing lesion was significantly higher in tumor recurrence compared with radiation injury (P = 0.001). Based on a fixed-effect model of analysis encompassing the six studies which used Cho/Cr ratios for evaluation (Q statistic = 8.388, I2 = 40.39%, P = 0.137), the pooled difference in means (0.77, 95%CI = 0.57 to 0.98) of the average Cho/Cr ratio was significantly higher in tumor recurrence than in tumor necrosis (P = 0.001). There was significant difference in ratios of Cho to NAA between recurrent tumor and necrosis (1.02, 95%CI = 0.03 to 2.00, P = 0.044). Conclusions MR spectroscopy and MR perfusion using Cho/NAA and Cho/Cr ratios and rCBV may increase the accuracy of differentiating necrosis from recurrent tumor in patients with primary brain tumors or metastases.

Image Characteristics as Predictors for Thoracoscopic Anatomic Lung Resection in Patients With Pulmonary Tuberculosis

BACKGROUND A variety of complications occur in patients with pulmonary tuberculosis. The feasibility of a thoracoscopic approach to anatomic lung resection for the complications of mycobacterial infection has not been well evaluated. METHODS We retrospectively analyzed chest computed tomography (CT) scans of patients who underwent anatomic lung resections without additional procedures for tuberculosis between January 2007 and September 2009. Image characteristics on chest CT scans were classified as bullae, pleural thickening, peribronchial lymph node calcification, tuberculoma, cavity, aspergilloma, atelectasis, and bronchiectasis, and graded according to the number of the lesions and degree of lobar involvement. Patients were divided into two groups, video-assisted thoracoscopic surgery (VATS) and thoracotomy for anatomic lung surgery, according to the eventual operative procedure. The variables between these two groups were compared using the Student t test; the image characteristics were compared using a χ2 test. RESULTS Fifty patients were enrolled; 21 given VATS and 29 given a thoracotomy. The VATS group had significantly lower gradings in pleural thickening, peribronchial lymph node calcification, tuberculoma, cavity, and aspergilloma than did the thoracotomy group (p=0.000, 0.015, 0.001, 0.023, and 0.022, respectively). Mean operative time, blood loss, and complication rate were not significantly different, but the mean hospital stay was significantly shorter (10.00 days versus 14.96 days, p=0.048) in the VATS group. CONCLUSIONS Multiple cavities, multiple aspergillomas, multilobar tuberculoma, extensive pleural thickening, and peribronchial lymph node calcification preclude VATS. It is reasonable to attempt a thoracoscopic approach in patients without these preoperative image characteristics.

Transarterial chemoembolization using gelatin sponges or microspheres plus lipiodol-doxorubicin versus doxorubicin-loaded beads for the treatment of hepatocellular carcinoma.

Objective To retrospectively compare treatment of hepatocellular carcinoma (HCC) with transarterial chemoembolization (TACE) using gelatin sponges or microspheres plus lipiodol-doxorubicin vs. doxorubicin-loaded drug-eluting beads (DEB). Materials and Methods A total of 158 patients with HCC received TACE from November 2010 to November 2011 were enrolled in this study, including 64 (40.5%) received TACE with lipiodol-doxorubicin and gelatin sponges (group A), 41 (25.9%) received TACE with lipiodol-doxorubicin and microspheres (group B), and 53 (33.5%) received TACE with doxorubicin-loaded DEB (group C). Tumor response and adverse events (AEs) were evaluated. Results No significant difference was found at baseline among the three groups. The doxorubicin dosage in group C was significantly (p < 0.001) higher compared to the dose used in groups A or B (median, 50 mg vs. 31 mg or 25 mg). Significantly (p < 0.001) more patients in group C achieved complete response compared to those in groups A or B (32.1% vs. 6.3% or 2.4%). Significantly (p < 0.001) less patients in group C had progressive disease compared to those in groups A or B (34.0% vs. 57.8% or 68.3%). Minor AEs were more common in groups A and B compared to group C, with rates of 54.7%, 34.1%, and 5.7%, respectively. Conclusion In patients with HCC, TACE with DEB offers better safety and efficacy profiles compared to either TACE with gelatin sponges or TACE with microspheres.

The Role of Video-Assisted Thoracoscopic Therapeutic Resection for Medically Failed Pulmonary Tuberculosis.

AbstractThere are few reports regarding video-assisted thoracoscopic therapeutic resection for medically failed pulmonary tuberculosis (TB). We reviewed our surgical results of video-assisted thoracoscopic surgery (VATS) therapeutic resection for pulmonary TB with medical failure, and its correlation with image characteristics on chest computed tomography (CT) scan.Between January 2007 and December 2012, among the 203 patients who had surgery for TB, the medical records of 89 patients undergoing therapeutic resection for medically failed pulmonary TB were reviewed. Clinical information and the image characteristics of CT scan were investigated and analyzed.Forty-six of the 89 patients undergoing successful VATS therapeutic resection had significantly lower grading in pleural thickening (P < 0.001), peribronchial lymph node calcification (P < 0.001), tuberculoma (P = 0.015), cavity (P = 0.006), and aspergilloma (P = 0.038); they had less operative blood loss (171.0 ± 218.7 vs 542.8 ± 622.8 mL; P < 0.001) and shorter hospital stay (5.2 ± 2.2 vs 15.6 ± 15.6 days; P < 0.001). They also had a lower percentage of anatomic resection (73.9% vs 93.0%; P = 0.016), a higher percentage of sublobar resection (56.5% vs 32.6%; P = 0.023), and a lower disease relapse rate (4.3% vs 23.3%; P = 0.009). Eighteen of the 38 patients with multi-drug resistant pulmonary tuberculosis (MDRTB) who successfully underwent VATS had significantly lower grading in pleural thickening (P = 0.001), peribronchial lymph node calcification (P = 0.019), and cavity (P = 0.017). They were preoperatively medicated for a shorter period of time (221.6 ± 90.8 vs 596.1 ± 432.5 days; P = 0.001), and had more sublobar resection (44.4% vs 10%), less blood loss (165.3 ± 148.3 vs 468.0 ± 439.9 mL; P = 0.009), and shorter hospital stay (5.4 ± 2.6 vs 11.8 ± 6.9 days; P = 0.001).Without multiple cavities, peribronchial lymph node calcification, and extensive pleural thickening, VATS therapeutic resection could be safely performed in selected patients with medically failed pulmonary TB as an effective adjunct with satisfactory results.

Use of carbon dioxide as negative contrast agent for magnetic resonance cholangiopancreatography

AIM To evaluate the effects of using CO(2) as negative contrast agent in decreasing the overlapping on the pancreaticobiliary system from intestinal fluids. METHODS We evaluated the magnetic resonance cholangiopancreatography (MRCP) images in 117 patients divided into two groups (group 1, without taking gas producing crystals to produce CO(2), n = 64; group 2, with CO(2), n = 53) in a 1.5T unit using MRCP sequence. Anatomic locations of intestinal fluids distribution, overlapping with common bile duct (CBD) and pancreatic duct (PD), were evaluated. RESULTS In the group with CO(2), the decrease in distribution of intestinal fluids was significant in the gastric antrum (P = 0.001) and duodenal bulb (P < 0.001), but not in the gastric fundus and body and in the second portion of the duodenum (P = 1.000, P = 0.171, and P = 0.584 respectively). In the group with CO(2), the decrease in overlapping with CBD was significant (P < 0.001), but the decrease in overlapping with PD was not (P = 0.106). CONCLUSION MRCP with carbon dioxide as negative contrast agent would decrease intestinal fluids in the gastric antrum and duodenal bulb, thereby decreasing overlapping with the CBD.

Quantitative assessment of iron in heart and liver phantoms using dual‑energy computed tomography

The aim of the present study was to determine the correlation between dual-energy computed tomography (DECT) Hounsfield units (HU) and iron concentration, as well as the correlation between HU and magnetic resonance imaging (MRI)-derived R2* values, in phantoms of the heart and liver tissue. Phantoms were constructed containing pig heart or liver tissue and varying concentrations of iron (0.1, 5, 10, 15, 20 and 25 mg/ml). The phantoms were then examined by DECT and MRI. Linear regression analysis was used to determine the correlations between HU and iron concentration and HU and R2* values. The HU value of DECT increased with increasing iron concentrations in the liver and heart phantoms in a linear manner. The slope of the HU value change against iron concentration revealed that ΔH80–140 provided a better discernment of iron concentration as compared with ΔH100–140. The derived R2 values were all >0.9 for the associations of DECT and MRI measurements with iron concentrations. Therefore, DECT may be used for the determination of iron concentration in the liver and heart tissue, with the results correlating with those obtained with MRI.

A novel method for the angiographic estimation of the percentage of spleen volume embolized during partial splenic embolization

PURPOSE To evaluate the efficacy of estimating the volume of spleen embolized in partial splenic embolization (PSE) by measuring the diameters of the splenic artery and its branches. MATERIALS AND METHODS A total of 43 liver cirrhosis patients (mean age, 62.19±9.65 years) with thrombocytopenia were included. Among these, 24 patients underwent a follow-up CT scan which showed a correlation between angiographic estimation and measured embolized splenic volume. Estimated splenic embolization volume was calculated by a method based on diameters of the splenic artery and its branches. The diameters of each of the splenic arteries and branches were measured via 2D angiographic images. Embolization was performed with gelatin sponges. Patients underwent follow-up with serial measurement of blood counts and liver function tests. The actual volume of embolized spleen was determined by computed tomography (CT) measuring the volumes of embolized and non-embolized spleen two months after PSE. RESULTS PSE was performed without immediate major complications. The mean WBC count significantly increased from 3.81±1.69×10(3)/mm(3) before PSE to 8.56±3.14×10(3)/mm(3) at 1 week after PSE (P<0.001). Mean platelet count significantly increased from 62.00±22.62×10(3)/mm(3) before PSE to 95.40±46.29×10(3)/mm(3) 1 week after PSE (P<0.001). The measured embolization ratio was positively correlated with estimated embolization ratio (Spearmans rho [ρ]=0.687, P<0.001). The mean difference between the actual embolization ratio and the estimated embolization ratio was 16.16±8.96%. CONCLUSIONS The method provides a simple method to quantitatively estimate embolized splenic volume with a correlation of measured embolization ratio to estimated embolization ratio of Spearmans ρ=0.687.

Isolated oculomotor nerve palsy caused by diffuse large B cell lymphoma.

A 51-year-old woman presented to neurosurgery clinic with progressive dropped right eyelid accompanied with blurred vision for 1 month. Neurological examination revealed anisocoria (R/L: 5 mm/3 mm), diminished right light reflex, and complete extraocular paresis, findings suggesting complete oculomotor nerve palsy. MRI showed enhancement of enlarged cisternal segment of right oculomotor nerve between superior cerebellar artery and posterior cerebral artery (Fig. 1). Differential diagnoses included schwannoma and lymphoma. Surgery was performed and pathology revealed diffuse large B cell lymphoma. She was treated with intravenous methotrexate (3.5 g/m) and methylprednisolone (200 mg/m) followed by concurrent chemoradiation of oral temozolomide (75 mg/m/day) and whole brain radiotherapy (36 Gy). After treatment, the oculomotor nerve palsy did not recover, but follow-up MRI revealed only minimal residual tumor at interpeduncular cistern. Isolated oculomotor nerve palsy from lymphoma is rare [1]. Those with large B cell lymphoma seem most likely to develop oculomotor nerve palsy [1].