Correlation between Intravoxel Incoherent Motion Magnetic Resonance Imaging Derived Metrics and Serum Soluble CD40 Ligand Level in an Embolic Canine Stroke Model

Characterization of parotid gland tumors: Whole-tumor histogram analysis of diffusion weighted imaging, diffusion kurtosis imaging, and intravoxel incoherent motion - A pilot study

PURPOSE

To investigate the diagnostic performance of histogram features of diffusion parameters in characterizating parotid gland tumors.

METHOD

From December 2018 to January 2023, patients who underwent diffusion weighted imaging (DWI), diffusion kurtosis imaging (DKI), and intravoxel incoherent motion (IVIM) were consecutively enrolled in this retrospective study. The histogram features of diffusion parameters, including apparent diffusion coefficient (ADC), diffusion coefficient (Dk), diffusion kurtosis (K), pure diffusion coefficient (D), pseudo-diffusion coefficient (DP), and perfusion fraction (FP) were analyzed. The Mann-Whitney U test was used for comparison between benign parotid gland tumors (BPGTs) and malignant parotid gland tumors (MPGTs). Receiver operating characteristic curve and logistic regression analysis were used to identify the differential diagnostic performance. The Spearman's correlation coefficient was used to analyze the correlation between diffusion parameters and Ki-67 labeling index.

RESULTS

For diffusion MRI, twenty-three histogram features of diffusion parameters showed significant differences between BPGTs and MPGTs (all P < 0.05). Compared with the DWI model, the IVIM model and combined model had better diagnostic specificity (58 %, 94 %, and 88 %, respectively; both corrected P < 0.001) and accuracy (64 %, 89 %, and 86 %, respectively; both corrected P = 0.006). The combined model was superior to the single DWI model with improved IDI (IDI improvement 0.25). Significant correlations were found between Ki-67 and ADCmean, Dkmean, Kmean, and Dmean (r = -0.57 to 0.53; all P < 0.05).

CONCLUSIONS

Whole-tumor histogram analysis of IVIM and combined diffusion model could further improve the diagnostic performance for differentiating BPGTs from MPGTs.

Crossed cerebellar diaschisis after acute ischemic stroke detected by intravoxel incoherent motion magnetic resonance imaging

PURPOSE

To study the value of 3.0 T magnetic resonance imaging with intravoxel incoherent motion (IVIM) in the diagnosis of the crossed cerebellar diaschisis (CCD) after the unilateral supratentorial acute ischemic stroke.

METHODS

Seventy-four patients with acute ischemic stroke who underwent intravoxel incoherent motion (IVIM), arterial spin labeling (ASL), and conventional magnetic resonance imaging (MRI) scanning were enrolled. Intravoxel incoherent motion-derived perfusion-related parameters including fast diffusion coefficient (D*), slow diffusion coefficient (D), vascular volume fraction (f), and arterial spin-labeling-derived cerebral blood flow (CBF) of bilateral cerebellum were measured.

RESULTS

In the CCD-positive group, D*, D, and CBF values of the contralateral cerebellum decreased compared with those of the ipsilesional cerebellum (P < 0.05), whereas f significantly increased (P < 0.05). A positive correlation was detected between the slow diffusion coefficient-based asymmetry index (AI-D) and the cerebral blood flow-based asymmetry index (AI-CBF) (r = 0.515, P < 0.01), whereas the vascular volume fraction-based asymmetry index (AI-f) had a negative correlation with the cerebral blood flow-based asymmetry index (AI-CBF) (r =  - 0.485, P < 0.01). Furthermore, the area under the receiver operating characteristic (ROC) curve value of AI-D and AI-f was 0.81 and 0.76, respectively.

CONCLUSIONS

The IVIM is feasible for the detection of CCD. This technique might provide opportunities to further investigate the pathophysiology of CCD.