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Background: Abusive head trauma (AHT) is the leading cause of death in infants with traumatic brain injury (TBI). Early recognition of AHT is important for improving outcomes, but it can be challenging due to its similar presentations with non-abusive head trauma (nAHT). This study aims to compare clinical presentations and outcomes between infants with AHT and nAHT, and to identify the risk factors for poor outcomes of AHT., Methods: We retrospectively analyzed infants of TBI in our pediatric intensive care unit from January 2014 to December 2020. Clinical manifestations and outcomes were compared between patients with AHT and nAHT. Risk factors for poor outcomes in AHT patients were also analyzed., Results: 60 patients were enrolled for this analysis, including 18 of AHT (30%) and 42 of nAHT (70%). Compared with those with nAHT, patients with AHT were more likely to have conscious change, seizures, limb weakness, and respiratory failure, but with a fewer incidence of skull fractures. Additionally, clinical outcomes of AHT patients were worse, with more cases undergoing neurosurgery, higher Pediatric Overall Performance Category score at discharge, and more anti-epileptic drug (AED) use after discharge. For AHT patients, conscious change is an independent risk factor for a composite poor outcome of mortality, ventilator dependence, or AED use (OR = 21.9, P = 0.04) CONCLUSION: AHT has a worse outcome than nAHT. Conscious change, seizures and limb weaknesses but not skull fractures are more common in AHT. Conscious change is both an early reminder of AHT and a risk factor for its poor outcomes., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023. Published by Elsevier B.V.)

Competing Interests: Declaration of competing interest The author has no conflicts of interest relevant to this article.

Background/purpose: Identifying child abuse is sometimes challenging due to its various presentations. To facilitate timely identification of critical or complex cases of physical abuse outside our child protection center, we established an outreach multidisciplinary team (OMDT) to support Kaohsiung City Government in 2014. The objective of this study was to describe our experience of OMDT services during a 6-year period and examine its role in assisting law enforcement., Methods: We retrospectively analyzed all OMDT cases from January 2014 to January 2020. Clinical characteristics and OMDT reports were reviewed. After inspection by our OMDT, cases were determined as indicating either a high risk or low risk of child abuse. Associations among clinical characteristics, radiographic findings, OMDT decisions and case outcomes including law enforcement and prosecution were examined., Results: Thirty-two cases (22 [68.8%] males and 10 [31.2%] females; mean age 24.2 months) received OMDT service, of whom 28 (87.5%) were admitted to the pediatric intensive care unit. The victims had an average of 2.2 types of wounds in 3.4 locations. The most common finding on radiography was subdural hemorrhage (18, 56.3%), followed by subarachnoid hemorrhage (31, 31.3%). Law enforcement was activated in 20 (64.5%) cases, and was only associated with the high-risk group as determined by the OMDT (p < 0.05) but not with any other variables., Conclusion: Our experience indicates that an OMDT can play an important role in child protection and activating law enforcement for children with complex or critical physical abuse. We suggest that in Taiwan, OMDT services should be incorporated into child protection centers, National Health Insurance system and governmental child protection policies., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Formosan Medical Association. Published by Elsevier B.V. All rights reserved.)

Competing Interests: Declaration of competing interest None declared.

Proper bone age assessment is crucial for the clinical diagnosis and evaluation of treatment responses. We investigated the applicability of Greulich and Pyle (GP), and Tanner and Whitehouse 3 (TW3) methods for children in modern Taiwan, using computer-aided diagnosis. Hand and wrist radiographs were obtained from 611 children (3-17 years) who came to our emergency department due to trauma. Ages 0 to 2 years old were excluded because of a limited number of cases. Skeletal maturation was assessed using the BoneXpert (version 2.5.4.1 automated software), which determines GP and TW3 bone age. The two scoring systems were evaluated for comparing the chronological ages in each subgroup. In boys, mean GP bone age vs mean chronological ages were delayed for ages 3 to 11 and advanced for age 12 to 17. In girls, mean GP bone age vs mean chronological ages was delayed for ages 4 to 8 and 17, and advanced for ages 3 and 9 to 17. In boys, the mean TW3 bone ages vs mean chronological ages were delayed for ages 5 to 10 except age 8, and advanced for ages 3 to 4, 8, and 11 to 15. In girls, the mean TW3 bone ages vs mean chronological ages were delayed for ages 4 to 12, and advanced for ages 3 and 13 to 14. By using the BoneXpert automatic software, we established bone age reference standards for children in Taiwan. Clinical application of GP and TW3 scoring methods can be adjusted according to our results to better assess bone age., (© 2020 The Authors. The Kaohsiung Journal of Medical Sciences published by John Wiley & Sons Australia on behalf of Kaohsiung Medical University.)

ABSTRACTBackground:Apathy is a condition characterized by a lack of motivation that manifests in emotional, behavioral, and cognitive domains. Although previous studies have indicated that apathy is associated with frontal lesions, few studies have focused on the different subdomains of apathy, and no in vivo human biochemical data have been obtained to examine the neurochemical changes related to apathy in patients with Alzheimer's disease (AD). Thus, we investigated the frontal neurochemical alterations related to apathy among patients with AD using proton magnetic resonance spectroscopy (1H MRS)., Methods: Apathy was assessed through the Apathy Evaluation Scale (AES). 1H MRS was performed to measure neurochemical metabolite levels in the anterior cingulate region and right orbitofrontal region. Associations between neurochemical metabolites and the total score and subscores of each domain of the AES were analyzed., Results: Altogether, 36 patients completed the study. Patients with lower N-acetylaspartate/creatine ratios (NAA/Cr) in the anterior cingulate region demonstrated higher total apathy scores (β = -0.56, p = 0.003) with adjustments for age, gender, educational level, dementia severity, and depression severity. In a further analysis, a lower NAA/Cr in the anterior cingulate region was associated with all subdomains of apathy, including cognition (β = -0.43, p = 0.028), behavior (β = -0.55, p = 0.002), and emotion (β = -0.50, p = 0.005). No statistically significant associations were discovered in the right orbitofrontal region., Conclusions: Our results suggest that apathy, in each of its cognitive, behavioral, or emotional subdomains is associated with brain neurochemical alterations in the anterior cingulate region. Abnormal neuronal integrity over the anterior cingulate cortex may exhibit a central role in causing all aspects of apathy in patients with AD.

The aim of the study is to evaluate the use of the tumor border in peripheral non-small cell lung cancer (NSCLC) as an indicator of pleural invasion.This retrospective study was performed at a single tertiary center. The analysis of 136 patients with peripheral NSCLC included 101 (74.3%) patients with pathologically proven pleural invasion and 35 (25.7%) patients without pleural invasion. The tumor borders on conventional computed tomography (CT) were classified into 5 types on lung window setting: type 1, S or reverse S border with a blunt angle; type 2, sharp angle; type 3, concave border with a blunt angle; type 4, straight border with a perpendicular angle; and type 5, convex border with a perpendicular or blunt angle. In patients with more than 1 tumor border type, the priority was type 5, 4, 3, 2, and 1. Blunt angle, pleural contact >3 cm, and adjacent pleural thickening were also recorded for comparison with pleural invasion of peripheral tumors.Tumor border types 2 and 5 significantly differed between patients with and without pleural invasion (P = .001 and P < .001, respectively). Patients with and without pleural invasion did not significantly differ in tumor border type 1, tumor border type 3, tumor border type 4, blunt angle, pleural contact >3 cm, or pleural thickening. Tumor border type 5 was a moderate indicator of pleural invasion with positive LR, 5.20; accuracy, 57%; sensitivity, 45%; specificity, 91%; PPV, 94%; and NPV, 36%. Tumor border type 2 was a weak indicator of pleural invasion with positive LR, 0.51; accuracy, 34%; sensitivity, 34%; specificity, 34%; PPV, 60%; and NPV, 15%.Tumor border type 5 has a high PPV and high specificity for predicting pleural invasion by peripheral NSCLC.

Background: Atypical teratoid/rhabdoid tumor (AT/RT) is a rare pediatric central nervous system malignancy with poor outcome. AT/RT is infrequently located in the spinal cord., Clinical Presentation: A 16-month-old boy presented with progressive urinary retention and weakness of the lower extremities. Magnetic resonance imaging of the spine revealed an intradural extramedullary mass occupying the spinal canal at the level of T10-L3. The tumor was successfully resected by using neuroendoscopy. Histopathology demonstrated rhabdoid cells with eccentric nuclei and eosinophilic cytoplasmic hyaline inclusions. Immunohistologically, the tumor cells showed positive for epithelial membrane antigen, vimentin and neuron-specific enolase, and negative for integrase interactor 1. After surgery, the patient showed significant improvement in sitting and other neurological signs but presenting with flaccid neurogenic bladder. Intrathecal chemotherapy under European Rhabdoid Registry (EU-RHAB) protocol with Doxorubicin, Carboplatin, Etoposide, Ifosfamide, Vincristine, Cyclophosphamide and Actinomycin-D was given. However, recurrent intradural extramedullary tumor at the level of T11-L2 developed in 3 months., Conclusion: We report a young Asian case of AT/RT in thoracolumbar spine with recurrent tumor shortly after complete surgical resection of the tumor., Competing Interests: The authors declare no conflict of interest.

Purpose: The purpose of this study was to compare brain metabolite concentration ratios determined by LCModel and Spectroscopy Analysis by General Electric (SAGE) quantitative methods to elucidate the advantages and disadvantages of each method., Materials and Methods: A total of 10 healthy volunteers and 10 patients with mild cognitive impairment (MCI) were recruited in this study. A point-resolved spectroscopy (PRESS) sequence was used to obtain the brain magnetic resonance spectroscopy (MRS) spectra of the volunteers and patients, as well as the General Electric (GE) MRS-HD-sphere phantom. The brain metabolite concentration ratios were estimated based on the peak area obtained from both LCModel and SAGE software. Three brain regions were sampled for each volunteer or patient, and 20 replicates were acquired at different times for the phantom analysis., Results: The metabolite ratios of the GE phantom were estimated to be myo-inositol (mI)/creatine (Cr): 0.70 ± 0.01, choline (Cho)/Cr: 0.37 ± 0.00, N-acetylaspartate (NAA)/Cr: 1.26 ± 0.02, and NAA/mI: 1.81 ± 0.04 by LCModel, and mI/Cr: 0.88 ± 0.15, Cho/Cr: 0.35 ± 0.01, NAA/Cr: 1.33 ± 0.03, and NAA/mI: 1.55 ± 0.26 by SAGE. In the healthy volunteers and MCI patients, the ratios of mI/Cr and Cho/Cr estimated by LCModel were higher than those estimated by SAGE. In contrast, the ratio of NAA/Cr estimated by LCModel was lower than that estimated by SAGE., Conclusion: Both methods were acceptable in estimating brain metabolite concentration ratios. However, LCModel was marginally more accurate than SAGE because of its full automation, basis set, and user independency.

Objective: The purpose of this study is to evaluate the diagnostic performance of split-bolus portal venous phase dual-energy CT (DECT) urography in patients with hematuria., Materials and Methods: True unenhanced and split-bolus portal venous phase contrast-enhanced weighted-average images were obtained in 171 patients with hematuria. Virtual unenhanced and iodine-overlay images were reconstructed from contrast-enhanced 80-kVp and tin-filtered 140-kVp scans. Images were independently reviewed by two radiologists who were blinded to the final diagnoses in two separate reading sessions: virtual unenhanced and iodine-overlay images (single phase) in the first session and true unenhanced and contrast-enhanced weighted-average images (dual phase) in the second session (mean ± SD, 52 ± 8 days later). Sensitivity, specificity, and accuracy of mass detection were calculated from the data of both reading sessions. The number of calculi detected on virtual unenhanced images was compared with the number detected on true unenhanced images. The difference in radiation dose between the single- and dual-phase protocols was calculated. The statistical significance was determined by ANOVA., Results: The sensitivity, specificity, and accuracy were 98.7%, 98.9%, and 98.8%, respectively, for the single-phase approach to malignant mass detection and 98.7%, 97.9%, and 98.3%, respectively, for the dual-phase approach (p > 0.05 for all comparisons). The overall sensitivity of stone detection was 86.7% (39/45) for virtual unenhanced images. Omitting the unenhanced scan reduced the mean radiation dose from 15.4 to 6.7 mSv., Conclusion: The diagnostic performance of both the single- and dual-phase approaches of portal venous phase split-bolus DECT urography is equally good in patients with hematuria, and single-phase acquisition has the added benefit of radiation reduction.

Purpose: To evaluate the association of pleural tags with visceral pleural invasion of non-small cell lung cancer (NSCLC) that does not abut the pleural surface., Materials and Methods: This retrospective study was approved by the institutional review board. Informed consent was waived. The study of NSCLC that does not abut the pleura in 141 patients (44 patients [31.2%] with visceral pleural invasion proved by pathologic analysis and 97 patients [68.8%] without pleural invasion) was conducted at a single tertiary center. The pleural tags were classified into three types (type 1, one or more linear pleural tag; type 2, one or more linear pleural tag with soft tissue component at the pleural end; and type 3, one or more soft tissue cord-like pleural tag) and prioritized into types 3, 2, and 1 when more than one type was present. Diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive likelihood ratio (LR) were calculated., Results: In the absence of pleural tags, no pleural invasion was found. The presence of type 2 pleural tags was moderately associated with visceral pleural invasion with the following results: positive LR, 5.06; accuracy, 71%; sensitivity, 36.4%; specificity, 92.8%; PPV, 76.2%; and NPV, 69.6%. Type 1 pleural tags provided weak evidence to rule out visceral pleural invasion (positive LR, 0.38). Type 3 pleural tags indicated minimal increase in the likelihood of visceral pleural invasion (positive LR, 1.68)., Conclusion: Type 2 pleural tags on conventional CT images can increase the accuracy of early diagnosis of visceral pleural invasion by NSCLC that does not abut the pleura., ((©) RSNA, 2015.)

Objective: The purpose of this study is to evaluate the image quality of split-bolus portal venous phase urography and the potential reduction of radiation dose by using a second-generation dual-source dual-energy CT (DECT) scanner., Materials and Methods: DECT urography was performed in 84 patients. Unenhanced CT was performed 20 minutes after drinking 800 mL of water. The split-bolus protocol consisted of a sequence of injections, as follows: 200 mL of normal saline (2.0 mL/s), 50 mL of contrast medium (2.5 mL/s) at 0 second, 70 mL of contrast medium (2.5 mL/s) at 360 seconds, and a saline flush of 25 mL. The scan was started at 420 seconds. Virtual unenhanced images were reconstructed from contrast-enhanced images. The mean CT density and signal-to-noise ratio (SNR) of the renal parenchyma, vessels, upper urinary tract, normal reference tissues, and tumors were measured for image quantitative analysis. Image quality and opacification of the collecting systems were rated by two radiologists using 3- or 4-point scales., Results: The SNR of all measured sites, except the renal pelvis, showed a statistically significant correlation (p < 0.001) between the true unenhanced and virtual unenhanced images. The overall sensitivity of stone detection was 87.5% (28/32) in virtual unenhanced images. Image quality of the renal parenchyma, arteries, and veins was excellent in 59.5%, 75.0%, and 97.6% of cases, respectively. Opacification of the intrarenal collecting systems, proximal, middle, and distal ureters, and bladder was complete in 92.9%, 83.9%, 78.6%, 77.4%, and 26.2% of patients, respectively. Omitting the unenhanced scan can reduce the mean radiation dose from 15.6 to 6.7 mSv., Conclusion: Portal venous phase split-bolus DECT urography provides sufficient image quality with potential to reduce radiation exposure.

Purpose: To assess the diagnostic accuracy, cancer staging, image quality, and radiation dose of 80-kVp computed tomography (CT) images for patients with colorectal cancers (CRCs) using sinogram-affirmed iterative reconstruction (SAFIRE)., Methods: Sixty-four consecutive patients (mean weight 62.5  ±  11.3 kg, mean BMI 24.1  ±  3.3 kg/m(2)) with known CRC underwent dual-energy CT. Data were reconstructed as a weighted average (WA) 120-kVp dataset. Both filtered back projection (FBP) and SAFIRE were applied to reconstruct the WA 120-Kvp (Protocol A, B) and 80-kVp (Protocol C, D) image sets. The image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the cancers, the normal reference tissues, and the effective dose for each protocol were assessed. The cancer detection, staging, and image quality were evaluated. Analysis of variance was used for statistical analysis., Results: Compared with the FBP datasets at WA 120-kVp (Protocol A) and 80-kVp (Protocol C), the SAFIRE-reconstructed images (Protocols B, D) demonstrated significantly lower image noise (P  <  0.0083). Protocol D yielded significantly higher CNRs and SNRs for the CRCs and normal reference tissues than did Protocols A and C (P  <  0.0083). Protocol D also exhibited a significantly higher CNR for the CRC and some normal reference tissues than did Protocol B (P  <  0.0083). For hypovascular liver metastases (n  =  10), Protocol D yielded better SNRs and significantly higher CNRs than did Protocol A (P  <  0.0083). Overall, accuracy for tumor staging and liver metastasis was 95.3% (61/64) and 100%, respectively, in all of the 4 protocols. The mean effective dose decreased 41% from the WA 120-kVp to the 80-kVp protocols (6.23 vs. 3.68 mSv)., Conclusions: The 80-kVp technique with SAFIRE provided high SNR, high CNR, and good accuracy for staging in nonobese patients with CRC. Our study results should be extrapolated to patient populations with a high BMI with caution. Further studies of high BMI patients are therefore warranted.

Background: The ability to give high priority to examinations with pathological findings could be very useful to radiologists with large work lists who wish to first evaluate the most critical studies. A computer-aided detection (CAD) system for identifying chest examinations with abnormalities has therefore been developed., Purpose: To evaluate the effectiveness of a CAD system on report turnaround times of chest examinations with abnormalities., Material and Methods: The CAD system was designed to automatically mark chest examinations with possible abnormalities in the work list of radiologists interpreting chest examinations. The system evaluation was performed in two phases: two radiologists interpreted the chest examinations without CAD in phase 1 and with CAD in phase 2. The time information recorded by the radiology information system was then used to calculate the turnaround times. All chest examinations were reviewed by two other radiologists and were divided into normal and abnormal groups. The turnaround times for the examinations with pathological findings with and without the CAD system assistance were compared., Results: The sensitivity and specificity of the CAD for chest abnormalities were 0.790 and 0.697, respectively, and use of the CAD system decreased the turnaround time for chest examinations with abnormalities by 44%., Conclusion: The turnaround times required for radiologists to identify chest examinations with abnormalities could be reduced by using the CAD system. This system could be useful for radiologists with large work lists who wish to first evaluate the most critical studies., (© The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

The aim of this study was to develop an automated method for the detection of endotracheal tube and location of its tip in paediatric chest radiographs. In this method, a seed point was first determined from the line crossing the cervical region and a line path was traced from the seed point. Two features, Lmax and C, were determined from the path and were combined to detect the existence of the endotracheal tube. Multiple thresholds applied to the line path were used to determine the candidate locations for the tip, and the most suitable location was selected from these candidates by analysing the image features. To evaluate the performance of detection of endotracheal tube existence, support vector machine was used to classify the images with and without endotracheal tubes on the basis of Lmax and C. The discriminant performance of the method was evaluated using receiver operating characteristic (ROC) analysis. To evaluate the precision of the detected tip locations, the tip locations in paediatric chest images were annotated by a radiologist. The distance (error) between the detected and annotated locations was used to evaluate detection precision for the tip location. The proposed method was evaluated using 528 images with endotracheal tubes and 816 images without endotracheal tubes. The discriminant performance in this study, evaluated as Az (area under the ROC curve), for detecting the existence of endotracheal tubes on the basis of the two features was 0.943±0.009, and the detection error of the tip location was 1.89±2.01mm. The proposed method obtained high performance results and could be useful for detecting the malposition of endotracheal tubes in paediatric chest radiographs., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Objectives: To evaluate the diagnostic accuracy and the potential radiation dose reduction of dual-energy CT (DECT) for tumor (T) staging of colorectal cancer (CRC) using iodine overlay (IO) and virtual nonenhanced (VNE) images., Materials and Methods: This retrospective study included 103 consecutive patients who underwent nonenhanced CT and enhanced DECT for preoperative CRC staging. Enhanced weighted-average (WA), IO and VNE images were reconstructed from enhanced 80 kVp and Sn140 kVp scans. Two radiologists assessed image qualities of the true nonenhanced (TNE) and VNE images. For T-staging, another two radiologists independently interpreted all scans in two separate reading sessions: in the first session, only images derived from the single phase DECT acquisition (IO and VNE images) were read. In the second reading session after 30 to 50 (average:42) days, the same assessment was again performed with the TNE and enhanced WA images thereby simulating conventional dual-phase single-energy CT. The tumor node metastasis (TNM) system was used for staging with histopathologic reports as gold standard. Analysis of variance was used for statistical analysis., Results: The signal-to-noise ratios (SNRs) of the tumors and normal reference tissues showed significant correlation between the TNE and VNE images (P<0.01). The mean iodine overlay value (48.4 HU±12.2) and enhancement (49.4 HU±11.8) value of CRCs had no significant difference (P = 0.52).The mean image noise on TNE (5.0±1.1) and VNE (5.3±1.1) images were similar (P = 0.07). The quantitative qualities of the VNE images were mildly inferior to the TNE images. Overall accuracy of T-stage CRC when using single-phase acquisition was slightly better than the dual-phase acquisition (90.3% vs 87.4%) (P = 0.51). The mean dose of the single-phase DECT acquisition was 6.2 mSv comparing with 14.3 mSv of dual-phase., Conclusion: Single-phase DECT using IO and VNE images yields a high accuracy in T-staging of CRCs. Thereby, the radiation exposure of the patients can be reduced.

This study developed a computerised method for fovea centre detection in fundus images. In the method, the centre of the optic disc was localised first by the template matching method, the disc-fovea axis (a line connecting the optic disc centre and the fovea) was then determined by searching the vessel-free region, and finally the fovea centre was detected by matching the fovea template around the centre of the axis. Adaptive Gaussian templates were used to localise the centres of the optic disc and fovea for the images with different resolutions. The proposed method was evaluated using three publicly available databases (DIARETDB0, DIARETDB1 and MESSIDOR), which consisted of a total of 1419 fundus images with different resolutions. The proposed method obtained the fovea detection accuracies of 93.1%, 92.1% and 97.8% for the DIARETDB0, DIARETDB1 and MESSIDOR databases, respectively. The overall accuracy of the proposed method was 97.0% in this study., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Background and Purpose: ESRD results in excessive accumulation of urea and toxic metabolites. Hemodialysis is usually performed to maintain health in patients with ESRD; however, it may cause silent white matter alterations in the earlier stages. Hence, this study aimed to perform voxelwise diffusion tensor analysis for global detection of subtle white matter alterations in patients with ESRD., Materials and Methods: Twenty-eight patients with ESRD and 25 age-matched control subjects were enrolled in this study. Each subject underwent CASI assessment and DTI. After spatial normalization of DTI images, voxelwise statistical analyses were performed to compare DTI parameters between the 2 groups., Results: In patients with ESRD, AD, RD, and MD values were significantly increased, whereas the FA value was significantly decreased, mostly in the corpus callosum, bilateral sagittal stratum, and pons. Multiple regression analysis further revealed that both RD and MD were positively correlated with the duration of hemodialysis in the pons; however, no significant correlation was observed with FA. Negative correlations of RD and MD and a positive correlation of FA with the CASI score were observed in the corona radiata., Conclusions: We concluded that voxelwise DTI analysis is helpful in the detection of white matter alterations caused by hemodialysis.

Rationale and Objectives: The aim of this study was to develop a computerized scheme for automated identity recognition based on chest radiograph features., Materials and Methods: The proposed method was evaluated on a database consisting of 1000 pairs of posteroanterior chest radiographs. The method was based on six features: length of the lung field, size of the heart, area of the body, and widths of the upper, middle, and lower thoracic cage. The values for the six features were determined from a chest image, and absolute differences in feature values between the two images (feature errors) were used as indices of image similarity. The performance of the proposed method was evaluated by receiver operating characteristic (ROC) analysis. The discriminant performance was evaluated as the area Az under the ROC curve., Results: The discriminant performance Az of the feature errors for lung field length, heart size, body area, upper cage width, middle cage width, and lower cage width were 0.794 ± 0.005, 0.737 ± 0.007, 0.820 ± 0.008, 0.860 ± 0.005, 0.894 ± 0.006, and 0.873 ± 0.006, respectively. The combination of the six feature errors obtained an Az value of 0.963 ± 0.002., Conclusion: The results indicate that combining the six features yields a high discriminant performance in recognizing patient identity. The method has potential usefulness for automated identity recognition to ensure that chest radiographs are associated with the correct patient., (Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.)

We compared the enhancement effect between a newly synthesized tissue-specific contrast agent, [Gd-DOTA-FPβG], and a commercially available agent, [Gd(DOTA)](-), in a murine model of liver tumor using a clinical magnetic resonance imaging scanner. The colon cancer cell lines with and without β-glucuronidase (βG) expression were implanted into the liver of mice. Self-synthesized gadolinium-based magnetic resonance contrast agent, [Gd(DOTA-FPβG)], was administered to measure enhancement on magnetic resonance images using a commercially available agent, [Gd(DOTA)](-), as control in a clinical 3.0 tesla (T) magnetic resonance scanner. In vivo fluorescence imaging and histopathology of the liver were also performed to compare and correlate with the magnetic resonance studies. The in vivo fluorescence imaging failed to depict a sufficiently intense signal for liver or liver tumor of mice without exposure of the liver following an incision on the abdominal wall. The tissue-specific magnetic resonance agent, [Gd(DOTA-FPβG)], caused significantly stronger enhancement in tumors expressing βG (CT26/mβG-eB7) than in tumors not expressing βG (CT26) (p < 0.05). In the magnetic resonance imaging studies using control agent [Gd(DOTA)](-), the tumors with and without βG expression depicted no significant difference in enhancement on the T1-weighted images. The [Gd(DOTA-FPβG)] also provided significantly more contrast uptake in the CT26/mβG-eB7 tumor than in the normal liver parenchyma, whereas the [Gd(DOTA)](-) did not. This study confirms that better contrast enhancement can be readily detected in vivo by the use of a tissue-specific magnetic resonance contrast agent to target tumor cells with specific biomarkers in a clinical magnetic resonance imaging scanner., (Copyright © 2012. Published by Elsevier B.V.)

β-Glucuronidase is a key lysosomal enzyme and is often overexpressed in necrotic tumor masses. We report here the synthesis of a pro receptor-induced magnetization enhancement (pro-RIME) magnetic resonance imaging (MRI) contrast agent ([Gd(DOTA-FPβGu)]) for molecular imaging of β-glucuronidase activity in tumor tissues. The contrast agent consists of two parts, a gadolinium complex and a β-glucuronidase substrate (β-d-glucopyranuronic acid). The binding association constant (KA) of [Gd(DOTA-FPβGu)] is 7.42 × 10(2), which is significantly lower than that of a commercially available MS-325 (KA = 3.0 × 10(4)) RIME contrast agent. The low KA value of [Gd(DOTA-FPβGu)] is due to the pendant β-d-glucopyranuronic acid moiety. Therefore, [Gd(DOTA-FPβGu)] can be used for detection of β-glucuronidase through RIME modulation. The detail mechanism of enzymatic activation of [Gd(DOTA-FPβGu)] was elucidated by LC-MS. The kinetics of β-glucuronidase catalyzed hydrolysis of [Eu(DOTA-FPβGu)] at pH 7.4 best fit the Miechalis-Menten kinetic mode with Km = 1.38 mM, kcat = 3.76 × 10(3), and kcat/Km = 2.72 × 10(3) M(-1) s(-1). The low Km value indicates high affinity of β-glucuronidase for [Gd(DOTA-FPβGu)] at physiological pH. Relaxometric studies revealed that T1 relaxivity of [Gd(DOTA-FPβGu)] changes in response to the concentration of β-glucuronidase. Consistent with the relaxometric studies, [Gd(DOTA-FPβGu)] showed significant change in MR image signal in the presence of β-glucuronidase and HSA. In vitro and in vivo MR images demonstrated appreciable differences in signal enhancement in the cell lines and tumor xenografts in accordance to their expression levels of β-glucuronidase.

To evaluate the competitive potential of a new lipophilic paramagnetic complex, Gd-Bz-TTDA [4-benzyl-3,6,10-tri (carboxymethyl)-3,6,10-triazado-decanedioic acid] compared with two other commercially available MR hepatobiliary contrast agents, gadobenate dimeglumine (Gd-BOPTA) and gadoxetic acid (Gd-EOB-DTPA), dynamic MR imaging studies were performed on normal and hepatocellular carcinoma (HCC) rat models using a 1.5-Tesla MR scanner. The results indicate that normal rats that were injected with 0.1 mmol/kg Gd-Bz-TTDA showed significantly more intense and persistent liver enhancement than those that were injected with the same dose of Gd-EOB-DTPA or Gd-BOPTA. All of these agents showed similar enhancement patterns in the implanted HCC. The liver-lesion contrast-to-noise ratios were higher and more persistent in rats that were injected with Gd-Bz-TTDA. These results indicate that Gd-Bz-TTDA is comparable with the commercially available hepatobiliary agents, Gd-EOB-DTPA and Gd-BOPTA, and can result in more intense and prolonged liver enhancement while still providing better liver-lesion discrimination. These results warrant further large-scale studies., (Copyright © 2012. Published by Elsevier B.V.)

A computerized scheme was developed for automated identification of erect posteroanterior (PA) and supine anteroposterior (AP) chest radiographs. The method was based on three features, the tilt angle of the scapula superior border, the tilt angle of the clavicle and the extent of radiolucence in lung fields, to identify the view of a chest radiograph. The three indices A(scapula), A(clavicle) and C(lung) were determined from a chest image for the three features. Linear discriminant analysis was used to classify PA and AP chest images based on the three indices. The performance of the method was evaluated by receiver operating characteristic analysis. The proposed method was evaluated using a database of 600 PA and 600 AP chest radiographs. The discriminant performances Az of A(scapula), A(clavicle) and C(lung) were 0.878 ± 0.010, 0.683 ± 0.015 and 0.962 ± 0.006, respectively. The combination of the three indices obtained an Az value of 0.979 ± 0.004. The results indicate that the combination of the three indices could yield high discriminant performance. The proposed method could provide radiologists with information about the view of chest radiographs for interpretation or could be used as a preprocessing step for analyzing chest images.

Objective: The purpose of this study was to evaluate the efficacy of MDCT in the differentiation of diseases involving giant gastric folds and to identify the features most useful for predicting the presence of malignant gastric disease., Materials and Methods: Blinded reviewers retrospectively analyzed 16-MDCT scans of 64 patients who had endoscopic findings of giant gastric folds. Thirty of these patients had histopathologic results showing scirrhous carcinoma; 15, large B-cell lymphoma; 14, acute gastric mucosal lesions; and five, Ménétrier disease. Unenhanced transparent volume-rendered images were assessed to determine the morphologic features of the whole stomach. Contrast-enhanced images were used to analyze wall thickness, stratification, enhancement pattern, and perigastric conditions. We used the Cramer phi-prime correlation coefficient to calculate the overall diagnostic accuracy of MDCT in several gastric disorders. Scatterplot analysis was used for overall diagnostic score, and analysis of the receiver operator characteristic curves of the neighboring two diseases was used to locate the cutoff values for best diagnostic accuracy. We used exact logistic regression to identify which MDCT image features were most predictive of the presence of malignant gastric disease., Results: The gastric wall was found to be significantly thicker in large B-cell lymphoma than in other disorders (p < 0.001). The overall diagnostic accuracy of MDCT in the four diseases was 100%. Loss of wall stratification was deemed the best MDCT predictor of the presence of malignancy., Conclusion: MDCT may be a reliable means of noninvasive diagnosis in the care of patients with endoscopically detected giant gastric folds and may be useful for differentiating benign from malignant disease.

Intrathoracic tumor is a rare entity in the pediatric population and neurogenic tumors account for 40-50% of childhood intrathoracic tumors. They can cause severe symptoms, such as respiratory distress, neurological dysfunction and metabolic disturbances. Posterior mediastinal ganglioneuroma (GN) usually occurs in children and can be found accidentally. Precise preoperative diagnosis is very difficult and has a great influence on surgical intervention. Here, we report a 6-year-old girl with a posterior mediastinal GN that was found incidentally on chest radiography. Computed tomography and magnetic resonance imaging demonstrated a right paraspinal tumor with punctuate calcification and intraspinal extension. (18)F-fluorodeoxyglucose positron emission tomography revealed low-grade fluorodeoxyglucose avidity of this tumor. Computed tomography and magnetic resonance imaging can characterize GN and positron emission tomography is helpful for differentiating benign or malignant lesions., (Copyright © 2010 Elsevier. Published by Elsevier B.V. All rights reserved.)

Kaposiform hemangioendothelioma is a very infrequent, locally aggressive vascular neoplasm, characterized by fascicular spindle cell proliferation. It occurs almost exclusively in infants and adolescents, and is often associated with Kasabach-Merritt phenomenon. The tumor is predominantly located subcutaneously or in the deep soft tissue of the extremities and trunk, peritoneum, or retroperitoneum. However, this tumor can sometimes be located on the head and neck. We report a case of kaposiform hemangioendothelioma of the maxillary sinus in a 4-month-old female infant presenting with cheek swelling, thrombocytopenia, anemia, and disseminated intravascular coagulation. Sinus computed tomography presented an enhancing, bone-destructing tumor. Magnetic resonance images showed an uncommon appearance as mostly low signal intensity on T2-weighted images., (Copyright 2010 Elsevier. Published by Elsevier B.V. All rights reserved.)

Accurate and consistent visualization of the entire coronary system with high-grade imaging quality is crucial for routine applications of multi-detector-computed tomography (MDCT) coronary angiography. To determine the imaging quality of 64-slice-MDCT coronary angiography, we respectively explored the quantitative parameters of imaging quality in 105 consecutive subjects (71 men, 34 women; aged 58.66 +/- 10.62 years) who underwent 64-slice-MDCT coronary angiography to screen for coronary disease. The interobserver agreement for semi-quantitative image quality, visible length, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the coronary arteries was good. The SNR and CNR of the proximal segments of the coronary arteries were superior to that of the distal segments of coronary arteries (p < 0.001). The visible length of the stenosed right coronary artery was significantly shorter than that of the non-stenosed right coronary artery (p = 0.03). The SNR and CNR of the stenosed and non-stenosed coronary arteries revealed no significant difference (p > 0.05). Body weight and body mass index were inversely related to the SNR and CNR of the aorta (p < 0.001). In conclusion, 64-slice-MDCT coronary angiography can provide excellent imaging quality of coronary arteries in subjects undergoing screening for coronary disease, although the SNR and CNR were relatively low at the distal segments of coronary arteries.

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.

Purpose: To investigate the correlation between muscle function and metabolism in muscle tissue of Duchenne muscular dystrophy (DMD) patients by in vivo proton magnetic resonance spectroscopy., Materials and Methods: In this prospective study, we enrolled 8 boys with DMD and 8 healthy volunteers. In vivo proton magnetic resonance spectroscopy of the soleus muscles was performed using a whole-body 3.0-Tesla imaging unit and a knee coil. The levels of trimethyl ammonium (TMA) and total creatine (tCr) were measured. We compared TMA/water, tCr/water, and TMA/tCr ratios, and scores for muscle function in the legs by using a t test., Results: Fat infiltrated the leg muscles in all patients but no volunteers. All patients had elevated creatine kinase levels. Magnetic resonance spectra of patients and volunteers showed TMA and tCr peaks. Ratios of TMA/water (P = 0.0015), tCr/water (P = 0.0167), and TMA/tCr (P = 0.0017), and muscle function scores (P = 0.0028) were significantly lower in patients than in volunteers. All patients had impaired muscle function, whereas all volunteers had normal function. Muscle function in the legs was negatively correlated with the TMA/tCr ratio (r2 = 0.878)., Conclusions: Metabolite ratios and muscle function scores were significantly decreased in patients with DMD when compared with normal control subjects. A statistically significant decrease in TMA/tCr ratio in patients with DMD as compared with control subjects was found to correlate with decreased muscle function.

Objective: The purpose of this study was to evaluate MDCT parameters for differentiating malignant (category T1 and T2) from benign gastric ulcers and to evaluate the performance characteristics of these predictors with optimal cutoff points determined in receiver operator characteristic analysis., Subjects and Methods: The subjects were 26 patients with gastric cancer (11 with T1 lesions, 15 with T2 lesions) and 26 patients with benign gastric ulcer. MDCT and virtual gastroscopic findings were analyzed according to four qualitative criteria: ulcer shape, base, and margin and changes in adjacent folds. The quantitative criteria ulcer size, thickness of the gastric wall around an ulcer, thickness of the enhanced ulcer base, and enhancement around an ulcer were measured on multiplanar reconstruction images. We calculated the sensitivity and specificity of each quantitative criterion. Receiver operator characteristic analysis was used to identify cutoff points yielding optimal sensitivity and specificity for the diagnosis of gastric cancer., Results: On virtual gastroscopy, ulcer shape and margin and gastric fold changes had sensitivities of 80.8%, 84.6%, and 90.9% and specificities of 76.9%, 73.1%, and 77.8%, respectively, in the diagnosis of gastric cancer. On multiplanar reconstruction images, thickness of the enhanced ulcer base and enhancement around the ulcer had sensitivities of 80.8% and 73.1% and specificities of 100% and 100%., Conclusion: MDCT combined with virtual gastroscopy and multiplanar reconstruction enhances the morphologic details of gastric ulcers and is a useful way to differentiate malignant (T1 and T2) and benign gastric ulcers.

It is important to differentiate malignant from benign gastric ulcers (GUs) because the early detection of malignancy offers the best prognosis and is essential for planning optimal therapy. However, the differential diagnosis between a malignant and benign gastric ulcer is sometimes difficult, and remains a great challenge. Recent advances in multidetector row-computed tomography (MDCT) with three-dimensional imaging software and multiplanar reformatted (MPR) images provide a potentially powerful tool for noninvasive gastric evaluation. Virtual gastroscopy (VG) is helpful in the detection and evaluation of GU in the same way as gastroscopy. In comparison with gastroscopy, VG images can depict abnormal endoluminal lesions with a wider field of view and they have no blind point because retrospective reconstruction is available. MPR images allow the radiologist to choose the optimal imaging plane to accurately evaluate the change of the gastric wall around the gastric ulcer avoiding partial volume averaging effects. This report describes the clinical usefulness of MDCT in differentiating malignant from benign GUs by using VG and MPR images.

Volvulus of the colon is an unusual cause of intestinal obstruction in the pediatric population. Splenic flexure colonic volvulus is the most uncommon site in children. We report a case of splenic flexure volvulus (SFV) in a 21-month-old boy with underlying cerebral palsy and epilepsy. He experienced abdominal distension, bilious vomiting and absence of bowel movement for 2 days. Abdominal radiography showed a proximal distended colon and a "coffee bean sign" at the left upper quadrant. Barium enema revealed a "bird beak sign" at the splenic flexure, which confirmed the diagnosis of SFV. Detorsion of SFV occurred while undergoing exploratory laparotomy. He received regular follow-up in the subsequent 3 years without recurrence.

Purpose: To prospectively evaluate accuracy of multi-detector row computed tomographic (CT) images for preoperative staging of gastric cancer by using surgical and histopathologic results as reference standards., Materials and Methods: This study had institutional review board approval; informed consent was obtained from all patients. Multi-detector row CT included acquisition of virtual gastroscopy images after air distention and contrast material-enhanced dynamic transverse and multiplanar reformation (MPR) images after water distention. Fifty-five consecutive patients with gastric cancer (38 men, 17 women; age range, 37-84 years; mean age, 63 years) underwent preoperative CT. All received 6 g of gas-producing crystals before unenhanced CT scanning for gastric distention and virtual gastroscopy. Patients drank 800-1000 mL of tap water to establish a background for dynamic contrast-enhanced CT scans. Images were obtained in late arterial, portal venous, and delayed phases with start delays of 40, 70, and 150 seconds, respectively. All patients underwent surgery. CT findings were compared with surgical and histopathologic results. Differences in accuracy of transverse and MPR images for T and N staging were assessed with the McNemar exact test. Statistical significance was inferred at P < .05., Results: Detection rates of primary tumors with transverse images, MPRs, and combinations of MPR and virtual gastroscopy images were 91% (50 of 55), 96% (53 of 55), and 98% (54 of 55), respectively. Overall accuracy in assessment of tumor invasion of the gastric wall (T stage) was significantly better with MPR images (89% [49 of 55]) than with transverse images (73% [40 of 55]) (P < .01). Overall accuracy for lymph node (N) staging was 78% (43 of 55) with MPR images and 71% (39 of 55) with transverse images. This difference was not significant (P = .103)., Conclusion: Multi-detector row CT with combined water and air distention can improve the accuracy of preoperative staging of gastric cancer. MPRs yield significantly better overall accuracy than transverse images for tumor staging but not for lymph node staging., ((c) RSNA, 2007.)

Background: When implanting a permanent central venous catheter, the usual aim is to place the tip at the superior vena cava/right atrial (SVC/RA) junction. However, data validating radiographic landmarks of the SVC/RA junction are limited. This investigation was undertaken to compare the radiographic landmarks with the SVC/RA junction as determined by transesophageal echocardiography (TEE)., Methods: In 20 adult oncologic patients undergoing implantation of a permanent subcutaneous central venous catheter, the catheter tip was placed in the SVC/RA junction under TEE guidance. The position of the catheter tip on chest X-ray, which represented the echocardiographic SVC/RA junction, was then compared with a standard radiographic landmark of the SVC/RA junction and with thoracic vertebral levels., Results: In all but two patients radiographic SVC/RA junctions were identified. The echocardiographic SVC/RA junction ranged from 0.6 cm above to 2.8 cm below the radiographic SVC/RA junction. There was a significant difference between the distance from the carina to the radiographic SVC/RA junction and the distance from the carina to the echocardiographic SVC/RA junction. The thoracic vertebral body correlating with the echocardiographic SVC/RA junction ranged from the sixth to the ninth level., Conclusion: Both the radiographic SVC/RA junction and the thoracic vertebral bodies are not reliable landmarks for the SVC/RA junction defined by TEE. Physicians should be aware that using the radiographic SVC/RA junction to confirm proper positioning of permanent central venous catheters risks placing the catheter tip in the upper SVC, with subsequent potential long-term complications. More reliable radiographic landmarks for the SVC/RA junction should be investigated.

Purpose: To prospectively investigate the apparent diffusion coefficient (ADC) and choline levels measured at hydrogen 1 ((1)H) magnetic resonance (MR) spectroscopy, to monitor therapeutic responses of hepatocellular carcinoma (HCC) to transcatheter arterial chemoembolization (TACE)., Materials and Methods: Institutional review board approval was obtained, and all patients and control subjects provided informed consent. Histologically proved large HCCs (>3 cm in diameter) were evaluated in 20 patients (16 men and four women; mean age, 59 years; range, 34-80 years) before TACE and 2-3 days after TACE. A control group of eight adults (five men and three women; mean age, 43 years; range, 24-76 years) with normal livers was examined by using the same protocol. Hepatic choline levels were measured by means of an external phantom replacement method, quantifying the peak at 3.2 ppm at (1)H MR spectroscopy. ADCs were measured for all lesions. A Wilcoxon rank sum test was used to compare absolute choline concentrations and ADCs at baseline between HCCs and normal liver parenchyma. Changes in choline levels and ADCs in the tumors before and after TACE were analyzed by using the Wilcoxon signed rank test., Results: The median preoperative choline level in patients with HCC (measured in 18 of the 20 patients) was 4.0 mmol/L (range, 0.0-17.2 mmol/L), which was significantly higher than that in patients with normal livers (n = 8) (median, 1.6 mmol/L; range, 0.0-2.1 mmol/L; P < .01). Among 18 patients with HCC, choline levels decreased significantly from before TACE to after TACE (P < .01). A significant increase in ADC from before TACE to after TACE in the 20 patients with HCC was also found (P < .01)., Conclusion: Hepatic choline levels and ADCs may allow monitoring of therapeutic responses of HCC to TACE although larger, more definitive and quantitative studies with clinical end points are needed., ((c) RSNA, 2006.)

Rationale and Objectives: For computerized analysis of chest images in the clinical environment, identification of frontal (posteroanterior/anteroposterior) and lateral chest radiographs is an important preprocessing step. In this study, we developed a method to distinguish frontal from lateral views of the chest radiographs based on an analysis of the projection profile., Materials and Methods: Projection profile is obtained by projecting a chest image on to the mediolateral axis. Two indices, body symmetry index and background percentage index, are computed from the projection profile. The combination of body symmetry index and background percentage index is used to determine the view of chest radiographs. The method is evaluated on a sample of 2000 frontal and 1000 lateral chest images., Results: The values of body symmetry index are found to be 1.18 +/- 0.23 and 3.07 +/- 1.42 for frontal and lateral chest images, respectively. The values of background percentage index are found to be 0.03 +/- 0.05 and 0.33 +/- 0.09 for frontal and lateral chest images, respectively. The discrimination is evaluated by linear discriminant analysis and receiver operating characteristic analysis. Area Az under the receiver operating characteristic curve with the combination of the two indices is 0.993., Conclusion: The method can be used as a preprocessing step for further analysis in chest radiographs.

Abnormalities in chest images often present as abnormal opacity or abnormal asymmetry. We have developed a novel method for automated detection of abnormalities in chest radiographs by use of these features. Our method is based on an analysis of the projection profile obtained by projecting the pixels data of a frontal chest image on to the mediolateral axis. Two indices, lung opacity index and lung symmetry index, are computed from the projection profile. Lung opacity index and lung symmetry index are then combined to detect gross abnormalities in chest radiographs. The values of lung opacity index are found to be 0.38 +/- 0.05 and 0.37 +/- 0.06 for normal right and left lung, respectively. The values of lung symmetry index are found to be 0.018 +/- 0.014 for normal chest images. The discrimination for the combination of the two indices is evaluated by linear discriminant analysis and receiver operating characteristic (ROC) analysis. Area Az under the ROC curve with the combination of the two indices in the classification of normal and abnormal chest images is 0.963.

Objective: Diffusion-weighted imaging (DWI) is usually performed before administration of intravenous contrast agents. Repetition of DWI is occasionally necessary after contrast administration, but the effects of contrast material on DWI and apparent diffusion coefficient (ADC) values in the abdomen have not yet been fully examined. The purpose of this work is to assess whether administration of gadolinium-based contrast material significantly affects DWI and ADC values at the focal hepatic lesions., Methods: The results of DWI at 3.0 T (Signa VH3; GE Medical Systems, Milwaukee, WI) were examined in 20 patients (age range: 33-86 years, mean age = 68 years) who were evaluated by means of a hepatic protocol at our hospital. Among the 20 patients studied, a total of 57 lesions were detected. Diffusion-weighted imaging was obtained using single-shot echo planar imaging with a b value of 500 s/mm. Patients were injected with 0.1 mmol/kg gadopentetate dimeglumine. The signal-to-noise ratio (SNR) of the liver and the hepatic lesions was examined, and the contrast-to-noise ratio (CNR) of each lesion was evaluated. In addition, the ADC values calculated from the DWI were compared before and after administration of contrast agent. The statistical significance of differences between precontrast and postcontrast administration was determined by use of a paired t test., Results: The SNR and CNR of the DWI were not significantly different before and after administration of contrast agent. The ADC values tended to decrease after administration of contrast agent for each focal hepatic lesion and the liver, although they did not reach statistical significance., Conclusion: There was no significant difference before and after administration of contrast agent in the SNR or CNR of DWI. This indicates the feasibility of postcontrast DWI as a substitute for an unsuccessful precontrast-enhanced study in clinical practice.

[Gd(TTDA-BOM)] 2- is a newly developed paramagnetic contrast agent.The ligand,TTDA-BOM,bears a benzyloxymethyl group so that the lipophilicity is increased. The water exchange rate for [Gd(TTDA-BOM)] 2- is significantly higher than that of [Gd(DTPA)] 2- and [Gd(BOPTA)] 2- .In addition, the bound relaxivity of this Gd (III) complex has a remarkably high value with HSA. Therefore,it has potential to be used as a blood pool contrast agent for MRI. The aim of this study is to investigate the characterization and imaging behavior of NMG2[Gd(TTDA-BOM)] in normal rat livers and hearts using a 3T high field whole-body MR scanner.The high field MR scanner is expected to have a higher signal to noise ratio. The relaxivities r1and r2for [Gd(TTDA-BOM)] 2- at 3T are 5.97 mM -1 s -1 and 7.99 mM -1 s -1 respectively, which are higher than those for [Gd(DTPA)] 2 (r1=4.64 mM -1 s -1 and r2= 5.08 mM -1 s -1 ). The dynamic MRI studies show that there is marked enhancement in livers and hearts right after the bolus injection and the enhancement ratios keep high until two hours. In conclusion, [Gd(TTDA-BOM)] 2- might have a good potential in both cardiovascular and hepatobiliary applications.

Purpose: To evaluate the potential of a new lipophilic paramagnetic complex [Gd(Bz-TTDA)]2- [(4s)-4-benzyl-3,6,10-tri(carboxymethyl)-3,6,10-triazadodecandioic acid]2- designed for use as a hepatobiliary MR contrast agent., Materials and Methods: MR imaging studies for normal and hepatocellular carcinoma (HCC) rat models were performed using a 1.5-T scanner. Sequential multislice T1-weighted turbo field echo (TFE) (TR/TE/flip angle: 15 msec/6.1 msec/25 degrees) coronal images of normal rats were obtained before and after intravenous injections of 0.1 mmol/kg [Gd(Bz-TTDA)]2- in study groups (N = 12) or 0.1 mmol/kg gadopentate dimeglumine (Gd-DTPA)2- in control groups (N = 12). Similar protocols of MR imaging with additional T2-weighted images were used for the rats with implanted HCC in both study and control groups (N = 12, in each group). MR images were analyzed to evaluate the time-enhancement change (% increase of signal-to-noise ratio [SI/N]) in normal liver, renal cortex, renal medulla, and tumors. The liver-lesion contrast-to-noise ratios (CNR) were also evaluated in study and control groups. The rats were killed immediately after the last MR scan to undergo autopsy and histopathologic observation. The acute toxicity test (medial lethal dose, LD50) in mice was also done., Results: The liver enhancement in normal rats reached a plateau 5-50 minutes after injection of [Gd(Bz-TTDA)]2-, maintained for three hours, then gradually declined. Intensity of enhancement in liver, renal cortex, and medulla after injection of [Gd(Bz-TTDA)]2- was significantly higher than with Gd-DTPA. The efficacy of tumor characterization with injection of [Gd(Bz-TTDA)]2- was similar to that of Gd-DTPA at the early dynamic phase of the contrast study. However, the liver-lesion CNRs were significantly higher in the study group in the later phase, when tumor enhancement decreased and liver enhancement persisted. The dose of LD50 in acute toxicity test of [Gd(Bz-TTDA)]2- in mice was 7.5 mmol/kg., Conclusion: The preliminary results in this animal study indicated that [Gd(Bz-TTDA)]2- has the potential of becoming a reliable liver MR contrast agent.

Background and Purpose: In theory, ionic solutes diffuse more slowly in cartilage than do nonionic solutes. We tested the hypothesis that the contrast ratio between scar and recurrent disk fragment on MR images is greater after IV administration of an ionic rather than a nonionic contrast medium when a clinical dose is used., Methods: Twenty patients who had recurrent lumbar disk herniation were enrolled in this study. The enhancement of epidural scar and recurrent disk fragment was measured at 5, 25, 40, and 50 min after IV injection of ionic and nonionic contrast media (0.1 mmol/kg), Results: The enhancement was consistently and significantly higher for scar than for recurrent disk fragment, although the contrast ratio between scar and recurrent disk fragment decreased between 5 and 50 min after the administration of each contrast medium. No significant difference was shown between ionic and nonionic contrast media in the enhancement of recurrent disk fragment at 5, 25, 40, and 50 min after injection. The contrast ratio between scar and recurrent disk fragment was not a significant difference at 5, 25, and 40 min after administration of both contrast media. At 50 min, the contrast ratio between scar and recurrent disk fragment was 1.32 +/- 0.41 with ionic contrast medium and 1.20 +/- 0.56 with nonionic contrast medium. The difference was significant., Conclusion: The contrast ratio between scar and recurrent disk fragment is affected by the timing of the imaging. Images obtained immediately after the injection of each contrast medium showed a greater contrast ratio than did delayed images. In addition, with the ionic medium, this difference was greater than with nonionic medium at 5, 25, 40, and 50 min after injection and that difference reached statistical significance at 50 min.

The new complex of Gd(III) with the 1,7-bis[(N-dimethyl(carbomoyl)methyl)-1,4,7-triazaheptane-1,4,7- triacetate[Gd(DTPA-BDMA)] is a non-ionic paramagnetic complex designed for use as an extracellular magnetic resonance imaging (MRI) contrast agent. The R1 relaxivity value of [Gd(DTPA-BDMA)] is 4.13 +/- 0.2 mM-1S-1, which is similar to that of [Gd(DTPA)]2- (4.08 mM-1S-1). The purpose of this study is to examine the acute toxicity and MRI characteristics of [Gd(DTPA-BDMA)]. Our results show that the lethal dose (LD50) of the [Gd (DTPA-BDMA)] is 10.58 mmol/kg in ICR mice, which is higher than that of [Gd (DTPA)]-2-(6.40 mmol/kg). The MR images demonstrate that the enhancing effect and renal clearance of [Gd(DTPA-BDMA)] are similar to that of [Gd(DTPA)]2- either in control group or CHA (Cheng hepatoma ascites) tumor model in Wistar rats (p > 0.05). These findings indicate that [(DTPA-BDMA)] has similar characteristics of [Gd(DTPA)]2- and has the potential of becoming a safe and reliable magnetopharmaceutical for the extracellular MRI contrast agent.

Purpose: To evaluate the usefulness of magnetic resonance (MR) cholangiography in excluding biliary atresia as the cause of neonatal cholestasis., Materials and Methods: MR cholangiography was performed on 10 control and 16 jaundiced neonates and infants aged 3 days to 5 months. Diagnosis of biliary atresia (n = 6) was confirmed with surgery and liver biopsy, with or without surgical cholangiography. Diagnosis of neonatal hepatitis (n = 9) was confirmed with clinical follow-up until jaundice resolved. In one infant, paucity of intrahepatic ducts was diagnosed at liver biopsy. MR cholangiography was performed with respiratory-triggered, heavily T2-weighted turbo spin-echo and optional inversion-recovery turbo spin-echo sequences. Diagnosis of biliary atresia was based on nonvisualization of either the common bile duct or common hepatic duct. Cholescintigraphy with technetium 99m disofenin was performed in all 16 jaundiced patients., Results: In the 10 controls, the nine patients with neonatal hepatitis, and the one infant with paucity of intrahepatic ducts, MR cholangiography clearly depicted the gallbladder and common hepatic and common bile ducts. MR cholangiography was 100% accurate in excluding biliary atresia as the cause of neonatal cholestasis, while 99mTc disofenin cholescintigraphic findings were false-positive in four of 10 patients with nonobstructive cholestasis., Conclusion: MR cholangiography can be used to depict the major biliary structures of neonates and small infants and to exclude biliary atresia as the cause of neonatal cholestasis by allowing visualization of the biliary tract.

Magnetic resonance cholangiopancreatography (MRCP) is an emerging imaging technique for direct visualization of biliary and pancreatic ducts without the need for an invasive procedure, ionizing radiation, or iodine contrast media administration. The purpose of this study was to evaluate the efficacy of non-breath-hold MRCP in depicting normal and diseased biliary and pancreatic ducts. A retrospective analysis of 162 patients who underwent MRCP was performed, and a comparison between MRCP and direct cholangiography was made. The overall accuracy of MRCP in diagnosing malignant and benign pancreaticobiliary diseases was also calculated. MRCP depicted more than three hepatic segments in 99% of patients with dilated intrahepatic ducts and in 63% of patients with nondilated intrahepatic ducts. MRCP demonstrated the main hepatic duct, gallbladder, and cystic duct in 100%, 89%, and 72% of patients, respectively. The dilated extrahepatic duct, nondilated extrahepatic duct, dilated pancreatic duct, and nondilated pancreatic duct were visualized in 100%, 98%, 95%, and 77% of patients, respectively. The accuracy of MRCP in diagnosing hepatolithiasis, cholecystolithiasis, and choledocholithiasis was 96%, 97%, and 96%, respectively. The obstruction levels and characteristics determined by MRCP were in agreement with those determined from direct cholangiography in 98% of malignant obstructions and 89% of benign obstructions. The overall accuracy of a combination of MRCP and conventional magnetic resonance imaging in diagnosing pancreaticobiliary diseases was 81% for malignant diseases, 86% for benign diseases, and 82% for stone diseases. We conclude that non-breath-hold MRCP can reliably depict normal and diseased pancreaticobiliary ducts except for cystic ducts and nondilated pancreatic ducts.

Gadolinium (III)-di(benzyl carbamoylmethyl) diethylenetrinitrilotriacetic acid [Gd(DTPA-BBA)] is a newly developed paramagnetic complex designed for use as a hepatobiliary-specific contrast agent. The purpose of this study was to examine the relaxivity, biodistribution, and magnetic resonance (MR) imaging characteristics of Gd(DTPA-BBA) in rats. Our results showed that the T1 relaxivity of Gd(DTPA-BBA) (3.89 dm3/mmol/s in aqueous solution) was similar to that of Gd(III) diethylenetriamine-pentaacetate [Gd(DTPA)]2- (4.08 dm3/mmol/s) and Gd(III) benzyloxypropionicte-traacetate [Gd(BOPTA)]2- (4.40 dm3/mmol/s). Biodistribution studies indicated that Gd(DTPA-BBA) exhibited hepatobiliary and urinary elimination. In MR imaging studies, Gd(DTPA-BBA) provided biphasic enhancement of normal liver parenchyma, which was characterized by an initial steep increase in enhancement followed by a plateau. The initial relative enhancement (RE%) of the liver, at 1 minute after administration of 0.2 mmol/kg Gd(DTPA-BBA) was 113 +/- 19. The plateau RE% of the liver (48 +/- 13) occurred within 10 minutes and persisted for at least 60 minutes after injection of the contrast agent. In addition, Gd(DTPA-BBA) provided better RE% of the liver than [Gd(DTPA)]2-. The contrast RE% of liver abscess capsules reached a plateau within 5 minutes after injection of 0.1 mmol/kg Gd(DTPA-BBA). Although the hepatic enhancement of Gd(DTPA-BBA) was inferior to that of [Gd(BOPTA)]2-, the results suggest that Gd(DTPA-BBA) has potential as an MR contrast agent for nonspecific and hepatobiliary uses.

Magnetic resonance (MR) imaging, which is able to demonstrate the actual size of adenoids by differentiating them from other soft-tissue structures, can be effectively used to study the normal development of adenoids. To assess the normal development of adenoids and to understand their role in the nasopharyngeal airway compromise, the adenoids of 290 children who had MR examination for other reasons were measured by midsagittal T1-weighted spin-echo MR image. The maximal thickness of adenoids (A), anteroposterior depth of the nasopharynx (N) and the adenoid-nasopharynx (A/N) ratios were obtained using this method. The results showed that of the infants under the age of 3 months only 2 out of 11 adenoids (18%) could be identified. By 4 months of age, adenoids could be identified in 6 of 8 infants (75%). After 5 months of age, all adenoids were well demonstrated by MR imaging. The adenoids developed rapidly during infancy and reached a plateau between 2- and 14 years of age with a mean thickness ranging from 10.7 to 12.2 mm. Finally, the adenoids regressed rapidly after 15 years old. The A/N ratios, which could be used to assess the airway compromise, had a plateau between 2- and 7 years of age. After that, with the steady growth of the nasopharynx, the possible role of adenoid in airway compromise will become increasingly less significant in later childhood.

Neuronal migration anomalies are a spectrum of brain malformations caused by insults to migrating neuroblasts during the sixth week to fifth month of gestation. To study the characteristics of MRI findings in migration anomalies, MR images of 36 patients (28 children and 8 adults) with migration anomalies were evaluated. Five patients had lissencephaly, eight had pachygyria, twelve had schizencephaly, six had heterotopias of gray matter, three had hemimegalencephaly, and two had polymicrogyria. The frequency of migration anomalies was 0.51% of all cranial MRI studies and 1.21% of pediatric cranial MRI studies at our hospital. The major clinical presentations of these patients were seizure (64%), development delay (42%), motor deficits (42%) and mental retardation (25%). Twenty-five patients (69%) associated with other brain anomalies, including: other migration anomalies in 12 cases (33%), absence of the septum pellucidum in 10 cases (28%), Dandy-Walker malformation/variant in 5 cases, arachnoid cyst in 4 cases, agenesis of the corpus callosum in 3 cases, holoprosencephaly in 2 cases, mega cisterna magna in 1 case and cephalocele in 1 case. Some of them presented with multiple complicated anomalies. As MR imaging provides superb gray-white matter distinction, details of cortical anatomy and multiplanar capability, it can clearly delineate the detail morphologic changes of the brain caused by neuronal migration disorders as well as the associated anomalies.