Ming Tsung Chuang

Bone Marrow Edema in Vertebral Compression Fractures: Detection with Dual-Energy CT

PURPOSE To assess the use of the dual-energy computed tomographic (CT) virtual noncalcium technique in the evaluation of bone marrow edema in vertebral compression fractures. MATERIALS AND METHODS This prospective study was approved by the institutional review board; informed consent was obtained from all patients. Sixty-three consecutive patients with 112 thoracic and/or lumbar vertebral compression fractures were studied between January 2011 and April 2012. All patients underwent both dual-energy CT (100 kV and Sn140 kV, where Sn indicates the use of a 0.4-mm tin filter) and magnetic resonance (MR) imaging. Dual-energy CT data were postprocessed by using a three-material decomposition algorithm for generating noncalcium images of the collapsed bodies. Two radiologists evaluated for the presence of abnormal attenuation alterations in the bone marrow by using color-coded maps and measured CT numbers on noncalcium grayscale images. Bone sclerosis and intravertebral air were evaluated with CT scans. MR images served as the reference standard. CT numbers were subjected to receiver operating characteristic curve analysis. RESULTS MR imaging depicted 46 edematous and 66 nonedematous vertebral compression fractures. Eighty-two bodies were classified as having less than 50% sclerosis and/or air. Significant differences in noncalcium CT numbers between edematous and nonedematous vertebral compression fractures were found for both readers (P < .0001). CT numbers for the diagnosis of bone marrow edema on the basis of MR imaging revealed areas under the receiver operating characteristic curve of 0.799 and 0.841 for readers 1 and 2, respectively (P = .56). Use of a cutoff value of -80 to differentiate edematous vertebral bodies resulted in a sensitivity of 96.3%, specificity of 98.2%, and accuracy of 97.6% in the group of vertebral bodies with less than 50% sclerosis and/or air. CONCLUSION Dual-energy CT virtual noncalcium images were able to depict bone marrow in the collapsed vertebral bodies, especially in those with less than 50% sclerosis and/or air.

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.

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.

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.

A CT-guided fat transversing coaxial biopsy technique for pancreatic lesion biopsy that avoids major organs and vessels

Background/Aims: The purpose of this study is to report our results using a computed tomography (CT)-guided fat transversing coaxial biopsy technique for pancreatic lesion biopsy that avoids major organs and vessels. We retrospectively reviewed the records of patients referred to our department for pancreatic mass biopsy. Patients and Methods: The records of patients (from June 2008 to August 2014) in whom biopsy was performed under CT guidance with a coaxial needle using a fat transversing technique were reviewed. Patient demographic data and biopsy outcomes were collected. We aimed to compare differences between lesion size and biopsy outcome, the independent two-samples t-test was used. Results: A total of 122 patients who underwent 17-G coaxial needle biopsy were included. The mean pancreatic lesion size was 3.2 cm, and in 30 patients it was more than 4 cm. The majority of lesions were located in the head of the pancreas (44.3%). No transorgan biopsies were performed. In most patients, the biopsy was performed via a fat traversing detour route (93.4%), and a successful diagnosis was made based on the biopsy outcome in 96.7% patients. Complications occurred in five patients (4.1%); three of the patients developed a fever, and two developed pancreatitis. All patients recovered with symptomatic treatment. Conclusion: CT-guided coaxial core biopsy of pancreatic lesions using a fat detour route appears to be a safe and effective method for obtaining pancreatic lesion biopsies with a high success rate and low complication rate.

Lung density standard deviations obtained using high-pitch dual-source computed tomography are valid predictors of bronchopulmonary dysplasia in preterm infants.

PURPOSE This study aimed to validate standard deviations of lung densities obtained using high-pitch dual-source computed tomography (DSCT) densitometry as indices of bronchopulmonary dysplasia (BPD) severity in premature infants. METHODS Data of preterm, late preterm group, and early term groups were evaluated. Mean and median standard deviations (SDmean, SDmedian) of CT lung density (CTLD) were calculated from CT images. RESULTS SDmean of CTLD in infants with severe BPD was significantly higher than that of infants without BPD (198.1 vs. 140.9, respectively; P=.002). CONCLUSIONS Study results support using high-pitch DSCT for BPD diagnosis and quantitative evaluation in prematurity.

Diffusion-weighted imaging as an aid in the diagnosis of the etiology of medial longitudinal fasciculus syndrome

PurposeInternuclear ophthalmoplegia is caused by a lesion; stroke, multiple sclerosis, brain metastases, or trauma may produce lesions of the medial longitudinal fasciculus (MLF). Imaging techniques, such as DWI, can help identify the site of the lesion in order to speed diagnosis and lead to appropriate treatment.MethodsOver an 8-month period, eight consecutive patients with suspected MLF syndrome (most secondary to ischemic stroke) underwent MRI examinations, including DWI sequencing, at an academic center in Taiwan.ResultsIn all eight patients, abnormal high-signal lesions were found close to the floor of the fourth ventricle on the dorsal side of the pons. A neuroanatomical comparison showed that the location of the lesions was identical to the anatomical position of the MLF.ConclusionUsing DWI, good clinico-radiological correlation was found in all eight ischemic stroke patients diagnosed with MLF syndrome. DWI may broaden the application of MRI in the diagnosis of MLF syndrome.

Shielding during x-ray examination of pediatric female patients with developmental dysplasia of the hip

Patients with developmental dysplasia of the hip (DDH) generally undergo multiple x-ray examinations of both hip joints. During these examinations, the gonads are completely exposed to radiation, unless shielded. Although many types and sizes of gonad shields exist, they often do not provide adequate protection because of size and placement issues; additionally, these shields are frequently omitted for female patients. Our aim was to assess gonad protection during x-ray examination that is provided by gonad shields designed for individual female patients with DDH.We retrospectively retrieved data from the Picture Archiving and Communication System database; pelvic plain x-ray films from 766 females, 18 years old or younger, were included in our analysis. Based on x-ray measurements of the anterior superior iliac spine, we developed a system of gonad shield design that depended on the distance between anterior superior iliac spine markers. We custom-made shields and then examined shielding rates and shielding accuracy before and after these new shields became available. Standard (general-purpose) shields were used before our custom design project was implemented. The shielding rate and shielding accuracy were, respectively, 14.5% and 8.4% before the project was implemented and 72.7% and 32.2% after it was implemented. A shield that is more anatomically correct and available in several different sizes may increase the likelihood of gonad protection during pelvic x-ray examinations.

Nefrostomia percutanea eseguita su reni con una sottile corticale renale: studio retrospettivo sulla produzione giornaliera di urina in 46 procedure di nefrostomia

Purpose. This study investigated whether a thin renal cortex or any morphological kidney measurements can be predictors of post percutaneous nephrostomy (PCN) renal function, thereby lessening the need for the procedure. Materials and methods. All patients underwent unilateral PCN that were performed under sonographic and fluoroscopic guidance. Kidney morphological measurements were subsequently taken to measure residual renal function; a thin renal cortex was defined from a computed tomography (CT) showing a cortical thickness <10 mm. Urine output was recorded daily, with patients divided into anuric and nonanuric groups. Results. Morphological measurements of residual renal function, such as renal length (p=0.004), renal width (p=0.004), renal thickness (p=0.008), and renal size (p=0.004) were significantly higher in nonanuric than anuric patients. Urine output increased by 85.47 ml/day for every millimetre increase in renal width (p=0.026) and 65.31 ml/day for every millimetre increase in renal thickness (p=0.024). Simple linear regression analyses showed that cancer patients had a significantly lower urine output (358.73 ml/day; p=0.046) than those without cancer. Conclusions. This study showed that urine output and other clinical data can provide an index to evaluate residual renal function before deciding to perform PCN procedures.PurposeThis study investigated whether a thin renal cortex or any morphological kidney measurements can be predictors of post percutaneous nephrostomy (PCN) renal function, thereby lessening the need for the procedure.Materials and methodsAll patients underwent unilateral PCN that were performed under sonographic and fluoroscopic guidance. Kidney morphological measurements were subsequently taken to measure residual renal function; a thin renal cortex was defined from a computed tomography (CT) showing a cortical thickness <10 mm. Urine output was recorded daily, with patients divided into anuric and nonanuric groups.ResultsMorphological measurements of residual renal function, such as renal length (p=0.004), renal width (p=0.004), renal thickness (p=0.008), and renal size (p=0.004) were significantly higher in nonanuric than anuric patients. Urine output increased by 85.47 ml/day for every millimetre increase in renal width (p=0.026) and 65.31 ml/day for every millimetre increase in renal thickness (p=0.024). Simple linear regression analyses showed that cancer patients had a significantly lower urine output (358.73 ml/day; p=0.046) than those without cancer.ConclusionsThis study showed that urine output and other clinical data can provide an index to evaluate residual renal function before deciding to perform PCN procedures.RiassuntoObiettivoQuesto studio ha valutato se una corticale renale sottile oppure qualsiasi misurazione morfologica del rene possano essere predittivi di funzionalità renale dopo nefrostomia percutanea (PCN), riducendo, in questo modo, la necessità di tale procedura.Materiali e metodiTutti i pazienti sono stati sottoposti a PCN unilaterale eseguita sotto guida ecografica e fluoroscopica. Successivamente sono state eseguite misurazioni morfologiche del rene per valutare la funzionalità renale residua; una corticale renale sottile è stata definita alla tomografia computerizzata (CT) mostrando uno spessore corticale <10 mm. La produzione di urina è stata misurata giornalmente e i pazienti sono stati suddivisi in due gruppi: anurici e non anurici.RisultatiMisurazioni morfologiche della funzionalità renale residua, quali lunghezza renale (p=0,004), larghezza renale (p=0,004), spessore renale (p=0,008) e dimensione renale (p=0,004) sono risultate significativamente più elevate nei pazienti non anurici rispetto ai pazienti anurici. La produzione di urina è risultata aumentata di 85,47 ml/die per ogni millimetro di incremento della larghezza renale (p=0,026) e di 65,31 ml/die per ogni millimetro di incremento dello spessore renale (p=0,024). Le analisi di regressione lineare semplice hanno mostrato che i malati di cancro hanno una produzione di urina significativamente più bassa (358,73 ml/die, p=0,046) rispetto ai pazienti sani.ConclusioniQuesto studio ha mostrato che la produzione di urina e altri dati clinici possono fornire un indice per valutare la funzionalità renale residua prima di decidere sulla esecuzione di procedure di PCN.