Intravoxel incoherent motion diffusion-weighted MR imaging parameters predict pathological classification in thymic epithelial tumors.
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ABSTRACT:
SUBMITTER: Li GF
PROVIDER: S-EPMC5546503 | biostudies-other | 2017 Jul
REPOSITORIES: biostudies-other
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Project description:The preoperative grading of gliomas, which is critical for guiding therapeutic strategies, remains unsatisfactory. We aimed to retrospectively assess the efficacy of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in the grading of gliomas. Forty-two newly diagnosed glioma patients underwent conventional MR imaging, DWI, and contrast-enhanced MR imaging. Parameters of apparent diffusion coefficient (ADC), slow diffusion coefficient (D), fast diffusion coefficient (D*), and fraction of fast ADC (f) were generated. They were tested for differences between low- and high-grade gliomas based on one-way ANOVA. Receiver-operating characteristic (ROC) analyses were conducted to determine the optimal thresholds as well as the sensitivity and specificity for grading. ADC, D, and f were higher in the low-grade gliomas, whereas D* tended to be lower (all P<0.05). The AUC, sensitivity, specificity and the cutoff value, respectively, for differentiating low- from high-grade gliomas for ADC, D and f, and differentiating high- from low-grade gliomas for D* were as follows: ADC, 0.926, 100%, 82.8%, and 0.7 × 10(-3) mm(2)/sec; D, 0.942, 92.3%, 86.2%, and 0.623 × 10(-3) mm(2)/sec; f, 0.902, 92.3%, 86.2%, and 35.3%; D*, 0.798, 79.3%, 84.6%, and 0.303 × 10(-3) mm(2)/sec. The IVIM DWI demonstrates efficacy in differentiating the low- from high-grade gliomas.
| S-EPMC4248278 | biostudies-other
Project description:BackgroundUsing magnetic resonance imaging (MRI) to explore the changes in microvascular perfusion fraction and the heterogeneity of the placenta during pregnancy.MethodsWe retrospectively reviewed 24 patients with normal pregnancies who underwent standard diffusion-weighted, diffusion kurtosis, and intravoxel incoherent motion MRI. The mean, minimum and maximum parameters including the apparent diffusion coefficient (ADC) and exponential ADC (eADC) from standard diffusion-weighted imaging (DWI), the diffusion coefficient (MD) and diffusion kurtosis (MK) from diffusion kurtosis imaging (DKI), and the pure diffusion coefficient (D), pseudo-diffusion coefficient (D*) and perfusion fraction (f) from intravoxel incoherent motion MR imaging (IVIM) were calculated from the whole placenta volumetric analysis and correlated with gestational age (GA) and volume of the placenta.ResultsA significant positive correlation was found between eADC mean, eADC max, MK mean, MK max, the volume of the whole placenta, and GA, and a negative correlation was found between ADC mean, ADC min, MD min, D mean, D min, D* min and GA. The f mean and MK max values positively correlated with the volume of the whole placenta.ConclusionseADC mean, eADC max, MK mean, MK max values increased with GA, while ADC mean, ADC min, MD min, D mean, D min, D* min decreased with GA. Secondly, the f mean and MK max also increased with placental volume. These results suggest the potential of diffusion and perfusion parameters to evaluate the placenta during its development using different DWI models.
| S-EPMC9011236 | biostudies-literature
Project description:The present study aimed to explore the value of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) in differentiating hepatocellular carcinoma (HCC) from intrahepatic cholangiocarcinoma (ICC). This study included 65 patients with malignant hepatic nodules (55 with HCC, 10 with ICC), and 17 control patients with normal livers. All patients underwent IVIM-DWI scans on a 3.0?T magnetic resonance imaging (MRI) scanner. The standard apparent diffusion coefficient (ADC), pure diffusion coefficient (Dslow), pseudo-diffusion coefficient (Dfast), and perfusion fraction (f) were obtained. Differences in the parameters among the groups were analysed using one-way ANOVA, with p?<?0.05 indicating statistical significance. Receiver operating characteristic (ROC) curve analysis was used to compare the efficacy of each parameter in differentiating HCC from ICC. ADC, Dslow, Dfast, f significantly differed among the three groups. ADC and Dslow were significantly lower in the HCC group than in the ICC group, while Dfast was significantly higher in the HCC group than in the ICC group; f did not significantly differ between the HCC and ICC groups. When the cut-off values of ADC, Dslow, and Dfast were 1.27 × 10-3 mm2/s, 0.81 × 10-3 mm2/s, and 26.04 × 10-3 mm2/s, respectively, their diagnostic sensitivities for differentiating HCC from ICC were 98.18%, 58.18%, and 94.55%, their diagnostic specificities were 50.00%, 80.00%, and 80.00%, and their areas under the ROC curve (AUCs) were 0.687, 0.721, and 0.896, respectively. Dfast displayed the largest AUC value. IVIM-DWI can be used to differentiate HCC from ICC.
| S-EPMC7206040 | biostudies-literature
Project description:BackgroundMyocardial microcirculation dysfunction is the most potent predictor of adverse cardiovascular events in hypertension. The current study aimed to apply intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) to assess hypertension-related microcirculation dysfunction.MethodsIn this prospective study, 102 participants were recruited from our hospital and underwent cardiac magnetic resonance (CMR) examination on a 3T scanning system. Hypertensive patients were divided into 3 subgroups based on blood pressure (BP) types. Two experienced CMR radiologists independently analyzed all images, and Bland-Altman analysis was applied to assess intra- and inter-observer reproducibility. Cardiac function indexes and IVIM-DWI parameters were compared between the hypertension and healthy control groups, as well as among the three hypertension subgroups.ResultsTotally 62 participants with hypertension and 27 healthy controls were included. 13 participants were excluded for poor quality of IVIM-DWI images. Significantly higher maximal left ventricular wall thickness (10.3±2.0 vs. 8.6±1.4 mm, P<0.001) and left ventricular mass index (49.0±9.1 vs. 42.1±7.5 g/m2, P<0.05) were observed inhypertension group compared with healthy control group. There were significant statistical differences in pseudo diffusion (D*) between them (81.3±16.3 vs. 111.8±18.9 mm2/s, P<0.001), as well as among the three hypertension subgroups (99.4±13.9 vs. 79.7±10.6 vs. 67.1±6.6 mm2/s, P<0.001). Participants with poor quality of IVIM-DWI images had higher heart rates (72.2±10.0 vs. 62.0±8.1 bpm, P<0.001).ConclusionsIVIM-DWI is feasible for quantitatively evaluating myocardial microcirculation dysfunction in hypertension. The D* parameter has a potential value for assessing the severity of microcirculation dysfunction in different BP categories.
| S-EPMC11320536 | biostudies-literature
Project description:BACKGROUND:Pediatric retroperitoneal tumors in the renal bed are often large and heterogeneous, and their diagnosis based on conventional imaging alone is not possible. More advanced imaging methods, such as diffusion-weighted (DW) MRI and the use of intravoxel incoherent motion (IVIM), have the potential to provide additional biomarkers that could facilitate their noninvasive diagnosis. PURPOSE:To assess the use of an IVIM model for diagnosis of childhood malignant abdominal tumors and discrimination of benign from malignant lesions. STUDY TYPE:Retrospective. POPULATION:Forty-two pediatric patients with abdominal lesions (n?=?32 malignant, n?=?10 benign), verified by histopathology. FIELD STRENGTH/SEQUENCE:1.5T MRI system and a DW-MRI sequence with six b-values (0, 50, 100, 150, 600, 1000 s/mm2 ). ASSESSMENT:Parameter maps of apparent diffusion coefficient (ADC), and IVIM maps of slow diffusion coefficient (D), fast diffusion coefficient (D*), and perfusion fraction (f) were computed using a segmented fitting model. Histograms were constructed for whole-tumor regions of each parameter. STATISTICAL TESTS:Comparison of histogram parameters of and their diagnostic performance was determined using Kruskal-Wallis, Mann-Whitney U, and receiver-operating characteristic (ROC) analysis. RESULTS:IVIM parameters D* and f were significantly higher in neuroblastoma compared to Wilms' tumors (P < 0.05). The ROC analysis showed that the best diagnostic performance was achieved with D* 90th percentile (area under the curve [AUC]?=?0.935; P?=?0.002; cutoff value?=?32,376 × 10-6 mm2 /s) and f mean values (AUC?=?1.00; P < 0.001; cutoff value?=?14.7) in discriminating between neuroblastoma (n?=?11) and Wilms' tumors (n?=?8). Discrimination between tumor types was not possible with IVIM D or ADC parameters. Malignant tumors revealed significantly lower ADC, D, and higher D* values than in benign lesions (all P < 0.05). DATA CONCLUSION:IVIM perfusion parameters could distinguish between malignant childhood tumor types, providing potential imaging biomarkers for their diagnosis. LEVEL OF EVIDENCE:4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1475-1486.
| S-EPMC6001424 | biostudies-literature
Project description:To investigate the usefulness of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) in discriminating the pathological complete response (pCR) to neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC), 42 patients underwent preoperative IVIM-DWI before (pre-nCRT) and after nCRT (post-nCRT). The values of pre-nCRT and post-nCRT IVIM-DWI parameters (ADC, D, D* and f), together with the percentage changes (∆% parametric value) induced by nCRT, were compared between the pCR (tumour regression grade [TRG] 4) and non-pCR (TRG 0, 1, 2 or 3) groups and between the GR (TRG 3 or 4) and PR (TRG 0, 1 or 2) groups based on the Dworak TRG system. After nCRT, the ADC and D values for LARC increased significantly (all P < 0.05). The TRG score revealed a positive correlation with pref (r = 0.357, P = 0.020), postD (r = 0.551, P < 0.001) and Δ%D (r = 0.605, P < 0.001). The pCR group (n = 10) had higher preD*, pref, postD, ∆%ADC and ∆%D values than the non-pCR group (n = 32) (all P < 0.05). The GR group (n = 15) exhibited higher postD, ∆%ADC and ∆%D values than the PR group (n = 27) (all P < 0.05). Based on ROC analysis, ∆%D had a higher area under the curve value than ∆%ADC (P = 0.009) in discriminating the pCR from non-pCR groups. In conclusion, IVIM-DWI may be helpful in identifying the pCR to nCRT for LARC and is more accurate than traditional DWI.
| S-EPMC5561073 | biostudies-other
Project description:BackgroundThe spleen is a frequent organ of leukemia metastasis. This study aimed to investigate the value of intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging (MRI) for assessing pathologic changes in the spleen and identifying early spleen involvement in patients with acute leukemia (AL).MethodsPatients with newly diagnosed AL and healthy controls were recruited between June 2020 and November 2022. All participants underwent abdominal IVIM diffusion-weighted imaging (DWI) at our hospital. IVIM parameters [pure diffusion coefficient (D); pseudo-diffusion coefficient (D*); and pseudo-perfusion fraction (f)] of the spleen were calculated by the segmented fitting method, and perfusion-diffusion ratio (PDR) was further calculated from the values of D, D* and f. Spleen volumes (SVs) were obtained by manually segmenting the spleen layer by layer. Clinical biomarkers of AL patients were collected. Patients were divided into splenomegaly group and normal SV group according to the individualized reference intervals for SV. IVIM parameters were compared among the control group, AL with normal SV group, and AL with splenomegaly group using one-way analysis of variance, followed by pairwise post hoc comparisons. The correlations of IVIM parameters with clinical biomarkers were analyzed in AL patients. The diagnostic performances of IVIM parameters and their combinations for differentiating among the three groups were compared.ResultsSeventy-nine AL patients (AL with splenomegaly: n=54; AL with normal SV: n=25) and 55 healthy controls were evaluated. IVIM parameters were significantly different among the three groups (P<0.001 for D, D* and f; P=0.001 for PDR). D and PDR showed significant differences between the control and AL with normal SV groups in pairwise comparisons (P<0.001, and P=0.031, respectively). D was correlated with white blood cell (WBC) counts (r=-0.424; 95% CI: -0.570, -0.211; P<0.001), lactate dehydrogenase (LDH) (r=-0.285; 95% CI: -0.486, -0.011; P=0.011), and bone marrow blasts (r=-0.283; 95% CI: -0.476, -0.067; P=0.012). D* (r=-0.276; 95% CI: -0.470, -0.025; P=0.014), f (r=0.514; 95% CI: 0.342, 0.664; P<0.001) and PDR (r=0.343; 95% CI: 0.208, 0.549; P=0.002) were correlated with LDH. The combination of IVIM parameters (AUC: 0.830; 95% CI: 0.729, 0.905) demonstrated better diagnostic efficacy than the single D* (AUC: 0.721; 95% CI: 0.608, 0.816; Delong test: Z=2.012, P=0.044) and f (AUC: 0.647; 95% CI: 0.532, 0.752; Delong test: Z=2.829, P=0.005), but was not significantly different from the single D (AUC: 0.756; 95% CI: 0.647, 0.846; Delong test: Z=1.676, P=0.094) in differentiating the splenomegaly group and normal SV group.ConclusionsIVIM diffusion-weighted MRI could be a potential alternative for assessing pathologic changes in the spleen from cellularity and angiogenesis, and D and PDR may be viable indicators to identify early spleen involvement in patients with AL.
| S-EPMC10784019 | biostudies-literature
Project description:ObjectivesTo determine the potential of intravoxel incoherent motion (IVIM) MR imaging for staging of hepatic fibrosis (HF).MethodsWe searched PubMed and EMBASE from their inception to 31 July 2015 to select studies reporting IVIM MR imaging and HF staging. We defined F1-2 as non-advanced HF, F3-4 as advanced HF, F0 as normal liver, F1 as very early HF, and F2-4 as significant HF. Then we compared stage F0 with F1, F0-1 with F2-3, and F1-2 with F3-4 using IVIM-derived parameters (pseudo-diffusion coefficient D*, perfusion fraction f, and pure molecular diffusion parameter D). The effect estimate was expressed as a pooled weighted mean difference (WMD) with 95% confidence interval (CI), using the fixed-effects model.ResultsOverall, we included six papers (406 patients) in this study. Significant differences in D* were observed between F0 and F1, F0-1 and F2-3, and F1-2 and F3-4 (WMD 2.46, 95% CI 0.83-4.09, P = 0.006; WMD 13.10, 95% CI 9.53-16.67, P < 0.001; WMD 14.34, 95% CI 10.26-18.42, P < 0.001, respectively). Significant differences in f were also found between F0 and F1, F0-1 and F2-3, and F1-2 and F3-4 (WMD 1.62, 95% CI 0.06-3.18, P = 0.027; WMD 5.63, 95% CI 2.74-8.52, P < 0.001; WMD 3.30, 95% CI 2.10-4.50, P < 0.001, respectively). However, D showed no differences between F0 and F1, F0-1 and F2-3, and F1-2 and F3-4 (WMD 0.05, 95% CI -0.01─0.11, P = 0.105; WMD 0.04, 95% CI -0.01─0.10, P = 0.230; WMD 0.02, 95% CI -0.02─0.06, P = 0.378, respectively).ConclusionsIVIM MR imaging provides an effective method of staging HF and can distinguish early HF from normal liver, significant HF from normal liver or very early HF, and advanced HF from non-advanced HF.
| S-EPMC4731200 | biostudies-literature
Project description:Background Currently, there are disputes about the parameters of diffusion kurtosis imaging (DKI), intravoxel incoherent motion (IVIM), and diffusion-weighted imaging (DWI) in predicting pathological grades and microvascular invasion (MVI) in hepatocellular carcinoma (HCC). The aim of our study was to investigate and compare the predictive power of DKI and IVIM-DWI parameters for preoperative evaluation of pathological grades and MVI in HCC. Methods PubMed, Web of Science, and Embase databases were searched for relevant studies published from inception to October 2021. Review Manager 5.3 was used to summarize standardized mean differences (SMDs) of mean kurtosis (MK), mean diffusivity (MD), tissue diffusivity (D), pseudo diffusivity (D*), perfusion fraction (f), mean apparent diffusion coefficient (ADCmean), and minimum apparent diffusion coefficient (ADCmin). Stata12.0 was used to pool the sensitivity, specificity, and area under the curve (AUC). Overall, 42 up-to-standard studies with 3,807 cases of HCC were included in the meta-analysis. Results The SMDs of ADCmean, ADCmin, and D values, but not those of D* and f values, significantly differed between well, moderately, and poorly differentiated HCC (P < 0.01). The sensitivity, specificity, and AUC of the MK, D, ADCmean, and ADCmin for preoperative prediction of poorly differentiated HCC were 69%/94%/0.89, 87%/80%/0.89, 82%/75%/0.86, and 83%/64%/0.81, respectively. In addition, the sensitivity, specificity, and AUC of the D and ADCmean for preoperative prediction of well-differentiated HCC were 87%/83%/0.92 and 82%/88%/0.90, respectively. The SMDs of ADCmean, ADCmin, D, MD, and MK values, but not f values, showed significant differences (P < 0.01) between MVI-positive (MVI+) and MVI-negative (MVI-) HCC. The sensitivity and specificity of D and ADCmean for preoperative prediction of MVI+ were 80%/80% and 74%/71%, respectively; the AUC of the D (0.87) was significantly higher than that of ADCmean (0.78) (Z = −2.208, P = 0.027). Sensitivity analysis showed that the results of the above parameters were stable and reliable, and subgroup analysis confirmed a good prediction effect. Conclusion DKI parameters (MD and MK) and IVIM-DWI parameters (D value, ADCmean, and ADCmin) can be used as a noninvasive and simple preoperative examination method to predict the grade and MVI in HCC. Compared with ADCmean and ADCmin, MD and D values have higher diagnostic efficacy in predicting the grades of HCC, and D value has superior diagnostic efficacy to ADCmean in predicting MVI+ in HCC. However, f value cannot predict the grade or MVI in HCC.
| S-EPMC9131658 | biostudies-literature
Project description:OBJECTIVES:Diffusion-weighted imaging (DWI) and the introduction of the intravoxel incoherent motion (IVIM) model have provided a unique method for evaluating perfusion and diffusion within a tissue without the need for a contrast agent. Despite its relevance, cardiac DWI has thus far been limited by low b values because of signal loss induced by physiological motion. The goal of this study was to develop a methodology for estimating IVIM parameters of in vivo cardiac magnetic resonance imaging using an efficient DWI acquisition framework. This was achieved by investigating various acquisition strategies (principal component analysis [PCA] filtering and temporal maximum intensity projection [PCATMIP] and single trigger delay [TD]) and fitting methods. MATERIAL AND METHODS:Simulations were performed on a synthetic dataset of diffusion-weighted signal intensity (SI) to determine the fitting method that would yield IVIM parameters with the greatest accuracy. The required number of b values to correctly estimate IVIM parameters was also investigated. Breath-hold DWI scans were performed for 12 volunteers to collect several TD values during diastole. Thirteen b values ranging from 0 to 550 s/mm were used. The IVIM parameters derived using the data from all the acquired TDs (PCATMIP technique) were compared with those derived using a single acquisition performed at an optimized diastolic time point (1TD). RESULTS:The main result of this study was that PCATMIP, when combined with a fitting model that accounted for T1 and T2 relaxation, provided IVIM parameters with less variability. However, an acquisition performed with 1 optimized diastolic TD provided results that were as good as those provided using PCATMIP if the R-R variability during the acquisition was sufficiently low (± 5%). Furthermore, the use of only 9 b values (that could be acquired in 2 breath-holds), instead of 13 b values (requiring 3 breath-holds), was sufficient to determine the IVIM parameters. CONCLUSIONS:This study demonstrates that IVIM is technically feasible in vivo and reports for the first time the perfusion fraction, f, and the diffusion coefficients, D and D*, for the cardiac DWI of healthy volunteers. Motion-induced signal loss, which is the main problem associated with cardiac DWI, could be avoided with the combined use of sliding acquisition during the cardiac cycle and image postprocessing with the PCATMIP algorithm. This study provides new perspectives for perfusion imaging without a contrast agent and demonstrates that IVIM parameters can act as promising tools to further characterize microvascular abnormalities or dysfunction.
| S-EPMC7453742 | biostudies-literature