A Comparison of Mean Displacement Values Using High b-Value Q-Space Diffusion-weighted MRI with Conventional Apparent Diffusion Coefficients in Patients with Stroke

Visualizing Non-Gaussian Diffusion: Clinical Application of q-Space Imaging and Diffusional Kurtosis Imaging of the Brain and Spine

“…The results may indicate that high b-value QSI might be a useful method for observing demyelination and axonal loss. Hori and colleagues 26 compared MDP values using q-space analysis with ADC using conventional Gaussian metrics in 22 acute or subacute ischemic lesions and found no correlation between ADC and MDP values; though ADC values decreased in all lesions, most lesions (16/22) had higher MDP values than normal brain tissue. A more detailed study is needed to evaluate these maps as potential biomarkers for patients with stroke, but the results suggest that MDP maps acquired from QSI data provide additional and unique information compared to those obtained from conventional diŠusion-weighted sequences (Fig.…”

“…The normal MDP in the white matter and grey matter is reported to be 3.3±0.8 and 7-9, 19 3.8±0.2 and 5-9, 24 6.6±0.2 and 8.44± 0.41, 22 9 and 11.9 mm. 25 This method is theoretically superior to conventional Gaussian diŠusion analysis, but few reports apply it to human studies 21,26 because QSI is timeconsuming for daily clinical use, generally taking a minimum of 10 min.…”

“…18,21 However, for q-space analysis, QSI-analyzer was introduced for calculating the FWHM of the PDF and the mean displacement of water molecules. 22,26,30,31 For diŠusional kurtosis analysis, diffusion kurtosis estimator (DKE) 29,32 and the combination of dTV¿FZR (http://www.ut-radiology. umin.jp/people/masutani/dTV.htm) and VOLUME-ONE software (http://www.volume-one.org/) have been introduced in the literature 33,34 (Fig.…”

Mean displacement map of spine and spinal cord disorders using high b-value q-space imaging-feasibility study

“…However, a low positive correlation between ADC and MDP values has been reported in some situations, for example, in ischemic lesions in the brain (28). Therefore, increased MDP values in the spinal cord would provide information in addition to the increased ADC in patients with cervical spondylosis.…”

“…All QSI data were transferred to an independent PC, and MDP maps were obtained for each MPG axis by using software (QSI-analyzer; 25,27,28) applying the theory of q-space analysis (24,25). All conventional DWI images were transferred to an independent workstation, and ADC maps were obtained.…”