Peritumoral Apparent Diffusion Coefficient Research Articles

Can peritumoral edema evaluated by Magnetic Resonance Imaging before neoadjuvant chemotherapy predict complete pathological response in breast cancer?

The complete pathological response (pCR) following neoadjuvant chemotherapy (NAC) in breast cancer is essential for the accurate prediction of prognosis. We aimed to evaluate the efficacy of the presence and type of peritumoral edema detected by magnetic resonance imaging (MRI) in predicting pCR to NAC in breast cancer patients. One hundred five patients with the diagnosis of invasive carcinoma were evaluated by MRI before NAC. Edema was evaluated in fat-suppressed T2-weighted images. The patients were categorized into three groups: patients with no peritumoral edema, patients with peritumoral edema, and patients demonstrating subcutaneous edema. The cases were categorized as being pCR and non-pCR. Molecular subtypes, lymphovascular invasion (LVI), tumor size, and apparent diffusion coefficient (ADC) were evaluated. A positive relationship was found between the presence of edema and tumor size. Subcutaneous edema was found to be statistically higher in non-pCR patients. While the number of pCR patients with subcutaneous edema was 17 (30.4%), the number of non-pCR patients with subcutaneous edema was 26 (53.1%) (p = 0.018). LVI was found to be statistically higher in patients with edema. The number of edema-negative and LVI (+) patients was 4 (15.4%), while the number of edema-positive and LVI (+) patients was 28 (35.4%) (p = 0.042). Intratumoral and peritumoral ADC values were significantly higher in tumors with edema. The presence of subcutaneous edema and LVI may be utilized for the prediction of pCR outcomes in breast cancer patients scheduled for NAC treatment.

Peritumoral ADC Values Correlate with the MGMT Methylation Status in Patients with Glioblastoma

Different results have been reported concerning the relationship of the apparent diffusion coefficient (ADC) values and the status of methylation as the promoter gene for the enzyme methylguanine-DNA methyltransferase (MGMT) in patients with glioblastomas (GBs). The aim of this study was to investigate if there were correlations between the ADC values of the enhancing tumor and peritumoral areas of GBs and the MGMT methylation status. In this retrospective study, we included 42 patients with newly diagnosed unilocular GB with one MRI study prior to any treatment and histopathological data. After co-registration of ADC maps with T1-weighted sequences after contrast administration and dynamic susceptibility contrast (DSC) perfusion, we manually selected one region-of-interest (ROI) in the enhancing and perfused tumor and one ROI in the peritumoral white matter. Both ROIs were mirrored in the healthy hemisphere for normalization. In the peritumoral white matter, absolute and normalized ADC values were significantly higher in patients with MGMT-unmethylated tumors, as compared to patients with MGMT-methylated tumors (absolute values p = 0.002, normalized p = 0.0007). There were no significant differences in the enhancing tumor parts. The ADC values in the peritumoral region correlated with MGMT methylation status, confirmed by normalized ADC values. In contrast to other studies, we could not find a correlation between the ADC values or the normalized ADC values and the MGMT methylation status in the enhancing tumor parts.

An initial study on the predictive value using multiple MRI characteristics for Ki-67 labeling index in glioma

Background and purposeKi-67 labeling index (LI) is an important indicator of tumor cell proliferation in glioma, which can only be obtained by postoperative biopsy at present. This study aimed to explore the correlation between Ki-67 LI and apparent diffusion coefficient (ADC) parameters and to predict the level of Ki-67 LI noninvasively before surgery by multiple MRI characteristics.MethodsPreoperative MRI data of 166 patients with pathologically confirmed glioma in our hospital from 2016 to 2020 were retrospectively analyzed. The cut-off point of Ki-67 LI for glioma grading was defined. The differences in MRI characteristics were compared between the low and high Ki-67 LI groups. The receiver operating characteristic (ROC) curve was used to estimate the accuracy of each ADC parameter in predicting the Ki-67 level, and finally a multivariate logistic regression model was constructed based on the results of ROC analysis.ResultsADCmin, ADCmean, rADCmin, rADCmean and Ki-67 LI showed a negative correlation (r = − 0.478, r = − 0.369, r = − 0.488, r = − 0.388, all P < 0.001). The Ki-67 LI of low-grade gliomas (LGGs) was different from that of high-grade gliomas (HGGs), and the cut-off point of Ki-67 LI for distinguishing LGGs from HGGs was 9.5%, with an area under the ROC curve (AUROC) of 0.962 (95%CI 0.933–0.990). The ADC parameters in the high Ki-67 group were significantly lower than those in the low Ki-67 group (all P < 0.05). The peritumoral edema (PTE) of gliomas in the high Ki-67 LI group was higher than that in the low Ki-67 LI group (P < 0.05). The AUROC of Ki-67 LI level assessed by the multivariate logistic regression model was 0.800 (95%CI 0.721–0.879).ConclusionsThere was a negative correlation between ADC parameters and Ki-67 LI, and the multivariate logistic regression model combined with peritumoral edema and ADC parameters could improve the prediction ability of Ki-67 LI.

Differentiation between High Grade Glioma and Solitary Brain Metastasis Using Combined Diffusion-Weighted Imaging and Diffusion Tensor Imaging

Background: High-grade gliomas (HGGs) and brain metastases (BMs) can display similar imaging characteristics on conventional MRI. In HGGs, the peritumoral edema is infiltrated by the malignant cells, which was not observed in BMs. Our study aims to determine whether the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values could differentiate HGGs from BMs. Results: Twenty patients with provisional MRI diagnosis of high grade gliomas WHO grade III &amp; IV versus metastatic brain tumors, examination was done on 1.5 tesla scanner, patients were divided into two groups based on pathology results, the fraction anisotropy (FA) was measured in the enhancing tumor parts and immediate peri-tumoral edema. The minimum and mean ADC in the enhancing tumor (ADCmin, ADCmean) and the minimum ADC in the peritumoral region (ADCedema) were measured from ADC maps. Values of FA and ADC measured in the peri-tumoral edema were significantly high in the metastatic than primary high malignant glial tumors, yet no significant differences in the values of FA and ADC measured in the enhancing tumor parts of the two groups. According to ROC curve analysis, a cutoff value of 0.119 for the FA measured in the peri-tumoral edema with sensitivity (100%) and specificity (75%) and a cutoff value of 1.7 x 10-3 for the ADCedema with sensitivity (87.5%) and specificity (75%) generated the best combination of for distinguishing between HGGs and BMs. Conclusion: FA and ADC values were found to distinguish between HGGs and solitary BMs. The peritumoral FA and ADC values are better than the intratumoral FA and ADC values in predicting the tumor type.

The value of 18F-FDG PET/MRI in prediction of microvascular invasion in hepatocellular carcinoma

Rationale and ObjectivesInvestigating the association between maximum standardized uptake value (SUVmax), peritumoral and intratumoral apparent diffusion coefficient (ADC) values and whether these parameters are useful in predicting the preoperative microvascular invasion (MVI) of hepatocellular carcinoma (HCC). Materials and methodsForty-four patients [8 women and 36 men, median age of 62 (21–76)] with single HCCs (≥2 cm) who underwent preoperative 18F-FDG PET/MRI were retrospectively evaluated. The peritumoral and intratumoral ADC values were evaluated on diffusion-weighted images using Image J an open software and the intratumoral SUVmax values were measured on fusion 18F-FDG PET/MRI images. Univariate and multivariate logistic regression analyses were performed to determine the most influential factor predicting MVI. Interobserver agreement was checked using the intraclass correlation coefficient (ICC). ResultsUnivariate analysis showed that the histologic grade, tumor size, maximum peritumoral ADC (PTband ADCmax), mean peritumoral ADC (PTband ADCmean), mean intratumoral ADC (IT ADCmean), and maximum SUV (SUVmax) correlated with MVI (p < 0.05). On multivariate analysis, the SUVmax was the only independent risk factor for the MVI of HCC [OR, 1.68; 95% CI (1.04–2.70); p = 0.032)]. An AUC value of 0.896, 95% CI, 0.786–1.0) had a sensitivity of 75% and specificity of 97% using the best cut-off SUVmax 5.85 to differentiate MVI-positive HCCs from MVI-negative. The PPV, NPV, and accuracy were 92.3%, 87%, and 89%, respectively. The ICC values were 0.95–0.99, a nearly perfect level of agreement. Conclusion18F-FDG PET/MRI is a useful noninvasive imaging tool for predicting the MVI of HCC.

Diffusion and perfusion imaging biomarkers of H3 K27M mutation status in diffuse midline gliomas.

H3K27M-mutant diffuse midline gliomas (M-DMGs) exhibit a clinically aggressive course. We studied diffusion-weighted imaging (DWI) and perfusion (PWI) MRI features of DMG with the hypothesis that DWI-PWI metrics can serve as biomarkers for the prediction of the H3K27M mutation status in DMGs. A retrospective review of the institutional database (imaging and histopathology) of patients with DMG (July 2016 to July 2020) was performed. Tumoral apparent diffusion coefficient (ADC) and peritumoral ADC (PT ADC) values and their normalized values (nADC and nPT ADC) were computed. Perfusion data were analyzed with manual arterial input function (AIF) and leakage correction (LC) Boxerman-Weiskoff models. Normalized maximum relative CBV (rCBV) was evaluated. Intergroup analysis of the imaging variables was done between M-DMGs and wild-type (WT-DMGs) groups. Ninety-four cases (M-DMGs-n = 48 (51%) and WT-DMGs-n = 46(49%)) were included. Significantly lower PT ADC (mutant-1.1 ± 0.33, WT-1.23 ± 0.34; P = 0.033) and nPT ADC (mutant-1.64 ± 0.48, WT-1.83 ± 0.54; P = 0.040) were noted in the M-DMGs. The rCBV (mutant-25.17 ± 27.76, WT-13.73 ± 14.83; P = 0.018) and nrCBV (mutant-3.44 ± 2.16, WT-2.39 ± 1.25; P = 0.049) were significantly higher in the M-DMGs group. Among thalamic DMGs, the min ADC, PT ADC, and nADC and nPT ADC were lower in M-DMGs while nrCBV (corrected and uncorrected) was significantly higher. Receiver operator characteristic curve analysis demonstrated that PT ADC (cut-off-1.245), nPT ADC (cut-off-1.853), and nrCBV (cut-off-1.83) were significant independent predictors of H3K27M mutational status in DMGs. DWI and PWI features hold value in preoperative prediction of H3K27M-mutation status in DMGs.

The Potential Role of Peritumoral Apparent Diffusion Coefficient Evaluation in Differentiating Glioblastoma and Solitary Metastatic Lesions of the Brain.

Differentiating glioblastoma (GBM) and solitary metastasis is not always possible using conventional magnetic resonance imaging (MRI) techniques. In conventional brain MRI, GBM and brain metastases are lesions with mostly similar imaging findings. In this study, we investigated whether apparent diffusion coefficient (ADC) ratios, ADC gradients, and minimum ADC values in the peritumoral edema tissue can be used to discriminate between these two tumors. This retrospective study was approved by the local institutional review board with a waiver of written informed consent. Prior to surgical and medical treatment, conventional brain MRI and diffusion-weighted MRI (b = 0 and b = 1000) images were taken from 43 patients (12 GBM and 31 solitary metastasis cases). Quantitative ADC measurements were performed on the peritumoral tissue from the nearest segment to the tumor (ADC1), the middle segment (ADC2), and the most distant segment (ADC3). The ratios of these three values were determined proportionally to calculate the peritumoral ADC ratios. In addition, these three values were subtracted from each other to obtain the peritumoral ADC gradients. Lastly, the minimum peritumoral and tumoral ADC values, and the quantitative ADC values from the normal-appearing ipsilateral white matter, contralateral white matter, and ADC values from cerebrospinal fluid (CSF) were recorded. For the differentiation of GBM and solitary metastasis, ADC3 / ADC1 was the most powerful parameter with a sensitivity of 91.7% and specificity of 87.1% at the cut-off value of 1.105 (p < 0.001), followed by ADC3 / ADC2 with a cut-off value of 1.025 (p = 0.001), sensitivity of 91.7%, and specificity of 74.2%. The cut-off, sensitivity and specificity of ADC2 / ADC1 were 1.055 (p = 0.002), 83.3%, and 67.7%, respectively. For ADC3 - ADC1, the cut-off value, sensitivity, and specificity were calculated as 150 (p < 0.001), 91.7%, and 83.9%, respectively. ADC3 - ADC2 had a cutoff value of 55 (p = 0.001), sensitivity of 91.7%, and specificity of 77.4, whereas ADC2 - ADC1 had a cut-off value of 75 (p = 0.003), sensitivity of 91.7%, and specificity of 61.3%. Among the remaining parameters, only the ADC3 value successfully differentiated between GBM and metastasis (GBM 1802.50 ± 189.74 vs. metastasis 1634.52 ± 212.65, p = 0.022). The integration of the evaluation of peritumoral ADC ratio and ADC gradient into conventional MR imaging may provide valuable information for differentiating GBM from solitary metastatic lesions.

Intratumoral and Peritumoral Apparent Diffusion Coefficient and MGMT mRNA Expression in Different Meningioma Histopathological Grade

BACKGROUND: Histopathological examination is the gold standard for diagnosing meningioma and determining the treatments. However, it is invasive in nature. This study was conducted to identify intratumoral and peritumoral apparent diffusion coefficient (ADC) value and mRNA O6-methylguanine-DNA methyltransferase (MGMT) expression in meningioma.METHODS: Data were collected from 39 patients who were clinically diagnosed with meningioma. However, only 37 patients met the inclusion criteria. These subjects then underwent examinations and received treatment from October 2017 to September 2018. Magnetic resonance imaging (MRI) data with diffusion-weighted imaging-apparent diffusion coefficient (DWI-ADC) sequence, histopathological diagnosis of meningioma, and results of MGMT mRNA expression were obtained.RESULTS: The most frequent type of low-grade and overall tumor was meningioma not otherwise specified (56.8%). For high-grade tumor, there were two atypical cases: atypical meningioma (2.7%) and rhabdoid meningioma (2.7%). Meningothelial meningioma had the highest mean value of minimum intratumoral ADC at 864.57±219 x10-3 mm2/s, whereas rhabdoid meningioma had the lowest at 417 x10-3 mm2/s. For minimum peritumoral ADC, rhabdoid meningioma had the highest mean value at 1,651 x10-3 mm2/s, while atypical meningioma has the lowest at 1,281 x10-3 mm2/s. For MGMT mRNA, meningothelial meningioma had the highest mean value at 10±1.2 fold change, whereas rhabdoid meningioma had the lowest mean at 6.18 fold change.CONCLUSION: WHO grade I meningiomas had higher minimum intratumoral ADC values and higher MGMT mRNA expression than the high-grade tumors. Minimum peritumoral ADC values differed across the histopathological grades.KEYWORDS: meningioma, RNA, messenger, MRI, methyltransferases, RT-PCR, ADC, MGMT mRNA

Comparison of Canine and Feline Meningiomas Using the Apparent Diffusion Coefficient and Fractional Anisotropy.

Meningiomas are the most common intracranial tumor in dogs and cats, and their surgical resection is often performed because they are present on the brain surface. Typical meningiomas show comparatively characteristic magnetic resonance imaging findings that lead to clinical diagnosis; however, it is necessary to capture not only macroscopic changes but also microstructural changes to devise a strategy for surgical resection and/or quality of removal. To visualize such microstructural changes, diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) have been used in human medicine. The aim of this retrospective study was to investigate the different characteristics of the apparent diffusion coefficient (ADC) from DWI and fractional anisotropy (FA) from DTI of meningioma between dogs and cats. Statistical analyses were performed to compare ADC and FA values between the intratumoral or peritumoral regions and normal-appearing white matter (NAWM) among 13 dogs (13 lesions, but 12 each in ADC and FA analysis) and six cats (seven lesions). The NAWM of cats had a significantly lower ADC and higher FA compared to dogs. Therefore, for a comparison between dogs and cats, we used ADC and FA ratios that were calculated by dividing the subject (intra- or peritumoral) ADC and FA values by those of NAWM on the contralateral side. Regarding the intratumoral region, feline meningiomas showed a significantly lower ADC ratio and higher FA ratio than canine meningiomas. This study suggested that ADC and FA may be able to distinguish a meningioma that is solid and easy to detach, like as typical feline meningiomas.

Diagnostic role of apparent diffusion coefficient combined with intratumoral susceptibility signals in differentiating high-grade gliomas from brain metastases.

The aim of this study was to assess whether tumoral and peritumoral apparent diffusion coefficient values and intratumoral susceptibility signals on susceptibility-weighted imaging could distinguish between high-grade gliomas and brain metastases, and to investigate their associations with the Ki-67 proliferation index. Fifty-seven patients with pathologically confirmed diagnoses of either high-grade glioma or brain metastasis were enrolled in this study (23 with high-grade gliomas and 34 with brain metastases). The minimum and mean apparent diffusion coefficients in the enhancing tumoral region (ADCmin and ADCmean) and the minimum apparent diffusion coefficient in the peritumoral region (ADCedema) were measured from apparent diffusion coefficient maps, and intratumoral susceptibility signal grades acquired by susceptibility-weighted imaging were calculated. Ki-67 proliferation index values were obtained from the hospital database. These parameters were evaluated using the Mann-Whitney U test, independent-sample t-test, Spearman correlation analysis, receiver operating characteristic curve, and logistic regression analyses. ADCmean, ADCmin values, and intratumoral susceptibility signal grades in brain metastases were significantly lower than those in high-grade gliomas (all p < 0.05). Ki-67 proliferation index values showed significant correlations with ADCmean, ADCmin, and intratumoral susceptibility signal grade in brain metastases (all p < 0.05), but no correlation was found in high-grade gliomas (all p > 0.05). According to receiver operating characteristic curve analysis, ADCmean achieved the highest diagnostic performance for discriminating high-grade gliomas from brain metastases. Furthermore, the combination of tumoral apparent diffusion coefficient parameters with intratumoral susceptibility signal grade provided a higher area under the curve than univariate parameters. The combination of tumoral apparent diffusion coefficient with intratumoral susceptibility signal grade can offer better diagnostic performances for differential diagnosis. Apparent diffusion coefficient and intratumoral susceptibility signal may reflect cellular proliferative activity in brain metastases, but not in high-grade gliomas.

Correlation of Peri-Tumoral Edema Determined in T2 Weighted Imaging with Apparent Diffusion Coefficient of Peritumoral Area in Patients with Breast Carcinoma

Background: Breast cancer may result in remodeling of adjacent normal appearing breast tissues. Magnetic resonance imaging (MRI) is increasingly used in the diagnosis and follow-up of breast cancer by means of diffusion weighted imaging, which is based on thermal motion of water molecules in the extracellular fluid. Objectives: We investigated the correlation of visual assessment of peri-tumoral edema with peri-tumoral and tumoral apparent diffusion coefficient (ADC) values. Patients and Methods: In this cross-sectional study, from 2016 to 2018, 78 patients with 89 malignant breast lesions (mean age, 47 years) were examined by 1.5-T breast MRI. The lesions were categorized based on the visual assessment of peri-tumoral edema on T2 weighted imaging (T2WI) into two groups: (A) with edema (36 lesions) and (B) without edema (53 lesions). Measuring ADC values in the contralateral normal breast tissue, peri-tumoral tissue and peri-tumoral-normal tissue ADC ratio were compared between the two groups for all lesions. Results: The number of in situ lesions was higher in group B (7.5% vs 2.7%) with the p value of 0.01. The mean of ADC values in the normal breast tissue was 1.76 × 10-3mm2/s. Tumor ADCs were significantly lower in group A compared to group B (0.95 × 10-3mm2/s vs. 1.11 × 10-3mm2/s) with the P value of 0.003. However, peri-tumoral ADCs were significantly higher in group A (1.82 × 10-3mm2/s vs. 1.53 × 10-3mm2/s) with the p value of 0.005. The peri-tumoral-normal tissue ADC ratio was 0.87 in group B and about 1 in group A. However, the difference between normal tissue ADCs and peri-tumoral ADCs was only significant (P value of 0.005) in group B. The cut-off point value for differentiating normal tissue ADCs and peri-tumoral ADCs was 1.61 × 10-3mm2/s with the sensitivity of 65% and specificity of 70%. Conclusion: Breast cancer with peri-tumoral edema has lower tumoral ADC values, higher peri-tumoral ADC values and lower prevalence of in situ lesions. Visual assessment of peri-tumoral edema on T2WI could predict the tumoral characteristic on diffusion-weighted imaging.

İntratümöral Ve Peritümöral ADC(Apperent Diffusion Coefficient) Değerlerinin Pediatrik Beyin Tümörlerinin Tanısında Önemi Var Mıdır?

INTRODUCTION: The motion of water particles within biological tissues, which is called random Brownian motion, is detected at the microscopic level by Diffusion-Weighted Imaging (DWI) sequence of Magnetic Resonance Image technique. The Apparent Diffusion Coefficient (ADC) calculated on DWI has been used for tumor diagnosis and grading. The purpose of this study was to evaluate of ADC values in the differential diagnosis of supratentorial and infratentorial pediatric brain tumors and to reveal the difference of peritumoral ADC measurements of pediatric patients from adult patients. METHODS: All of the 56 pediatric patients included in this retrospective study had lesions &gt;1 cm in diameter on magnetic resonance image and all of the diagnosies were confirmed by histopathology. Intratumoral and peritumoral ADC values and ratios were measured in diffusion weighted Magnetic Resonance Image. RESULTS: The 58.9% (n=33) of these tumors were supratentorial and 41.1% (n=23) were infratentorial. ADC values and ADC ratios were significantly lower in high-grade tumors than low-grade tumors (p&lt;0.05). Peritumoral ADC values in high-grade tumors were lower than low grade tumors (p&lt;0.05). The cut-off value of the ADC ratio between these two groups was 1 and the ADC cut-off value was 1.1*10-3 mm2/s. DISCUSSION AND CONCLUSION: In the differentiation of low and high-grade pediatric brain tumors, cut-off values of 1.1*10_3mm2/s for ADC Value and 1.0 for ADC Ratio may be useful. Although, peritumoral ADC values differ in children compared to the adult group, both intratumoral and peritumoral ADC values can help for grading pediatric brain tumors.

Peritumoral ADC values in breast cancer: region of interest selection, associations with hyaluronan intensity, and prognostic significance

ObjectivesWe aimed to evaluate the differences in peritumoral apparent diffusion coefficient (ADC) values by four different ROI selection methods and to validate the optimal method. Furthermore, we aimed to evaluate if the peritumor-tumor ADC ratios are correlated with axillary lymph node positivity and hyaluronan accumulation.MethodsAltogether, 22 breast cancer patients underwent 3.0-T breast MRI, histopathological evaluation, and hyaluronan assay. Paired t and Friedman tests were used to compare minimum, mean, and maximum values of tumoral and peritumoral ADC by four methods: (M1) band ROI, (M2) whole tumor surrounding ROI, (M3) clockwise multiple ROI, and (M4) visual assessment of ROI selection. Subsequently, peritumor/tumor ADC ratios were compared with hyaluronan levels and axillary lymph node status by the Mann-Whitney U test.ResultsNo statistically significant differences were found among the four ROI selection methods regarding minimum, mean, or maximum values of tumoral and peritumoral ADC. Visual assessment ROI measurements represented the less time-consuming evaluation method for the peritumoral area, and with sufficient accuracy. Peritumor/tumor ADC ratios obtained by all methods except the clockwise ROI (M3) showed a positive correlation with hyaluronan content (M1, p = 0.004; M2, p = 0.012; M3, p = 0.20; M4, p = 0.025) and lymph node metastasis (M1, p = 0.001; M2, p = 0.007; M3, p = 0.22; M4, p = 0.015), which are established factors for unfavorable prognosis.ConclusionsOur results suggest that the peritumor/tumor ADC ratio could be a readily applicable imaging index associated with axillary lymph node metastasis and extensive hyaluronan accumulation. It could be related to the biological aggressiveness of breast cancer and therefore might serve as an additional prognostic factor.Key Points• Out of four different ROI selection methods for peritumoral ADC evaluation, measurements based on visual assessment provided sufficient accuracy and were the less time-consuming method.• The peritumor/tumor ADC ratio can provide an easily applicable supplementary imaging index for breast cancer assessment.• A higher peritumor/tumor ADC ratio was associated with axillary lymph node metastasis and extensive hyaluronan accumulation and might serve as an additional prognostic factor.

Noninvasive assessment of H3 K27M mutational status in diffuse midline gliomas by using apparent diffusion coefficient measurements

PurposeH3 K27M-mutant diffuse midline gliomas are associated with worse prognosis than H3 K27M wild-type gliomas. In the present study, we sought to evaluate the conventional magnetic resonance imaging (cMRI) of H3 K27M-mutant glioma and examine whether diffusion-weighted imaging (DWI) derived apparent diffusion coefficient (ADC) could noninvasively predict H3 K27M mutational status in brain diffuse midline gliomas. Materials and methodsThe institutional review board approved this study and waived the requirement for informed consent. Thirty-eight patients with brain diffuse midline gliomas were retrospectively reviewed. The parameters of preoperative cMRI were evaluated. The minimal ADC, peritumoral ADC, ratio of minimal ADC, and ratio of peritumoral ADC were measured, and significant differences between the two groups were identified by logistic regression analysis adjusted for age and tumor location. Receiver operating characteristic curves and logistic regression analysis adjusted for age and tumor location were used to assess the diagnostic performances of the minimal ADC, peritumoral ADC, ratio of minimal ADC, and ratio of peritumoral ADC. ResultsH3 K27M-mutant gliomas in different locations have diverse imaging characteristics. Minimal ADC, peritumoral ADC, ratio of minimal ADC, and ratio of peritumoral ADC values were significantly lower in the H3 K27M-mutant gliomas than in the wild-type gliomas (P < 0.05). The combination of ratio of minimal ADC and ratio of peritumoral ADC provided the largest area under the curve (AUC) of 0.872 in defining H3 K27M-mutational status. ConclusionsThe combination of ratio of minimal ADC and ratio of peritumoral ADC can noninvasively detect the H3 K27M mutational status in brain diffuse midline gliomas.

Breast MRI for prediction of lymphovascular invasion in breast cancer patients with clinically negative axillary lymph nodes

ObjectiveTo retrospectively assess magnetic resonance imaging (MRI) findings that can predict lymphovascular invasion (LVI) in invasive breast cancer patients who were diagnosed with clinically negative axillary lymph nodes (LNs) preoperatively. MethodsThis study included 140 lesions of 140 patients who underwent preoperative breast MRI and breast surgery, with omission of axillary LN dissection. Clinical characteristics and MRI findings were evaluated. The T2 signal intensity (SI) ratio (mean T2 SI of the tumor/mean T2 SI of the muscle), tumor apparent diffusion coefficient (ADC) value, peritumoral ADC value, peritumor-tumor ADC ratio (peritumoral maximum ADC value/tumor mean ADC value), and ADC value of the contralateral breast parenchyma were retrospectively assessed. Statistical analyses were performed to identify significant factors for predicting LVI. Inter-observer variability was calculated. ResultsThe tumor ADC value (all ages: p = 0.005; age ≤ 55: p < 0.001), peritumoral ADC value (age ≤ 55: p = 0.04), and peritumor-tumor ADC ratio (all ages: p < 0.001; age ≤ 55: p < 0.001) were significantly associated with LVI on univariate analysis. Multivariate logistic regression analysis revealed significant differences in the pathological size of the invasive component and the tumor ADC value for predicting LVI (odds ratio [OR]: 3.43; 95% confidence interval [CI]: 1.41–8.32; p = 0.007; OR: 16.0; 95% CI: 1.89–136; p = 0.01, respectively). Inter-observer agreement was substantial for the tumor ADC value (intraclass correlation coefficient [ICC] = 0.77; 95% CI: 0.70–0.83) and the ADC value of the contralateral breast parenchyma (ICC = 0.68; 95% CI: 0.59–0.76). There was moderate agreement for the peritumoral ADC value (ICC = 0.53; 95% CI: 0.40–0.64) and the peritumor-tumor ADC ratio (ICC = 0.49; 95% CI: 0.35–0.61) and fair agreement for the T2 SI ratio (ICC = 0.30; 95% CI: 0.15–0.45). ConclusionWe found that the tumor ADC value, peritumoral ADC value, and peritumor-tumor ADC ratio were predictive MRI findings for LVI in patients aged ≤55. The tumor ADC value was the most significant predictor for LVI; moreover, inter-observer agreement for the tumor ADC value was substantial between two blinded observers with differences in interpretation experience.

RCBV- and ADC-based Grading of Meningiomas With Glimpse Into Emerging Molecular Diagnostics.

Introduction:This study was conducted to grade meningiomas based on relative Cerebral Blood Volume (rCBV) and Apparent Diffusion Coefficient (ADC) to help surgeons plan the approach and extent of operation as well as decide on the need of any adjuvant radio/chemo therapy. The current and evolving genomic, proteomic, and spectroscopic technologies are also discussed which can supplement the current radiologic methods and procedures in grading meningiomas.Methods:A total of 35 patients with meningioma prospectively underwent basic MR sequences (T1W, T2W, T2W/FLAIR) in axial, sagittal and coronal planes followed by Diffusion Weighted (DW) imaging having b value of 1000 (minimum ADC values used for analysis). Then, gadobenate dimeglumine/meglumine gadoterate was administered (0.1 mmol/kg at a rate of 4 mL/s) followed by saline flush (20 mL at a rate of 4 mL/s). Next, T2*W/FFE dynamic images were acquired; dynamics showing maximum fall in intensity was used for creating rCBV and relative Cerebral Blood Flow (rCBF) maps and calculating rCBV.Results:Both maximum rCBV and minimum ADC within the tumor were not significant for differentiating benign from malignant meningiomas. A cut-off maximum rCBV of 2.5 mL/100 g in peritumoral edema was 75% sensitive, 84.6% specific, and 83.3% accurate in differentiating benign from malignant meningiomas.Conclusion:Benign and malignant meningiomas can be differentiated based on maximum rCBV in peritumoral edema but ADC values within the tumor are insignificant in differentiating benign and malignant tumors. rCBV values within tumor, however, may be helpful in subtyping meningiomas, especially transitional and meningothelial meningiomas.

Impact of Angiotensin-II receptor blockers on vasogenic edema in glioblastoma patients.

Glioblastoma patients often require chronic administration of steroids due to peri-tumoral edema. Preliminary studies showed that treatment with Angiotensin-II Receptor Blockers (ARBs) for high blood pressure might be associated with reduced peri-tumoral edema. In this study, we aim to radiologically assess the effect of ARBs on peri-tumoral edema. We conducted a cross-sectional survey on patients with newly diagnosed GBM. Patients treated with ARBs for high blood pressure were paired to non ARB-treated patients based on similar age, tumor location and tumor size. Patients taking steroids at the time of pre-operative Magnetic Resonance Imaging were excluded from the study. In each pair of patients, we compared the volumes of peri-tumoral hyper T2-Fluid Attenuated Inversion Recovery (FLAIR) signal and the Apparent Diffusion Coefficient (ADC) in the same area. Eleven (11) ARB-treated patients were selected and paired to 11 non ARB-treated controls. Volumes of peri-tumoral hyper T2-FLAIR signal were significantly lower in the ARB-treated group than in the non ARB-treated group (p = 0.02). Additionally, peri-tumoral ADCs were also significantly lower in the treated group (p = 0.02), suggesting that the peri-tumoral area in this group had less edematous features. These results suggest that ARBs may reduce the volume of peri-tumoral hyper T2-FLAIR signal by decreasing edema.

NIMG-44IMPACT OF ANGIOTENSIN-II RECEPTOR BLOCKERS ON VASOGENIC EDEMA IN GLIOBLASTOMA PATIENTS

BACKGROUND: A significant morbidity in glioblastoma (GBM) patients is related to peri-tumoral edema, which requires chronic administration of steroids. Preliminary studies have shown that treatment with Angiotensin-II receptor blockers (ARBs) for high blood pressure might be associated with reduced peri-tumoral edema. Our goal in this study was to radiologically assess the effect of ARBs on peri-tumoral vasogenic edema. METHODS: We conducted a cross-sectional survey on patients with newly diagnosed GBM. Patients treated with ARBs for high blood pressure were paired to non ARB-treated patients, based on similar age, tumor location and longest diameter. Patients taking steroids at the time of their pre-operative Magnetic Resonance Imaging were not eligible for this study. In each pair of patients, we compared the volumes of peri-tumoral hyper T2 FLAIR signal and the apparent diffusion coefficient (ADC) selected in the same area. RESULTS: Eleven (11) patients treated with ARBs were selected and paired to 11 non ARB-treated controls. Volumes of peri-tumoral hyper T2 FLAIR signal were significantly lower in the ARB-treated group than in the non ARB-treated group (p = 0.02). Peri-tumoral ADCs were also significantly lower in the treated group (p = 0.02), suggesting that brain surrounding the tumor had less edematous characteristics when patients were treated with ARBs. CONCLUSION: All together, these results suggest that ARBs could reduce the volume of peri-tumoral hyper T2 FLAIR signal by decreasing vasogenic edema.

Apparent diffusion coefficient and Magnetic resonance spectroscopy in grading of malignant brain neoplasms

AimThis work aims to study the role of combined apparent diffusion coefficient (ADC) and Magnetic resonance spectroscopy (MRS) in grading malignant brain neoplasms. MethodsA prospective study included 40 patients who were evaluated by standard contrast enhanced MRI, diffusion weighted imaging and multivoxel spectroscopy. ResultsStatistically significant difference was found between tumoral ADC values in low grade versus high grade tumors and metastasis and also between the peritumoral ADC values in metastasis versus low and high grade tumors. Statistically significant difference is noticed between tumoral Cho/Cr ratio values in low grade versus high grade tumors and metastasis, and also peritumoral Cho/Cr ratio values in low grade and metastasis versus high grade tumors. Statistically significant difference between tumoral Cho/NAA ratio in low grade versus high grade tumors and metastasis and lastly between peritumoral Cho/NAA ratio in low grade and metastasis versus high grade tumors was found. Lipid and lactate peaks were found frequently in high grade tumors and metastasis. ConclusionThe combination of calculated ADC values and MR spectroscopy is useful in grading of malignant brain tumors and were more useful together than each on its own.

Diagnostic Value of Peritumoral Minimum Apparent Diffusion Coefficient for Differentiation of Glioblastoma Multiforme From Solitary Metastatic Lesions

In glioblastoma multiforme, the peritumoral region may be infiltrated with malignant cells in addition to vasogenic edema, whereas in a metastatic deposit, the peritumoral areas comprise predominantly vasogenic edema. The purpose of this study was to determine whether the minimum apparent diffusion coefficient (ADC) can be used to differentiate glioblastoma from solitary metastasis on the basis of cellularity levels in the enhancing tumor and in the peritumoral region. Seventy-three patients underwent conventional MRI and diffusion-weighted imaging (DWI) before undergoing treatment. The minimum ADC was measured in the enhancing tumor, peritumoral region, and contralateral normal white matter. To determine whether there was a statistical difference between metastasis and glioblastoma, we analyzed patient age and sex, minimum ADC value, and ADC ratio of the two groups. A receiver operating characteristic (ROC) curve analysis was used to determine the cutoff value of the minimum ADC that had the best combination of sensitivity and specificity for distinguishing between glioblastoma and metastasis. The mean minimum ADC values and mean ADC ratios in the peritumoral regions of glioblastomas were significantly higher than those in metastases. However, the mean minimum ADC values and mean ADC ratios in enhancing tumors showed no statistically significant difference between the two groups. According to ROC curve analysis, a cutoff value of 1.302 × 10(-3) mm(2)/s for the minimum peritumoral ADC value generated the best combination of sensitivity (82.9%) and specificity (78.9%) for distinguishing between glioblastoma and metastasis. Although the characteristics of solitary metastasis and glioblastoma multiforme may be similar on conventional MRI, DWI can offer diagnostic information to distinguish between the tumors.