Chen Hoffmann

Stony Brook University, Stony Brook, New York, United States

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Publications (37)112.47 Total impact

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    ABSTRACT: Conventional magnetic resonance imaging (MRI) is unable to differentiate tumor/nontumor enhancing tissues. We have applied delayed-contrast MRI for calculating high resolution treatment response assessment maps (TRAMs) clearly differentiating tumor/nontumor tissues in brain tumor patients. One hundred and fifty patients with primary/metastatic tumors were recruited and scanned by delayed-contrast MRI and perfusion MRI. Of those, 47 patients underwent resection during their participation in the study. Region of interest/threshold analysis was performed on the TRAMs and on relative cerebral blood volume maps, and correlation with histology was studied. Relative cerebral blood volume was also assessed by the study neuroradiologist. Histological validation confirmed that regions of contrast agent clearance in the TRAMs >1 h post contrast injection represent active tumor, while regions of contrast accumulation represent nontumor tissues with 100% sensitivity and 92% positive predictive value to active tumor. Significant correlation was found between tumor burden in the TRAMs and histology in a subgroup of lesions resected en bloc (r(2) = 0.90, P < .0001). Relative cerebral blood volume yielded sensitivity/positive predictive values of 51%/96% and there was no correlation with tumor burden. The feasibility of applying the TRAMs for differentiating progression from treatment effects, depicting tumor within hemorrhages, and detecting residual tumor postsurgery is demonstrated. The TRAMs present a novel model-independent approach providing efficient separation between tumor/nontumor tissues by adding a short MRI scan >1 h post contrast injection. The methodology uses robust acquisition sequences, providing high resolution and easy to interpret maps with minimal sensitivity to susceptibility artifacts. The presented results provide histological validation of the TRAMs and demonstrate their potential contribution to the management of brain tumor patients. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
    Neuro-oncology. 11/2014;
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    ABSTRACT: Objectives To evaluate effects of cytomegalovirus (CMV) infection on apparent diffusion coefficient (ADC) values of the fetal brain in utero.Methods Fifty-eight sequential fetal head magnetic resonance imaging (feMRI) scans of PCR-verified CMV-infected fetuses were retrospectively (2008–2012) analyzed and compared to a normal control group. Gestational age (GA) at infection ranged from 1–32 weeks, and feMRI scanning was performed at GA 24–38. The frontal, parietal, temporal and occipital lobes (mainly white matter), basal ganglia (BG), thalamus, pons and cerebellum were analyzed by assessing ADC values. Two pregnancies were terminated and PM correlation was available. Regional ADC measurements were similarly obtained from 36 GA-matched uninfected fetuses.ResultsADC values of the CMV-infected fetuses significantly and negatively correlated with GA in all brain regions except the basal ganglia. The cerebellum had the steepest decline (r =0.52, P < .0001). Maternal age correlated positively with ADC in the frontal lobe (P < .05). Age at infection and overt pathological changes did not significantly affect ADC. ADC values of affected fetuses were significantly reduced in the frontal (P < .0001), parietal (P < .0001), occipital (P = .0005), and temporal (P = .001) lobes and thalamus (P = .006) compared to non-infected fetuses.ConclusionsCMV infection of the fetal brain results in a highly significant, region-dependent reduction of ADC values in the frontal, parietal, occipital and temporal lobes and thalamus, probably reflecting hypercellularity and inclusion bodies in damaged areas. Further studies are needed to determine if reduction in ADC values may serve as a prognostic factor in CMV-infected fetuses.
    Ultrasound in Obstetrics and Gynecology 11/2014; · 3.56 Impact Factor
  • Anat Biegon, Chen Hoffmann
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    ABSTRACT: Application of modern magnetic resonance imaging (MRI) techniques to the live fetus in utero is a relatively recent endeavor. The relative advantages and disadvantages of clinical MRI relative to the widely used and accepted ultrasonographic approach are the subject of a continuing debate; however the focus of this review is on the even younger field of quantitative MRI as applied to non-invasive studies of fetal brain development. The techniques covered under this header include structural MRI when followed by quantitative (e.g., volumetric) analysis, as well as quantitative analyses of diffusion weighted imaging, diffusion tensor imaging, magnetic resonance spectroscopy and functional MRI. The majority of the published work reviewed here reflects information gathered from normal fetuses scanned during the 3(rd) trimester, with relatively smaller number of studies of pathological samples including common congenital pathologies such as ventriculomegaly and viral infection.
    World journal of radiology. 08/2014; 6(8):523-9.
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    ABSTRACT: Chronic measles virus infection of the brain causes subacute scelrosisng panencephalitis (SSPE) a progressive, relentless fatal disorder. We report a 52 year old male who developed focal, chronic persistent measles virus infection of the brain following interferon and ribaverin therapy for hepatitis C, who responded to steroid therapy. This case, diametrically different from SSPE, has two unique features, its focal nature and its permissive response to steroids, that may add to the understanding of the pathogenesis of SSPE and the mechanism enabling viruses to evade the immune response and establish persistent brain infection. ANN NEUROL 2014. © 2014 American Neurological Association.
    Annals of Neurology 05/2014; · 11.19 Impact Factor
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    ABSTRACT: Apparent diffusion coefficient (ADC) values in the developing fetus can be used in the diagnosis and prognosis of prenatal brain pathologies. To this end, we measured regional ADC in a relatively large cohort of normal fetal brains in utero. Diffusion-weighted imaging (DWI) was performed in 48 non-sedated 3rd trimester fetuses with normal structural MR imaging results. ADC was measured in white matter (frontal, parietal, temporal, and occipital lobes), basal ganglia, thalamus, pons, and cerebellum. Regional ADC values were compared by one-way ANOVA with gestational age as covariate. Regression analysis was used to examine gestational age-related changes in regional ADC. Four other cases of CMV infection were also examined. Median gestational age was 32 weeks (range, 26-33 weeks). There was a highly significant effect of region on ADC, whereby ADC values were highest in white matter, with significantly lower values in basal ganglia and cerebellum and the lowest values in thalamus and pons. ADC did not significantly change with gestational age in any of the regions tested. In the four cases with fetal CMV infection, ADC value was associated with a global decrease. ADC values in normal fetal brain are relatively stable during the third trimester, show consistent regional variation, and can make an important contribution to the early diagnosis and possibly prognosis of fetal brain pathologies.
    Neuroradiology 04/2014; · 2.70 Impact Factor
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    Neurobiology of Aging 03/2014; 35(3):719. · 6.17 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSE:Accurate measurement of the lateral ventricles is of paramount importance in prenatal diagnosis. Possible conflicting classifications caused by their measurement in different sectional planes by sonography and MR imaging are frequently raised. The objective of our study was to evaluate the agreement between ultrasonography and MR imaging in the measurement of the lateral ventricle diameter in the customary sectional planes for each technique.MATERIALS AND METHODS:Measurement of both lateral ventricles was performed prospectively in 162 fetuses from 21 to 40 weeks of gestational age referred for evaluation due to increased risk for cerebral pathology. The mean gestational age for evaluation was 32 weeks. The measurements were performed in the customary plane for each technique: axial plane for sonography and coronal plane for MR imaging.RESULTS:The 2 techniques yielded results in substantial agreement by using intraclass correlation and κ coefficient score tests. When we assessed the clinical cutoff of 10 mm, the κ score was 0.94 for the narrower ventricle and 0.84 for the wider ventricle, expressing almost perfect agreement. The Bland-Altman plot did not show any trend regarding the actual width of the ventricle, gestational week, or interval between tests. Findings were independent for fetal position, sex, and indication for examination.CONCLUSIONS:Our study indicates excellent agreement between fetal brain ultrasonography and MR imaging as to the diagnosis of fetal ventriculomegaly in the customarily used sectional planes of each technique.
    American Journal of Neuroradiology 01/2014; · 3.17 Impact Factor
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    ABSTRACT: To compare measurement of the lateral cerebral ventricular diameter using either the traditional axial view or the coronal plane. Prospective study on144 fetuses, 77 evaluated as part of a routine fetal scan and 67 referred for a neurosonogram. Distal lateral ventricles were measured both in axial and coronal plane. Good visualization of the ventricles was achieved in 91% of the cases using the coronal plane (both ventricles) and in 95% of the cases using the axial plane (only the distal ventricle) [p-value >0.001]. The mean width of the distal lateral ventricle in the axial plane was 7.9 ± 1.9 mm versus 8.2 ± 1.9 mm on the coronal plane [p-value <0.001]. This larger diameter by 0.3 mm was not dependent on the indication for the scan or the gestational age. Slight asymmetry was present on coronal images in the routine group (0.2 mm), and that was even larger in the referral group (1.6 mm) [p-value <0.001]. Coronal measurement of both ventricles is feasible, and has the advantage over measurement in the axial view in which only the distal ventricle is clearly visible and measurable. This article is protected by copyright. All rights reserved.
    Prenatal Diagnosis 12/2013; · 2.68 Impact Factor
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    ABSTRACT: Monochorionic twins, treated by laser due to twin-twin-transfusion syndrome (TTTS) are at increased risk of neurodevelopment impairment. Our aim was to evaluate the additional value of Diffusion Weighted Imaging (DWI) over fetal sonography and T2-MRI in detection of acute ischemic cerebral lesions shortly following fetoscopic laser coagulation (FLC). This is a prospective cohort study of patients with TTTS treated by FLC. All patients underwent fetal brain DWI and T2-MRI within 24-96 hours after the procedure and a follow-up MRI at 30-32 weeks of gestation. All patients also had frequent evaluation by fetal sonography until delivery. Thirty patients with TTTS were included in the study. Eight pregnancies (group A) resulted in survival of only one twin after the procedure, whereas the other 22 pregnancies resulted in dual twin survival (Group B). Two fetuses in group A and 4 fetuses in group B had evidence of transient bleeding in the germinal matrix. Three fetuses in group B while none in group A had diffused ischemic changes in the white matter. One fetus died in-utero 24 hours after the MRI. The other 2 fetuses in group B demonstrated an acute infarct 24-48 hours after the procedure. Subsequent scans at 28-29 and 32 weeks showed brain atrophy compatible with an old infarct. DWI can demonstrate cerebral damage immediately after FLC. Larger cohorts are needed to determine the role of fetal MRI in the prenatal assessment and follow-up of patients with TTTS.
    Ultrasound in Obstetrics and Gynecology 12/2013; · 3.56 Impact Factor
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    ABSTRACT: PURPOSE To evaluate the agreement between ultrasound (US) and fetal head magnetic resonance imaging (feMRI) head biometry. METHOD AND MATERIALS A retrospective analysis was performed on 60 sequential feMRI scans obtained between 2011-2013 following US diagnosis of microcephaly w/wo severe intrauterine growth retardation (IUGR: head circumference ≤-2 standard deviations [SD] and estimated fetal weight [EFW] ≤2 SD). Inclusion criteria were single fetus and fewer than 21 days between performance of US and feMRI. The mean gestational age (GA) of fetuses at US and feMRI acquisition was 33±3.3 and 34±3 weeks, respectively. The mean interval between US and feMRI scanning was 7.3±6 days. Biparietal diameter (BPD) and occipitofrontal diameter (OFD) results were converted to percentiles and SD by Chervenak and Hadlock normograms for US and compared to Garel normograms for feMRI. US measurements of OFD were recorded in 36/60 of the scans. Data on GA, EFW and interval between scans were also recorded. RESULTS Forty-two of the 60 fetuses with US-suspected microcephaly (70%) were IUGR. BPD values were ≤-2 SD in only 5 (8.3%) according to feMRI (P<0.001). OFD measurements on feMRI were ≤-2 SD in 2 fetuses (5.5%) (P<0.001). Abnormal anatomical findings were observed In 5 cases. CONCLUSION There is discrepancy between US and feMRI findings in the assessment of fetal head biometry. US measurements are performed only on the skull, while feMRI enables direct measurement of the brain. Abnormal anatomical findings are more predictive for true microcephaly in both US and feMRI. Thus, diagnosis of microcephaly by US alone is not sufficient and should be validated by feMRI before a final diagnosis is established and consultations with the parents are held. CLINICAL RELEVANCE/APPLICATION The diagnosis of microcephaly can lead to pregnancy termination, and diagnosis by US alone is insufficient and requires confirmation by a feMRI study.
    Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
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    ABSTRACT: Systemic lupus erythematosus (SLE) is a complex autoimmune disorder involving multiple organs. One of the main sites of SLE morbidity is the central nervous system (CNS), specifically the brain. In this article we review several imaging modalities used for CNS examination in SLE patients. These modalities are categorized as morphological and functional. Special attention is given to magnetic resonance imaging (MRI) and its specific sequences such as diffusion-weighted imaging (DWI), diffuse tensor imaging (DTI) and magnetic resonance spectroscopy (MRS). These modalities allow us to better understand CNS involvement in SLE patients, its pathophysiology and consequences.
    The Israel Medical Association journal: IMAJ 07/2013; 15(7):382-6. · 0.98 Impact Factor
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    ABSTRACT: OBJECTIVE: To describe the nature of central nervous system (CNS) anomalies diagnosed during the third trimester following a normal anatomy scan at 21-24 weeks of gestation. METHODS: Retrospective cohort study of all pregnant women referred to the fetal medicine unit at Sheba Medical Center between 2005 and 2011 due to fetal CNS anomalies detected at the late second and third trimester following a normal anatomy scan at 21-24 weeks of gestation. RESULTS: During the study period, 47 patients were diagnosed with fetal CNS anomalies at a median gestational age of 31.1 weeks (range 24-38). The 4 most common anomalies found included intracranial cysts (19%), mild ventriculomegaly (15%), absence or dysgenesis of the corpus callosum (10%) and intracerebral hemorrhage (10%). Other CNS anomalies detected in this group of patients included hydrocephalus, Dandy walker malformation, large cysterna magna, microcephalus with lissencephaly, craniosynestosis, periventricular pseudocysts, global brain ischemia, cerebellar hypoplasia and sub-ependymal nodule. CONCLUSIONS: Fetal brain continues to evolve throughout gestation and therefore some of the CNS anomalies can be diagnosed only during late second and third trimester of pregnancy. Consequently, in patients who have a third trimester scan for any reason, assessment of the fetal CNS should be considered. This article is protected by copyright. All rights reserved.
    Prenatal Diagnosis 05/2013; · 2.68 Impact Factor
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    ABSTRACT: Misinterpretation of head computerized tomographic (CT) scans by radiology residents in the emergency department (ED) can result in delayed and even erroneous radiology diagnoses. Better knowledge of pitfalls and environmental factors may decrease the occurrence of these errors. To evaluate common misinterpretations of head CT scans by radiology residents in a level I trauma center ED. We studied 955 head CT scans of patients admitted to our ED from January 2010 to May 2011. They were reviewed separately by two senior neuroradiologists and graded as being unimportant (score of 1), important but not requiring emergent treatment (score of 2), and important requiring urgent treatment (score of 3). We recorded the time of day the examination was performed, the year of residency, the site, subsite and side of the lesion, the pathology, the anatomical mistake, false-positive findings, and the attending neuroradiologists' score. A total of 955 examinations were interpreted of which 398 had misinterpreted findings that were entered into the database, with the possibility of multiple errors per examination. The overall misinterpretation rate was 41%. The most commonly missed pathologies were chronic infarcts, hypodense lesions, and mucosal thickening in the paranasal sinuses. The most common sites for misdiagnosis were brain lobes, sinuses and deep brain structures. The highest percentage of misinterpretation occurred between 2.30 p.m. and 8 p.m. and the lowest between midnight and 8 a.m. (P < 0.05). The overall percentage of errors involving pathologies with a score of 3 by at least one of the neuroradiologists was 4.7%. Third-year residents had an overall higher error rate and first-year residents had significantly more false-positive misinterpretations compared to the other residents. The percentage of errors made by our residents in cases that required urgent treatment was comparable to the published data. We believe that the intense workload of radiology residents contributes to their misinterpretation of head CT findings.
    The Israel Medical Association journal: IMAJ 05/2013; 15(5):221-5. · 0.98 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 04/2013; · 3.56 Impact Factor
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    ABSTRACT: PURPOSE: To define the normal T2* values of liver in the third trimester of pregnancy in normal fetuses. MATERIALS AND METHODS: Multi-echo gradient echo T2* sequence was applied to the fetal abdomen in the axial plane in women undergoing a fetal MRI (1.5 Tesla [T], MRI system). A region of interest, best visualizing in the liver parenchyma was used for measurements. Studies were independently read by two experienced readers to assess intra- and interobserver variability. RESULTS: The study cohort included 46 pregnant women undergoing fetal MRI for any indication other than liver pathology evaluation. Three scans were excluded due to fetal motion. Average maternal and gestational age were 33 ± 4 years and 31.9 ± 3 weeks, respectively. Average T2* values were found to be 19.7 ± 7.4 ms. The intra- and interobserver agreement were very good: 0.93 and 0.8-0.084, respectively. CONCLUSION: T2* MRI allows noninvasive evaluation liver iron content in the third trimester fetus. Measured values at this stage of pregnancy are significantly lower compared with values cited in the literature for adults. This is of major importance in the correct diagnosis of fetal iron overload states. We propose this as the standard reference when evaluating fetal iron overload pathology. J. Magn. Reson. Imaging 2013. © 2013 Wiley Periodicals, Inc.
    Journal of Magnetic Resonance Imaging 04/2013; · 2.57 Impact Factor
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    ABSTRACT: MRI differentiation between metastases and high grade gliomas is a challenging task. Contrast enhancement and size of edema do not provide clear-cut differentiators. The differences in the properties of the peritumoral edema between these tumor types may be exploited to distinguish between them, using MRI perfusion sequences, which are capable of imaging edema in the clinical setting and may be a reliable method to make this differentiation. To assess the ability of perfusion-weighted imaging to differentiate between high grade gliomas andbrain metastases. During 5 months, 21 patients (age 40-85, median age 61, 16 males and 5 females) with either glioblastoma multiforme (GBM) or metastasis (pathology proven), underwent MRI for assessment of the tumor prior to surgery. Most of the scans were done at 3 Tesla. The scans included perfusion-weighted imaging sequences. Perfusion in the tumor, in the peritumoral edema and in normal tissue were assessed using Functool software. The ratios of tumor perfusion and peritumoral edema perfusion to normal tissue perfusion were calculated and compared. Bleeding artifact precluded perfusion assessment in four patients. There was no statistically significant difference between the tumor perfusion ratios of high grade gliomas and those of metastases. The edema perfusion ratios were higher in GBM than in metastases (P = 0.007). Perfusion-weighted imaging of peritumoral edema can help to differentiate between GBM and metastases.
    The Israel Medical Association journal: IMAJ 02/2013; 15(2):103-5. · 0.98 Impact Factor
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    ABSTRACT: The pituitary gland is crucially important in the function of the endocrine axis. So far, antenatal depiction of the pituitary gland was possible only using magnetic resonance imaging. We describe antenatal visualization of the pituitary gland using 2- and 3-dimensional sonography. The appearance of the gland on sonography seems to be superior compares to prenatal magnetic resonance imaging. In cases with midline anomalies of the brain, face, or cranium, depiction of the pituitary gland is feasible and recommended.
    Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 10/2012; 31(10):1675-80. · 1.40 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 09/2012; 40(S1). · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 09/2012; 40(S1). · 3.56 Impact Factor
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    Ultrasound in Obstetrics and Gynecology 09/2012; 40(S1). · 3.56 Impact Factor

Publication Stats

115 Citations
112.47 Total Impact Points

Institutions

  • 2014
    • Stony Brook University
      • Department of Medicine
      Stony Brook, New York, United States
  • 2009–2014
    • Sheba Medical Center
      • Department of Pathology
      Gan, Tel Aviv, Israel
    • Mount Sinai School of Medicine
      • Department of Psychiatry
      Manhattan, NY, United States
  • 2013
    • Ministry of Health (Israel)
      Yerushalayim, Jerusalem District, Israel
  • 2009–2013
    • Tel Aviv University
      • • Department of Obstetrics and Gynecology
      • • Department of Neurology
      Tel Aviv, Tel Aviv, Israel
  • 2006
    • Yale University
      New Haven, Connecticut, United States