Keywords: Diffusion Analysis & Visualization, Hematologic, multiple myeloma, whole-body diffusion-weighted imaging

Motivation: Is there any difference in the ttADC histogram parameters at different ISS stages in multiple myeloma patients with diffuse infiltration visually?

Goal(s): The goal was to explore the difference in ttADC histogram parameters and clinical indicators in multiple myeloma patients with diffuse infiltration at different ISS stages.

Approach: The ttADC histogram parameters were obtained by sketching the lesions of the whole body on WB-DWI images using MRTTL software.

Results: Age, hemoglobin, creatinine, and ttADC_5% were different at different ISS stages.

Impact: Diffuse infiltration is generally thought to be associated with a poorer prognosis for MM patients. Our study shows that although all patients have diffuse infiltration, different ttADC histogram parameters may result in different prognosis.

Keywords: DWI/DTI/DKI, Tumor, cervical cancer; radiotherapy;diffusion-weighted imaging;apparent diffusion coeffificient

Motivation: Radiotherapy (RT) is regarded as standard therapy for locally advanced cervical cancer. To date there are no accepted modalities that can reliably predict treatment response.

Goal(s): Present study aimed to explore the baseline and interim-ADC as well as change in ADC for predicting treatment outcomes. 

Approach: 80 patients underwent pelvis MRI at least three times: before treatment, juring the course of RT and after completion of RT. Following values were calculated: Pre-ADC , Interim-ADC, △ADC and △%ADC. Treatment outcome was assessed by RECIST. 

Results: Pre-treatment tumor size and interim-ADC could be potential biomarkers for predicting treatment outcomes in cervical cancer patients referred for RT. 

Impact: The results of present study can evaluate the early efficacy of RT, in order to allow for the timely adjustment of treatment plans, improve the efficacy and prognosis, and provide a reference for the clinical individualized treatment of cervical cancer.

Keywords: Microstructure, Cancer

Motivation: Preoperative evaluation of rectal lesions remains challenging, we need better methods to evaluate malignant and benign lesions, and to estimate prognostic factors for rectal cancer.

Goal(s): To explore the application value of cellular microstructural mapping by td-dMRI in evaluating the histological type and prognostic factors of rectal lesions.

Approach: Sixty-six patients with rectal lesions were enrolled in this study. MRI was performed on a 3T scanner (Ingenia Elition, Philips Healthcare, Best, the Netherlands). All subjects underwent conventional MRI, oscillating gradient spin-echo (OGSE) and pulse gradient spin-echo (PGSE).

Results: Our preliminary results illustrated that td-dMRI are useful in preoperative evaluation of rectal lesions.

Impact: Cellular microstructural mapping by time-dependent diffusion MRI has great potential in preoperative evaluation of rectal lesions. The results illustrated that it could be helpful in differentiating malignant and benign lesions, distinguishing AC from MC, and in predicting the TB status.

Keywords: DWI/DTI/DKI, Diffusion/other diffusion imaging techniques

Motivation: Revised International Staging System stage II multiple myeloma (R-ISS II MM) patients have considerable prognostic heterogeneity.

Goal(s): Use quantitative parameters of bone marrow segmentation on whole-body diffusion-weighted imaging (WB-DWI) for risk stratification among R-ISS II MM patients.

Approach: Univariate and multivariate analyses of clinical features and quantitative parameters of bone marrow segmentation extracted from MR Total Tumor Load software were used to identify predictors of progression-free survival and overall survival (OS).

Results: On multivariate analysis, mean apparent diffusion coefficient (odds ratio=1.003, p=0.029, 95% confidence interval [95%CI]: 1.000-1.003) and albumin (odds ratio=0.942, p=0.051, 95%CI: 0.888-1.000) were independent predictors of OS.

Impact: Quantitative parameters of bone marrow segmentation on WB-DWI can predict OS in R-ISS II MM patients, suggesting that these parameters can facilitate prognostic assessment of R-ISS II MM patients.

Keywords: DWI/DTI/DKI, Breast

Motivation: Breast MRI increasingly includes ultra-high b-value DWI, but technical and patient-related challenges can cause mismatches to morphologic sequences. Co-registration strategies are needed to reliably apply AI-algorithms to the data.

Goal(s): The study examines how different co-registration orders for ultra-high b-value acquisitions in multiparametric breast MRI impact co-localization to morphologic sequences, both quantitatively and qualitatively.

Approach: This IRB-approved retrospective study of 144 multiparametric breast MRI exams with ultra-high b-value DWI, assessed different co-registration algorithms using ANTs library methods quantitatively and qualitatively.

Results: The sequential arrangement of contrasts used during co-registration significantly affects cross-sequence congruence of lesions in multiparametric breast MRI incorporating ultra-high b-value DWI.

Impact: The study highlights the relevance of considering different sequential arrangements used during co-registration in ultra-high b-value DWI.

Keywords: Diffusion Modeling, High-Field MRI, Microstructure

Motivation: The potential of dMRI microstructure mapping at 7 Tesla is largely unexplored, due to ultra-high field challenges related to spatial distortions and uneven excitation.

Goal(s): Assessing 7T dMRI for white matter microstructure estimation at 7T and examining the impact of acquisition protocol on model estimates.

Approach: Standard Model parameter maps were derived  from two acquisition protocols (b_max=3 vs b_max=13 $$$ms/\mu m^2$$$), to further investigate the relationship between parameter estimates both at ROI and voxel level.

Results: We report high contrast-to-noise ratio microstructure maps. Our results highlight stronger region-wise and voxel-wise correlations between SM parameters in the higher b-value protocol.

Impact: The diffusion microstructure field can greatly benefit from clinically-approved high-field systems with strong gradients, with flexibility to balance SNR, spatial resolution, and q-t sampling.

Keywords: Diffusion Modeling, Breast

Motivation: This study focus on improving imaging time and image quality while accurately distinguishing between benign and malignant breast lesions.

Goal(s): To assess the diagnostic capabilities of the FROC diffusion model combined with SMS technology for breast lesions.

Approach: Compare two diffusion model, the traditional single-index DWI model and the FROC, and then evaluate their diagnostic performance, image quality, and the consistency of results using SMS technology.

Results: FROC combined with SMS offered a feasible and effective approach for distinguishing benign and malignant breast lesions, while the diagnostic performance of D and β values from FROC was potentially superior to the traditional ADC values.

Impact: The research introduces an innovative approach that combines the FROC-DWI model with SMS technology to enhance the efficiency and diagnostic capabilities of breast imaging, potentially improving patient outcomes and reducing unnecessary invasive procedures.

Keywords: Microstructure, Kidney

Motivation: OGSE-MRI provides more information on kidney cancer prognosis, metastasis possibility, specific survival rate in the future.

Goal(s): To explore whether parameters derived from OGSE can demonstrate microstructure in clear cell renal cell carcinoma

Approach: Patients suspected of ccRCC who underwent diffusion-weighted imaging were employed to quantify the time-dependent diffusion MRI-based microstructural parameters cell diameter (D), intracellular volume fraction (vin), cellularity, and diffusivities (Dex).

Results: ccRCC with high WHO/ISUP grade show higher cellularity and vin, while lower D and Dex parameters.

Impact: The OGSE MRI parameters correlates with pathologic grades and demonstrates promise for characterizing renal carcinoma.

Keywords: Microstructure, Brain

Motivation: Gliomas are a very heterogeneous primary brain tumor. Their heterogeneity lies not only at the microscopic (genetic / biochemical) level, but at the mesoscopic (cellular morphology) level and macroscopic (tissue pathology) level.

Goal(s): To better understand the underpinnings of the glioma heterogeneity.

Approach: We applied the Multimodal Apparent Diffusion (MAD) method and Fuzzy C Means to multi b‑value diffusion weighted magnetic resonance imaging, up to b‑value of 10K s/mm², on 54 glioma patients.

Results: We discerned 15 normal appearing tissue types and 19 lesion types, including 3 voracious solid tumor, 5 recruiting solid tumor, 3 edema, and 7 b₀ attenuated types.

Impact: Each stage in the glioma’s progression manifests in unique changes in MAD parameter signatures. The ability to to more precisely understand the heterogeneous microstructure involved can be used to improved diagnosis and prognosis of gliomas.

Keywords: Simulation/Validation, Diffusion/other diffusion imaging techniques, Bayesian Analysis

Motivation: Measurement of ADC in body DWI is typically assumed to be isotropic and therefore the use of single-direction diffusion encoding imaging is commonplace. Estimation of induced bias by this assumption is needed.

Goal(s): To determine whether Bayesian estimation of ADC measurement bias from DTI data suffers from any systematic errors and thus can be used reliably in clinical datasets.

Approach: We use simulation studies over a range of true fractional-anisotopy (FA), signal-to-noise ratio (SNR) and mean-diffusivity parameters, and investigate the accuracy of Bayesian estimation approaches.

Results: Bayesian estimation of ADC bias appears accurate over the range of tested parameters.

Impact: Accurate estimation of ADC bias from single-direction diffusion-encoding schemes is possible using Bayesian approaches in combination with data acquired using a multi-directional diffusion-encoding scheme. This enables pixel-wise estimation of bias and could negate the need for directly acquiring paired datasets.

Keywords: Microstructure, Diffusion/other diffusion imaging techniques

Motivation: Noninvasive measurement of liver cell sizes and densities is clinically important.

Goal(s): Assess the repeatability of liver cell size and density mapping using MRI cytometry, a diffusion MRI-based imaging technique.

Approach: In vivo MRI cytometry was repeated twice with intervals of 2-7 days for six healthy subjects.

Results: MRI-derived liver cell size and density exhibited high repeatability, with significant correlations (r² = 0.89 and 0.91 for cell size and cell density, respectively; [P< 0.0001]). 

Impact: Our findings indicate that a liver MRI cytometry protocol can be implemented on standard clinical 3T scanners with satisfactory repeatability in under 12 minutes, thus affirming the potential for broader clinical adoption in the future.

Keywords: Diffusion Reconstruction, Tractography & Fibre Modelling, rTMS,first-episode depression

Motivation: The neuropathological mechanisms of repetitive transcranial magnetic stimulation (rTMS) for the treatment of depression are unclear.

Goal(s): The aim of this study was to explore the effects of rTMS on the brain glymphatic system using Diffusion MR Technique in patients with first-episode depression before and after treatment.

Approach: Diffusion tensor image analysis along the perivascular space (DTI-ALPS) as a non-invasive method for evaluating the activity of the glymphatic system in human brain by using diffusion images.

Results: The left ALPS index of patients with first-episode depression is lower than that of healthy people, and it is increased after rTMS treatment.

Impact: This study demonstrated the DTI-ALPS method to assess lymphatic system activity in first-episode depression patients before and after rTMS treatment. The abnormality of ALPS index may provide a potential biomarker for explaining depression, and rTMS can cause changes in ALPS.

Keywords: DWI/DTI/DKI, Diffusion/other diffusion imaging techniques

Motivation: High-b-value diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) with b value = 3000 s/mm² are independent predictors of overall survival.

Goal(s): To explore the feasibility of synthetic high-b-value DWI and ADC values in diagnosis of glioma using actually scanned ones as standard reference. 

Approach: To assess scanned and synthetic multiple high-b-value MUSE DWI and ADC of 5 patients with low-grade glioma and 3 patients with high-grade glioma.

Results:  All synthetic high-b-value DWIs had superior image quality and diagnostic efficacy of glioma to all scanned DWIs. The scanned and synthetic ADC were significantly different between different b values.

Impact: Synthetic high-b-value MUSE DWI can provide better image quality and diagnostic efficiency of grading glioma without consuming extra scan time, encouraging us to promote the utility of setting up synthetic high-b-value MUSE DWI as routine.

Keywords: Microstructure, Diffusion/other diffusion imaging techniques, NODDI; intermittent exotropia; microstructural changes; TBSS; binocular function

Motivation: Intermittent exotropia (IXT) is quite common in children. The exact pathogenesis is not clear, which makes it difficult to make early diagnosis and evaluate progression.

Goal(s): To investigate the microstructural changes in vivo in children with IXT and explore the potential neuropathological mechanisms.

Approach: 31 IXT children and 37 controls were enrolled. Brain gray matter (GM) and the white matter (WM) regions extracted from their whole-brain MRI data were compared using the NODDI technology and TBSS method.

Results: Microstructural changes in GM and WM between the two groups were found, located in the visual perception and oculomotor control associated areas.

Impact: The parameters derived from NODDI can demonstrate the microstructural abnormalities in primary, advanced visual center and oculomotor center pathway, which maybe a potential tool in diagnosis and evaluation the IXT patients.

Keywords: Diffusion Analysis & Visualization, Diffusion/other diffusion imaging techniques

Motivation: Diffusion-relaxation correlation spectroscopic imaging (DR-CSI) may be a useful tool for advancing our understanding of X-linked adrenoleukodystrophy (ALD) and its impact on white matter.

Goal(s): To measure the changes in white matter composition and microenvironment in ALD patients using DR-CSI.

Approach: Recruited four groups of participants. DR-CSI was utilized with a multi-parametric approach, considering both diffusion and relaxation properties to provide a comprehensive view of the tissue microenvironment. Data analysis was performed to quantify changes in white matter composition.

Results: In the context of ALD, DR-CSI can effectively differentiate between the diverse tissue compartments by examining diffusion and relaxation characteristics.

Impact: This is of significant relevance for the diagnosis and treatment strategies of this rare disease. Moreover, the study results offer information regarding differences among ALD phenotypes, which holds potential value for individualized treatment and management development.