Publications by authors named "Arash Bedayat"

31 Publications

Temporally aware volumetric generative adversarial network-based MR image reconstruction with simultaneous respiratory motion compensation: Initial feasibility in 3D dynamic cine cardiac MRI.

Magn Reson Med 2021 Jul 13. Epub 2021 Jul 13.

Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.

Purpose: Develop a novel three-dimensional (3D) generative adversarial network (GAN)-based technique for simultaneous image reconstruction and respiratory motion compensation of 4D MRI. Our goal was to enable high-acceleration factors 10.7X-15.8X, while maintaining robust and diagnostic image quality superior to state-of-the-art self-gating (SG) compressed sensing wavelet (CS-WV) reconstruction at lower acceleration factors 3.5X-7.9X.

Methods: Our GAN was trained based on pixel-wise content loss functions, adversarial loss function, and a novel data-driven temporal aware loss function to maintain anatomical accuracy and temporal coherence. Besides image reconstruction, our network also performs respiratory motion compensation for free-breathing scans. A novel progressive growing-based strategy was adapted to make the training process possible for the proposed GAN-based structure. The proposed method was developed and thoroughly evaluated qualitatively and quantitatively based on 3D cardiac cine data from 42 patients.

Results: Our proposed method achieved significantly better scores in general image quality and image artifacts at 10.7X-15.8X acceleration than the SG CS-WV approach at 3.5X-7.9X acceleration (4.53 ± 0.540 vs. 3.13 ± 0.681 for general image quality, 4.12 ± 0.429 vs. 2.97 ± 0.434 for image artifacts, P < .05 for both). No spurious anatomical structures were observed in our images. The proposed method enabled similar cardiac-function quantification as conventional SG CS-WV. The proposed method achieved faster central processing unit-based image reconstruction (6 s/cardiac phase) than the SG CS-WV (312 s/cardiac phase).

Conclusion: The proposed method showed promising potential for high-resolution (1 mm ) free-breathing 4D MR data acquisition with simultaneous respiratory motion compensation and fast reconstruction time.
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http://dx.doi.org/10.1002/mrm.28912DOI Listing
July 2021

CT evaluation of unrepaired/incidental congenital cardiovascular diseases in adults.

Diagn Interv Imaging 2021 Apr 21;102(4):213-224. Epub 2020 Oct 21.

Department of Radiological Sciences, Thoracic and Diagnostic Cardiovascular Imaging, David Geffen School of Medicine, 90095 Los Angeles, CA, USA.

Congenital heart disease (CHD) affects approximately one million people in the USA with the number increasing by 5% each year. Patients are usually both diagnosed and treated in infancy, however many of them may have subclinical CHD that remains undiagnosed until late adulthood. Patients with complex CHD tend to be symptomatic and are diagnosed at a younger age than those with a single defect. CHDs can be divided into three categories, including cardiac, great vessels and coronary artery anomalies. Recent advances in computed tomography (CT) technology with faster acquisition time and improved spatial resolution allow for detailed evaluation of cardiac morphology and function. The concomitant increased utilization of CT has simultaneously led to more sensitive detection and more thorough diagnosis of CHD. Recognition of and understanding the imaging attributes specific to each anomaly is important for radiologists in order to make a correct and definite diagnosis. This article reviews the spectrum of CHDs, which persist into adulthood that may be encountered by radiologists on CT.
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http://dx.doi.org/10.1016/j.diii.2020.09.011DOI Listing
April 2021

Four-dimensional Multiphase Steady-State MRI with Ferumoxytol Enhancement: Early Multicenter Feasibility in Pediatric Congenital Heart Disease.

Radiology 2021 Jul 20;300(1):162-173. Epub 2021 Apr 20.

From the Diagnostic Cardiovascular Imaging Laboratory, Department of Radiological Sciences (K.L.N., T.Y., A.B., P.H., J.P.F.), and Division of Cardiology (K.L.N.), David Geffen School of Medicine at UCLA, 300 Medical Plaza, B119, Los Angeles, CA 90095; VA Greater Los Angeles Healthcare System, Los Angeles, Calif (K.L.N.); Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pa (R.M.G., M.A.F., K.K.W.); Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital, Chicago, Ill (L.M.G., C.K.R.); and Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Ill (L.M.G., C.K.R.).

Background The value of MRI in pediatric congenital heart disease (CHD) is well recognized; however, the requirement for expert oversight impedes its widespread use. Four-dimensional (4D) multiphase steady-state imaging with contrast enhancement (MUSIC) is a cardiovascular MRI technique that uses ferumoxytol and captures all anatomic features dynamically. Purpose To evaluate multicenter feasibility of 4D MUSIC MRI in pediatric CHD. Materials and Methods In this prospective study, participants with CHD underwent 4D MUSIC MRI at 3.0 T or 1.5 T between 2014 and 2020. From a pool of 460 total studies, an equal number of MRI studies from three sites ( = 60) was chosen for detailed analysis. With use of a five-point scale, the feasibility of 4D MUSIC was scored on the basis of artifacts, image quality, and diagnostic confidence for intracardiac and vascular connections ( = 780). Respiratory motion suppression was assessed by using the signal intensity profile. Bias between 4D MUSIC and two-dimensional (2D) cine imaging was evaluated by using Bland-Altman analysis; 4D MUSIC examination duration was compared with that of the local standard for CHD. Results A total of 206 participants with CHD underwent MRI at 3.0 T, and 254 participants underwent MRI at 1.5 T. Of the 60 MRI examinations chosen for analysis (20 per site; median participant age, 14.4 months [interquartile range, 2.3-49 months]; 33 female participants), 56 (93%) had good or excellent image quality scores across a spectrum of disease complexity (mean score ± standard deviation: 4.3 ± 0.6 for site 1, 4.9 ± 0.3 for site 2, and 4.6 ± 0.7 for site 3; < .001). Artifact scores were inversely related to image quality ( = -0.88, < .001) and respiratory motion suppression ( < .001, = -0.45). Diagnostic confidence was high or definite in 730 of 780 (94%) intracardiac and vascular connections. The correlation between 4D MUSIC and 2D cine ventricular volumes and ejection fraction was high (range of = 0.72-0.85; < .001 for all). Compared with local standard MRI, 4D MUSIC reduced the image acquisition time (44 minutes ± 20 vs 12 minutes ± 3, respectively; < .001). Conclusion Four-dimensional multiphase steady-state imaging with contrast enhancement MRI in pediatric congenital heart disease was feasible in a multicenter setting, shortened the examination time, and simplified the acquisition protocol, independently of disease complexity. Clinical trial registration no. NCT02752191 © RSNA, 2021 See also the editorial by Roest and Lamb in this issue.
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http://dx.doi.org/10.1148/radiol.2021203696DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8248952PMC
July 2021

Pulmonary vein and left atrial posterior wall isolation for the treatment of atrial fibrillation: Comparable outcomes for adults with congenital heart disease.

J Cardiovasc Electrophysiol 2021 Jul 14;32(7):1868-1876. Epub 2021 Apr 14.

UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine, Los Angeles, California, USA.

Introduction: Optimal treatment strategies for ACHD with AF are unknown. This study sought to assess outcomes of pulmonary vein isolation (PVI) ± left atrial (LA), posterior wall isolation (PWI) for adults with congenital heart disease (ACHD), and atrial fibrillation (AF).

Methods: A retrospective review of all cryoballoon (CB) PVI ± PWI procedures at a single center over a 3-year period were performed. Clinical characteristics and outcomes for patients with and without ACHD were compared. The primary outcome was the occurrence of atrial tachyarrhythmia at 12-months postablation after a 90-day blanking period.

Results: Three-hundred and sixteen patients (mean: 63 ± 12 years, [63% male]) underwent CB PVI ± PWI during the study, including 31 (10%) ACHD (simple 35%, moderate 39% complex 26%; nonparoxysmal AF in 52%). ACHD was younger (51 vs. 64 years; p < .001) with a lower CHADS DS -VASc score (1.2 vs. 2.1; p = .001) but had a greater LA diameter (4.9 vs. 4.0 cm; p < .001) and a number of prior cardioversions (0.9 vs. 0.4; p < .001) versus controls. 12-month freedom from recurrent AF was similar for ACHD and controls (76% vs. 80%; p = .6) and remained nonsignificant in multivariate analysis (hazard ratio: 1.8, 95% confidence interval: 0.7-5.1; p = .22). At 12-months postablation, 75% of ACHD versus 93% of control patients were off antiarrhythmic drug therapy (p = .07).

Conclusion: This study demonstrates younger age and lower conventional stroke risk, yet clinically advanced AF for ACHD relative to controls. CB PVI ± PWI was an effective strategy for the treatment of AF among all forms of ACHD with similar 12-month outcomes as compared to controls.
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http://dx.doi.org/10.1111/jce.15027DOI Listing
July 2021

Case 286: Sarcoidlike Granulomatosis and Lymphadenopathy-Thoracic Manifestations of Nivolumab Drug Toxicity.

Radiology 2021 02;298(2):471-475

From the Department of Radiology, Ronald Reagan UCLA Medical Center, 757 Westwood Plaza, Suite 1638, Los Angeles, CA 90095.

History A 70-year-old man had a posterior left thigh lesion confirmed to be biopsy-proven melanoma. The patient underwent wide excision and sentinel node biopsy, which showed absence of residual melanoma. Two years later, the patient noticed a subcentimeter subcutaneous lump in his thigh. Repeat excisional biopsy showed involvement of the surrounding soft tissue, consistent with a satellite lesion. Follow-up combined PET/CT revealed satellite nodules around the primary lesion, enabling confirmation of subcutaneous metastatic disease. The patient was subsequently started on nivolumab, an anti-programmed cell death 1 (PD-1) immune checkpoint inhibitor that blocks PD-1 and is approved as a first-line treatment in patients with advanced metastatic melanoma. On the baseline scan prior to starting nivolumab, there were no CT findings that suggested metastatic disease, nor were there enlarged mediastinal or hilar lymph nodes. Five months after initiation of nivolumab treatment, the first follow-up chest CT scan was performed and showed new findings in the mediastinum and bilateral lungs. The patient remained asymptomatic during the treatment period. Furthermore, the subcutaneous metastatic disease remained stable during the treatment period, and no other site of metastatic disease was noted on follow-up CT scans obtained during the first 5 months of treatment. The patient had no prior history of infectious or occupational exposures. During the nivolumab treatment cycle, his pertinent laboratory values and physical examination findings were unremarkable.
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http://dx.doi.org/10.1148/radiol.2021191247DOI Listing
February 2021

Case 286.

Radiology 2020 Oct;297(1):237-238

From the Department of Radiology, Ronald Reagan UCLA Medical Center, 757 Westwood Plaza, Suite 1638, Los Angeles, CA 90095.

History A 70-year-old man had a posterior left thigh lesion confirmed to be biopsy-proven melanoma. The patient underwent wide excision and sentinel node biopsy, which showed absence of residual melanoma. Two years later, the patient noticed a subcentimeter subcutaneous lump in his thigh. Repeat excisional biopsy showed involvement of the surrounding soft tissue, consistent with a satellite lesion. Follow-up combined PET/CT revealed satellite nodules around the primary lesion, enabling confirmation of subcutaneous metastatic disease. The patient was subsequently started on nivolumab, an anti-programmed cell death 1 (PD-1) immune checkpoint inhibitor that blocks PD-1 and is approved as a first-line treatment in patients with advanced metastatic melanoma. On the baseline scan prior to starting nivolumab, there were no CT findings that suggested metastatic disease, nor were there enlarged mediastinal or hilar lymph nodes. Five months after initiation of nivolumab treatment, the first follow-up chest CT scan was performed and showed new findings in the mediastinum (Fig 1) and bilateral lungs (Figs 2, 3). The patient remained asymptomatic during the treatment period. Furthermore, the subcutaneous metastatic disease remained stable during the treatment period, and no other site of metastatic disease was noted on follow-up CT scans obtained during the first 5 months of treatment. The patient had no prior history of infectious or occupational exposures. During the nivolumab treatment cycle, his pertinent laboratory values and physical examination findings were unremarkable.
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http://dx.doi.org/10.1148/radiol.2020191246DOI Listing
October 2020

Recent Innovations in Renal Vascular Imaging.

Radiol Clin North Am 2020 Jul 11;58(4):781-796. Epub 2020 May 11.

Department of Radiological Sciences, Thoracic and Diagnostic Cardiovascular Imaging, David Geffen School Medicine, University of California Los Angeles (UCLA), 10945 Le Conte Avenue, Suite 3371, Los Angeles, CA 90095, USA.

Noninvasive imaging of the vascular renal system is a common request in diagnostic radiology. Typical indications include suspected renovascular hypertension, vasculitis, neoplasm, vascular malformation, and structural diseases of the kidney. Profound knowledge of the renal anatomy, including vascular supply and variants, is mandatory for radiologists and allows for optimized protocolling and interpretation of imaging studies. Besides renal ultrasound, computed tomography and MR imaging are commonly requested cross-sectional studies for renal and renal vascular imaging. This article discusses basic renal vascular anatomy, common imaging findings, and current and potential future imaging protocols for various renovascular pathologic conditions.
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http://dx.doi.org/10.1016/j.rcl.2020.02.010DOI Listing
July 2020

Chronic airspace disease: Review of the causes and key computed tomography findings.

World J Radiol 2020 Apr;12(4):29-47

Department of Radiology, Northwestern University, Chicago, IL 60611, United States.

Chronic airspace diseases are commonly encountered by chest, body or general radiologists in everyday practice. Even though there is significant overlap in the imaging findings of different causes of chronic airspace disease, some key clinical, laboratory and imaging findings can be used to guide the radiologist to the correct diagnosis. The goal of this article is to review and compare these features.
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http://dx.doi.org/10.4329/wjr.v12.i4.29DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7191307PMC
April 2020

Abdominal wall and pelvic hernias: classic and unusual hernias and their mimics.

Clin Imaging 2020 Aug 1;64:57-66. Epub 2020 Apr 1.

Department of Radiology, Warren Alpert School of Medicine at Brown University, Providence, RI, USA.

Abdominal and pelvic wall hernias are classically defined as a weakness or opening of the muscular wall through which abdominal or pelvic tissues protrude. The aim of this manuscript is to review the imaging findings of abdominal and pelvic wall hernias and their mimics and to discuss pearls and pitfalls for accurately diagnosing and classifying these entities.
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http://dx.doi.org/10.1016/j.clinimag.2020.03.007DOI Listing
August 2020

Tracheobronchial Tumors: Radiologic-Pathologic Correlation of Tumors and Mimics.

Curr Probl Diagn Radiol 2020 Jul - Aug;49(4):275-284. Epub 2019 Apr 8.

Department of Radiology, Duke University, Durham, NC, USA; Department of diagnostic Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH; Department of Radiology, Stanford University Medical center, Stanford, CA.

Tracheobronchial masses encompass a broad spectrum of entities, ranging from benign and malignant neoplasms to infectious and inflammatory processes. This article reviews the cross-sectional findings of tracheal tumors and tumor-like entities, correlates imaging findings with histologic pathology, and discusses pearls and pitfalls in accurately diagnosing and classifying tracheal tumors and mimics.
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http://dx.doi.org/10.1067/j.cpradiol.2019.04.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7115773PMC
March 2021

Interatrial septum: A pictorial review of congenital and acquired pathologies and their management.

Clin Imaging 2019 May - Jun;55:53-64. Epub 2019 Feb 6.

Department of Radiology, Duke University Medical Center, Durham, NC, USA. Electronic address:

There are many different congenital abnormalities and acquired pathologies involving the interatrial septum. Differentiation of these pathologies significantly affects patient management. We have reviewed the various interatrial septal pathologies and discussed their congenital associates, clinical significance, and management. After reading this article, the reader should be able to better characterize the interatrial septal pathologies using the optimal imaging tools, and have a better understanding of their clinical significance and management.
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http://dx.doi.org/10.1016/j.clinimag.2019.02.002DOI Listing
October 2019

Left Atrium Maximal Axial Cross-Sectional Area is a Specific Computed Tomographic Imaging Biomarker of World Health Organization Group 2 Pulmonary Hypertension.

J Thorac Imaging 2017 Mar;32(2):121-126

*Department of Radiology †Department of Pulmonary and Critical Care Medicine §Department of Cardiovascular Medicine ∥Department of Radiology, Division of Biostatistics ‡Vera Moulton Wall Center for Pulmonary Vascular Disease, Stanford Health Care, Stanford, CA.

Purpose: Left heart disease is associated with left atrial enlargement and is a common cause of pulmonary hypertension (PH). We investigated the relationship between left atrium maximal axial cross-sectional area (LA-MACSA), as measured on chest computed tomography (CT), and PH due to left heart disease (World Health Organization group 2) in patients with right heart catheterization-proven PH.

Materials And Methods: A total of 165 patients with PH who had undergone right heart catheterization with pulmonary artery pressure and pulmonary capillary wedge pressure (PCWP) measurements and nongated chest CTs were included. LA-MACSA, LA anterior-posterior, and LA transverse measurements were independently obtained using the hand-drawn region-of-interest and distance measurement tools on standard PACS by 2 blinded cardiothoracic radiologists. Nonparametric statistical analyses and receiver operating characteristic curve were performed.

Results: Forty-three patients had group 2 PH (PCWP>15 mm Hg), and 122 had nongroup 2 PH (PCWP≤15 mm Hg). Median LA-MACSA was significantly different between the group 2 PH and nongroup 2 PH patients (2312 vs. 1762 mm, P<0.001). Interobserver concordance correlation for LA-MACSA was high at 0.91 (P<0.001). At a threshold of 2400 mm, LA-MACSA demonstrated 93% specificity for classifying group 2 PH (area under the curve, 0.73; P<0.001).

Conclusions: LA-MACSA is a readily obtainable and reproducible measurement of left atrial enlargement on CT and can distinguish between group 2 and nongroup 2 PH with high specificity.
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http://dx.doi.org/10.1097/RTI.0000000000000252DOI Listing
March 2017

A Private Investigation: Radiologic-Pathologic Correlation of Testicular Tumors.

Curr Probl Diagn Radiol 2017 May - Jun;46(3):242-256. Epub 2016 May 20.

Department of Radiology, University of Massachusetts Medical School, Worcester, MA.

To review the classification of testicular tumors, describe the sonographic and pathologic features of each tumor type, and discuss the mimics, diagnostic pitfalls, and management of testicular tumors. Method consists of pictorial review. We review sonographic and pathologic findings of several testicular tumors and tumorlike entities. Although ultrasound is the first-line imaging modality to differentiate between intratesticular and extratesticular location of an intrascrotal mass, it is not specific for intratesticular lesion characterization. Therefore, correlation with histology sampling is often necessary.
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http://dx.doi.org/10.1067/j.cpradiol.2016.05.002DOI Listing
November 2017

Association Between Confidence Level of Acute Pulmonary Embolism Diagnosis on CTPA images and Clinical Outcomes.

Acad Radiol 2015 Dec 26;22(12):1555-61. Epub 2015 Sep 26.

Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital & Harvard Medical School, 75 Francis St, Boston MA 02115; Department of Radiology, Juntendo University, Tokyo, Japan. Electronic address:

Rationale And Objectives: The purpose was to evaluate clinical characteristics associated with low confidence in diagnosis of acute pulmonary embolism (PE) as expressed in computed tomography pulmonary angiography (CTPA) reports and to evaluate the effect of confidence level in PE diagnosis on patient clinical outcomes.

Materials And Methods: This study included radiology reports from 1664 consecutive CTPA considered positive for acute PE (8/2003-5/2010). All reports were retrospectively assessed for the level of confidence in diagnosis. Baseline characteristics and outcomes (therapies related to PE and short-term mortality) were compared between high and low confidence groups. Multivariable logistic and Cox regression analyses were used to analyze the relationship between the confidence level and outcomes.

Results: One-hundred sixty of 1664 (9.6%) reports had language that reflected a low confidence in PE diagnosis. The low confidence group had smaller (segmental and subsegmental) suspected emboli (prevalence, 72.5% vs. 50.7%; P < .001) and more comorbidities. The low confidence group had a lower likelihood of receiving PE-related therapies (adjusted odds ratio [OR], 0.18; 95% confidence interval, 0.10-031, P < .001), but there was no change in the all-cause and PE-related 30-day and/or 90-day mortality (OR of death for low confidence, 0.81-1.13, P values > .5).

Conclusions: Roughly 10% of positive CTPA reports had uncertainty in PE findings, and patients with reports categorized as low confidence had smaller emboli and more comorbidities. Although the low confidence group was less likely to receive PE-related therapies, patients in this group were not associated with higher probability of short-term mortality.
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http://dx.doi.org/10.1016/j.acra.2015.08.018DOI Listing
December 2015

Breast: Sezary Syndrome: A Unique Presentation.

Breast J 2015 Jul-Aug;21(4):423-7. Epub 2015 May 3.

Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts.

Sezary syndrome is a subtype of cutaneous T cell lymphoma which usually presents as generalized skin disease with erytheroderma. Distal organ involvement is rare and is usually a late finding in the course of the disease. Breast involvement is extremely rare. Herein, we present a case report of a patient whose initial presentation involved an intramammary lymph node prior to the onset of more characteristic skin disease. Sezary syndrome was confirmed by cythopathologic findings.
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http://dx.doi.org/10.1111/tbj.12422DOI Listing
May 2016

Classification of CT pulmonary angiography reports by presence, chronicity, and location of pulmonary embolism with natural language processing.

J Biomed Inform 2014 Dec 10;52:386-93. Epub 2014 Aug 10.

Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, United States.

In this paper we describe an efficient tool based on natural language processing for classifying the detail state of pulmonary embolism (PE) recorded in CT pulmonary angiography reports. The classification tasks include: PE present vs. absent, acute PE vs. others, central PE vs. others, and subsegmental PE vs. others. Statistical learning algorithms were trained with features extracted using the NLP tool and gold standard labels obtained via chart review from two radiologists. The areas under the receiver operating characteristic curves (AUC) for the four tasks were 0.998, 0.945, 0.987, and 0.986, respectively. We compared our classifiers with bag-of-words Naive Bayes classifiers, a standard text mining technology, which gave AUC 0.942, 0.765, 0.766, and 0.712, respectively.
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http://dx.doi.org/10.1016/j.jbi.2014.08.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4261018PMC
December 2014

Computed tomography and echocardiography in patients with acute pulmonary embolism: part 2: prognostic value.

J Thorac Imaging 2014 Jan;29(1):W7-12

*Applied Imaging Science Laboratory, Department of Radiology †Department of Medicine, Cardiovascular Division ‡Department of Medicine, Brigham and Women's Hospital & Harvard Medical School, Boston §Department of Radiology, University of Massachusetts Medical School, Worcester, MA.

Purpose: The aim of the study was to compare the prognostic value of right ventricular (RV) dysfunction detected on computed tomography pulmonary angiography (CTPA) and transthoracic echocardiography (TTE) in patients with acute pulmonary embolism (PE).

Materials And Methods: From all consecutive CTPAs performed between August 2003 and May 2010 that were positive for acute PE (n=1744), those with TTE performed within 48 hours of CTPA (n=785) were selected as the study cohort. Multivariate logistic regression analysis was performed to assess the association of CTPA RV/left ventricular (LV) diameter ratio and TTE RV strain with PE-related 30-day mortality, including other associated factors as covariates. The predictive ability (area under the curve) was compared between the model including the CT RV/LV diameter ratio and that including TTE RV strain. Test characteristics of the 2 modalities were calculated.

Results: Both CT RV/LV diameter ratio and TTE RV strain were independently associated with PE-related 30-day mortality (adjusted odds ratio=1.14, P=0.023 for 0.1 increment of the CT RV/LV diameter ratio; and odds ratio=2.13, P=0.041 for TTE RV strain). History of congestive heart failure and malignancy were independent predictors of PE-related mortality, while there was significantly lower mortality associated with anticoagulation use. The model including TTE RV strain and that including CT RV/LV had similar predictive ability (area under the curve=0.80 vs. 0.81, P=0.50). The sensitivity, specificity, and positive and negative predictive values of TTE RV strain and CT RV/LV diameter ratio at a cutoff of ≥1.0 were similar for PE-related 30-day mortality.

Conclusions: Both RV strain on TTE and an increased CT RV/LV diameter ratio are predictors of PE-related 30-day mortality with similar prognostic significance.
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http://dx.doi.org/10.1097/RTI.0000000000000048DOI Listing
January 2014

Computed tomography and echocardiography in patients with acute pulmonary embolism: part 1: correlation of findings of right ventricular enlargement.

J Thorac Imaging 2014 Jan;29(1):W1-6

*Department of Medicine, Cardiovascular Division †Applied Imaging Science Laboratory, Department of Radiology §Department of Medicine, Brigham and Women's Hospital & Harvard Medical School, Boston ‡Department of Radiology, University of Massachusetts Medical School, Worcester, MA.

Purpose: To evaluate the correlation between the computed tomography (CT)-derived right ventricle (RV) to left ventricle (LV) diameter ratio and the RV size determined by echocardiography in patients with acute pulmonary embolism.

Materials And Methods: Consecutive CT pulmonary angiography examinations (August 2003 to May 2010) from a single, large, urban teaching hospital were retrospectively reviewed. For a cohort of 777 subjects who underwent echocardiography within 48 hours of the CT acquisition, the qualitative RV size (divided into 5 categories) extracted from the echocardiography report was correlated with the CT-derived RV/LV diameter ratio.

Results: There was moderate correlation (Spearman rank correlation coefficient=0.54, P<0.001) between the CT-derived RV/LV ratio and the RV size as determined by echocardiography. The correlation coefficient and the concordance rate were inversely related to the time difference between the acquisitions of the 2 modalities.

Conclusions: CT and echocardiography findings to assess the RV size after acute pulmonary embolism have moderate correlation.
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http://dx.doi.org/10.1097/RTI.0000000000000047DOI Listing
January 2014

Correlation between early direct communication of positive CT pulmonary angiography findings and improved clinical outcomes.

Chest 2013 Nov;144(5):1546-1554

Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital & Harvard Medical School, Boston, MA. Electronic address:

Background: Despite a general consensus that rapid communication of critical radiology findings from radiologists to referring physicians is imperative, a possible association with superior patient outcomes has not been confirmed. The objective of this study was to evaluate the correlation between early direct communication of CT image findings by radiologists to referring physicians and better clinical outcomes in patients with acute pulmonary embolism (PE).

Methods: This was a retrospective, single-institution, cohort study that included 796 consecutive patients (February 2006 to March 2010) who had acute PE confirmed by CT pulmonary angiography (CTPA) and whose treatment had not been initiated at the time of CTPA acquisition. The time from CTPA to direct communication of the diagnosis was evaluated for its association with time from CTPA to treatment initiation and with 30-day mortality. Cox regression analysis was performed with inverse probability weighting by propensity scores calculated using 20 potential confounding factors.

Results: In 93.4% of patients whose first treatment was anticoagulation, the referring physicians started treatment after receiving direct notification of the diagnosis from the radiologist. Late communication (> 1.5 h after CTPA; n = 291) was associated with longer time to treatment initiation (adjusted hazard ratio [HR], 0.714; 95% CI, 0.610-0.836; P < .001) and higher all-cause and PE-related 30-day mortality (HR, 1.813; 95% CI, 1.163-2.828; P = .009; and HR, 2.625; 95% CI, 1.362-5.059; P = .004, respectively).

Conclusions: Delay (> 1.5 h of CTPA acquisition) in direct communication of acute PE diagnosis from radiologists to referring physicians was significantly correlated with a higher risk of delayed treatment initiation and death within 30 days.
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http://dx.doi.org/10.1378/chest.13-0308DOI Listing
November 2013

Malignancy and acute pulmonary embolism: risk stratification including the right to left ventricle diameter ratio in 1596 subjects.

J Thorac Imaging 2013 May;28(3):196-201

Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA.

Purpose: To test the hypothesis that subjects with a known malignancy at the time of acute pulmonary embolism (PE) have different clinical characteristics and predictors of 30-day all-cause mortality when compared with subjects with no known malignancy.

Materials And Methods: A retrospective (August 2003 to March 2010) cohort of 1596 consecutive positive (for acute PE) computed tomography pulmonary angiograms (CTPAs) performed at a single, large, urban teaching hospital was separated into those from subjects with (n=835) and those from subjects without (n=761) a known malignancy. Clinical characteristics were compared between groups, and a logistic regression model determined predictors of 30-day all-cause mortality for each group.

Results: Subjects with malignancy were older (60.8±13.9 vs. 54.5±18.8 y, P<0.001), had fewer risk factors for PE, and had a higher 30-day all-cause mortality (19.6% vs. 3.2%, P<0.001). The malignancy group had fewer predictors of death compared with the nonmalignancy group; advanced age, presence of coronary artery disease, history of stroke, and chronic obstructive lung disease were significantly more predictive of death in the nonmalignancy population. An enlarged right ventricle on CTPA (right to left ventricular diameter ratio >1.0) had a higher risk of 30-day death only among subjects with no known malignancy at the time of the CTPA (odds ratio=4.08, 95% confidence interval: 1.67-9.96).

Conclusions: Among subjects who present with acute PE, those with a malignancy had different clinical characteristics and predictors of mortality when compared with the cohort of subjects with no known malignancy. A computed tomography-derived right to left ventricular diameter ratio predicts 30-day all-cause mortality only for those subjects who do not have a malignancy.
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http://dx.doi.org/10.1097/RTI.0b013e3182870bf9DOI Listing
May 2013

Comparison of coronary plaque subtypes in male and female patients using 320-row MDCTA.

Atherosclerosis 2013 Feb 13;226(2):428-32. Epub 2012 Dec 13.

Emory University Hospital, Midtown, GA, USA; Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Room L347, Boston, MA 02215, USA.

Objective: Determine plaque subtype and volume difference in male and female patients with obstructive and non-obstructive CAD using 320-row MDCTA.

Materials And Methods: 128 patients with suspected CAD underwent MDCTA. All studies were divided into two groups based on disease severity. 0-70% stenosis (non-obstructive CAD) & >70% (obstructive). All were compared for plaque quantity and subtypes by gender. Main arteries, RCA, LM, LAD and LCX were analyzed using Vitrea 5.2 software to quantify fatty, fibrous and calcified plaque. Thresholds for coronary plaque quantification (volume in mm(3)) were preset at 35 ± 12 HU for fatty, 90 ± 24 HU for fibrous and >130 HU for calcified/mixed plaque and analyzed using STATA software.

Results: Total plaque burden in 118 patients [65M: 53F] was significantly higher in all arteries in males compared to females with non-obstructive disease. Total plaque volume for males vs. females was: RCA: 10.10 ± 5.02 mm(3) vs. 6.89 ± 2.75 mm(3), respectively, p = 0.001; LAD: 7.21 ± 3.38 mm(3) vs. 5.89 ± 1.93 mm(3), respectively, p = 0.04; LCX: 9.13 ± 3.27 mm(3) vs. 7.16 ± 1.73 mm(3), respectively, p = 0.002; LM 15.13 ± 4.51 mm(3) vs. 11.85 ± 4.03 mm(3), respectively, p = 0.001. In sub-analyses, males had significantly more fibrous and fatty plaque in LM, LAD & LCX than females. However in the RCA, only fibrous plaque was significantly greater in males. Calcified plaque volume was not significantly different in both genders. Only 8% of patients had obstructive CAD (>70% stenosis); there was no significant difference in plaque volume or subtypes.

Conclusion: In patients with non-obstructive CAD, males were found to have significantly higher total coronary plaque volume with predominance of fibrous and fatty subtypes compared to females of the same age and BMI. There was no significant difference in plaque subtype or volume in patients with obstructive disease.
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http://dx.doi.org/10.1016/j.atherosclerosis.2012.11.033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4758671PMC
February 2013

Histopathologic and clinical findings of congenital nephrotic syndrome in Iranian children: a study of two centers.

Iran J Kidney Dis 2012 Nov;6(6):426-31

Department of Pathology and Oncopathology Research Center, Ali-Asghar Children Hospital, Tehran University of Medical Sciences, Tehran, Iran.

Introduction: Congenital nephrotic syndrome (CNS), an uncommon form of kidney disease, presents during the first year of life and is a diagnostic and therapeutic challenge for the pediatricians as well as pediatric nephrologists. Our study is the first study of Iranian children with CNS in two pediatric nephrology centers in Tehran, Iran.

Materials And Methods: We reviewed medical charts of 30 infants diagnosed with CNS from 1990 to 2005.

Results: There were 15 boys and 15 girls with CNS (mean age, 1.7 months). The presentation of the disease was nephrotic syndrome in 96.6% of the patients. Eighty percent of the patients presented within 3 months of life and 16 in the neonatal period. The Finnish type of CNS was seen in 43.3% and diffuse mesangial sclerosis in 50%. Preterm labor and low birth weight was seen in 20%. A family history of nephrotic syndrome in infancy was noted for 8 children (26.7%). Numerous complications of nephrotic syndrome occurred in 73.3%. Seventy percent of the patients had 27 episodes of infections. Sepsis was seen in 43.3% of the children, of which 61.5% were caused by gram-negative bacteria and 38.6% were caused by Staphylococcus aureus. Thrombotic complications and hypertension developed in 6.6% and 23.3% of the patients, respectively. The mortality rate of patients was 86.6%.

Conclusions: Diffuse mesangial sclerosis is an important cause of CNS. The outcome of our patients was poor and most of our patients died before reaching the age of 5 years old.
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November 2012

Statistical methods for predicting mortality in patients diagnosed with acute pulmonary embolism.

Acad Radiol 2012 Dec;19(12):1465-73

Department of Biostatistics, Harvard University, Cambridge, MA, USA.

Rationale And Objectives: Risk stratification in pulmonary embolism (PE) guides patient management. The purpose of this study was to develop and test novel mortality risk prediction models for subjects with acute PE diagnosed using computed tomographic pulmonary angiography in a large cohort with comprehensive clinical data.

Materials And Methods: Retrospective analyses of 1596 consecutive subjects diagnosed with acute PE from a single, large, urban teaching hospital included two modern statistical methods to predict survival in patients with acute PE. Landmark analysis was used for 90-day mortality. Adaptive least absolute shrinkage and selection operator (aLASSO), a penalization method, was used to select variables important for prediction and to estimate model coefficients. Receiver-operating characteristic analysis was used to evaluate the resulting prediction rules.

Results: Using 30-day all-cause mortality outcome, three of the 16 clinical risk factors (the presence of a known malignancy, coronary artery disease, and increased age) were associated with high risk, while subjects treated with anticoagulation had lower risk. For 90-day landmark mortality, subjects with recent operations had a lower risk for death. Both prediction rules developed using aLASSO performed well compared to standard logistic regression.

Conclusions: The aLASSO regression approach combined with landmark analysis provides a novel tool for large patient populations and can be applied for clinical risk stratification among subjects diagnosed with acute PE. After positive results on computed tomographic pulmonary angiography, the presence of a known malignancy, coronary artery disease, and advanced age increase 30-day mortality. Additional risk stratification can be simplified with these methods, and future work will place imaging-based prediction of mortality in perspective with other clinical data.
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http://dx.doi.org/10.1016/j.acra.2012.09.008DOI Listing
December 2012

The variability in prognostic values of right ventricular-to-left ventricular diameter ratios derived from different measurement methods on computed tomography pulmonary angiography: a patient outcome study.

J Thorac Imaging 2012 Sep;27(5):331-6

Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital, Boston, MA 02115, USA.

Purpose: To evaluate variability in right ventricular-to-left ventricular (RV/LV) diameter ratios introduced by differences in measurement methods and the subsequent influence on the accuracy of predicting outcomes for patients with acute pulmonary embolism (PE).

Materials And Methods: For 200 consecutive computed tomography pulmonary angiograms positive for acute PE, RV/LV diameter ratios were retrospectively measured using 3 different 4-chamber reformations and from axial images alone. The first 4-chamber reformation method (4ch-1) was a single oblique technique using LV morphology landmarks; the other 2 methods (4ch-2 and 4ch-3) were double oblique techniques that created an intermediate short-axis image to identify the maximum RV diameter but with different approaches to reach short-axis images. Interobserver variability was measured using 30 cases. Receiver-operating characteristic analysis compared the accuracy of predicting outcomes among the 4 measurements for PE-related death, and for death or the need for intensive therapies (composite outcome).

Results: The difference in median RV/LV diameter ratios was insignificant among 4ch-2 (1.01), 4ch-3 (1.02), and axial (1.03) datasets, whereas that from 4ch-1 (0.93) was significantly lower (P<0.001). Correlation between observers was excellent for all 4 datasets (r=0.881 to 0.925). Compared with 4ch-1, the other 3 datasets equally achieved higher accuracy in predicting PE-related 30-day mortality (area under curve: 0.55 vs. 0.69 to 0.73, P=0.007 to 0.019) and a composite outcome (area under curve: 0.65 vs. 0.77 to 0.78, P=0.003 to 0.010).

Conclusions: Double oblique 4-chamber reformation methods that use intermediate short-axis images to optimize RV size predict outcomes better in patients with acute PE than do single oblique methods using only LV landmarks; however, their accuracy is not superior to that from measurements based on axial images.
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http://dx.doi.org/10.1097/RTI.0b013e3182350a35DOI Listing
September 2012

Coronary enhancement for prospective ECG-gated single R-R axial 320-MDCT angiography: comparison of 60- and 80-mL iopamidol 370 injection.

AJR Am J Roentgenol 2011 Oct;197(4):844-50

Department of Radiology, Applied Imaging Science Laboratory, Brigham and Women's Hospital & Harvard Medical School, 75 Francis St, Boston, MA 02115, USA.

Objective: The objective of our study was to evaluate the difference in coronary enhancement provided by 60 versus 80 mL of contrast medium (370 mg I/mL) for prospectively ECG-gated single-heartbeat axial 320-MDCT.

Materials And Methods: We retrospectively evaluated 108 consecutive 320-MDCT angiography studies. Group 1 (n = 36) received 60 mL of an iodinated contrast medium and group 2 (n = 72), 80 mL. All patients were imaged with a standardized protocol: iopamidol 370 followed by 40 mL of saline, both administered at a rate of 6 mL/s. Two imagers subjectively assessed image quality throughout the coronary arteries. Region-of-interest attenuation (HU) measurements were performed in the aorta plus the proximal and distal coronary arteries.

Results: Subjective analysis of all coronary segments showed slightly better image quality for group 2. Patients in group 1 had significantly (p < 0.05) lower mean attenuation values for the individual coronary vessels. Nevertheless, 96.7% of all coronary segments in the group 1 patients had an attenuation of greater than 300 HU; when analysis was limited to group 1 patients with a body mass index of greater than 30, 92.8% of the segments were more than 300 HU, and all segments measured more than 250 HU.

Conclusion: An injection protocol based on 60 mL of iopamidol (370 mg I/mL) for prospectively ECG-gated wide-area detector single-heartbeat coronary CT angiography (CTA) has less coronary enhancement than a protocol based on 80 mL. However, using 60 mL, more than 96% of coronary segments had sufficient enhancement (i.e., > 300 HU), supporting the general use of 60-mL protocols for clinical wide-area detector coronary CTA.
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http://dx.doi.org/10.2214/AJR.10.5980DOI Listing
October 2011

Subjective assessment of right ventricle enlargement from computed tomography pulmonary angiography images.

Int J Cardiovasc Imaging 2012 Apr 14;28(4):965-73. Epub 2011 Jun 14.

Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital & Harvard Medical School, Boston, MA 02115, USA.

To retrospectively evaluate prognostic accuracy of subjective assessment of right ventricle (RV) enlargement on CT pulmonary angiography (CTPA) images in comparison with objective measures of RV enlargement in patients with acute pulmonary embolism (PE). For 200 consecutive patients with acute PE, two readers blinded to patient outcomes subjectively determined whether the maximum RV diameter was greater than that of the left ventricle (LV) using axial CTPA images. For the objective measurements, RV/LV diameter ratios were calculated using axial images and 4-chamber reformatted images. For all assessments, sensitivities and specificities for predicting PE-related death within 30-days and a composite outcome including PE-related death or the need for intensive therapies were compared. The agreement between two readers was 91.5% (kappa = 0.83) and all other assessments had pair-wise agreement over 75% (kappa = 0.53-0.72). There was no significant difference in sensitivity between the subjective and objective methods for predicting both outcomes. The specificity for subjective RV enlargement (55.4-67.7%) was significantly higher than objective measures (45.8-53.1%), except for the 4-chamber views where, for one reader, the specificity of the subjective evaluation was higher but did not reach statistical significance. Complex measurements of RV/LV diameter ratios may not be needed to maximize the prognostic value from CTPA. The radiologist who interprets the CTPA images should report RV enlargement when the RV diameter subjectively appears larger than the LV.
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http://dx.doi.org/10.1007/s10554-011-9903-5DOI Listing
April 2012

Reduced exposure using asymmetric cone beam processing for wide area detector cardiac CT.

Int J Cardiovasc Imaging 2012 Feb 19;28(2):381-8. Epub 2011 Feb 19.

Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.

The purpose of this study was to estimate dose reduction after implementation of asymmetrical cone beam processing using exposure differences measured in a water phantom and a small cohort of clinical coronary CTA patients. Two separate 320 × 0.5 mm detector row scans of a water phantom used identical cardiac acquisition parameters before and after software modifications from symmetric to asymmetric cone beam acquisition and processing. Exposure was measured at the phantom surface with Optically Stimulated Luminescence (OSL) dosimeters at 12 equally spaced angular locations. Mean HU and standard deviation (SD) for both approaches were compared using ROI measurements obtained at the center plus four peripheral locations in the water phantom. To assess image quality, mean HU and standard deviation (SD) for both approaches were compared using ROI measurements obtained at five points within the water phantom. Retrospective evaluation of 64 patients (37 symmetric; 27 asymmetric acquisition) included clinical data, scanning parameters, quantitative plus qualitative image assessment, and estimated radiation dose. In the water phantom, the asymmetric cone beam processing reduces exposure by approximately 20% with no change in image quality. The clinical coronary CTA patient groups had comparable demographics. The estimated dose reduction after implementation of the asymmetric approach was roughly 24% with no significant difference between the symmetric and asymmetric approach with respect to objective measures of image quality or subjective assessment using a four point scale. When compared to a symmetric approach, the decreased exposure, subsequent lower patient radiation dose, and similar image quality from asymmetric cone beam processing supports its routine clinical use.
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http://dx.doi.org/10.1007/s10554-011-9814-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3111872PMC
February 2012

Urine macrophage migration inhibitory factor (MIF) in children with urinary tract infection: a possible predictor of acute pyelonephritis.

Pediatr Nephrol 2009 Jan 18;24(1):105-11. Epub 2008 Sep 18.

Urology and Nephrology Research Center, Labbafi Nejad Hospital, Tehran, Iran.

Macrophage migration inhibitory factor (MIF) is an important pro-inflammatory cytokine expressed at sites of inflammation. We have assessed this factor (MIF) in urinary tract infections with the aim of determining a non-invasive and sensitive method to differentiate upper and lower renal involvement. Thirty-three pediatric patients with urinary track infection (25 with acute pyelonephritis, eight with acute cystitis) and 40 healthy subjects were recruited for this prospective case-control study. Pyelonephritis was differentiated from cystitis by dimercaptosuccinic acid (DMSA) scan. Urinary MIF concentration was determined using an enzyme-linked immunosorbent assay method. The urine MIF/creatinine (Cr) ratio was significantly higher in pyelonephritis patients than in those with acute cystitis and the control group (P < 0.001). The optimal cut-point of 4.90 pg/micromol Cr for the urine MIF/Cr ratio has the potential to be a biomarker for distinguishing patients with acute pyelonephritis from those with acute cystitis. Determination of the urinary MIF was also useful in selecting the patients at risk of permanent renal damage. Of those patients with pyelonephritis, based on the DMSA scan at the time of infection, scarring on follow-up DMSA scan 9-12 months later occurred in patients with the highest urinary MIF/Cr ratios. We conclude that the urine MIF/Cr ratio is a sensitive test for differentiating acute pyelonephritis from acute cystitis and also for detecting children with acute pyelonephritis who are at a higher risk for permanent renal scars in the future.
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http://dx.doi.org/10.1007/s00467-008-0969-9DOI Listing
January 2009

Leech endoparasitism: report of a case and review of the literature.

Eur J Pediatr 2009 Jan 12;168(1):39-42. Epub 2008 Jun 12.

Digestive Disease Research Center, Shariati Hospital, Medical sciences/Tehran University, 72, Karegar Shomali Avenue, 17th street, 1438837431, Tehran, Iran.

We report the case of an 11-year-old boy who presented with fresh blood in his mouth and a history of sore throat during the past 2 weeks that was unresponsive to antibiotic therapy. Inspection of the oral cavity revealed a black circular mass attached to the posterior wall of the oropharynx. This mass was determined to be a live engorged leech. Leech endoparasitism is caused by aquatic leeches that attach themselves to mucus membranes of body cavities after the host has swum in bodies of fresh water or drunk from unsafe water sources. Pharyngeal hirudiniasis may present in different forms depending on the exact location of the parasite in the body and must be included in the list of differential diagnosis for common conditions such as pharyngitis, hemoptysis or anemia in pediatric patients living in endemic areas.
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http://dx.doi.org/10.1007/s00431-008-0706-1DOI Listing
January 2009