Intratumoral Susceptibility Signal Research Articles

Intravoxel incoherent motion and enhanced T2*-weighted angiography for preoperative prediction of microvascular invasion in hepatocellular carcinoma.

To investigate the value of the combined application of intravoxel incoherent motion (IVIM) and enhanced T2*-weighted angiography (ESWAN) for preoperative prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC). 76 patients with pathologically confirmed HCC were retrospectively enrolled and divided into the MVI-positive group (n=26) and MVI-negative group (n=50). Conventional MRI, IVIM, and ESWAN sequences were performed. Three region of interests (ROIs) were placed on the maximum axial slice of the lesion on D, D*, and f maps derived from IVIM sequence, and R2* map derived from ESWAN sequence, and intratumoral susceptibility signal (ITSS) from the phase map derived from ESWAN sequence was also automatically measured. Receiver operating characteristic (ROC) curves were drawn to evaluate the ability for predicting MVI. Univariate and multivariate logistic regression were used to screen independent risk predictors in clinical and imaging information. The Delong's test was used to compare the differences between the area under curves (AUCs). The D and D* values of MVI-negative group were significantly higher than those of MVI-positive group (P=0.038, and P=0.023), which in MVI-negative group were 0.892×10-3 (0.760×10-3, 1.303×10-3) mm2/s and 0.055 (0.025, 0.100) mm2/s, and in MVI-positive group were 0.591×10-3 (0.372×10-3, 0.824×10-3) mm2/s and 0.028 (0.006, 0.050)mm2/s, respectively. The R2* and ITSS values of MVI-negative group were significantly lower than those of MVI-positive group (P=0.034, and P=0.005), which in MVI-negative group were 29.290 (23.117, 35.228) Hz and 0.146 (0.086, 0.236), and in MVI-positive group were 43.696 (34.914, 58.083) Hz and 0.199 (0.155, 0.245), respectively. After univariate and multivariate analyses, only AFP (odds ratio, 0.183; 95% CI, 0.041-0.823; P = 0.027) was the independent risk factor for predicting the status of MVI. The AUCs of AFP, D, D*, R2*, and ITSS for prediction of MVI were 0.652, 0.739, 0.707, 0.798, and 0.657, respectively. The AUCs of IVIM (D+D*), ESWAN (R2*+ITSS), and combination (D+D*+R2*+ITSS) for predicting MVI were 0.772, 0.800, and, 0.855, respectively. When IVIM combined with ESWAN, the performance was improved with a sensitivity of 73.1% and a specificity of 92.0% (cut-off value: 0.502) and the AUC was significantly higher than AFP (P=0.001), D (P=0.038), D* (P=0.023), R2* (P=0.034), and ITSS (P=0.005). The IVIM and ESWAN parameters showed good efficacy in prediction of MVI in patients with HCC. The combination of IVIM and ESWAN may be useful for noninvasive prediction of MVI before clinical operation.

Peranan Sekuen Susceptibility Weight Imaging (SWI) Pada Pemeriksaan MRI Brain Pada Kasus Tumor

The aim of the research is to find out the role of the transverse suspectibility weighted imaging (SWI) sequence in brain MRI examination techniques in tumor cases. The research method used in this research is a qualitative descriptive study that uses a literature study approach to explore, analyze and identify information about how the Susceptibility Weighted Imaging (SWI) sequence plays a role in the Brain MRI examination process in patients who have tumors. The results and discussion of the literature review show: 1) Susceptibility-Weighted Imaging (SWI) on MRI brain has an important role in detecting blood degradation products, calcification and iron accumulation in glioblastoma. SWI allows visualization of small blood vessels, detection of iron, as well as identification of areas of calcification within the tumor, providing a more detailed picture of the nature and malignancy of glioblastoma. The Intratumoral Susceptibility Signal (ITSS) on SWI images is a visual marker associated with microhemorrhage, neoangiogenesis, and calcification, enabling tumor grading based on the frequency and distribution of these signals. In addition, Intralesional Susceptibility Signal (ILSS) also has an important role in differentiating glioblastoma from abscesses and metastases, with high levels of ILSS tending to be associated with tumor severity. Thus, the integration of SWI and ITSS and ILSS analysis can make a significant contribution to the characterization and assessment of the level of malignancy. 2) Susceptibility-Weighted Imaging (SWI) in the diagnosis of glioblastoma has the advantage of providing internal visualization of the tumor with high resolution. SWI is highly sensitive to differences in tissue susceptibility, allows the detection of neovascularization, hemorrhage, and calcification within glioblastoma, and provides detailed information about cerebral vascular anatomy. The advantages of SWI include its ability to image the Intratumoral Susceptibility Signal (ITSS) and Intralesional Susceptibility Signal (ILSS) and increase the visibility of low signal intensity structures. However, its shortcomings, namely sensitivity to artifacts, dependence on susceptibility phenomena, and subjective interpretation are aspects that need to be considered.

Magnetic resonance imaging-derived parameters to predict response to regorafenib in recurrent glioblastoma.

Regorafenib is a multikinase inhibitor, approved as a preferred regimen for recurrent glioblastoma (rGB). Although its effects on prolonging survival could seem modest, it is still unclear whether a subset of patients, potentially identifiable by imaging biomarkers, might experience a more substantial positive effect. Our aim was to evaluate the potential value of magnetic resonance imaging-derived parameters as non-invasive biomarkers to predict response to regorafenib in patients with rGB. 20 patients with rGB underwent conventional and advanced MRI at diagnosis (before surgery), at recurrence and at first follow-up (3months) during regorafenib. Maximum relative cerebral blood volume (rCBVmax) value, intra-tumoral susceptibility signals (ITSS), apparent diffusion coefficient (ADC) values, and contrast-enhancing tumor volumes were tested for correlation with response to treatment, progression-free survival (PFS), and overall survival (OS). Response at first follow-up was assessed according to Response Assessment in Neuro-Oncology (RANO) criteria. 8/20 patients showed stable disease at first follow-up. rCBVmax values of the primary glioblastoma (before surgery) significantly correlated to treatment response; specifically, patients with stable disease displayed higher rCBVmax compared to progressive disease (p = 0.04, 2-group t test). Moreover, patients with stable disease showed longer PFS (p = 0.02, 2-group t test) and OS (p = 0.04, 2-group t test). ITSS, ADC values, and contrast-enhancing tumor volumes showed no correlation with treatment response, PFS nor OS. Our results suggest that rCBVmax of the glioblastoma at diagnosis could serve as a non-invasive biomarker of treatment response to regorafenib in patients with rGB.

Prediction of Ki-67 labeling index, ATRX mutation, and MGMT promoter methylation status in IDH-mutant astrocytoma by morphological MRI, SWI, DWI, and DSC-PWI.

Noninvasive detection of molecular status of astrocytoma is of great clinical significance for predicting therapeutic response and prognosis. We aimed to evaluate whether morphological MRI (mMRI), SWI, DWI, and DSC-PWI could predict Ki-67 labeling index (LI), ATRX mutation, and MGMT promoter methylation status in IDH mutant (IDH-mut) astrocytoma. We retrospectively analyzed mMRI, SWI, DWI, and DSC-PWI in 136 patients with IDH-mut astrocytoma.The features of mMRI and intratumoral susceptibility signals (ITSS) were compared using Fisher exact test or chi-square tests. Wilcoxon rank sum test was used to compare the minimum ADC (ADCmin), and minimum relative ADC (rADCmin) of IDH-mut astrocytoma in different molecular markers status. Mann-Whitney U test was used to compare the rCBVmax of IDH-mut astrocytoma with different molecular markers status. Receiver operating characteristic curves was performed to evaluate their diagnostic performances. ITSS, ADCmin, rADCmin, and rCBVmax were significantly different between high and low Ki-67 LI groups. ITSS, ADCmin, and rADCmin were significantly different between ATRX mutant and wild-type groups. Necrosis, edema, enhancement, and margin pattern were significantly different between low and high Ki-67 LI groups. Peritumoral edema was significantly different between ATRX mutant and wild-type groups. Grade 3 IDH-mut astrocytoma with unmethylated MGMT promoter was more likely to show enhancement compared to the methylated group. mMRI, SWI, DWI, and DSC-PWI were shown to have the potential to predict Ki-67 LI and ATRX mutation status in IDH-mut astrocytoma. A combination of mMRI and SWI may improve diagnostic performance for predicting Ki-67 LI and ATRX mutation status. Conventional MRI and functional MRI (SWI, DWI, and DSC-PWI) can predict Ki-67 expression and ATRX mutation status of IDH mutant astrocytoma, which may help clinicians determine personalized treatment plans and predict patient outcomes. • A combination of multimodal MRI may improve the diagnostic performance to predict Ki-67 LI and ATRX mutation status. • Compared with IDH-mutant astrocytoma with low Ki-67 LI, IDH-mutant astrocytoma with high Ki-67 LI was more likely to show necrosis, edema, enhancement, poorly defined margin, higher ITSS levels, lower ADC, and higher rCBV. • ATRX wild-type IDH-mutant astrocytoma was more likely to show edema, higher ITSS levels, and lower ADC compared to ATRX mutant IDH-mutant astrocytoma.

Apparent Diffusion Coefficient Values and Intra-tumoral Susceptibility Signals in Meningiomas and Schwannomas: Useful Tools for Challenging Cases

Background: We aimed to estimate the diagnostic accuracy of apparent diffusion coefficient values (ADC) and intra-tumoral susceptibility signals (ITSS) in differentiating meningiomas and schwannomas. Methods: This retrospective study included 41 patients with 23 histopathologically proven meningiomas (20 patients with benign meningioma and 3 patients with high-grade meningioma) and 18 schwannomas. We calculated the mean ADC values and ADC ratio from ADC maps and intratumoral susceptibility signals (ITSS) in susceptibility-weighted imaging (SWI) for all patients. The quantitative variables were compared between the tumor groups using t test and the qualitative variables were compared between them using Chi-square test. Results: In this study, the mean ADC value of meningiomas (0.86±0.11×10-3 mm2 /s, range 0.67-1.04) was lower than schwannomas (1.32±0.16×10-3 mm2 /s, range 1.10-1.65) with no overlap in the range of ADC values. The mean ADC ratio of schwannomas (2.0±0.29, range 1.45- 2.58) was higher than meningiomas (1.24±0.17, range 0.83-1.64) with some overlap. We found significant difference in mean ADC value and ADC ratio between meningiomas and schwannomas. The presence of intratumoral microhemorrhages (ITSS-H) in SWI was more suggestive of schwannomas and the presence of calcification was in favor of benign meningiomas. We did not find any significant difference in mean ADC value and ADC ratio between benign and high-grade meningiomas with considerable overlap in their range. Conclusion: Additional magnetic resonance imaging findings such as ADC values and ITSS in SWI can help better pre-operative diagnosis of meningiomas and schwannomas, particularly in challenging patients.

High intratumoral susceptibility signal grade on susceptibility-weighted imaging: a risk factor for hemorrhage after stereotactic biopsy.

This study aimed to examine the association of preoperative intratumoral susceptibility signal (ITSS) grade with hemorrhage after stereotactic biopsy (STB). The authors retrospectively reviewed 66 patients who underwent STB in their institution. Preoperative factors including age, sex, platelet count, prothrombin time-international normalized ratio, activated thromboplastin time, antiplatelet agent use, history of diabetes mellitus and hypertension, target location, anesthesia type, and ITSS data were recorded. ITSS was defined as a dot-like or fine linear low signal within a tumor on susceptibility-weighted imaging (SWI) and was graded using a 3-point scale: grade 1, no ITSS within the lesion; grade 2, 1-10 ITSSs; and grade 3, ≥ 11 ITSSs. Postoperative final tumor pathology was also reviewed. The association between preoperative variables and the size of postoperative hemorrhage was examined. Thirty-four patients were men and 32 were women. The mean age was 66.6 years. The most common tumor location was the frontal lobe (27.3%, n = 18). The diagnostic yield of STB was 93.9%. The most common pathology was lymphoma (36.4%, n = 24). The ITSS was grade 1 in 37 patients (56.1%), grade 2 in 14 patients (21.2%), and grade 3 in 15 patients (22.7%). Interobserver agreement for ITSS was almost perfect (weighted kappa = 0.87; 95% CI 0.77-0.98). Age was significantly associated with ITSS (p = 0.0075). Postoperative hemorrhage occurred in 17 patients (25.8%). Maximum hemorrhage diameter (mean ± SD) was 1.78 ± 1.35 mm in grade 1 lesions, 2.98 ± 2.2 mm in grade 2 lesions, and 9.51 ± 2.11 mm in grade 3 lesions (p = 0.01). Hemorrhage > 10 mm in diameter occurred in 10 patients (15.2%), being symptomatic in 3 of them. Four of 6 patients with grade 3 ITSS glioblastomas (66.7%) had postoperative hemorrhages > 10 mm in diameter. After adjusting for age, ITSS grade was the only factor significantly associated with hemorrhage > 10 mm (p = 0.029). Compared with patients with grade 1 ITSS, the odds of postoperative hemorrhage > 10 mm in diameter were 2.57 times higher in patients with grade 2 ITSS (95% CI 0.31-21.1) and 9.73 times higher in patients with grade 3 ITSS (95% CI 1.57-60.5). ITSS grade on SWI is associated with size of postoperative hemorrhage after STB.

Improvement grading brain glioma using T2 relaxation times and susceptibility-weighted images in MRI

Developing a new non-invasive, and accurate method for glioma grading for glioma treatment and management is very important. Magnetic resonance imaging (MRI) has many applications in the field of neuroimaging. The study aims to create a precise way to improve glioma grading using different MRI image weights. There were 47 participants in this study. A 1.5 T MRI scanner acquired T2 multi-echoes (T2 ME) with eight echoes for T2 maps reconstruction, Susceptibility-Weighted Imaging (SWI), and T1 post-contrast. T2 maps were reconstructed from T2 ME data using homemade MATLAB code. To compare T2 relaxation times and intratumoral susceptibility signal intensity (ITSS) between the high-grade gliomas (HGGs) and low-grade gliomas (LGGs) and other analyses, we used SPSS software. There was a significant difference in T2 relaxation times and ITSS between the HGGs and LGGs. The average T2 relaxation times in HGGs and LGGs were 0.12 and 0.16 s, respectively. Further analysis showed that the ITSS in HGGs is significantly greater than in LGGs. There was a significant negative correlation between T2 relaxation times and ITSS in gliomas. It is interesting to note that combining T2 relaxation times, ITSS, and tumor enhancement status data with a multivariate binary logistic regression model can increase the area under the curve (AUC) to 0.94 for glioma-grade classification. We recommended the clinical use of combined T2 maps, SWI, and T1 post-contrast image-weights data with a multivariate binary logistic regression model for improving glioma grading.

Differentiation between germinoma and other pineal region tumors using diffusion-and susceptibility-weighted MRI

PurposeTo evaluate the effectiveness of diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) for differentiation between germinoma and other pineal region tumors. MethodThis retrospective study consisted of 72 patients with pathologically proven pineal region tumors between January 2010 and August 2020. Tumors were classified as germinomas (40), non-germinomatous germ cell tumors (11) (NGGCT), pineal parenchymal tumors (10) (PPT), and other types of tumors (11). Visual scale score, ADC values and SWI intratumoral susceptibility signal (ITSS) score were analyzed and compared to histopathology data. ResultsThe mean apparent diffusion coefficient (ADCmean) and minimum apparent diffusion coefficient (ADCmin) ratio of germinoma were significantly lower than NGGCT. ADCmean or ADCmin cut-off ratio of ≤ 1.48 or ≤ 1.32 allowed for discrimination between germinoma and NGGCT with sensitivity and specificity of 100 % and 63.6 %. An ADCmin cut-off ratio of ≥ 0.93 allowed for discrimination between germinoma and PPT with sensitivity and specificity of 60 % and 80.0 %. ADCmin cut-off ratio of ≤ 1.15 allowed for discrimination of germinoma from other types of tumors with sensitivity and specificity of 87.5 % and 54.5 %. ConclusionsADC ratio can differentiate germinoma from other types of pineal region tumors. Our initial results suggest that ITSS score was not significantly correlated with specific histology subtype.

PEDT-5 PREOPERATIVE MAGNETIC RESONANCE IMAGING AND INTRAOPERATIVE BLOOD LOSS IN CHILDHOOD POSTERIOR FOSSA TUMORS

Abstract Background and Purpose For removal of childhood posterior fossa tumors, it is important to control bleeding while internally decompressing the tumor. Evaluation of tumor vascularity by preoperative magnetic resonance imaging (MRI) is thought to be effective in predicting and controlling blood loss. In this study, we evaluated the relationship between imaging features, mainly susceptibility-weighted imaging (SWI), and the amount of intraoperative blood loss. Methods Among childhood posterior fossa tumors operated on by the same surgeon between January 2016 and March 2022, 9 cases in which preoperative MRI data could be analyzed and total or subtotal resection was achieved were included. The SWI: intratumoral susceptibility signals (ITSS) grade, an index of tumor vascularity, was used to evaluate the association between the degree of vascularity (ITSS: 0-2 vs. ITSS: 3) and multiple factors, including intraoperative blood loss, in a univariate analysis. In addition, the intraoperative blood loss was analyzed by multivariate analysis. Results There were 3 males and 6 females with a median age of 6 years (5-11). Seven medulloblastomas, one atypical teratoid/rhabdoid tumor, and one ependymoma were included. Univariate analysis showed that patients with higher vascularity (ITSS: 3) had significantly higher intraoperative blood loss (p=0.016) and larger tumor volume (p=0.032). In multivariate analysis with age, degree of contrast enhancement, degree of vascularity, tumor volume, and degree of tumor resection as independent variables, the degree of vascularity was not significantly associated with intraoperative blood loss (p=0.477), but only with tumor volume (p=0.036). Conclusion Although the degree of tumor vascularity may be related to intraoperative blood loss, there was a strong correlation between the degree of vascularity and tumor volume, and multivariate analysis of intraoperative blood loss showed that only tumor volume was a significant factor. Higher tumor vascularity was associated with larger tumor volume, which may result in increased intraoperative bleeding.

Contributional role of susceptibility-weighted imaging and apparent diffusion coefficient in pediatric brain tumor grading

BackgroundCentral nervous system neoplasms are a primary cause of mortality and one of the most frequent solid tumors in children. Magnetic resonance imaging (MRI) plays a key role in the diagnosis and treatment response of pediatric brain tumors as well as providing us with functional information regarding cellularity, metabolism, and neoangiogenesis. This study aimed to evaluate the contributional role of susceptibility-weighted imaging (SWI) and diffusion weight imaging (DWI) in pediatric brain tumor grading by assessing the intratumoral susceptibility signals (ITSS), apparent diffusion coefficient (ADC), and relative ADC (rADC).ResultsA significant correlation was noted between the (ITSS) score and the brain tumor grade (P < 0.001) with a descending trend in the low-grade tumor (ITSS score 0 = 14/29, score 1 = 11/29, and score 2 = 4/29) and an ascending trend in the high-grade tumor (ITSS score 0 = 4/41, score 1 = 9/41 and score 2 = 22/41). No embryonal tumor showed an ITSS score of 0. Apparent diffusion coefficient sensitivity and specificity were 82.9% and 82.8%, respectively, while rADC sensitivity and specificity were 91.4% and 86.2%, respectively. For high-grade tumors, the ITSS score 2 had a significant positive prediction (P = 0.009) and the rADC value had a significant negative prediction (P = 0.031).ConclusionsSusceptibility-weighted imaging ITSS score, ADC, and rADC have a promising role in preoperative pediatric brain tumor grading and should be considered as complementary sequences to routine MRI studies.

Grading of IDH-mutant astrocytoma using diffusion, susceptibility and perfusion-weighted imaging

BackgroundThe accurate grading of IDH-mutant astrocytoma is essential to make therapeutic strategies and assess the prognosis of patients. The purpose of this study was to investigate the usefulness of DWI, SWI and DSC-PWI in grading IDH-mutant astrocytoma.MethodsOne hundred and seven patients with IDH-mutant astrocytoma who underwent DWI, SWI and DSC-PWI were retrospectively reviewed. Minimum apparent diffusion coefficient (ADCmin), intratumoral susceptibility signal intensity(ITSS) and maximum relative cerebral blood volume (rCBVmax) values were assessed. ADCmin, ITSS and rCBVmax values were compared between grade 2 vs. grade 3, grade 3 vs. grade 4 and grade 2 + 3 vs. grade 4 tumors. Logistic regression, tenfold cross-validation,and receiver operating characteristic (ROC) curve analyses were used to assess their diagnostic performances.ResultsGrade 4 IDH-mutant astrocytomas showed significantly lower ADCmin and higher rCBVmax as compared to grade 3 tumors (adjusted P < 0.001). IDH-mutant grade 3 astrocytomas showed significantly lower ITSS levels as compared with grade 4 tumors (adjusted P < 0.001). ITSS levels between IDH-mutant grade 2 and grade 3 astrocytomas were significantly different (adjusted P = 0.002). Combined the ADCmin, ITSS and rCBVmax resulted in the highest AUC for differentiation grade 2 and grade 3 tumors from grade 4 tumors.ConclusionADCmin, rCBVmax and ITSS can be used for grading the IDH-mutant astrocytomas. The combination of ADCmin, ITSS and rCBVmax could improve the diagnostic performance in grading of IDH-mutant astrocytoma.

High-Resolution Intratumoral Susceptibility Signal (ITSS) as an Adjunctive Imaging Tool in the Evaluation of Treatment Response of Brain Metastases Following Stereotactic Radiosurgery

Purpose: To evaluate the longitudinal change of intra-tumoral susceptibility signal (ITSS) on high-resolution SWI as an adjunctive imaging tool to evaluate treatment response of brain metastasis following stereotactic radiosurgery. This approach will allow further stratification of the patients and guide clinical decision making. Methods: An IRB approved retrospective study included 63 brain metastatic lesions within 49 patients (33 females and 16 males) who have undergone stereotactic radiosurgery with at least one follow-up MRI and available clinical data. The average age was 63.17 years (±1.48, ranged from 34-83 years). The longitudinal change in ITSS was categorized into 3 groups; increased, stable and decreased. The treatment response of each lesion was evaluated according to the longitudinal change in size, enhancement and susceptibility at the baseline and follow-up MRIs. Chi-square test was used to compare differences in categorical variables. Receiver operating characteristics (ROC) curve was used to evaluate the accuracy of including longitudinal change in ITSS with size and enhancement pattern in determining the treatment response following SRS. Results: Our results demonstrated higher sensitivity and specificity when including longitudinal change in ITSS with size and enhancement for the evaluation of the treatment response of brain metastatic lesions treated with SRS. There was statistically significant difference between the different ITSS and enhancement patterns at baseline and follow-up MRIs (Wilcoxon Signed Ranks Test (p = .000, and .003) respectively. The multiparametric analysis of the longitudinal change in size, contrast enhancement, and ITSS in the evaluation of treatment response in the follow-up MRIs, showed that the sensitivity and specificity significantly improved (AUC 0.953). Conclusion: High resolution SWI can contribute as an imaging biomarker with supplemental information for monitoring treatment and predicting treatment response. High resolution SWI can complement the standard contrast enhanced T1 images to evaluate treatment response with a multiparametric MRI approach.

Intra-tumoral susceptibility signal: a post-processing technique for objective grading of astrocytoma with susceptibility-weighted imaging

Susceptibility-weighted imaging (SWI) is sensitive to the accumulation of paramagnetic substances, such as hemorrhage and increased venous vasculature, both being frequently found in high-grade tumors. The purpose of this retrospective study is to differentiate high-grade and low-grade astrocytoma by objectively measuring quantitative intra-tumoral susceptibility signals (qITSS) on SWI. Precontrast SWI and 3D contrast-enhanced T1WI of 65 patients with astrocytoma were collected at 1.5 Tesla. All tumors were histologically confirmed and classified into two groups: high grade (WHO grade III and IV, n=50) and low grade (WHO grade II, n=15). After manual delineation of the tumor on T1WI, normalized contrast (NC) was calculated voxel by voxel within the tumor by using the concept of contrast to noise ratio. Thresholding on NC was applied to detect qITSS, and the volumetric percentage of qITSS can be obtained for each tumor. Two-sample t-test was applied to examine significant difference of qITSS percentage between high-grade and low-grade astrocytoma for different NC thresholds, ranging from 4 to 20. Receiver operating characteristic analysis was performed to evaluate the performance of differentiation. P value was less than 0.01 for a large range of NC thresholds [4-20], reflecting significant difference of qITSS percentage between high-grade and low-grade astrocytoma. The area under the receiver operating characteristic curve was larger than 0.9 at NC thresholds from 8 to 16 and peaks at 0.949 with a NC threshold of 14. It was shown that astrocytoma grading by qITSS percentage is successful for a wide range of NC threshold, demonstrating robustness on threshold selection. Without relying on the selection of slice position and at the same time providing objective identification of hypointense signal in SWI, the qITSS percentage can be used to distinguish high-grade and low-grade astrocytoma reliably.

Advanced multiparametric MRI-based scoring for isocitrate dehydrogenase mutation prediction of gliomas.

To propose an advanced multiparametric magnetic resonance imaging (MRI)-based scoring system and evaluate its diagnostic accuracy with respect to the isocitrate dehydrogenase (IDH) mutation status of gliomas. This prospective observational study included 50 consecutive patients with suspected gliomas, enrolled for pre-operative MRI. The exclusion criteria were previous surgery, biopsy, or chemo/radiotherapy and contraindications to the gadolinium-based contrasts or MRI acquisition. A standardized brain-MRI protocol using a 3-Tesla machine and 16-channel head coil consisted of pre-contrast axial-T2WI, FLAIR, DTI, 3D-ASL perfusion, SWI, 3D-T1WI, and post-contrast axial-DSC perfusion followed by 3D-T1WI and MR spectroscopy. ROIs were drawn from the tumoral centre, periphery, and peritumoral oedema (3 ROIs for each) followed by normalization using the ROIs over the contralateral normal white matter. The cut-off values for the statistically significant (p <0.05) continuous variables were derived by drawing receiver operating characteristic (ROC) curves. A 7-point "glioma-score" was derived from the 3 categorical (T2/FLAIR-mismatch, contrast enhancement, and intratumoral susceptibility signals) and 4 continuous ROI-based variables (ADC, FA, ASL-CBF, and DSC-CBV). The predictability of IDH mutant status using the multiparametric advanced MRI-based glioma score was statistically significant (sensitivity = 69.23%, specificity = 95.65%, PPV = 94.74%, NPV = 73.33%). A glioma score of more than 4.5 out of 7 predicted the IDH-mutation status with higher specificity and sensitivity compared to each of the individual imaging variables. The advanced multiparametric MRI-based glioma score can predict the IDH-mutation status with high statistical significance.

Multiparametric differentiation of intracranial central nervous system lymphoma and high-grade glioma using diffusion-, perfusion-, susceptibility-weighted magnetic resonance imaging, and spectroscopy

Aims and Objectives: To observe the characteristics of primary central nervous system lymphoma (PCNSL) and high-grade glioma (HGG) in diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI), susceptibility-weighted imaging (SWI) and spectroscopy, and differentiate them based on these parameters. Materials and Methods: A total of 45 patients diagnosed with the central nervous system (CNS) neoplasm on magnetic resonance imaging (MRI) using 1.5 Tesla MRI Siemens Magnetom Avanto (Siemens, Germany) and with subsequent histopathological evidence as glioblastoma or CNS lymphoma were included. The study was completed over a period of 2 years. Results: It was found that DWI is effective in the differentiation of HGGs and PCNSLs. A total of 20 (57.1%) HGGs showed diffusion restriction, whereas 9 (90%) of the PCNSLs showed diffusion restriction. The mean apparent diffusion coefficient (ADC) (×10–6 mm2/s) in PCNSLs was 646 whereas, in HGGs, it was found to be 824.3. Thirty-one (88.6%) of the HGGs showed increased perfusion. The mean value of rCBVmean in HGG was found to be 4.06 and the mean value of rCBVmax was 3.63. None of the PCNSLs showed increased perfusion. The mean value of rCBVmean in PCNSLs was 0.097 and rCBVmax was 0.133. 30 (85.7%) of HGGs showed significant areas of blooming on SWI (in the form of intratumoral susceptibility signals [ITSS]). None of the PCNSLs showed blooming. All HGGs and PCNSLs showed increased choline and decreased N acetyl aspartate (NAA) on spectroscopy. Mean Choline/Creatine (Cho/Cr) in HGGs was found to be 3.06, whereas in PCNSLs, it was 1.84. Conclusion: It is important to make a distinction between HGG and PCNSL as the treatment modalities are different for both. Multiparametric evaluation of ADC, ITSS, and rCBVmean allows the differentiation of PCNSLs and solid glioblastoma which supports the integration of advanced MR imaging techniques including DSC-PWI, DWI, and SWI for the routine diagnostic workup of these tumors.

Qualitative and quantitative diagnosis of intramuscular hemangioma subtypes: Diagnostic performance comparison of ESWAN and conventional MRI.

Preoperative identification of intramuscular hemangioma (IMH) subtypes (capillary hemangioma, cavernous hemangioma, and mixed hemangioma) is urgently necessary. Enhanced T2*-weighted angiography (ESWAN) is sensitive to vessels and metabolites and can be used to diagnose IMH subtypes. To compare the diagnostic performances of ESWAN and conventional magnetic resonance imaging (MRI) for qualitative and quantitative diagnosis of IMH subtypes. In total, 23 patients with IMHs were examined using conventional MRI and ESWAN. The signal intensity ratios (SIRs) of conventional MRI and ESWAN were measured. There was no significant difference for volume among the three subtypes (P = 0.124, P = 0.145). Various shapes and MRI signals were shown in the three subtypes of IMH. There was no significant difference for SIRs of conventional MRI (P = 0.558, P = 0.259, P = 0.385, P = 0.347). However, there was a significant difference for SIRs of ESWAN parameters (P = 0.050, P < 0.001, P = 0.005, P = 0.002). Capillary hemangiomas can be diagnosed when R2* SIR is <0.912 and intratumoral susceptibility signal (ITSS) percentage is <29.085%. Cavernous hemangiomas should be considered when R2* SIR is >0.912, ITSS percentage >35.226%, and phase SIR >2.536. In addition, mixed hemangiomas should be considered when T2* SIR is >0.662 and R2* SIR <1.618. Conventional MRI can only display the volume, shape, and signal of IMHs. 3D-MinIP imaging of ESWAN can show the veins and minor hemorrhage. SIRs of ESWAN parameters including T2* value, R2* value, phase value, and percentage of ITSS can be used to quantitatively diagnose capillary hemangiomas, cavernous hemangiomas, and mixed hemangiomas.

Feasibility of intravoxel incoherent motion in the assessment of tumor microvasculature and blood-brain barrier integrity: a case-based evaluation of gliomas.

To evaluate the feasibility of intravoxel incoherent motion (IVIM) in assessing blood-brain barrier (BBB) integrity and microvasculature in tumoral tissue of glioma patients. Images from 8 high-grade and 4 low-grade glioma patients were acquired on a 3T MRI scanner. Acquisition protocol included pre- and post-contrast T1- and T2-weighted imaging, FLAIR, dynamic susceptibility contrast (DSC), and susceptibility-weighted imaging (SWI). In addition, IVIM was acquired with 15 b-values and fitted under the non-negative least square (NNLS) model to output the diffusion (D) and pseudo-diffusion (D*) coefficients, perfusion fraction (f), and f times D* (fD*) maps. IVIM perfusion-related maps were sensitive to (1) blood flow and perfusion alterations within the microvasculature of brain tumors, in agreement with intra-tumoral susceptibility signal (ITSS); (2) enhancing areas of BBB breakdown in agreement with DSC maps as well as areas of BBB abnormality that was not detected on DSC maps; (3) enhancing perfusion changes within edemas; (4) detecting early foci of increased perfusion within low-grade gliomas. The results suggest IVIM may be a promising approach to delineate tumor extension and progression in size, and to predict histological grade, which are clinically relevant information that characterize tumors and guide therapeutic decisions in patients with glioma.

Role of susceptibility weighted imaging (SWI) in assessment of intra axial brain neoplasms in adults

Abstract Background Susceptibility weighted imaging (SWI) is a 3D gradient-echo MR technique that is based on blood oxygen level dependent (BOLD) induced phase effects between the venous blood and the surrounding brain parenchyma. SW-MR imaging allows for noninvasive visualization of small veins at submillimeter resolution and, therefore, is used to depict venous architecture in brain lesions. The extreme sensitivity of SWI for the detection of neovascularity (venous blood), haemorrhage, and calcification has been an indispensable tool for characterization of the internal architecture of brain tumours. Objectives Is to evaluate the role of Susceptibility weighted imaging in assessment of adults Intra axial brain Neoplasms, and its ability to characterize them into high and low grade lesions in comparison to histopathology which will be used as gold standard. Methods A cross sectional study including 31 patients suspecting intracranial brain neoplasm radiologically and clinically, conducted at Private center, the patients were investigated using Siemens machine Magnetom Skyra 3T, the period was between January 2018 till the end of June 2019 . Results Our study included 31 patients. Including 15 female and 16 male patients, with the patient’s age ranging from 20 to 68 years old with median 48 years old ranging from 35.75 (25% percentile) to 58.75 (75% percentile). Among total cases, there were 8 patients with grade 2 glioma, 10 patients with grade 3 glioma and 6 patients with grade 4 glioma, 2 patients with lymphoma and 5 patients with brain metastasis (1 lung cancer and 4 breast cancer). All the patients were evaluated with MRI including SWI sequence with special comment on the number of the intratumoral susceptibility signal (ITSS), the size of the ITSS, its morphology as well as the ratio of the ITSS to the tumor size, which were then correlated with the patient histopathological results obtained later. The study revealed that the best parameter to accurately grade the tumor is the number of ITSS within the lesion with P value 0.001, followed by the size of the ITSS with P value 0.002 and Pearson Chi-Square value equals 20.6, while the lowest one was the ratio of the ITSS to the tumor size with P value 0.002 Pearson Chi-Square value equals 17.3. Our study showed that the morphology alone was not able to accurately grade the tumor with P value 0.007 ( Not significant) Conclusion SWI using 3T MR system provides quite useful information for preoperative tumor grading. There seems to be a strong correlation between pathological grading and that assessed with SWI.

Prediction of H3K27M mutation status of diffuse midline gliomas using MRI features.

Presurgical prediction of H3K27M mutation in diffuse midline gliomas (DMGs) on MRI is desirable. The purpose of this study is to elaborate conventional MRI (cMRI) features of H3K27M-mutant DMGs and identify features that could discriminate them from wild-type (WT) DMGs. CMRI features of 123 patients with DMG were evaluated conforming to the institutional research protocols. Multimodality MRI was performed on 1.5 or 3.0 Tesla MR Scanners with imaging protocol, including T1-weighted (w), T2w, fluid-attenuated inversion recovery, diffusion-weighted, susceptibility-weighted, and postcontrast T1w sequences. Pertinent cMRI features were annotated along the lines of Visually AcceSAble Rembrandt Images features, and Intra Tumoral Susceptibility Signal score (ITSS) was evaluated. R software was used for statistical analysis. Sixty-one DMGs were H3K27M-mutant (mutant DMGs). The patients in the H3K27M-mutant DMG group were younger compared to the WT-DMG group (mean age 24.13 ± 13.13 years vs. 35.79±18.74 years) (p = 0.016). The two groups differed on five cMRI features--(1) enhancement quality (p = 0.032), (2) thickness of enhancing margin (p = 0.05), (3) proportion of edema (p = 0.002), (4) definition of noncontrast-enhancing tumor (NCET) margin (p = 0.001), and (5) cortical invasion (p = 0.037). The mutant DMGs showed greater enhancement and greater thickness of enhancing margin, while the WT DMGs exhibited significantly larger edema proportion with poorly defined NCET margins and cortical invasion. ITSS was not significantly different among the groups. CMRI features like enhancement quality, the thickness of the enhancing margin, proportion of edema, definition of NCET margin, and cortical invasion can discriminate between the H3K27M-mutant and WT DMGs.

Susceptibility-weighted Imaging: Technical Essentials and Clinical Neurologic Applications.

Susceptibility-weighted imaging (SWI) evolved from simple two-dimensional T2*-weighted sequences to three-dimensional sequences with improved spatial resolution and enhanced susceptibility contrast. SWI is an MRI sequence sensitive to compounds that distort the local magnetic field (eg, calcium and iron), in which the phase information can differentiate. But the term SWI is colloquially used to denote high-spatial-resolution susceptibility-enhanced sequences across different MRI vendors and sequences even when phase information is not used. The imaging appearance of SWI and related sequences strongly depends on the acquisition technique. Initially, SWI and related sequences were mostly used to improve the depiction of findings already known from standard two-dimensional T2*-weighted neuroimaging: more microbleeds in patients who are aging or with dementia or mild brain trauma; increased conspicuity of superficial siderosis in Alzheimer disease and amyloid angiopathy; and iron deposition in neurodegenerative diseases or abnormal vascular structures, such as capillary telangiectasia. But SWI also helps to identify findings not visible on standard T2*-weighted images: the nigrosome 1 in Parkinson disease and dementia with Lewy bodies, the central vein and peripheral rim signs in multiple sclerosis, the peripheral rim sign in abscesses, arterial signal loss related to thrombus, asymmetrically prominent cortical veins in stroke, and intratumoral susceptibility signals in brain neoplasms.