Apparent Diffusion Coefficient Values Of Lesions Research Articles

Clinical feasibility of deep learning reconstruction in liver diffusion-weighted imaging: Improvement of image quality and impact on apparent diffusion coefficient value

PurposeDiffusion-weighted imaging (DWI) of the liver suffers from low resolution, noise, and artifacts. This study aimed to investigate the effect of deep learning reconstruction (DLR) on image quality and apparent diffusion coefficient (ADC) quantification of liver DWI at 3 Tesla. MethodIn this prospective study, images of the liver obtained at DWI with b-values of 0 (DWI0), 50 (DWI50) and 800 s/mm2 (DWI800) from consecutive patients with liver lesions from February 2022 to February 2023 were reconstructed with and without DLR (non-DLR). Image quality was assessed qualitatively using Likert scoring system and quantitatively using signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and liver/parenchyma boundary sharpness from region-of-interest (ROI) analysis. ADC value of lesion were measured. Phantom experiment was also performed to investigate the factors that determine the effect of DLR on ADC value. Qualitative score, SNR, CNR, boundary sharpness, and apparent diffusion coefficients (ADCs) for DWI were compared using paired t-test and Wilcoxon signed rank test. P < 0.05 was considered statistically significant. ResultsA total of 85 patients with 170 lesions were included. DLR group showed a higher qualitative score than the non-DLR group. for example, with DWI800 the score was 4.77 ± 0.52 versus 4.30 ± 0.63 (P < 0.001). DLR group also showed higher SNRs, CNRs and boundary sharpness than the non-DLR group. DLR reduced the ADC of malignant tumors (1.105[0.904, 1.340] versus 1.114[0.904, 1.320]) (P < 0.001), but there was no significant difference in the diagnostic value of malignancy for DLR and non-DLR groups (P = 57.3). The phantom study confirmed a reduction of ADC in images with low resolution, and a stronger reduction of ADC in heterogeneous structures than in homogeneous ones (P < 0.001). ConclusionsDLR improved image quality of liver DWI. DLR reduced the ADC value of lesions, but did not affect the diagnostic performance of ADC in distinguishing malignant tumors on a 3.0-T MRI system.

The value of multimodal functional magnetic resonance imaging in differentiating p53abn from p53wt endometrial carcinoma.

Endometrial carcinoma (EC) is the sixth most common cancer in women. P53 gene expression in patients with endometrial cancer can predict the efficacy and prognosis of patients with neoadjuvant therapy. To explore the value of multimodal magnetic resonance imaging (MRI) in differentiating p53 abnormal (p53abn) from p53 wild-type (p53wt) EC. Data from 47 EC patients, including 14 p53abn cases and 33 p53wt cases, were retrospectively analyzed. The preoperative MRI sequences included amide proton transfer weighted (APTw) imaging, T2 mapping, mDIXON-Quant imaging and diffusion-weighted imaging (DWI). After post-processing, APT, T2, transverse relaxation rate (R2*), fat fraction (FF) and apparent diffusion coefficient (ADC) maps were obtained. The APT, T2, R2*, FF and ADC values for lesions of the two groups of cases were measured by two observers who were blind to the pathological data. The APT value and R2* value in the p53abn group were higher than those in the p53wt group, while the ADC value was lower (all P < 0.05). There was no statistically significant difference in T2 value and FF value between the two groups (all P > 0.05). The area under curve of APT, R2*, ADC and combined APT + R2*+ADC values for identification of p53abn and p53wt EC were 0.739, 0.689, 0.718 and 0.820, respectively (all P > 0.05). APTw, mDIXON-Quant and DWI techniques can be usedfor quantitative identification of p53abn and p53wt EC. The multimodal MRI provides a new way for preoperative quantitative evaluation of EC molecular typing, which has certain clinical application value.

Longitudinal monitoring of Apparent Diffusion Coefficient (ADC) in patients with prostate cancer undergoing MR-guided radiotherapy on an MR-Linac at 1.5 T: a prospective feasibility study.

Hybrid MRI linear accelerators (MR-Linac) might enable individualized online adaptation of radiotherapy using quantitative MRI sequences as diffusion-weighted imaging (DWI). The purpose of this study was to investigate the dynamics of lesion apparent diffusion coefficient (ADC) in patients with prostate cancer undergoing MR-guided radiation therapy (MRgRT) on a 1.5T MR-Linac. The ADC values at a diagnostic 3T MRI scanner were used as the reference standard. In this prospective single-center study, patients with biopsy-confirmed prostate cancer who underwent both an MRI exam at a 3T scanner (MRI3T) and an exam at a 1.5T MR-Linac (MRL) at baseline and during radiotherapy were included. Lesion ADC values were measured by a radiologist and a radiation oncologist on the slice with the largest lesion. ADC values were compared before vs. during radiotherapy (during the second week) on both systems via paired t-tests. Furthermore, Pearson correlation coefficient and inter-reader agreement were computed. A total of nine male patients aged 67 ± 6 years [range 60 - 67 years] were included. In seven patients, the cancerous lesion was in the peripheral zone, and in two patients the lesion was in the transition zone. Inter-reader reliability regarding lesion ADC measurement was excellent with an intraclass correlation coefficient of (ICC) > 0.90 both at baseline and during radiotherapy. Thus, the results of the first reader will be reported. In both systems, there was a statistically significant elevation of lesion ADC during radiotherapy (mean MRL-ADC at baseline was 0.97 ± 0.18 × 10-3 mm2/s vs. mean MRL-ADC during radiotherapy 1.38 ± 0.3 × 10-3 mm2/s, yielding a mean lesion ADC elevation of 0.41 ± 0.20 × 10-3 mm2/s, p < 0.001). Mean MRI3T-ADC at baseline was 0.78 ± 0.165 × 10-3 mm2/s vs. mean MRI3T-ADC during radiotherapy 0.99 ± 0.175 × 10-3 mm2/s, yielding a mean lesion ADC elevation of 0.21 ± 0.96 × 10-3 mm2/s p < 0.001). The absolute ADC values from MRL were consistently significantly higher than those from MRI3T at baseline and during radiotherapy (p < = 0.001). However, there was a strong positive correlation between MRL-ADC and MRI3T-ADC at baseline (r = 0.798, p = 0.01) and during radiotherapy (r = 0.863, p = 0.003). Lesion ADC as measured on MRL increased significantly during radiotherapy and ADC measurements of lesions on both systems showed similar dynamics. This indicates that lesion ADC as measured on the MRL may be used as a biomarker for evaluation of treatment response. In contrast, absolute ADC values as calculated by the algorithm of the manufacturer of the MRL showed systematic deviations from values obtained on a diagnostic 3T MRI system. These preliminary findings are promising but need large-scale validation. Once validated, lesion ADC on MRL might be used for real-time assessment of tumor response in patients with prostate cancer undergoing MR-guided radiation therapy.

Value of diffusion‐weighted imaging in diagnosis and therapy response assessment of hepatic fungal infection in patients with acute leukemia

To investigate the role of diffusion-weighted imaging (DWI) for diagnosis and posttreatment assessment of hepatic fungal infection in patients with acute leukemia. Patients with acute leukemia and highly suspected hepatic fungal infection were collected in the study. All the patients underwent MRI examination, including initial and follow-up DWI. The apparent diffusion coefficient (ADC) values of the lesions and the normal liver parenchyma were compared using Student's t-test. The ADC values of the hepatic fungal lesions of pretreatment and posttreatment were compared using paired t-test. A total of 13 patients with hepatic fungal infections have enrolled this study. Hepatic lesions were rounded or oval shaped, measured from 0.3 to 3 cm in diameter. The lesions showed significantly hyperintense signal on DWI and markedly hypointense signal on the ADC map, reflecting a marked restricted diffusion. The mean ADC values of the lesions were significantly lower than those of normal liver parenchyma (1.08 ± 0.34 × 10-3 vs. 1.98 ± 0.12 × 10-3 mm2 /s, p < 0.001). After treatment, the mean ADC values of the lesions were significantly increased when comparing with those of pretreatment (1.39 ± 0.29 × 10-3 vs. 1.06 ± 0.10 × 10-3 mm2 /s, p = .016). DWI can provide diffusion information of hepatic fungal infection in patients with acute leukemia, which could be taken as a valuable tool for diagnosis and therapy response assessment of these patients.

Utility of apparent diffusion coefficient (ADC) values in differentiating benign and malignant skull lesions with histopathological (HPE) correlation

AimAssess role of ADC in differentiating benign and malignant skull lesions and to evaluate the added value of ADC over conventional MRI in facilitating the differentiation. Materials and methods53 patients (24 males, 29 females; age 3–75 years) were subjected to both conventional and Diffusion weighted (DWI) MR imaging. DWI was performed using a single-shot SE EPI sequence with b-values of 0& 1000 s/mm2 on 1.5 T MR scanner. Margins of the lesion, number, soft-tissue component, local extension, periosteal reaction and enhancement pattern were the parameters used for differentiating benign & malignant lesions by conventional MRI. ADC values (mean of 3 ROIs over solid component) were calculated. Conventional MRI characteristics and ADC value of lesions were evaluated & compared using statistical analysis. These findings were compared and correlated with histopathology of the skull lesions. Results24 malignant and 29 benign lesions were identified on HPE (Histopathological examination) in 53 patients. ADC cut-off value of 0.96 × 10−3 mm2/s obtained from ROC curve was found to have 75.47% accuracy, 87.5% sensitivity, 65.52% specificity, 67.74% PPV and 86.36% NPV for differentiating malignant from benign lesions. Statistically significant differences (p < 0.05) were seen in the mean ADC values of malignant (0.64 ± 0.42 × 10−3 mm2/s) and benign lesions (1.14 ± 0.56 × 10−3 mm2/s). The sensitivity, specificity, PPV and NPV in differentiating benign & malignant skull lesions were found to be 58.33%, 62.07%, 56% and 64.29% respectively, with diagnostic accuracy of 60.38% on using conventional MRI alone and 75%, 72.41%, 69.23% and 77.78% respectively, with diagnostic accuracy of 73.58% on using conventional MRI with ADC. ConclusionADC is a promising non-invasive parameter that facilitates differentiation between benign and malignant skull lesions. It is a robust biomarker to narrow differentials when conventional imaging features are indeterminate.

Contribution of diffusion weighted MRI to the differential diagnosis of renal masses

ntroduction and aim. We aimed to assess the usefulness of diffusion weighted imaging (DWI) and apparent diffusion coefficients (ADCs) for characterizing renal masses. Material and method. In this retrospective study we measured the ADC values of renal masses at b=0, b=500 and b=1000. Measurements were made by placing a circular region of interest with a diameter of 1 cm.ADC values from normal renal parenchyma were taken to define the ADC and to compare with the ADC values of the lesions. Results. A total of 72 lesions of 54 patients were included.40 of the masses were benign and 32 were malignant. The ADC values of benign lesions at both b values were significantly higher than malignant lesions. We found the lowest values in angiomyolipomas (AMLs) and oncocytomas and the highest values in Bosniac type I cysts. Similarities was found between the ADC values of some AMLs and the RCCs. In terms of statistical results, the inclusion of AMLs in the analysis did not significantly affect the difference between malignant and benign lesions. Conclusion. In our study, the ADC values of benign renal masses were higher than those of normal renal parenchyme, which is higher than those of malignant renal masses.The lowest ADC values were observed in AMLs and oncocytomas.

Evaluation of the Effect of Patient Preparation Using Castor Oil on ADC Value of Focal Liver Lesion.

PurposeTo estimate the role of patient preparation using castor oil on the ADC value of focal liver lesion.Patients and MethodsRetrospective case-control study over more than two years. Magnetic resonance imaging (MRI) scan, including diffusion-weighted imaging (DWI) of the upper abdomen performed for 87 cases and 71 controls in patients with focal hepatic hemangiomas. Cases were prepared using castor oil prior to the scan without identifiable unwanted effect, while controls did not receive any special preparation. Since liver hemangioma is a common lesion, it was selected and used as a sample. Apparent Diffusion Coefficient (ADC) values of focal liver lesion were calculated in cases and controls.ResultsThe mean ADC value of liver hemangioma was lower in cases compared to controls; the mean ADC value was (2.21±0.39x10ˉ3mm2/s) in cases and (2.51±0.49x10ˉ3mm2/s) in controls. Left lobes were more affected by lesions; the mean ADC value of the left lobe lesions was (2.26±0.37 x10ˉ3mm2/s) and (2.86±0.43 x10ˉ3mm2/s) in cases and controls, respectively. The ADC value of lesions in the right lobe was (2.19±0.39x10ˉ3mm2/s) in cases and (2.39± 0.45x10ˉ3mm2/s) in controls. There was a significant segmental ADC variation; lesions at segments II, III, IVb, and V demonstrated illusive ADC elevation in controls.ConclusionThere is erroneous elevation of lobar and segmental ADC value of liver hemangiomas in non prepared patients. This Potential source of error (peristalsis, partial volume, and paramagnetic gas effect of gastrointestinal tract) on hepatic lesions’ ADC value can be avoided by proper preparation using castor oil prior to MRI scanning.

Quantitative analysis of diffusion-weighted imaging and signal-to-noise ratio on the efficacy of albendazole liposome in the treatment of cerebral alveolar echinococcosis

OBJECTIVE: To investigate the feasibility of diffusion-weighted imaging (DWI) and signal-to-noise ratio (SNR) of lesions in evaluating the efficacy of albendazole liposomes in the treatment of cerebral alveolar echinococcosis (CAE).MATERIALS AND METHODS: Sixteen patients with CAE who met the inclusion criteria from April 2017 to December 2020 were enrolled. All patients underwent routine magnetic resonance sequence examination and DWI examination. The b-value were 1000 s/mm2 and 3000 s/mm2. The apparent diffusion coefficient (ADC) value and SNR of lesions before and after treatment were compared. The data of each group were statistically analyzed by Wilcoxon signed-rank sum test.RESULTS: After 1 year of treatment with albendazole liposomes, the SNR of lesions on T2WI sequence increased. There was a significant difference between the SNR of the same lesion before and after follow-up (P < 0.05). The ADC values of lesion parenchyma and edema area before and after treatment were compared. The difference between them was statistically significant in the both b values (ADC of parenchyma, P < 0.05; ADC of edema area, P < 0.001). Through binary linear classification, it was found that under the same b value, the effect of drugs on the edema area was more obvious than that on the parenchyma area; under different b values, the higher the b value, the higher the ability to evaluate the curative effect of drug therapy.CONCLUSION: Albendazole liposome is effective in the treatment of CAE, and long-term imaging follow-up of patients with CAE treated with albendazole liposome is necessary. When the change in conventional images is inapparent, the quantitative analysis of ADC value and SNR of lesions on T2WI can provide an objective basis for the evaluation of the curative effect of drug treatment in CAE.

Acute and subacute prostate MRI findings after MRI-guided transurethral ultrasound ablation of prostate cancer.

Magnetic resonance imaging (MRI)-guided transurethral ultrasound ablation (TULSA) is an emerging method for treatment of localized prostate cancer (PCa). TULSA-related subacute MRI findings have not been previously characterized. To evaluate acute and subacute MRI findings after TULSA treatment in a treat-and-resect setting. Six men with newly diagnosed MRI-visible and biopsy-concordant clinically significant PCa were enrolled and completed the study. Eight lesions classified as PI-RADS 3-5 were focally ablated using TULSA. One- and three-week follow-up MRI scans were performed between TULSA and robot-assisted laparoscopic prostatectomy. TULSA-related hemorrhage was detected as a subtle T1 hyperintensity and more apparent T2 hypointensity in the MRI. Both prostate volume and non-perfused volume (NPV) markedly increased after TULSA at one week and three weeks after treatment, respectively. Lesion apparent diffusion coefficient values increased one week after treatment and decreased nearing the baseline values at the three-week MRI follow-up. The optimal timing of MRI follow-up seems to be at the earliest at three weeks after treatment, when the post-procedural edema has decreased and the NPV has matured. Diffusion-weighted imaging has little or no added diagnostic value in the subacute setting.

Apparent diffusion coefficient (ADC) values of serous, endometrioid, and clear cell carcinoma of the ovary: pathological correlation.

Primary epithelial ovarian cancer is divided into several subtypes. The relationships between apparent diffusion coefficient (ADC) values and their subtypes have not yet been established. To investigate whether ADC values of epithelial ovarian cancer vary according to histologic tumor cellularity and evaluate the difference of clear cell carcinoma (CCC), high-grade serous carcinoma (HGSC), and endometrioid carcinoma (EC). This retrospective study included 51 cases of epithelial ovarian cancer (17 CCC, 20 HGSC, and 14 EC) identified by magnetic resonance imaging with pathological confirmation. All patients underwent diffusion-weighted imaging and the ADC values of lesions were measured. We counted the tumor cells in three high-power fields and calculated the average for each case. The Spearman's correlation coefficient test was used to analyze correlation between ADC values and tumor cellularity. The ADC values of HGSC, EC, and CCC were compared using the Steel-Dwass test. The ADC values of all cases were significantly inversely correlated with tumor cellularity (rs = -0.761; P < 0.001). The mean ± SD ADC values (×10-3 mm2/s) of CCC, HGSC, and EC were 1.24 ± 0.17 (range 0.98--1.65), 0.84 ± 0.10 (range 0.67--1.06), and 0.84 ± 0.10 (range 0.67--1.07). The mean ± SD tumor cellularity of CCC, HGSC, and EC was 162.88 ± 63.28 (range 90.33--305.67), 440.60 ± 119.86 (range 204.67--655.67), and 461.02 ± 81.86 (range 333.33--602.33). There is a significant inverse correlation between ADC values and tumor cellularity in epithelial ovarian cancer. The mean ADC value of CCC was higher than those of HGSC and EC, seemingly due to the low cellularity of CCC.

Comparison of ADC Value and Prognostic Factors in Invasive Ductal Carcinoma

Objective: Aim of this study is to investigate whether there is a correlation by comparison of apparent diffusion coefficient (ADC) in invasive ductal carcinoma patients whom magnetic resonance imaging (MRI) was performed before surgery with prognostic factors such as tumour grade, estrogen/progesterone receptors (ER/PR), HER2/neu (c-erbB-2 protooncogene), level of Ki-67. Methods: We retrospectively reviewed breast MRI in our radiology department between 2015 and 2017. The patients in whom diagnosed as not otherwise specified invasive ductal carcinoma (NOSIDC) after tru-cut biopsy and had preoperatively performed MRI were included in this study. Results: The retrospective review yielded 27 patients and evaluated ADC value in 30 lesions. Mean ADC value of lesions was 0,911x10-3mm2 /s (0,456-1,30x10-3mm2 /s) and mean ADC value of normal breast parenchyma was 1,613x10-3mm2 /s (1,116-2,453x10- 3mm2 /s). Statistically significant difference was not found between grade 1 (1 lesion), grade 2 (19 lesions), grade 3 (10 lesions), ER positive (25 lesions), ER negative (4 lesions), PR positive (1 lesion), PR negative (8 lesions), HER2 negative (21 lesions), HER2 positive (8 lesions) cases (grade; p=0.074, ER; p=0.57, PR; p=0.66, HER2; p=0.58). Mean ADC value was 0,855x10-3mm2 /s (0.660-1.30 x10-3mm²/s) in lesions of high Ki-67 proliferative index (20 lesions) and was 1,040x10- 3mm2 /s (0.985-1.70 x10-3mm²/s) in lesions of low Ki-67 proliferative index (5 lesions). Statistically significant difference between these two groups was found (p=0.007). Conclusion: In our evaluated prognostic factors, correlation with ADC value was found only in Ki-67 proliferative index and statistically significant difference was not found in the others.

Role of ADC values in assessing clinical response and identifying residual disease post-chemo radiation in uterine cervix cancer.

Objectives:To evaluate the role of apparent diffusion coefficient (ADC) values in assessing response after chemo-radiotherapy in cervix cancer and investigate the utility of ADC as a tool to identify residual disease, after the treatment completion.Methods:A prospective study was done in 100 patients with histopathologically proven cancer of uterine cervix who were classified as either complete response (CR) or residual disease posttreatment. MRI was done pretreatment and after 6 weeks post-treatment with chemo-radiation. 53 patients among the cohort also underwent a fluoro-deoxy glucose positron-emission computed tomography (FDG-PET CT). ADC values, change in ADC values, and metabolic activity obtained from FDG-PET CT were correlated with clinical outcome, and statistical analysis was done to determine the better tool for assessing response evaluation between ADC and PET-CT.Results:Residual lesions have notably lower ADC value than that of posttreatment changes. The mean ADC values of residual tumors: 1.26 ± 0.238 × 10−3 mm2/s and mean ADC values of lesions due to posttreatment changes: 1.540 ± 0.218 × 10−3 mm2/s (statistically significant difference between malignant and posttreatment lesions, P < 0.05). ADC has 67% sensitivity, 83% specificity, 35% positive predictive values (PPV), 95% negative predictive values (NPV), and 81% accuracy in differentiating residual disease from post treatment changes. PPV, NPV, sensitivity, and specificity with PET-CT were 93%, 89%, 98%, and 73%, respectively. PPV, NPV, sensitivity, and specificity of contrast MRI were 16%, 91%, 58%, and 59%, respectively.Conclusion:Diffusion imaging differentiates residual cervix malignancies from post treatment changes based on ADC values and can be a promising and evocative biomarker. Complimentary use of ADC and PET/CT may increase diagnostic confidence.

Effect of region of interest on ADC and interobserver variability in thyroid nodules

BackgroundTo determine the effect of region of interest (ROI) on tumor’s apparent diffusion coefficient (ADC) and interobserver variability in thyroid nodules.MethodsThirty-three individuals with 45 pathologically-confirmed thyroid nodules were assessed by preoperative diffusion-weighted imaging (DWI) with b values of 0 and 400 s/mm2, respectively. Two readers evaluated the ADC values of lesions based on three ROI techniques: whole-volume, single-slice and small solid-sample groups. Interobserver variability was analyzed for all ROI techniques, and the mean ADCs of benign and cancerous thyroid nodules were compared.ResultsFor the mean ADCs of non-cancerous thyroid nodules, average differences and limits of agreement (LOAs) between readers were 0.00 [− 0.17–0.17] × 10− 3 mm2/s for whole-volume ROI (ICC = 0.967), 0.00 [− 0.26–0.26] × 10− 3 mm2/s for single-slice ROI (ICC = 0.932) and − 0.02 [− 0.38–0.41] × 10− 3 mm2/s for small solid-sample ROI (ICC = 0.823). For the mean ADCs of cancerous thyroid nodules, average differences and LOAs between readers were − 0.05 [− 0.23–0.13] × 10− 3 mm2/s (ICC = 0.885), 0.01 [− 0.23–0.25] × 10− 3 mm2/s (ICC = 0.839) and − 0.07 [− 0.52–0.39] × 10− 3 mm2/s (ICC = 0.579) for the three ROI methods, respectively. The mean ADC values were more scattered in the small solid-sample ROI group in comparison with the whole-volume and single-slice groups, in noncancerous and cancerous specimens. Of all three ROI techniques, whole-volume ROI-determined ADC had the highest combined sensitivity (80.0%), specificity (88.3%) and Youden index (0.683), with a cut-off of 1.84 × 10− 3 mm2/s.ConclusionsThe ROI method overtly affects ADC measurements in benign and cancerous thyroid nodules. Small solid-sample ROI yielded the worst interobserver variability of average ADC measurements.

Clinical value of magnetic resonance imaging in identifying multiple cerebral gliomas from primary central nervous system lymphoma.

Clinical value of magnetic resonance imaging (MRI) in identifying and diagnosing multiple cerebral glioma (MCG) from primary central nervous system lymphoma (PCNSL) was evaluated. A total of 21 patients with MCG diagnosed clinically and pathologically in Zhangzhou Municipal Hospital from March 2016 to April 2017 were selected as group A, and 30 patients with PCNSL diagnosed in Zhangzhou Affiliated Hospital of Fujian Medical University during the same period as group B. Plain MRI, enhanced MRI and diffusion weighted imaging (DWI) were performed in all patients, the apparent diffusion coefficient (ADC) value of lesions was measured, and the diagnostic efficacy of ADC for MCG and PCNSL was evaluated by receiver operating characteristic (ROC) curve. The incidence of hippocampus lesions, patchy and cystic lesions, and the heterogeneous signal of plain scan in group A was significantly higher than that in group B (P<0.05), and the incidence of basal ganglia lesions was significantly lower than that in group B (P<0.05). Mass lesions in group A were significantly less than those in group B (P<0.05). The ADC value of lesions in group A was significantly higher than that in contralateral normal white matter (P<0.05), the ADC value in group B was significantly lower than that in normal contralateral white matter (P<0.05), so the ADC value in group A was significantly higher than that in group B (P<0.05). The location, lesion shape and signal characteristic of MCG and PCNSL have their own specificity; there are significant differences in DWI signal and ADC color map signal intensity of the lesions; ADC has certain diagnostic value for MCG and PCNSL; the differential diagnosis of MCG from PCNSL by MRI is of great significance.

Statistical Analysis of the Apparent Diffusion Coefficient in Patients with Clinically Mild Encephalitis/Encephalopathy with a Reversible Splenial Lesion Indicates That the Pathology Extends Well beyond the Visible Lesions.

Purpose:To investigate whether the genu of the corpus callosum is involved in patients with clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) type I.Methods:Twenty-three cases of clinically confirmed MERS I were analyzed retrospectively, and MRI features of the lesion were observed. The apparent diffusion coefficient (ADC) values of the same region of interests in lesions at the splenium and genu of the corpus callosum were measured before and after treatment (i.e., four groups), and the average ADC values were calculated. Paired t-tests were used to compare the ADC values of lesions in the splenium and genu before and after treatment. Independent sample t-tests were used to compare the values in the splenium and genu after treatment.Results:The mean ADC values of the splenium before and after treatment were 0.448 ± 0.124 and 0.790 ± 0.070 × 10−3 mm2/s, respectively, showing significant difference (P < 0.01). The mean ADC values in the genu before and after treatment were 0.783 ± 0.067 and 0.829 ± 0.070 × 10−3 mm2/s, respectively, also showing significant difference (P < 0.01). There was no significant difference in the ADC values between the splenium and genu after treatment (P > 0.05).Conclusion:The genu showed a slight restriction in diffusion in the acute stage of type I MERS. After treatment, this diffusion restriction diminished as it typically does in the splenium. Our results indicate that the pathology in MERS extends well beyond the visible lesions.

Apparent diffusion coefficient values in differential diagnosis and prognostic prediction of solitary of fibrous tumor/hemangiopericytoma (WHOII) and atypical meningioma.

It is difficult to distinguish solitary of fibrous tumor/hemangiopericytoma (SFT/HPC) from atypical meningioma (AM) by conventional imaging.As far as we know,diffusion weighting imaging may identify them effectively. The purpose of this study was to determine the role of apparent diffusion coefficient (ADC) values to distinguish and predict prognosis of solitary of fibrous tumor/hemangiopericytoma (SFT/HPC) (WHOII) and atypical meningioma (AM). Preoperative diffusion-weighted imaging (DWI) of 30 cases with histopathologic and immunhistochemical testified SFT/HPC WHOII (n= 11) and AM (n= 19) were performed retrospectively. The ADC values of lesion, peritumoral edema, normal white matter and lesion NADC ratio (lesion ADC values/ADC values of normal white matter (NWN ADC)) were compared. The immunhistochemical markers (Ki-67, CD34, Vim, EMA, GFAP, S-100, PR, CD56) were compared. The correlation between the ADC values and Ki-67 index was evaluated. The mean lesion ADC values of SFT/HPC (1.15 ± 0.04 × 10-3mm2/s) was significantly higher than that of AM (0.80 ± 0.04 × 10-3mm2/s) (t= 23.824, p< 0.05). The mean NADC ratio was lower for AM (1.03 ± 0.06) compared with SFT/HPC (1.51 ± 0.05) (t= 23.105, p< 0.05). The mean edema ADC for SFT/HPC (1.47 ± 0.06 × 10-3mm2/s) was lower compared with AM (1.68 ± 0.05 × 10-3mm2/s) (t=-9.926, p< 0.05 ). There was no statistical difference between the two groups of NWM ADC (t=-1.475, p> 0.05) . The mean Ki-67 of SFT/HPC (7.18 ± 2.60%) was lower than the mean Ki-67 of AM (13.58 ± 4.50%) (t=-4.934, p< 0.05). The CD34 showed statistically differences between two groups (X2= 13.659, p< 0.05). The EMA also showed statistically differences between two groups (X2= 4.474, p< 0.05). Vim,GFAP, S-100, PR, CD56 showed no statistical difference in the two group (p> 0.05). The pearson analysis indicated that there was a negative correlation between lesion ADC and Ki-67 in SFT/HPC group (r=-0.770, p< 0.05) and AM group (r=-0.727, p< 0.05). There was also a negative correlation between lesion NADC ratio and Ki-67 in SFT/HPC group (r=-0.673, p< 0.05) and AM group (r=-0.707, p< 0.05). There was a positive correlation between edema ADC and Ki-67 in SFT/HPC group (r= 0.819, p< 0.05) and AM group (r= 0.942, p< 0.05). Furthermore,there was no correlation between NWM A DC and Ki-67 in SFT/HPC group (r=-0.403, p> 0.05) and AM group (r= 0.202, p> 0.05). The lesion ADC, lesion NADC ratio and edema ADC can distinguish the SFT/HPC WHO II from AM and be helpful to predict prognosis of the two tumors before operation. Further more, histopathologic and immunhistochemical can make a definite diagnosis of the two tumors.

Role of diffusion-weighted MRI in evaluation of patients with salivary gland tumors

Background and objectives Diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values give appreciable information about tumor cellularity with tissue contrast between the active and necrotic areas within the tumor. Aim of the work The aim of this study was to investigate the capacity of diffusion MRI to predict benign and malignant salivary gland tumors, using ADC value and DWI. Patients and methods This study included 40 patients (24 male and 16 female). Sixteen patients had malignant lesions and 24 had benign ones. The DWI was obtained with b values including 0 and 800 mm2/s. The ADC was generated by measuring identical images at different b values and represented as ADC map, from which the ADC value was calculated. This was a prospective randomized controlled trial. Informed consent was obtained from parents or guardians. Results The absolute ADC value of lesions was significantly different between benign and malignant salivary gland tumors (P Conclusion The use of DWI and ADC values can provide better assessment of salivary gland tumors and predict benign and malignant lesions.

Role of Diffusion Weighted Magnetic Resonance Imaging in Evaluation of Patients with Salivary Glands Tumors

Background: The diffusion weighted imaging and ADC value give appreciable information about tumor cellularity with tissue contrast between the active and necrotic areas within the tumor. This would be valuable and could direct the beneficial site for interventional procedure and biopsy to be taken from the viable tumoral tissue especially in case with non-enhanced studies due to renal impairment. Objective: The aim of this study was to investigate the capacity of Diffusion MRI to predict the benign and malignant Salivary gland tumors, using ADC value and DWI. Patients and Methods: This study included 40 patients (24 male and 16 female). Sixteen patients had malignant lesions and twenty-four had benign ones. The DWI was obtained with b values including 0 and 800mm2/second. The Apparent Diffusion Coefficient (ADC) generated by measuring identical images at different b-values and represented as ADC map, from which the ADC value was calculated. Results: The absolute ADC value of lesions was significantly different between benign and malignant salivary gland tumors (p<0.001). The sensitivity of ADC in differentiating benign from malignant lesions in our study was 93.7% indicating a high true positive rate. Hence, if the average ADC is below 0.85 x 10 -3 mm2/sec, there is high probability that the mass will be malignant with high specificity of 95.8 %. Results revealed that the mean ADC value of benign and malignant salivary gland tumors were 1.33±0.46x 10-3 mm2/s and 0.65±0.21 x 10-3 mm2/s, respectively. The mean ADC value of benign was significantly higher than that of malignant lesions. Conclusion:Theuse of DWI and ADC values can provide better assessment of salivary gland tumors and predict the benign and malignant lesions.

508 (PB-141) - High reproducibility of breast lesion apparent diffusion coefficient values based on fixed size and shape region of interest in diffusion weighted imaging

508 (PB-141) - High reproducibility of breast lesion apparent diffusion coefficient values based on fixed size and shape region of interest in diffusion weighted imaging

Gadoterate meglumine decreases ADC values of breast lesions depending on the b value combination

To retrospectively evaluated the influence of administration of the gadolinium based intravenous contrast agent (G-CA) on apparent diffusion coefficient (ADC) values in ADC maps generated using multiple b value combinations. A total of 106 women underwent bilateral 3.0 T breast MRI. As an internal validation, diffusion-weighted imaging (b values of 0, 200, 400, 600, 800 s/mm2) was performed before and after the G-CA (gadoterate meglumine (0.2 ml/kg, 3 ml/s)). Whole lesion and fibroglandular tissue (FGT) covering region-of-interests (ROIs) were drawn on the b = 800 s/mm2 images; ROIs were then propagated to multiple retrospectively generated ADC maps. Twenty-seven patients (mean age 55.8 ± 10.8 years) with 32 mass-like enhancing breast lesions including 25 (78.1 %) histopathologically malignant lesions were enrolled. Lesion ADC values were statistically significantly higher in pre-G-CA than post-G-CA ADC maps (ADC0,200,400,600,800: 1.05 ± 0.35 × 10−3 mm2/s vs. 1.02 ± 0.36 × 10−3 mm2/s (P < 0.05); ADC0,200,400: 1.25 ± 0.42 × 10−3 mm2/s vs. 1.20 ± 0.35 × 10−3 mm2/s (P < 0.05)). ADC values between pre- and post-contrast maps were not statistically different when the maps were generated using other b value combinations. Contrast agent administration did not affect the FGT ADC values. G-CA statistically significantly reduced the ADC values of breast lesions on ADC maps generated using the clinically widely utilized b values.