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Featured researches published by Kresimir Dolic.


Radiology | 2011

Use of MR venography for characterization of the extracranial venous system in patients with multiple sclerosis and healthy control subjects.

Robert Zivadinov; Alexandra Lopez-Soriano; Bianca Weinstock-Guttman; Claudiu Schirda; Christopher Magnano; Kresimir Dolic; Cheryl Kennedy; Christina Brooks; Justine Reuther; Kristin Hunt; Michelle Andrews; Michael G. Dwyer; David Hojnacki

PURPOSE To investigate the differences in the extracranial venous system in patients with multiple sclerosis (MS) and healthy control (HC) subjects by using magnetic resonance (MR) venography. MATERIALS AND METHODS This HIPAA-compliant, prospective study was approved by the local institutional review board, and all participants gave informed consent. Fifty-seven patients, 41 (72%) with relapsing-remitting MS and 16 (28%) with secondary-progressive MS, and 21 HC subjects were imaged with a 3-T MR unit by using two-dimensional (2D) time-of-flight (TOF) and three-dimensional (3D) time-resolved imaging of contrast kinetics (TRICKS) sequences. In addition, six MS patients and six HC subjects underwent two sequential MR venographic examinations during 1 week to test image-reimage reproducibility. The morphologic features of internal jugular vein flow were classified as absent, pinpoint, flattened, crescentic, or ellipsoidal flow. Only absent and pinpoint flow were considered abnormal. The flow of the vertebral veins was classified as absent or present. The prominence of collateral neck veins and venous asymmetries between the left and right sides were assessed. Differences among groups were tested with a two-tailed Mann-Whitney two-sample rank-sum test. RESULTS No significant differences in morphologic features of flow in the internal jugular veins and vertebral veins were found between MS patients and HC subjects in any of the examined MR venographic parameters. No differences in asymmetry or prominence were found between MS patients and HC subjects. There was modest agreement (κ = 0.67) between 2D TOF and 3D TRICKS sequences. Image-reimage reproducibility showed modest agreement (κ = 0.66) for 2D TOF and low agreement for 3D TRICKS (κ = 0.33). CONCLUSION No significant differences in the extracranial venous systems between MS patients and HC subjects were detected by using MR venography. Standardized guidelines are needed to define parameters for the presence of venous anomalies.


Expert Review of Neurotherapeutics | 2011

Chronic cerebrospinal venous insufficiency in multiple sclerosis: diagnostic, pathogenetic, clinical and treatment perspectives

Robert Zivadinov; Murali Ramanathan; Kresimir Dolic; Karen Marr; Yuval Karmon; Adnan H. Siddiqui; Ralph H. B. Benedict; Bianca Weinstock-Guttman

Chronic cerebrospinal venous insufficiency (CCSVI) was recently described in multiple sclerosis patients. CCSVI is characterized by impaired brain venous drainage due to outflow obstruction in the extracranial venous system, mostly related to anomalies in the internal jugular and azygos veins. The current CCSVI diagnosis is based on Doppler sonography of extracranial and transcranial venous hemodynamics criteria. To date, prevalence estimates of CCSVI, provided by different groups using various imaging methods of assessment, vary widely from none to 100%. There is an urgent need to define and validate the spectrum of cranial/extracranial venous anomalies and to establish reliable, diagnostic gold-standard test(s). The potential usefulness of endovascular treatment for CCSVI in multiple sclerosis patients is still unknown.


PLOS ONE | 2011

Risk factors for chronic cerebrospinal venous insufficiency (CCSVI) in a large cohort of volunteers.

Kresimir Dolic; Bianca Weinstock-Guttman; Karen Marr; Vesela Valnarov; Ellen Carl; Jesper Hagemeier; Christina Brooks; Colleen K. Kilanowski; David Hojnacki; Murali Ramanathan; Robert Zivadinov

Background The role of intra- and extra-cranial venous system impairment in the pathogenesis of various vascular, inflammatory and neurodegenerative neurological disorders, as well as in aging, has not been studied in detail. Nor have risk factors been determined for increased susceptibility of venous pathology in the intra-cranial and extra-cranial veins. The aim of this study was to investigate the association between presence of a newly proposed vascular condition called chronic cerebrospinal venous insufficiency (CCSVI) and environmental factors in a large volunteer control group without known central nervous system pathology. Methods and Findings The data were collected in a prospective study from 252 subjects who were screened for medical history as part of the entry criteria and participated in the case-control study of CCSVI prevalence in multiple sclerosis (MS) patients, and then were analyzed post-hoc. All participants underwent physical and Doppler sonography examinations, and were assessed with a structured environmental questionnaire. Fullfilment of ≥2 positive venous hemodynamic (VH) criteria on Doppler sonography was considered indicative of CCSVI diagnosis. Risk and protective factors associated with CCSVI were analyzed using logistic regression analysis. Seventy (27.8%) subjects presented with CCSVI diagnosis and 153 (60.7%) presented with one or more VH criteria. The presence of heart disease (p = .001), especially heart murmurs (p = .007), a history of infectious mononucleosis (p = .002), and irritable bowel syndrome (p = .005) were associated with more frequent CCSVI diagnosis. Current or previous smoking (p = .029) showed a trend for association with more frequent CCSVI diagnosis, while use of dietary supplements (p = .018) showed a trend for association with less frequent CCSVI diagnosis. Conclusions Risk factors for CCSVI differ from established risk factors for peripheral venous diseases. Vascular, infectious and inflammatory factors were associated with higher CCSVI frequency.


American Journal of Neuroradiology | 2012

Intra- and extraluminal structural and functional venous anomalies in multiple sclerosis, as evidenced by 2 noninvasive imaging techniques.

Kresimir Dolic; Karen Marr; Vesela Valnarov; Michael G. Dwyer; Ellen Carl; Y. Karmon; Cheryl Kennedy; Christina Brooks; Colleen K. Kilanowski; Kristin Hunt; Adnan H. Siddiqui; David Hojnacki; B. Weinstock-Guttman; Robert Zivadinov

Here is another article that should add to the controversy over the relationship between MS and venous anomalies. The authors assessed the utility of sonography and MRV (2 different techniques) for detecting intra- and extraluminal venous abnormalities in 150 patients with MS and 63 matched controls. Results were as follows: patients with MS had significantly more intraluminal and structural abnormalities than controls and patients with progressive MS had more extraluminal and flow abnormalities than those with nonprogressive disease. BACKGROUND AND PURPOSE: Chronic cerebrospinal venous insufficiency (CCSVI) is a vascular condition characterized by anomalies of the main extracranial cerebrospinal venous routes that interfere with normal venous outflow. Research into CCSVI will determine its sensitivity and specificity for a diagnosis of MS, its prevalence in MS patients, and its clinical, MRI, and genetic correlates. Our aim was to investigate the prevalence and number of intra- and extraluminal structural and functional extracranial venous abnormalities by using DS and MRV, in patients with MS and HCs. MATERIALS AND METHODS: One hundred fifty patients with MS, 104 (69.3%) with RR and 46 (30.7%) with a progressive MS course, and 63 age- and sex-matched HCs were scanned with 3T MR imaging by using TOF and TRICKS sequences (only patients with MS). All subjects underwent DS examination for intra- and extraluminal structural and functional abnormalities of the IJVs. Absent/pinpoint IJV flow morphology on MRV was considered an abnormal finding. Prominence of collateral extracranial veins was assessed with MRV. RESULTS: Patients with MS had a significantly higher number of functional (P < .0001), total (P = .001), and intraluminal (P = .005) structural IJV DS abnormalities than HCs. There was a trend for more patients with MS with extraluminal IJV DS abnormalities (P = .023). No significant differences were found on the MRV IJV flow morphology scale between patients with MS and HCs. Patients with progressive MS showed more extraluminal IJV DS abnormalities (P = .01) and more MRV flow abnormalities on TOF (P = .006) and TRICKS (P = .01) than patients with nonprogressive MS. There was a trend for a higher number of collateral veins in patients with MS than in HCs (P = .016). CONCLUSIONS: DS is more sensitive than MRV in detecting intraluminal structural and functional venous abnormalities in patients with MS compared with HCs, whereas MRV is more sensitive in showing collaterals.


Neurology | 2014

Prospective randomized trial of venous angioplasty in MS (PREMiSe)

Adnan H. Siddiqui; Robert Zivadinov; Ralph H. B. Benedict; Yuval Karmon; Jihnhee Yu; Mary L. Hartney; Karen Marr; Vesela Valnarov; Cheryl Kennedy; Murali Ramanathan; Deepa P. Ramasamy; Kresimir Dolic; David Hojnacki; Ellen Carl; Elad I. Levy; Hopkins Ln; Bianca Weinstock-Guttman

Objective: We report the results of the investigation of safety and efficacy of venous angioplasty in patients with multiple sclerosis (MS) with findings of extracranial venous anomalies, considered hallmarks of chronic cerebrospinal venous insufficiency (CCSVI), in a 2-phase study (ClinicalTrials.gov NCT01450072). Methods: Phase 1 was an open-label safety study (10 patients); phase 2 was sham-controlled, randomized, and double-blind (10 sham procedure, 9 treated). All study patients fulfilled venous hemodynamic screening criteria indicative of CCSVI. Assessment was at 1, 3, and 6 months postprocedure with MRI, clinical, and hemodynamic outcomes. Primary endpoints were safety at 24 hours and 1 month, venous outflow restoration >75% at 1 month, and effect of angioplasty on new lesion activity and relapse rate over 6 months. Secondary endpoints included changes in disability, brain volume, cognitive tests, and quality of life. Results: No perioperative complications were noted; however, one patient with history of syncope was diagnosed with episodic bradycardia requiring placement of a pacemaker before discharge. Doppler evidence-based venous hemodynamic insufficiency severity score (VHISS) was reduced >75% compared to baseline in phase 1 (at 1 month) but not phase 2. In phase 2, higher MRI activity (cumulative number of new contrast-enhancing lesions [19 vs 3, p = 0.062] and new T2 lesions [17 vs 3, p = 0.066]) and relapse activity (4 vs 1, p = 0.389) were identified as nonsignificant trends in the treated vs sham arm over 6 months. Using analysis of covariance, significant cumulative new T2 lesions were related to larger VHISS decrease (p = 0.028) and angioplasty (p = 0.01) over the follow-up. No differences in other endpoints were detected. Conclusion: Venous angioplasty is not an effective treatment for MS over the short term and may exacerbate underlying disease activity. Classification of evidence: This is a Class I study demonstrating that clinical and imaging outcomes are no better or worse in patients with MS identified with venous outflow restriction who receive venous angioplasty compared to sham controls who do not receive angioplasty. This study also includes a Class IV phase 1 study of safety in 10 patients receiving the angioplasty procedure.


BMC Medicine | 2013

The role of noninvasive and invasive diagnostic imaging techniques for detection of extra-cranial venous system anomalies and developmental variants

Kresimir Dolic; Adnan H. Siddiqui; Yuval Karmon; Karen Marr; Robert Zivadinov

The extra-cranial venous system is complex and not well studied in comparison to the peripheral venous system. A newly proposed vascular condition, named chronic cerebrospinal venous insufficiency (CCSVI), described initially in patients with multiple sclerosis (MS) has triggered intense interest in better understanding of the role of extra-cranial venous anomalies and developmental variants. So far, there is no established diagnostic imaging modality, non-invasive or invasive, that can serve as the “gold standard” for detection of these venous anomalies. However, consensus guidelines and standardized imaging protocols are emerging. Most likely, a multimodal imaging approach will ultimately be the most comprehensive means for screening, diagnostic and monitoring purposes. Further research is needed to determine the spectrum of extra-cranial venous pathology and to compare the imaging findings with pathological examinations. The ability to define and reliably detect noninvasively these anomalies is an essential step toward establishing their incidence and prevalence. The role for these anomalies in causing significant hemodynamic consequences for the intra-cranial venous drainage in MS patients and other neurologic disorders, and in aging, remains unproven.


Journal of Vascular and Interventional Radiology | 2013

Comparison of Intravascular Ultrasound with Conventional Venography for Detection of Extracranial Venous Abnormalities Indicative of Chronic Cerebrospinal Venous Insufficiency

Yuval Karmon; Robert Zivadinov; Bianca Weinstock-Guttman; Karen Marr; Vesela Valnarov; Kresimir Dolic; Cheryl Kennedy; David Hojnacki; Ellen Carl; Jesper Hagemeier; L. Nelson Hopkins; Elad I. Levy; Adnan H. Siddiqui

PURPOSE To investigate prevalence of extracranial abnormalities in azygos and internal jugular (IJ) veins using conventional venography and intravascular ultrasound (IVUS) in patients with multiple sclerosis (MS) being evaluated for chronic cerebrospinal venous insufficiency, a condition of vascular hemodynamic dysfunction. MATERIALS AND METHODS PREMiSe (Prospective Randomized Endovascular therapy in Multiple Sclerosis) is a venous angioplasty study that enrolled 30 patients with relapsing MS. The patients fulfilled two or more venous hemodynamic extracranial Doppler sonography screening criteria. Phase I of the study included 10 patients and was planned to assess safety and standardize venography, IVUS, and angioplasty and blinding procedures; phase II enrolled 20 patients and further validated diagnostic assessments using the two invasive techniques. Venography was considered abnormal when ≥ 50% lumen-diameter restriction was detected. IVUS was considered abnormal when ≥ 50% lumen-diameter restriction, intraluminal defects, or reduced pulsatility was detected. RESULTS No venography-related or IVUS-related complications, including vessel rupture, thrombosis, or side effects of contrast media were recorded among the 30 study patients. IVUS-detected venous abnormalities, including chronic, organized, thrombus-like inclusions were observed in 85% of azygos, 50% of right IJ, and 83.3% of left IJ veins, whereas venography demonstrated stenosis of ≥ 50% in 50% of azygos, 55% of right IJ, and 72% of left IJ veins. Sensitivity of venography for detecting IVUS abnormalities was 52.9%, 73.3%, and 80% for the azygos, left IJ, and right IJ veins, respectively. CONCLUSIONS IVUS assessment of azygos and IJ veins showed a higher rate of venous abnormalities than venography. IVUS provides a diagnostic advantage over conventional venography in detecting extracranial venous abnormalities indicative of chronic cerebrospinal venous insufficiency.


BMC Neurology | 2013

Multimodal noninvasive and invasive imaging of extracranial venous abnormalities indicative of CCSVI: Results of the PREMiSe pilot study

Robert Zivadinov; Yuval Karmon; Kresimir Dolic; Jesper Hagemeier; Karen Marr; Vesela Valnarov; Cheryl Kennedy; David Hojnacki; Ellen Carl; L. Nelson Hopkins; Elad I. Levy; Bianca Weinstock-Guttman; Adnan H. Siddiqui

BackgroundThere is no established noninvasive or invasive diagnostic imaging modality at present that can serve as a ‘gold standard’ or “benchmark” for the detection of the venous anomalies, indicative of chronic cerebrospinal venous insufficiency (CCSVI). We investigated the sensitivity and specificity of 2 invasive vs. 2 noninvasive imaging techniques for the detection of extracranial venous anomalies in the internal jugular veins (IJVs) and azygos vein/vertebral veins (VVs) in patients with multiple sclerosis (MS).MethodsThe data for this multimodal imaging comparison pilot study was collected in phase 2 of the “Prospective Randomized Endovascular therapy in Multiple Sclerosis” (PREMiSe) study using standardized imaging techniques. Thirty MS subjects were screened initially with Doppler sonography (DS), out of which 10 did not fulfill noninvasive screening procedure requirements on DS that consisted of ≥2 venous hemodynamic extracranial criteria. Accordingly, 20 MS patients with relapsing MS were enrolled into the multimodal diagnostic imaging study. For magnetic resonance venography (MRV), IJVs abnormal findings were considered absent or pinpoint flow, whereas abnormal VVs flow was classified as absent. Abnormalities of the VVs were determined only using non-invasive testing. Catheter venography (CV) was considered abnormal when ≥50% lumen restriction was detected, while intravascular ultrasound (IVUS) was considered abnormal when ≥50% restriction of the lumen or intra-luminal defects or reduced pulsatility was found. Non-invasive and invasive imaging modality comparisons between left, right and total IJVs and between the VVs and azygos vein were performed. Because there is no reliable way of non-invasively assessing the azygos vein, the VVs abnormalities detected by the non-invasive testing were compared to the azygos abnormalities detected by the invasive testing. All image modalities were analyzed in a blinded manner by more than one viewer, upon which consensus was reached. The sensitivity and specificity were calculated using contingency tables denoting the presence or absence of vein-specific abnormality findings between all imaging modalities used individually as the benchmark.ResultsThe sensitivity of CV + IVUS was 68.4% for the right and 90% for the left IJV and 85.7% for the azygos vein/VVs, compared to venous anomalies detected on DS. Compared to the venous anomalies detected on MRV, the sensitivity of CV + IVUS was 71.4% in right and 100% in left IJVs and 100% in the azygos vein/VVs; however, the specificity was 38.5%, 38.9% and 11.8%, respectively. The sensitivity between the two invasive imaging techniques, used as benchmarks, ranged from 72.7% for the right IJV to 90% for the azygos vein but the IVUS showed a higher rate of venous anomalies than the CV. There was excellent correspondence between identifying collateral veins on MRV and CV.ConclusionsNoninvasive DS screening for the detection of venous anomalies indicative of CCSVI may be a reliable approach for identifying patients eligible for further multimodal invasive imaging testing of the IJVs. However, the noninvasive screening methods were inadequate to depict the total amount of azygos vein/VVs anomalies identified with invasive testing. This pilot study, with limited sample size, shows that both a non-invasive and invasive multimodal imaging diagnostic approach should be recommended to depict a range of extracranial venous anomalies indicative of CCSVI. However, lack of invasive testing on the study subjects whose results were negative on the DS screening and of healthy controls, limits further generalizibility of our findings. In addition, the findings from the 2 invasive techniques confirmed the existence of severe extracranial venous anomalies that significantly impaired normal blood outflow from the brain in this group of MS patients.


Neurological Research | 2012

Heart disease, overweight, and cigarette smoking are associated with increased prevalence of extra-cranial venous abnormalities.

Kresimir Dolic; Bianca Weinstock-Guttman; Karen Marr; Vesela Valnarov; Ellen Carl; Jesper Hagemeier; Cheryl Kennedy; Colleen K. Kilanowski; David Hojnacki; Murali Ramanathan; Robert Zivadinov

Abstract Objectives: Most of the extra-cranial venous abnormalities have been previously described as truncular venous malformations. In this hypothesis-driven study, we evaluated possible association of risk/protective factors with the presence of truncular and functional venous abnormalities in internal jugular veins (IJVs) in a large cohort of volunteers without known central nervous system (CNS) pathology. Methods: The study included 240 controls who underwent physical and Doppler sonography (DS) examinations for the presence of intra- and extra-luminal structural and functional abnormalities of the IJVs, and were assessed with a physical examination and structured environmental questionnaire for demographic characteristics, presence of autoimmune and other concomitant diseases, vascular risk factors, environmental factors, and habits. Logistic regression analysis was used to test which risk/protective factors were associated with the presence and number of extra-cranial venous abnormalities. Results: Subjects with heart disease (P<0·001), overweight (P = 0·005), and smoking (P = 0·016) had a significantly increased number of intra-luminal structural venous abnormalities. Presence of heart disease increased the risk of a malformed valve 12·9 times (95% CI: 5·4–31·3, P<0·001), while smoking increased it 2·21 times (95% CI: 1–4·9, P = 0·033). Being overweight (P = 0·003), a history of mononucleosis (P = 0·012) and smoking (P = 0·042) increased risk for presence of a flap. No association was found between the investigated risk factors and extra-luminal or functional venous abnormalities. However, use of dietary and herbal supplements had a protective role for the presence of functional venous abnormalities. Conclusions: There is a close association between intra-luminal, structural, extra-cranial, venous system pathology and the presence of heart disease, overweight, and smoking.


American Journal of Neuroradiology | 2012

Unclear Value of Positional MR Angiography in Evaluating Cerebral Venous Outflow Hemodynamics

Kresimir Dolic; Karen Marr; Robert Zivadinov

We read with interest the article entitled “Positional Venous MR Angiography: An Operator-Independent Tool to Evaluate Cerebral Venous Outflow Hemodynamics,” originally published in the American Journal of Neuroradiology on-line on November 3, 2011.[1][1] We believe that the authors did not

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Robert Zivadinov

State University of New York System

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Karen Marr

State University of New York System

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Bianca Weinstock-Guttman

State University of New York System

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David Hojnacki

State University of New York System

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Ellen Carl

State University of New York System

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Vesela Valnarov

State University of New York System

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Jesper Hagemeier

State University of New York System

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Christina Brooks

State University of New York System

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