Comparison of Short-Tau Inversion Recovery With Short-Tau Inversion Recovery-Slice Encoding for Metal Artifact Correction for Spine Imaging at 1.5 T in the Setting of Metallic Implants.

OBJECTIVE: To compare the image quality of short-tau inversion recovery (STIR) and the STIR-slice encoding for metal artifact correction (SEMAC) sequence for postsurgery spine magnetic resonance imaging (MRI). METHODS: Twenty-nine patients with metallic spinal implants who underwent spinal 1.5 T MRI with STIR and STIR-SEMAC sequences between July 2016 and November 2020 were retrospectively enrolled. Qualitative assessments were performed using 5-point scales; higher scores indicated better image quality. For screw metal artifact analysis, scores were obtained for artifacts on vertebral bodies and neural foramina, screw artifact widths, and bone marrow signal intensities. For patient-based analysis, scores were obtained for imaging quality and fat suppression quality, signal intensity, and cerebrospinal fluid noise. A paired t test was performed for statistical analyses. RESULTS: We analyzed 163 screws in 29 patients. In the screw metal artifact analysis, the vertebral body and neural foramen scores were significantly higher for the STIR-SEMAC images than for the STIR (all P < 0.001). The artifact width in the STIR-SEMAC images (9.8 ± 3.4 mm) was significantly smaller than that in the STIR images (16.0 ± 4.7 mm, P < 0.001). In patient-based analysis, the fat suppression and imaging quality scores were significantly higher for the STIR-SEMAC images than for the STIR images (all P < 0.001). The cerebrospinal fluid signal intensity, noise, and signal-to-noise ratios were significantly higher for the STIR images (all P < 0.005). CONCLUSIONS: Short-tau inversion recovery-SEMAC sequences provide good metallic artifact reduction and fat suppression for postsurgery spine 1.5 T MRI.

Reliability and benefits of single-energy projection-based metallic artifact reduction (SEMAR) in the different orthopedic hardware for the hip.

OBJECTIVE: To evaluate the performance and reliability of the single-energy metal artifact reduction (SEMAR) algorithm in patients with different orthopedic hardware at the hips. MATERIALS AND METHODS: A total of 153 patients with hip instrumentation who had undergone CT with adaptive iterative dose reduction (AIDR) 3D and SEMAR algorithms between February 2015 and October 2019 were included retrospectively. Patients were divided into 5 groups by the hardware type. Two readers with 21 and 13 years of experience blindly reviewed all image sets and graded the extent of artifacts and imaging quality using 5-point scales. To evaluate reliability, the mean densities and image noises were measured at the urinary bladder, veins, and fat in images with artifacts and the reference images. RESULTS: No significant differences were found in the mean densities of the urinary bladder, veins, and fat between the SEMAR images with artifacts (7.57 ± 9.49, 40.29 ± 23.07, 86.78 ± 38.34) and the reference images (7.77 ± 6.2, 40.27 ± 8.66, 89.10 ± 20.70) (P = .860, .994, .392). Image noises of the urinary bladder in the SEMAR images with artifacts (14.25 ± 4.50) and the SEMAR reference images (9.69 ± 1.29) were significantly higher than those in the AIDR 3D reference images (9.11 ± 1.12) (P < .001; P < .001). All AIDR 3D images were non-diagnostic (overall quality ≤ 3) and less than a quarter of the SEMAR images were non-diagnostic (16.7-23.7%), mainly in patients with prostheses [reader 1: 91.7% (22/24); reader 2: 92.6% (25/27)]. CONCLUSION: The SEMAR algorithm significantly reduces metal artifacts in CT images, more in patients with internal fixations than in patients with prostheses, and provides reliable attenuation of soft tissues.

Fat-Water Swaps in Iterative Decomposition of Water and Fat With Echo Asymmetry and Least-Squares Estimation Magnetic Resonance Imaging for Postinstrumentation Spine.

OBJECTIVE: To determine the frequencies of fat-water swaps in iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) water-only images of the postinstrumentation spine and discuss the efficiency of in-phase imaging in improving visibility of the thecal sac. MATERIALS AND METHODS: A total of 276 patients (167 women; mean age, 62.3 years; range, 23-89 years) with metallic devices on the lumbar spine who received complete routine 1.5 T MR imaging, including axial and sagittal images of T1-weighted, T2-weighted, and T2-weighted IDEAL sequences, were included. The exclusion criteria were significant motion artifacts and severe metallic artifacts in any one of the sequences. The images were reviewed by two radiologists to identify fat-water swaps that were divided into 3 groups: extraspinal swaps, intraspinal swaps in sagittal images, and intraspinal swaps in axial images. The qualitative evaluations for the spinal canal in axial images were performed by rating on a five-point scale. Side-by-side comparisons of T2-weighted images and IDEAL in-phase images were also performed. RESULTS: In patient-based data of 276 patients, extraspinal fat-water swaps were noted in 10 patients (3.6%) and intraspinal swaps were noted in 160 patients (58.0%). The intraspinal swaps had a higher incidence in the patients with more levels of metallic devices with screws and the trend was not noted in the extraspinal swaps. A total of 928 axial levels were evaluated in the level-based data of axial images. T1-weighted, T2-weighted, and IDEAL in-phase images had significantly better imaging quality than the IDEAL water-only images (3.9 ± 0.4, 3.9 ± 0.3, 3.8 ± 0.4 vs 3.0 ± 1.3, all P < 0.001). Compared with T2-weighted images, most of the IDEAL in-phase images (reader 1, 90.9%; reader 2, 86.7%) present similar quality. CONCLUSION: Iterative decomposition of water and fat with echo asymmetry and least-squares estimation sequence can provide good fat suppression in most spine MRI with metallic devices but the loss of cerebrospinal fluid signal intensities due to fat-water swaps are noted in more than half of postinstrumentation spine. Routine reconstruction of in-phase images is recommended to improve evaluation of the thecal sac by avoiding pitfall caused by fat-water swaps.

Myoepithelial carcinoma of tibia mimic giant cell tumor: a case report with emphasis on MR features.

Intraosseous myoepithelial carcinoma is an extremely rare type of bone tumor that most often presents in the long tubular bones, but also occurs in small tubular bones and the axial skeleton. We report the radiographic images and complete magnetic resonance (MR) features of a 44-year-old male with right knee pain of 7 months' duration. The radiographic findings and convention MR images indicated a giant cell tumor of the bone. The dynamic contrast-enhanced images showed a patent with the early wash-in and early wash-out usually noted in a giant cell tumor of the bone. Only water restriction on diffusion-weighted imaging (DWI) showed the malignant impression. Care should be taken when conventional images indicate giant cell tumor of the bone, as intraosseous myoepithelial carcinoma, although rare, can mimic this more common diagnosis. Further studies with DWI are warranted.

Fracture of the polyethylene tibial post in the posterior-stabilized total knee prosthesis: arthrographic and CT arthrographic diagnosis.

Fracture of the polyethylene tibial post in the posterior-stabilized total knee prosthesis is often delayed in diagnosis due to its nonspecific symptoms and the radiolucent characteristic of polyethylene on conventional radiography. Therefore, the diagnosis is always established by arthroscopy. Notwithstanding recent advances in imaging modalities, we are presently aware of only two related case reports on MRI and even no reports about arthrographic or CT-arthrographic diagnosis of fractured tibial post. We hereby report a case of a 58-year-old female patient who developed recurrent knee pain during the third year after total knee arthroplasty. The displaced polyethylene tibial post was clearly outlined by administered contrast material in the posterior knee. Under the diagnosis of fracture of the tibial post, the patient underwent isolated replacement of the broken polyethylene insert. Her knee pain significantly improved after the operation.

Disruptions of brain structural network in end-stage renal disease patients with long-term hemodialysis and normal-appearing brain tissues.

OBJECTIVE: End-stage renal disease (ESRD) patients on hemodialysis were demonstrated to exhibit silent and invisible white-matter alterations which would likely lead to disruptions of brain structural networks. Therefore, the purpose of this study was to investigate the disruptions of brain structural network in ESRD patients. MATERIALS AND METHODS: Thiry-three ESRD patients with normal-appearing brain tissues and 29 age- and gender-matched healthy controls were enrolled in this study and underwent both cognitive ability screening instrument (CASI) assessment and diffusion tensor imaging (DTI) acquisition. Brain structural connectivity network was constructed using probabilistic tractography with automatic anatomical labeling template. Graph-theory analysis was performed to detect the alterations of node-strength, node-degree, node-local efficiency, and node-clustering coefficient in ESRD patients. Correlational analysis was performed to understand the relationship between network measures, CASI score, and dialysis duration. RESULTS: Structural connectivity, node-strength, node-degree, and node-local efficiency were significantly decreased, whereas node-clustering coefficient was significantly increased in ESRD patients as compared with healthy controls. The disrupted local structural networks were generally associated with common neurological complications of ESRD patients, but the correlational analysis did not reveal significant correlation between network measures, CASI score, and dialysis duration. CONCLUSION: Graph-theory analysis was helpful to investigate disruptions of brain structural network in ESRD patients with normal-appearing brain tissues.

Added value of delayed computed tomography angiography in primary intracranial hemorrhage and hematoma size for predicting spot sign.

Background The computed tomography angiography (CTA) spot sign represents active contrast extravasation within acute primary intracerebral hemorrhage (ICH) and is an independent predictor of hematoma expansion (HE) and poor clinical outcomes. The spot sign could be detected on first-pass CTA (fpCTA) or delayed CTA (dCTA). Purpose To investigate the additional benefits of dCTA spot sign in primary ICH and hematoma size for predicting spot sign. Material and Methods This is a retrospective study of 100 patients who underwent non-contrast CT (NCCT) and CTA within 24 h of onset of primary ICH. The presence of spot sign on fpCTA or dCTA, and hematoma size on NCCT were recorded. The spot sign on fpCTA or dCTA for predicting significant HE, in-hospital mortality, and poor clinical outcomes (mRS ≥ 4) are calculated. The hematoma size for prediction of CTA spot sign was also analyzed. Results Only the spot sign on dCTA could predict high risk of significant HE and poor clinical outcomes as on fpCTA ( P < 0.05). With dCTA, there is increased sensitivity and negative predictive value (NPV) for predicting significant HE, in-hospital mortality, and poor clinical outcomes. The XY value (product of the two maximum perpendicular axial dimensions) is the best predictor (area under the curve [AUC] = 0.82) for predicting spot sign on fpCTA or dCTA in the absence of intraventricular and subarachnoid hemorrhage. Conclusion This study clarifies that dCTA imaging could improve predictive performance of CTA in primary ICH. Furthermore, the XY value is the best predictor for CTA spot sign.

The association of the amounts of epicardial fat, P wave duration, and PR interval in electrocardiogram.

BACKGROUND: The relationship of epicardial fat and cardiac arrhythmias has been described in many studies. The association of the amounts of epicardial fat and the characteristics of electrocardiogram (ECG) remains unclear. The purpose of this study was to elucidate the association between the amounts of epicardial fat and the characteristics of ECG. METHODS: A total of 100 consecutive patients who received multi-detector computer tomography (MDCT) were enrolled. The amounts of epicardial fat, including total heart, total atria, total ventricles, right atrium (RA), right ventricle (RV), left atrium (LA), and left ventricle (LV) regions, were measured. The PR interval in lead II, the P wave duration in lead I, the characteristics of inter-atrial conduction block manifested in ECG, the corrected QT interval (QTc) and the QT dispersion of a 12­lead ECG were measured manually by a computer caliper. RESULTS: The PR interval was correlated with the amounts of epicardial fat including total heart, total atria, total ventricles, RA, RV, LA, and LV (R = 0.295, p = 0.003; R = 0.379, p < 0.001; R = 0.284, p = 0.003; R = 0.415, p < 0.001; R = 0.287, p < 0.001; R = 0.33, p < 0.001; R = 0.244, p = 0.014). The P wave duration of lead I was also correlated with the amounts of epicardial fat (R = 0.202, p = 0.043; R = 0.283, p = 0.004; R = 0.225, p = 0.024; R = 0.365, p < 0.001; R = 0.256, p = 0.001; R = 0.20, p = 0.046; R = 0.199, p = 0.048) but the QTc interval and the QT dispersion were not. Inter-atrial conduction block was also associated with the amounts of epicardial fat, including total atria, RA and LA in univariate analysis (odds ratio (OR): 1.04, 95% of confidence interval (CI): 1.01-1.06, p = 0.015; OR: 1.08, 95% CI: 1.02-1.15, p = 0.011; OR: 1.05, 95% CI: 1.01-1.10, p = 0.031). In multivariate analysis of linear regression, the amounts of RA epicardial fat was most significantly associated with the PR interval, and the P wave duration (ß value: 1.30, 95% CI: 0.59-2.02, p < 0.001; ß value: 0.81, 95% CI: 0.34-1.28, p = 0.001). In multivariate analysis of logistic regression, inter-atrial conduction block was also significantly associated with the amounts of RA epicardial fat (odds ratio (OR): 1.08, 95% CI: 1.02-1.15, p = 0.011). CONCLUSIONS: The PR interval, P wave duration and inter-atrial conduction block were associated with the amounts of epicardial fat, which might imply an effect for arrhythmogenesis.

Altered brain activation during response inhibition and error processing in subjects with Internet gaming disorder: a functional magnetic imaging study.

The aim of the present study was to evaluate the impulsivity and brain correlates of response inhibition and error processing among subjects with Internet gaming disorder (IGD). We evaluated the response inhibition and error processing by functional magnetic resonance imaging (fMRI) in subjects with IGD and controls. Twenty-six men with IGD for at least 2 years and 23 controls with no history of IGD were recruited as the IGD and control groups, respectively. All subjects performed the event-related designed Go/No-go task under fMRI and completed questionnaires related to Internet addiction and impulsivity. The IGD group exhibited a higher score for impulsivity than the control group. The IGD group also exhibited higher brain activation when processing response inhibition over the left orbital frontal lobe and bilateral caudate nucleus than controls. Both the IGD and control groups exhibited activation of the insula and anterior cingulate cortex during error processing. The activation over the right insula was lower in the subjects with IGD than the control group. Our results support the fact that the fronto-striatal network involved in response inhibition, and the salience network, anchored by the anterior cingulate and insula, contributes to error processing. Further, adults with IGD have impaired insular function in error processing and greater activation of the fronto-striatal network in order to maintain their response inhibition performance.

Association between lumbar muscle size and bone mineral density in nonfractured postmenopausal women with and without osteoporosis.

OBJECTIVE: Estrogen deficiency in postmenopausal women is associated with bone loss and a decline in muscle mass. However, the associations between lumbar muscle size and bone mineral density (BMD) in postmenopausal women with and without osteoporosis remain unclear. The aim of this study was to investigate the associations between lumbar muscle size and BMD in nonfractured postmenopausal women with osteoporosis and those with osteopenia. METHODS: A total of 89 postmenopausal women with osteopenia (n = 53) and osteoporosis (n = 36) were retrospectively enrolled in this study from 2014 to 2022. All participants underwent lumbar magnetic resonance imaging and dual-energy absorptiometry within a month. The lean lumbar muscle sizes at different lumbar levels were quantitatively evaluated on axial T1-weighted images. The associations between lumbar muscle size and BMD were analyzed using Pearson's correlation analysis. RESULTS: The osteoporosis group had significantly smaller lean psoas muscle sizes than the osteopenia group. Based on the correlation analysis, the erector spinae and multifidus muscle sizes were significantly associated with lumbar and femoral neck BMDs in the osteoporosis group. However, no significant association was found between lean psoas muscle size and BMDs in the osteopenia group. Thus, the associations between lumbar muscle decline and bone loss differed between postmenopausal women with osteoporosis and those with osteopenia. CONCLUSIONS: The study findings suggest differences in the associations between BMD and lumbar muscle size between postmenopausal women with osteoporosis and those with osteopenia.

Q-ball imaging with PROPELLER EPI acquisition.

Q-ball imaging (QBI) is an imaging technique that is capable of resolving intravoxel fiber crossings; however, the signal readout based on echo-planar imaging (EPI) introduces geometric distortions in the presence of susceptibility gradients. This study proposes an imaging technique that reduces susceptibility distortions in QBI by short-axis PROPELLER EPI acquisition. Conventional QBI and PROPELLER QBI data were acquired from two 3T MR scans of the brains of five healthy subjects. Prior to the PROPELLER reconstruction, residual distortions in single-blade low-resolution b0 and diffusion-weighted images (DWIs) were minimized by linear affine and nonlinear diffeomorphic demon registrations. Subsequently, the PROPELLER keyhole reconstruction was applied to the corrected DWIs to obtain high-resolution PROPELLER DWIs. The generalized fractional anisotropy and orientation distribution function maps contained fewer distortions in PROPELLER QBI than in conventional QBI, and the fiber tracts more closely matched the brain anatomy depicted by turbo spin-echo (TSE) T2-weighted imaging (T2WI). Furthermore, for fixed T(E), PROPELLER QBI enabled a shorter scan time than conventional QBI. We conclude that PROPELLER QBI can reduce susceptibility distortions without lengthening the acquisition time and is suitable for tracing neuronal fiber tracts in the human brain.

In vivo 1H MRS for musculoskeletal lesion characterization: which factors affect diagnostic accuracy?

In vivo (1)H MRS is a noninvasive imaging technique for the identification of malignancy. Musculoskeletal lesions vary in their composition, causing field inhomogeneity and magnetic susceptibility effects which may be technical and diagnostic challenges for MRS. This study investigated the factors that affect diagnostic accuracy in the use of MRS for the characterization of musculoskeletal neoplasms. During a 7-year period, 210 consecutive patients with musculoskeletal lesions larger than 1.5 cm in diameter were examined. MRS of a single-voxel point-resolved spectroscopy sequence with TE = 135 ms was undertaken using a 1.5-T scanner. Lesions with a choline signal-to-noise ratio larger than 3.0 were considered to be malignant tumors. The diagnostic accuracy was calculated for all lesions and for subgroups on the basis of lesion type (bone and soft tissue), lesion composition (mixed and solid nonsclerotic), lesion size (≤4, >4-10 and >10 cm), MR scanner (MR scanner 1 and 2) and selected voxel size (≤3, >3-8 and >8 cm(3)). Multivariate logistic regressions were performed to estimate the associations between each factor and diagnostic accuracy. The diagnostic accuracy was 73.3% for all lesions. The accuracy was 54.4% for mixed lesions and 80.4% for solid nonsclerotic lesions (p < 0.001). The diagnostic accuracy was lower for larger lesions [86.8% for lesions of ≤4 cm, 71.6% for lesions of >4-10 cm (p = 0.04) and 63.6% for lesions of >10 cm (p = 0.007)]. There was no difference in diagnostic accuracy for bone versus soft-tissue lesions or as a function of MR scanner or voxel size. By the use of multivariate logistic regression, a solid nonsclerotic lesion was 3.15 times (95% confidence interval, 1.59-6.27) more likely than a mixed lesion to have a diagnosis (p = 0.001). MRS can be used to characterize musculoskeletal lesions, particularly solid nonsclerotic lesions.

Feasibility of Arterial Spin Labeling Magnetic Resonance Imaging for Musculoskeletal Tumors with Optimized Post-Labeling Delay.

Arterial spin labeling (ASL) magnetic resonance imaging (MRI) is used to perform perfusion imaging without administration of contrast media. However, the reliability of ASL for musculoskeletal tumors and the influence of post-labeling delay (PLD) have not been fully clarified. This study aimed to evaluate the performance of ASL with different PLDs in the imaging of musculoskeletal tumors. Forty-five patients were enrolled and were divided into a malignant group, a hypervascular benign group, a hypovascular benign group and a control group. The tissue blood flow (TBF) of the lesions and normal muscles was measured and the lesion-to-muscle TBF ratio and differences were calculated. The results showed that both the TBF of lesions and muscles increased as the PLD increased, and the TBF of muscles correlated significantly and positively with the TBF of lesions (all p < 0.05). The TBF and lesion-to-muscle TBF differences of the malignant lesions were significantly higher than those of the hypovascular benign lesions and the control group in all PLD groups (all p < 0.0125) and only those of the hypervascular benign lesions in the longest PLD (3025 ms) group (p = 0.0120, 0.0116). In conclusion, ASL detects high TBF in malignant tumors and hypervascular benign lesions, and a longer PLD is recommended for ASL to differentiate musculoskeletal tumors.

Spine trabecular bone scores and bone mineral density of postmenopausal Taiwanese women.

OBJECTIVES: The aims of the study were to determine the mean trabecular bone score (TBS) of postmenopausal Taiwanese women and to analyze the value of TBS in predicting osteoporosis. METHODS: A total of 1,915 postmenopausal women with lumbar spine and hip bone mineral density (BMD) and spine TBS were enrolled from a single medical center into this study. The women's BMD and TBS were measured using dual x-ray absorptiometry (Discovery Wi; Hologic, Bedford, Mass) and iNsight software (Med-Imaps SASU, Merignac, France), respectively. The women's demographic characteristics; lumbar spine, total hip, and femoral neck BMD; and lumbar spine TBS were recorded, and correlations among the parameters were identified using a 2-tailed Pearson test, in which a P value less than 0.05 was considered statistically significant. We developed simple linear regression models to represent changes related to TBS and performed an analysis of variance on the selected variables. RESULTS: The average age of the women was 62.5 ± 9.1 years (range, 25.7-93.7 years). The mean TBS was 1.300 ± 0.086 (range, 1.015-1.596). The TBS was weakly and negatively correlated with body mass index ( r = -0.078) and moderately and positively correlated with the lumbar spine BMD ( r = 0.619). The patients' lowest BMD values among those measured at multiple sites revealed a higher rate of osteoporosis (32.5%) than those measured at individual sites. Degraded TBS were noted in 21.2% of the participants, and a combination of BMD and TBS results predicted more individuals (7.8%) at a high risk of fracture than did the BMD result only. The rates of both osteoporosis and degraded TBS increased with age. CONCLUSIONS: Bone mineral density and TBS can be used in combination to predict osteoporosis in a greater number of postmenopausal Taiwanese women. Because the incidence of osteoporosis is the highest among older women, clinicians should pay careful attention to TBS degradation among older patients without low BMD.

Reliability of Gradient-Echo Magnetic Resonance Elastography of Lumbar Muscles: Phantom and Clinical Studies.

Magnetic resonance elastography (MRE) has been used to successfully characterize the mechanical behavior of healthy and diseased muscles, but no study has been performed to investigate the reliability of MRE on lumbar muscles. The objective of this work was to determine the reliability of MRE techniques on lumbar muscles in both ex vivo phantom and in vivo human studies. In this study, fresh porcine leg muscles were used in the phantom study, and 80 healthy adults (38.6 ± 11.2 years, 40 women) were recruited in the human study. Five repeated stiffness maps were obtained from both the phantom and human muscles by using a gradient-echo MRE sequence with a pneumatic vibration on a 1.5 T MR scanner. The technical failure rate, coefficient of variation (CV), and quality score were assessed to evaluate the reliability of MRE, respectively. Analysis of variance was performed to compare the stiffness between different lumbar muscles, and the difference was significant if p < 0.05 after Bonferroni correction. The results showed that the MRE achieved a zero technical failure rate and a low CV of stiffness (6.24 ± 1.41%) in the phantom muscles. However, in the human study, the MRE exhibited high CVs of stiffness (21.57%−25.24%) in the lumbar muscles, and the technical failure rate was higher in psoas muscles (60.0−66.3% in) than in paraspinal muscles (0.0−2.5%). Further, higher quality scores were noticed in paraspinal muscles (7.31−7.71) than those in psoas muscles (1.83−2.06). In conclusion, the MRE was a reliable technique to investigate the mechanical property of lumbar muscles, but it was less reliable to assess stiffness in psoas muscles than paraspinal muscles.

Cerebral metabolic changes in neurologically presymptomatic patients undergoing haemodialysis: in vivo proton MR spectroscopic findings.

OBJECTIVE: To prospectively investigate and detect early cerebral metabolic changes in patients with end-stage renal disease (ESRD) by using in vivo proton MR spectroscopy (MRS). METHODS: We enrolled 32 patients with ESRD and 32 healthy controls between the ages of 26 and 50 years. Short echo time single-voxel proton MRS was acquired from volumes of interest (VOIs) located in the frontal grey and white matter, temporal white matter and basal ganglia. The choline/phospatidylcholine (Cho), myo-inositol (mI), N-acetylaspartate (NAA) and total creatine (tCr) peaks were measured and the metabolic ratios with respect to tCr were calculated. RESULTS: In the ESRD group, significant elevations of the Cho/tCr and mI/tCr ratios were observed for the frontal grey matter, frontal white matter, temporal white matter and basal ganglia as compared with controls. There was no significant difference in the NAA/tCr ratios at all VOIs between the ESRD patients and the healthy controls. CONCLUSIONS: Proton MRS is a useful and non-invasive imaging tool for the detection of early cerebral metabolic changes in neurologically presymptomatic ESRD patients.

Differentiation between malignant and benign gastric ulcers: CT virtual gastroscopy versus optical gastroendoscopy.

PURPOSE: To retrospectively compare computed tomographic virtual gastroscopy (VG) and conventional optical gastroendoscopy for the differentiation of malignant and benign gastric ulcers. MATERIALS AND METHODS: The institutional review board approved this study and confirmed that informed consent was not required. Gastric ulcers in 115 patients (mean age, 64.7 years; range, 31-86 years; 61 men, 54 women) were evaluated by using endoscopy and VG. Ulcer shape, base, and margin and periulcer folds were evaluated by two independent reviewers. Malignant gastric ulcers were identified by irregular, angulated, or geographic shape; uneven base; irregular or asymmetric edges; and disrupted or moth-eaten appearance of periulcer folds near the crater edge and/or clubbed or fused folds. Benign gastric ulcers were identified by smooth and regular shapes, even bases, clearly demarcated and regular edges, and folds that tapered and converged toward the ulcer. The performance of VG and endoscopy for the diagnosis of benign and malignant gastric ulcers was evaluated by using histopathologic results as the reference standard. The McNemar test was used to compare VG and endoscopic data. A P value less than .05 was considered to indicate a significant difference. RESULTS: At histopathologic examination, 39 gastric ulcers were benign, while 76 were malignant. VG and endoscopy had sensitivities of 92.1% (70 of 76) and 88.2% (67 of 76), respectively, for overall diagnosis of malignant gastric ulcers, and specificities of 91.9% (34 of 37) and 89.5% (34 of 38), respectively, for overall diagnosis of malignant gastric ulcers. Endoscopy was more sensitive in depicting malignancy according to ulcer base (85.5% [65 of 76] vs 68.4% [52 of 76]) (P = .034), and VG was more specific in depicting malignancy according to ulcer margin (78.4% [29 of 37] vs 63.2% [24 of 38]) (P = .034). CONCLUSION: VG and endoscopy were almost equally useful in distinguishing between malignant and benign gastric ulcers. SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/2522081249/DC1.

Subclinical white matter integrity in subjects with cumulative lead exposure.

PURPOSE: To evaluate microstructural changes in the white matter of patients who were exposed to lead and to compare differences in fractional anisotropy (FA) between these patients and control subjects. MATERIALS AND METHODS: Institutional review board approval and subject informed consent were obtained for this HIPAA-compliant study. Nineteen factory workers who had been exposed to lead and 18 healthy volunteers who had not were enrolled. FA values and T2-weighted fluid-attenuation inversion-recovery magnetic resonance images were obtained at several regions of interest (the bilateral parietal, frontal, occipital, and temporal white matter and the genu and splenium of the corpus callosum). Lead levels were measured in the blood, midtibia, and patella. The Student t test was used to compare the difference in continuous variables between the two groups. Pearson correlation coefficients were used to assess the association between two variables. RESULTS: There were no significant differences in sex, age, body mass index, smoking history, betel nut consumption, or alcohol consumption between the factory workers and the volunteers. The number of milk drinkers among factory workers was significantly higher than that among volunteers (P < .001). The factory workers had significantly higher blood (P < .001), patella (P < .001), and midtibia (P = .005) lead levels than did the volunteers. Mean FA in the factory workers was lower than that in the volunteers at the same anatomic location; significant differences between the groups were noted bilaterally in the parietal, frontal, occipital, and temporal white matter. There was no significant difference in mean diffusivity values and mean T2 ratios between the factory workers and the volunteers. CONCLUSION: Decreased FA was associated with exposure to lead. Negative correlations between FA and blood, midtibia, and patella lead levels suggest that FA may be a useful index of early white matter damage. SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/2522080653/DC1.

End-stage renal disease: in vivo diffusion-tensor imaging of silent white matter damage.

PURPOSE: To characterize and compare regional differences in anisotropy in patients with end-stage renal disease (ESRD) and in control subjects to understand the effect of ESRD and hemodialysis on the microstructures of white matter. MATERIALS AND METHODS: This study was approved by an institutional review board; written informed consent was obtained. From March 2007 to December 2007, 34 patients (16 men, 18 women; mean age, 40.0 years; range, 26-50 years) with ESRD who were undergoing dialysis and 35 control subjects (16 men, 19 women; mean age, 38.3 years; range, 25-49 years) were enrolled. There was no significant sex or age difference between the ESRD and control groups. By using a 1.5-T imager, fractional anisotropy (FA) data obtained at diffusion-tensor magnetic resonance (MR) imaging (echo-planar imaging, 33 directions; b value, 1000 sec/mm(2)) and at T2-weighted fluid-attenuated inversion recovery (FLAIR) MR imaging of the bilateral parietal, frontal, occipital, and temporal lobe white matter, as well as the genu and splenium of the corpus callosum, were compared. The Cognitive Abilities Screening Instrument (CASI) was administered to all participants at imaging. RESULTS: The ESRD group had significantly lower FA values in all regions than the control group. FA values were generally lower in older patients and in those who had been undergoing dialysis for a longer duration. Duration of dialysis was more often than age found to be correlated with differences in FA values. In areas in which there was a significant correlation between age, duration, and FA values, the regression coefficients were greater for those who had been undergoing dialysis longer than for those who were older. Patients with ESRD had significantly lower CASI scores than control subjects (P = .03). There were no significant group differences in FLAIR values (P = .25-.89). CONCLUSION: Changes in FA values may be used to follow-up white matter changes in patients with ESRD who are undergoing maintenance dialysis. SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/2523080484/DC1.

Septic arthritis as the initial manifestation of fatal Vibrio vulnificus septicemia in a patient with thalassemia and iron overload.

Vibrio vulnificus infection is an uncommon but potentially fatal disease in children such that prompt recognition has prognostic implications. We describe here the case of a 9-year-old female with thalassemia and iron overload who presented with septic arthritis as an atypical initial manifestation of fatal V. vulnificus septicemia. This report underscores the possibility of septic arthritis as an early manifestation of V. vulnificus septicemia. Pediatricians should be alert to this extremely invasive disease, especially in children with iron overload.