A Validation Study of Multicenter Diffusion Tensor Imaging: Reliability of Fractional Anisotropy and Diffusivity Values

Fox, Robert J.; Sakaie, Kenneth Earl; Lee, J.-C.; Debbins, Josef P.; Liu, Y.; Arnold, Douglas L.; Melhem, Elias R.; Smith, Carl H.; Philips, Mariamma; Lowe, Mark J.; Fisher, Elizabeth

doi:10.3174/ajnr.a2844

Cited by 129 publications

(120 citation statements)

References 25 publications

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“…DTI quantifies subtle white matter differences in normalappearing white matter on traditional MRI scans. Fractional anisotropy (FA), an index obtained through DTI, represents the degree of anisotropy, or strength of diffusion direction, of water molecules within these tracts, providing a reliable assessment of microstructural integrity of white matter fibers (Fox et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

White Matter Integrity in Highly Traumatized Adults With and Without Post-Traumatic Stress Disorder

Fani

King

Jovanović

et al. 2012

Neuropsychopharmacol

113

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Prior structural imaging studies of post-traumatic stress disorder (PTSD) have observed smaller volumes of the hippocampus and cingulate cortex, yet little is known about the integrity of white matter connections between these structures in PTSD samples. The few published studies using diffusion tensor imaging (DTI) to measure white matter integrity in PTSD have described individuals with focal trauma rather than chronically stressed individuals, which limits generalization of findings to this population; in addition, these studies have lacked traumatized comparison groups without PTSD. The present DTI study examined microstructural integrity of white matter tracts in a sample of highly traumatized African-American women with (n ¼ 25) and without (n ¼ 26) PTSD using a tract-based spatial statistical approach, with threshold-free cluster enhancement. Our findings indicated that, relative to comparably traumatized controls, decreased integrity (measured by fractional anisotropy) of the posterior cingulum was observed in participants with PTSD (po0.05). These findings indicate that reduced microarchitectural integrity of the cingulum, a white matter fiber that connects the entorhinal and cingulate cortices, appears to be associated with PTSD symptomatology. The role of this pathway in problems that characterize PTSD, such as inadequate extinction of learned fear, as well as attention and explicit memory functions, are discussed.

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Section: Introductionmentioning

confidence: 99%

White Matter Integrity in Highly Traumatized Adults With and Without Post-Traumatic Stress Disorder

Fani

King

Jovanović

et al. 2012

Neuropsychopharmacol

113

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“…With many centers contributing relatively few patients, variability between sites must be minimized. There have been several reports comparing diffusion measurements in multicenter studies 5 , 6 , 7 , 8 documenting significant variability for scanners of the same model using essentially identical technique and parameters. Many aspects of scanner performance have been reported to affect the measurement results and introduce discrepancies in the measurement (14) .…”

Section: Discussionmentioning

confidence: 99%

“…Repeatability and reproducibility data were not collected from sites participating in this study. Therefore, it is difficult to assess whether the variability of all the metrics is due to the systematic difference of machines from different vendors, as mentioned in the studies by Volimar et al, Zhu et al, Fox et al, and Teipel et al, 5 , 6 , 7 , 8 or due to random errors in the MRI measurements. Since the goal of this study was to evaluate a QC methodology for multicenter trial, knowing under what circumstance the site needs to undergo hardware/software adjustment is important.…”

Section: Discussionmentioning

confidence: 99%

“…These technique‐related effects may both mask and mimic biological changes in white matter. There have been several reports comparing diffusion measurements in multicenter studies 5 , 6 , 7 , 8 documenting significant variability for scanners of the same model using essentially identical technique and parameters. Conducting a multicenter study using quantitative analysis of diffusion tensor data requires a uniform quality control procedure to ensure that: (i) data from different sites are not biased and can be combined for statistical analysis; and (ii) data of substandard quality are excluded.…”

Section: Introductionmentioning

confidence: 99%

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Assessment of diffusion tensor image quality across sites and vendors using the American College of Radiology head phantom

Wang

Seo

Huang

et al. 2016

J Applied Clin Med Phys

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The purpose of this study was to explore the feasibility of assessing quality of diffusion tensor imaging (DTI) from multiple sites and vendors using American College of Radiology (ACR) phantom. Participating sites (Siemens false(n=2false), GE false(n=2false), and Philips false(n=4false)) reached consensus on parameters for DTI and used the widely available ACR phantom. Tensor data were processed at one site. B0 and eddy current distortions were assessed using grid line displacement on phantom Slice 5; signal‐to‐noise ratio (SNR) was measured at the center and periphery of the b=0 image; fractional anisotropy (FA) and mean diffusivity (MD) were assessed using phantom Slice 7. Variations of acquisition parameters and deviations from specified sequence parameters were recorded. Nonlinear grid line distortion was higher with linear shimming and could be corrected using the 2nd order shimming. Following image registration, eddy current distortion was consistently smaller than acquisition voxel size. SNR was consistently higher in the image periphery than center by a factor of 1.3–2.0. ROI‐based FA ranged from 0.007 to 0.024. ROI‐based MD ranged from 1.90×10−3 to 2.33×10−3mm2/sfalse(median=2.04×10−3mm2/sfalse). Two sites had image void artifacts. The ACR phantom can be used to compare key quality measures of diffusion images acquired from multiple vendors at multiple sites.PACS number(s): 87.57.‐s, 87.19.lf

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“…93 A multicenter validation study indicated that fractional anisotropy was the most comparable DTI measure across centers and endorsed its use in multicenter clinical trials. 94 Werring et al 95 demonstrated that a steady and moderate increase of the apparent diffusion coefficient can precede the development of new plaques by 6 -8 months, and they indicated that structural changes in prelesion normal-appearing white matter occur before inflammation and BBB leakage.…”

Section: Future Areasmentioning

confidence: 99%

Current and Emerging Therapies in Multiple Sclerosis: Implications for the Radiologist, Part 2—Surveillance for Treatment Complications and Disease Progression

McNamara¹,

Sugrue²,

Murray

et al. 2017

AJNR Am J Neuroradiol

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SUMMARY: An understanding of the new generation of MS drugs in conjunction with the key role MR imaging plays in the detection of disease progression, opportunistic infections, and drug-related adverse effects is of vital importance to the neuroradiologist. Part 1 of this review outlined the current treatment options available for MS and examined the mechanisms of action of the various medications. It also covered specific complications associated with each form of therapy. Part 2, in turn deals with the subject of pharmacovigilance and the optimal frequency of MRI monitoring for each individual patient, depending on his or her unique risk profile. Special attention is given to the diagnosing of progressive multifocal leukoencephalopathy in patients treated with natalizumab as this is a key area in which neuroradiologists can contribute to improved patient outcomes. This article also outlines the aims of treatment and reviews the possibility of "no evidence of disease activity" becoming a treatment goal with the availability of more effective therapies. Potential future areas and technologies including image subtraction, brain volume measurement and advanced imaging techniques such as double inversion recovery are also reviewed. It is anticipated that such advancements in this rapidly developing field will improve the accuracy of monitoring an individual patient's response to treatment. ABBREVIATIONS:BV ϭ brain volume; DIR ϭ double inversion recovery; DMT ϭ disease-modifying therapy; IRIS ϭ immune reconstitution inflammatory syndrome;

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A Validation Study of Multicenter Diffusion Tensor Imaging: Reliability of Fractional Anisotropy and Diffusivity Values

Cited by 129 publications

References 25 publications

White Matter Integrity in Highly Traumatized Adults With and Without Post-Traumatic Stress Disorder

White Matter Integrity in Highly Traumatized Adults With and Without Post-Traumatic Stress Disorder

Assessment of diffusion tensor image quality across sites and vendors using the American College of Radiology head phantom

Current and Emerging Therapies in Multiple Sclerosis: Implications for the Radiologist, Part 2—Surveillance for Treatment Complications and Disease Progression

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