Lower Mean Apparent Diffusion Coefficient Research Articles

Apparent diffusion coefficient values in differentiating benign and malignant thoracic masses in children and young adults.

In children and young adults, tumors in the chest and thoracic wall exhibit a wide variety of types, making it challenging to differentiate between benign and malignant cases before invasive histopathological examination. To evaluate the utility of apparent diffusion coefficient (ADC) for discriminating malignant thoracic masses in children and young adults. This retrospective study included chest magnetic resonance imaging (MRI) scans in patients aged <30 years. Patients' age and sex, tumor location (mediastinum or thoracic wall), tumor size, MR characteristics including necrosis or hemorrhage, and ADC values were assessed. Malignant masses were found in older patients (mean age = 18.0 ± 8.1 vs. 10.6, ± 9.1 years; P = 0.008), had lower mean ADC values (0.765 ± 0.298 vs. 2.051 ± 0.855 × 10-3 mm2/s; P < 0.001), and showed more internal hemorrhage (6/12 vs. 17/86; P = 0.031) compared to benign masses. Univariate and multivariate regression analyses also showed significant differences in age, tumor size, and ADC values. In the diagnostic performance analysis, age (area under the receiver operating characteristic curve [AUC] = 0.723, 95% confidence interval [CI] = 0.624-0.809; P = 0.004) and ADC mean value (AUC = 0.941, 95% CI = 0.874-0.978, P < 0.001) were significant. The optimal cutoff values were 13 years for age (sensitivity = 83.3%, specificity = 61.6%) and an ADC mean of 1.196 × 10-3 mm²/s (sensitivity = 100%, specificity = 86.1%) for discriminating malignant from benign thoracic masses. When evaluating thoracic masses in children and young adults, older age and lower ADC values help identify malignancy.

Lesions of uncertain malignant potential in breast: Role of multiparametric MRI and histopathological correlation

Objectives This study aims to retrospectively evaluate the role of multiparametric magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping, in predicting the histopathological upgrade of B3 breast lesions. The primary objective is to calculate the mean ADC values for B3 and B5 lesions. The secondary objective involves evaluating the kinetic enhancement patterns of these lesions. Materials and Methods This retrospective analysis includes patients who underwent MR mammography between 2019 and 2023 in our institution and subsequently underwent trucut biopsy and histopathologically proven to be either B3 or B5 category breast lesions. Results Student’s t-test was used to find out the significant difference in ADC between the two groups. B5 lesions had lower mean ADC value (0.8 ± 0.2 ×10–3 mm2/sec, p = 0.026), whereas B3 lesions had higher mean ADC value (1.1 ± 0.3 × 10–3 mm2/sec, p = 0.026). Conclusion The multiparametric MRI including DWI in high-risk breast lesions would help in predicting their pathological behavior non-invasively. Identifying the mean ADC value and MR morphological characteristics in these lesions may guide clinicians in reducing misdiagnosis and over-treatment.

Magnetic resonance diffusion-weighted imaging in lacrimal gland lymphoma versus inflammation: A comparative study.

To determine the role of diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) in differentiating the inflammatory process and malignant lymphoma of the lacrimal gland. A retrospective analysis of all subjects who underwent lacrimal gland biopsy and magnetic resonance (MR) imaging with DWI sequences during a 10-year period at the Sheba Medical Center, Israel. The lacrimal glands' ADC values were documented bilaterally by blinded observers and correlated with the final histology verified diagnoses. Twenty-eight patients were included, with 19 females (68%) with a mean ± SD age of 48.1 ± 25.7 years. The right orbit was involved in 14 cases (50%) and the left in 13 (46%); one patient (4%) had bilateral involvement. Seventeen cases (61%) had a final diagnosis of idiopathic inflammation or dacryoadenitis, and six cases (21%) were diagnosed with lymphoma. Additional diagnoses included pleomorphic adenoma in 3 (11%), adenoid cystic carcinoma, and solitary fibrous tumor. Lower mean ADC values were observed in the lymphoma versus inflammatory group (1.03 × 10-3 Vs. 1.45 × 10-3, P = 0.02). Restricted diffusion on MR imaging can serve as a diagnostic tool in the differentiation between inflammatory processes of the lacrimal gland and lymphoma.

399 Source Localization of Burst Suppression in Post-Cardiac Arrest Patients

OBJECTIVES/GOALS: Burst suppression is a neurophysiological marker associated with severe hypoxic-ischemic injury following cardiac arrest. The goal of this study is to identify the anatomical regions of the brain associated with burst suppression post-cardiac arrest. METHODS/STUDY POPULATION: 86 comatose patients post-cardiac arrest admitted to the neurological-ICU from Massachusetts General Hospital and Brigham and Women’s Hospital were included in this study. EEG data after return of spontaneous circulation were preprocessed and artifact was rejected. Burst segments were extracted for source localization analysis from epochs with burst suppression. Four bursts for each patients were manually selected. The source of the bursts were obtained using the Champagne algorithm and mapped on the Desikan-Killiany atlas. The source for each burst was defined as any region of interest (ROI) with power &gt; = 75th percentile relative to all ROIs. The power of the bursts at each source was correlated with the burden of brain injury measured using apparent diffusion coefficient (ADC) per ROI. RESULTS/ANTICIPATED RESULTS: 48 (56%) patients had burst suppression. 5 (10.4%) of patients with burst suppression were independent at the time of hospital discharge. Preliminary analyses was performed on 6 patients (24 bursts in total). ROI’s determined to be sources in a majority of the burst (&gt;=13) were bilateral superior frontal, rostral middle frontal, parstriangularis precentral, superior parietal, inferior parietal, right post central, superior temporal, lateral occipital, and left middle temporal ROI. A lower mean ADC intensity was associated with a higher EEG power in the bilateral superior frontal (r = -0.80, p &lt; 0.0001; r = -0.677, p &lt; 0.001, respectively), left superior parietal (r = -0.53, p = 0.009), left middle temporal (r = -0.43, p = 0.042) ROI. DISCUSSION/SIGNIFICANCE: The source of bursts in patients post-cardiac arrest experiencing burst suppression is not well defined. This study will improve our understanding of how burst suppression is a measure of cortical injury, how it may relate to the burden of injury found on ADC imaging, and patient outcomes.

Amide proton transfer-weighted MRI for renal tumors: Comparison with diffusion-weighted imaging

To investigate the potential of amide proton transfer-weighted (APTw) MRI in identifying benign and malignant renal tumors and to evaluate whether APTw MRI can add diagnostic value to diffusion-weighted imaging (DWI). Participants with renal tumor underwent preoperative multiparametric MRI, including APTw MRI and DWI. The APTw and apparent diffusion coefficient (ADC) of malignant tumors and benign tumors were calculated independently by two radiologists and compared. The value of the mean APTw and the mean ADC for differentiating malignant and benign tumors was evaluated by receiver operating characteristic analysis. In total, 65 participants (mean age, 59years ±14; 41 men) were evaluated: 54 with malignant and 11 with benign renal tumors. Malignant renal tumors showed higher mean APTw values [2.03% (1.63) vs 1.00% (1.60); P<0.01] and lower mean ADC values (1.22×10-3mm2/s±0.37 vs 1.51×10-3mm2/s±0.37; P<0.05) than benign renal tumors. The area under the receiver operating characteristic curve (AUC) of APTw, ADC and the combination of them for the identification of benign and malignant renal tumors was 0.78(95% CI: 0.66, 0.87; P<0.001),0.70(95% CI: 0.54, 0.86; P<0.05) and 0.79 (95% CI: 0.67, 0.88; P<0.001). The optimal cutoff value for mean APTw was 2.14% (sensitivity, 74%; specificity, 73%). There was no difference between these three parameters for differentiating malignant from benign renal tumors (P>0.05). The APTw MRI has the potential use as an imaging biomarker for renal malignant and benign tumors.

Imaging findings of granular cell tumours of the head and neck

To review the imaging characteristics of granular cell tumours in the head and neck and assess their associations with pathological findings. Eleven patients (10 [91%] women, mean age 43 years) with histopathologically confirmed granular cell tumours were included in this study. Preoperative imaging studies were performed, including computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound. The location of the tumours, their imaging features, and histopathological findings were analysed. Among the 11 granular cell tumours, four (36%), three (27%), and two (18%) tumours were found in the submucosal layer, subcutaneous layer, and intramuscular area, respectively. On CT, all tumours exhibited homogeneous iso-attenuating enhancement compared with adjacent muscle, and nine out of the 11 tumours (81%) demonstrated well-defined margins. On T2-weighted imaging (T2WI), four out of five tumours (80%) demonstrated iso-signal intensity compared with adjacent muscles, and four tumours (80%) exhibited homogeneous signal intensity. The apparent diffusion coefficient (ADC) values ranged from 0.68-0.81×10-3 mm2/s. Histopathological examination revealed densely packed tumour cells with variable amounts of fibrous stroma. Granular cell tumours were characterised by well-defined and iso-signals on T2WI and low mean ADC values, and were predominantly located in the submucosal, subcutaneous, or intramuscular areas in middle-aged women. The characteristic locations, demographic characteristics, and imaging findings can help to differentiate granular cell tumours from other soft-tissue tumours in the head and neck.

Adjunct value of qualitative and quantitative analysis of diffusion-weighted imaging in musculoskeletal tumors

Abstract: BACKGROUND AND AIM: Diffusion-weighted imaging (DWI) has now become an integral component of the musculoskeletal tumor protocol magnetic resonance imaging (MRI). Although a conventional radiograph is still considered the primary modality, MRI is invariably performed for further characterization of the tumor. Being a fast noncontrast sequence and considering its role in detecting highly cellular lesions, DWI can prove as a helpful tool for those who have inconclusive radiographic or conventional MRI diagnosis. The aim of this study was to determine the role of DWI and apparent diffusion coefficient (ADC) value in the evaluation and differentiation of malignant and benign bones and soft-tissue neoplasms. We also derived a cutoff ADC value to differentiate the above two. MATERIALS AND METHODS: This is an IRB-approved retrospective study of 85 patients with histopathologically proven bone (n = 61, 47 malignant and 14 benign) or soft-tissue (n = 24, 21 malignant and 3 benign) neoplasms. Conventional MR features such as size, margins, T1/T2 signal intensity, cortical breach/bone expansion/medullary involvement, and neurovascular bundle involvement were assessed. DWI analysis was done by a blinded radiologist having MRI reporting experience of 3 years by placing three regions of interest on solid (nonnecrotic) components, and mean ADC values were derived for each neoplasm. These were confirmed by another senior radiologist with an experience of more than 15 years with MRI. Histopathological diagnosis was considered a gold standard. Mean ADC values of the benign and malignant groups were compared statistically. Sensitivity, specificity, and diagnostic accuracy were obtained. Receiver operating characteristic (ROC) curves were generated, and a cutoff ADC value was derived to differentiate benign and malignant tumors. RESULTS: True visual diffusion restriction was confirmed among 34/47 malignant bone tumors on b-800 DW images, whereas 10/14 benign bone tumors showed facilitated diffusion. Similarly, visual restriction was seen among 20/21 malignant soft tumors, whereas 2 out of 3 benign soft-tissue tumors showed visually facilitated diffusion. Statistically, a significant difference was noted between the mean ADC value of malignant (1.20 ± 0.68 × 10−3 mm2/s) and benign bone tumors (1.57 ± 0.69 × 10−3 mm2/s) (P = 0.04). Relatively high ADC values were noted in the chondrosarcoma group (n = 19), with 11/19 chondrosarcomas showing facilitated diffusion with a mean ADC value of 1.73 × 10−3 mm2/s. Similarly, among benign bone tumors, contrary to expectation, relatively lower ADC values were noted in giant cell tumors (n = 4) with a mean ADC value of 1.18 × 10−3 mm2/s. For soft-tissue tumors, a lower mean ADC value was noted for the malignant (0.85 ± 0.26 × 10−3 mm2/s) versus the benign group (1.33 ± 0.20 × 10−3 mm2/s) (P = 0.006). For bone neoplasms, a cutoff mean ADC value of 1.1 × 10−3 mm2/s was derived from the ROC curve with sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 72.3%, 71.4%, 89.5%, and 43.5%, respectively. For the soft-tissue group, a cutoff mean ADC value of 1.0 × 10−3 mm2/s was achieved with sensitivity, specificity, PPV, and NPV of 100%, 85.7%, 50%, and 100%, respectively. CONCLUSIONS: In addition to conventional MR, DWI with ADC analysis is a powerful tool in musculoskeletal tumor evaluation and an ADC cutoff value may help differentiate benign from malignant neoplasms. In chondroid malignancies, relatively high ADC values may be seen and DWI analysis may not be as useful.

Post-reperfusion acute MR diffusion in stroke is a potential predictor for clinical outcome in rats

Middle cerebral artery occlusion (MCAO) models show substantial variability in outcome, introducing uncertainties in the evaluation of treatment effects. Early outcome predictors would be essential for prognostic purposes and variability control. We aimed to compare apparent diffusion coefficient (ADC) MRI data obtained during MCAO and shortly after reperfusion for their potentials in acute-phase outcome prediction. Fifty-nine male rats underwent a 45-min MCAO. Outcome was defined in three ways: 21-day survival; 24 h midline-shift and neurological scores. Animals were divided into two groups: rats surviving 21 days after MCAO (survival group, n = 46) and rats dying prematurely (non-survival/NS group, n = 13). At reperfusion, NS group showed considerably larger lesion volume and lower mean ADC of the initial lesion site (p < 0.0001), while during occlusion there were no significant group differences. At reperfusion, each survival animal showed decreased lesion volume and increased mean ADC of the initial lesion site compared to those during occlusion (p < 10–6), while NS group showed a mixed pattern. At reperfusion, lesion volume and mean ADC of the initial lesion site were significantly associated with 24 h midline-shift and neurological scores. Diffusion MRI performed soon after reperfusion has a great impact in early-phase outcome prediction, and it works better than the measurement during occlusion.

Magnetic resonance imaging signal characteristics associated with prognosis of skull base chordoma after gamma knife radiosurgery

To investigate the association between the magnetic resonance imaging (MRI) signal characteristics of skull base chordoma and radiosurgical outcomes. Twenty-four patients with skull base chordomas treated with Gamma Knife radiosurgery (GKRS) after previous surgical resection were retrospectively (2001-2021) examined. Pre-GKRS MRIs were analyzed for RT2 (tumor-to-brainstem signal intensity ratio on T2-weighted imaging), RCE (tumor-to-brainstem signal intensity ratio on contrast-enhanced T1-weighted imaging), and mean apparent diffusion coefficient (ADC). Correlations of the parameters with patient survival and local tumor progression were made by using Cox regression and Kaplan-Meier analyses. During a median follow-up of 46months after GKRS, 9 patients died with significantly more local tumor progression events (median number: 2 vs 0, P = .012) than did 15 alive patients. On multivariable analysis, higher mean ADC was associated with longer patient survival (P = .016) after GKRS. The actuarial 5-year overall survival rates were 88.9% versus 54.7% for chordomas with an ADC of ≥ 1270 × 10-6 mm2/s versus < 1270 × 10-6 mm2/s. RT2 < 1.5 (P = .038) and RCE > 1.57 (P = .022) were associated with a lower probability of local tumor control. Lower mean ADC values are associated with shorter patient survival in skull base chordomas after GKRS. Diffusion-weighted imaging may help in GKRS planning and outcome prediction for these patients.

Estimation of colon cancer grade and metastatic lymph node involvement using DWI/ADC sequences.

The potential benefit of neoadjuvant chemotherapy (NAC) in colon cancer is under evaluation. There is a need to improve preoperative non-invasive diagnostics using techniques that provide more accurate staging information in assessing patient eligibility for NAC. To investigate the link between the tumor grade (pathohistological confirmed) and the N status (corresponding to lymph node involvement) with apparent diffusion coefficient (ADC) values. A total of 17 patients planned for surgical resection had a biopsy confirming colon carcinoma and participated in the study. Abdominal magnetic resonance imaging with diffusion-weighted imaging/ADC sequence was recorded before surgery. The tumor and all visible lymph nodes were manually delineated directly on a grayscale ADC map for every single slice and detected to access the total tumor and summarized lymph node volume. The mean ADC value was further calculated for the mean tumor and mean lymph node values. Low-grade tumors had a mean ADC equivalent to 1225 ± 170×10-6 mm2/s, and the coefficient of high-grade tumors was 1444 ± 69×10-6 mm2/s. The group of patients with positive lymph nodes in operative tissue samples (N+) exhibited lower mean ADC values (1023 ± 142×10-6 mm2/s) as opposed to the group without metastatic lymph nodes (N-) with ADC values of 1260 ± 231×10-6 mm2/s. The mean whole-tumor ADC is associated with the histological tumor grade, and the mean ADC value of whole-volume abdominal lymph nodes could assume real nodal infiltration.

Magnetic Resonance Imaging and Diffusion Weighted Imaging-Based Histogram in Predicting Mesenchymal Transition High-Grade Serous Ovarian Cancer

To investigate the value of magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) findings in predicting mesenchymal transition (MT) high-grade serous ovarian cancer (HGSOC). Patients with HGSOC were enrolled from May 2017 to December 2020, who underwent pelvic MRI including DWI (b=0,1000 s/mm2) before surgery, and were assigned to the MT HGSOC or non-MT HGSOC group according to histopathology results. Clinical characteristics and MRI features including DWI-based histogram metrics were assessed and compared between the two groups. Univariate and multivariate analyses were performed to identify the significant variables associated with MT HGSOC - these variables were then incorporated into a predictive nomogram, and ROC curve analysis was subsequently carried out to evaluate diagnostic performance. A total of 81 consecutive patients were recruited for pelvic MRI before surgery, including 37 (45.7%) MT patients and 44 (54.3%) non-MT patients. At univariate analysis, the features significantly related to MT HGSOC were identified as absence of discrete primary ovarian mass, pouch of Douglas implants, ovarian mass size, tumor volume, mean, SD, median, and 95th percentile apparent diffusion coefficient (ADC) values (all p < 0.05). At multivariate analysis, the absence of discrete primary ovarian mass {odds ratio (OR): 46.477; p=0.025}, mean ADC value ≤ 1.105 (OR: 1.023; p=0.009), and median ADC value ≤ 1.038 (OR: 0.982; p=0.034) were found to be independent risk factors associated with MT HGSOC. The combination of all independent criteria yielded the largest AUC of 0.82 with a sensitivity of 83.87% and specificity of 66.67%, superior to any of the single predictor alone (p ≤ 0.012). The predictive C-index nomogram performance of the combination was 0.82. The combination of absence of discrete primary ovarian mass, lower mean ADC value, and median ADC value may be helpful for preoperatively predicting MT HGSOC.

The role of Fast spin-echo T2-weighted and diffusion-weighted imaging for spine bone marrow changes evaluation in postmenopausal women with osteoporosis

BackgroundTo prospectively investigate the role of Fast spin-echo T2-weighted (FSE T2-w) and diffusion-weighted imaging (DWI) in magnetic resonance imaging (MRI) for detecting spine bone marrow changes in postmenopausal women with osteoporosis (OP). A total of 101 postmenopausal women, mean age of 60.97 ± 7.41 (range 52–68) years old, who underwent dual-energy X-ray absorptiometry of the spine, were invited to this study and divided into three bone density (normal, osteopenic, and osteoporotic) groups based on T-score. After that MRI scan with both FSE T2-w and DWI of the vertebral body was done to calculate the signal-to-noise ratio (SNR) and apparent diffusion coefficient (ADC). Finally, MRI findings were compared in patients, between three groups and correlated with bone marrow density.ResultsThe osteoporotic group showed significantly lower mean ADC values, compared to osteopenic and normal groups (0.58 ± 0.02 vs. 0.36 ± 0.05 vs. 0.24 ± 0.06 × 10–3 mm2/s, p < 0.001). According to these results, a significant positive correlation was found between T-scores and ADC values (r = 0.652, p < 0.001). The mean SNR in FSE T2-w images for normal, osteopenic, and osteoporotic groups was calculated 5.61 ± 0.32, 5.48 ± 0.55, and 6.63 ± 0.67, respectively. No significant correlation was found between the mean SNR and T-score for all groups (r = − 0.304, p > 0.05).ConclusionsDWI can be used as a noninvasive, quantitative, and valuable technique for OP evaluation. While, routine MRI needs more investigation to be demonstrated as a reliable diagnostic indicator for OP.

The prognostic value of mean apparent diffusion coefficient measured with diffusion-weighted magnetic resonance image in patients with prostate cancer treated with definitive radiotherapy

To assess the correlation between initial tumor apparent diffusion coefficient (ADC) values and clinicopathological parameters in prostate cancer (PCa) patients treated with definitive radiotherapy (RT). Additionally, the prognostic factors for freedom from biochemical failure (FFBF) and progression-free survival (PFS) in this patient cohort were analyzed. The clinical data of 503 patients with biopsy-confirmed PCa were evaluated retrospectively. All patients had clearly evident tumors on diffusion-weighted magnetic resonance imaging (DW-MRI) for ADC values. Univariable and multivariable analyses were used to determine prognostic factors for FFBF and PFS. The median follow-up was 72.9months. The 5-year FFBF and PFS rates were 93.2% and 86.2%, respectively. Significantly lower ADC values were found in patients with a high PSA level; advanced clinical stage; higher ISUP score, and higher risk group than their counterparts. Receiver operating characteristic (ROC) curve analysis revealed an ADC cut-off value of 0.737×10-3mm2/sec for tumor recurrence. Patients who progressed had a lower mean ADC value than those who did not (0.712±0.158 vs. 1.365±0.227×10-3mm2/sec; p<0.001). There was a significant difference in 5-year FFBF (96.3% vs. 90%; p<0.001) and PFSrates (83.8% vs. 73.5%; p=0.002) between patients with higher and lower mean ADC values. The FFBF and PFS were found to be correlated with tumor ADC value and ISUP grades in multivariable analysis. Additionally, older age was found to be a significant predictor of worse PFS. Lower ADC values were found in patients with high-risk characteristics such as a high serum PSA level, stage or grade of tumor, or high-risk disease, implying that ADC values could be used to predict prognosis. Lower ADC values and higher ISUP grades were associated with an increased risk of BF and progression, implying that treatment intensification may be required in these patients.

Magnetic resonance imaging of methotrexate-related lymphoproliferative disorder with a chief complaint of oral symptoms.

To determine the magnetic resonance imaging (MRI) features of methotrexate-related lymphoproliferative disorder (MTX-LPD) in the oral cavity of a patient with a chief complaint of oral symptoms. We included six patients who visited our hospital between November 2014 and November 2019, histopathologically diagnosed with MTX-LPD. All images were examined using 3T MRI and reviewed by two radiologists. Masses were detected in five cases; all masses demonstrated signal hypointensity and homogeneous signal hyperintensity on T1- and T2-weighted images with fat suppression. Homogeneous enhancement with fat suppression was evident on post-contrast T1-weighted imaging. We performed dynamic contrast-enhanced MRI in three cases and observed early enhancement with a low washout ratio pattern in all cases. Four patients underwent diffusion-weighted MRI and revealed low mean apparent diffusion coefficient (ADC) of 0.57 (range 0.5-0.65) × 10-3 mm2/s. We reported on the imaging characteristics of six rare cases of MTX-LPD in the oral cavity. Homogeneous hyperintensity on fat-suppressed T2-weighted images and low ADC values are possible features of MTX-LPD. Moreover, MTX-LPD can be differentiated from other carcinomas in the oral cavity.

Preoperative Apparent Diffusion Coefficient Values for Differentiation between Low and High Grade Meningiomas: An Updated Systematic Review and Meta-Analysis.

The meta-analysis aimed to compare the preoperative apparent diffusion coefficient (ADC) values between low-grade meningiomas (LGMs) and high-grade meningiomas (HGMs). Medline, Cochrane, Scopus, and Embase databases were screened up to January 2022 for studies investigating the ADC values of meningiomas. The study endpoint was the reported ADC values for LGMs and HGMs. Further subgroup analyses between 1.5T and 3T MRI scanners, ADC threshold values, ADC in different histological LGMs, and correlation coefficients (r) between ADC and Ki-67 were also performed. The quality of studies was evaluated by the quality assessment of diagnostic accuracy studies (QUADAS-2). A χ2-based test of homogeneity was performed using Cochran’s Q statistic and inconsistency index (I2). Twenty-five studies with a total of 1552 meningiomas (1102 LGMs and 450 HGMs) were included. The mean ADC values (×10−3 mm2/s) were 0.92 and 0.79 for LGMs and HGMs, respectively. Compared with LGMs, significantly lower mean ADC values for HGMs were observed with a pooled difference of 0.13 (p < 0.00001). The results were consistent in both 1.5T and 3T MRI scanners. For ADC threshold values, pooled sensitivity of 69%, specificity of 82%, and AUC of 0.84 are obtained for differentiation between LGMs and HGMs. The mean ADC (×10−3 mm2/s) in different histological LGMs ranged from 0.87 to 1.22. Correlation coefficients (r) of mean ADC and Ki-67 ranged from −0.29 to −0.61. Preoperative ADC values are a useful tool for differentiating between LGMs and HGMs. Results of this study provide valuable information for planning treatments in meningiomas.

Magnetic resonance imaging findings associated with recurrence in idiopathic granulomatous mastitis

To evaluate magnetic resonance imaging (MRI) findings related to recurrence of idiopathic granulomatous mastitis (IGM). Demographic data [age, number of births, duration of lactation period, body mass index (BMI) and presence of recurrence] of 71 patients who were diagnosed with IGM were analyzed retrospectively. Characteristics of IGM (maximum width, location, involvement of the retroareolar region, deep tissue, skin), fibroglandular density (FGD), background parenchymal enhancement (BPE), distribution and pattern of contrast enhancement, presence of prepectoral edema, abscesses, fistulae, axillary lymphadenopathies on MRI and apparent diffusion coefficient (ADC) values from the pathological area were recorded. The recurrence rate in patients was 59% (42/71). We found a statistically significant relationship between recurrence and BPE (p=0.028) and mean ADC (p=0.035) values (for the cut-off of 1.00×10-3mm2/s; sensitivity=61.9%, specificity=69%, AUC=0.648). However, patients' age (p=0.346), lactation period (p=0.470), number of births (p=0.774), BMI (p=0.630) maximum width of the area of enhancement (p=0.112), involvement of the retroareolar region (p=0.290), deep tissue (p=0.285), skin (p=0.230), distribution (p=0.857) and enhancement pattern (p=0.157), presence of prepectoral edema (p=0.094), abscesses (p=0.441), fistulae (p=0.809), lymphadenopathies (p=0.571), and FGT (p=0.098) were not significantly associated with recurrence. Our results revealed that recurrent IGM patients showed high BPE and lower mean ADC values. We think that high BPE and low mean ADC (<1.00×10-3mm2/s) on MRI at the diagnosis stage may be a sign of possible future recurrence, and it will be beneficial to follow the patients more closely and arrange the treatment algorithms accordingly.

The impact of multiparametric MRI features to identify the presence of prevalent cribriform pattern in the peripheral zone tumors.

To assess the role of the multiparametric Magnetic Resonance Imaging (mpMRI) in predicting the cribriform pattern in both the peripheral and transition zones (PZ and TZ) clinically significant prostate cancers (csPCas). We retrospectively evaluated 150 patients who underwent radical prostatectomy for csPCa and preoperative mpMRI. Patients with negative (n = 25) and positive (n = 125) mpMRI, stratified according to the presence of prevalent cribriform pattern (PCP, ≥ 50%) and non-PCP (< 50%) at specimen, were included. Difference between the two groups were evaluated. Multivariate logistic regression was used to identify predictors of PCP among mpMRI parameters. The receiver operating characteristic (ROC) analysis was performed to evaluate the area under the curve (AUC) of apparent diffusion coefficient (ADC) and ADC ratio in detecting lesions harboring PCP. Considering 135 positive lesions at the mpMRI, 30 (22.2%) and 105 (77.8%) harbored PCP and non-PCP PCa. The PCP lesions had more frequently nodular morphology (83.3% vs 62.9%; p = 0.04) and significantly lower mean ADC value (0.87 ± 0.16 vs 0.95 ± 0.18; p = 0.03) and ADC ratio (0.52 ± 0.09 vs 0.60 ± 0.14; p = 0.003) when compared with non-PCP lesions. At univariate and multivariate analyses, mean ADC and ADC ratio resulted as independent predictors of the presence of the PCP of the PZ tumors(OR: 0.025; p = 0.03 and OR: 0.001; p = 0.004, respectively). At the ROC analysis, the AUC of mean ADC and ADC ratio to predict the presence of PCP in patients with PZ suspicious lesion at the mpMRI were 0.69 (95% CI 0.56-0.81P, p = 0.003) and 0.72 (95% CI 0.62-0.82P, p = 0.001), respectively. The mpMRI may correctly identify PCP tumors of the PZ and the mean ADC value and ADC ratio can predict the presence of the cribriform pattern in the PCa.

Magnetic Resonance Imaging Parameters for Noninvasive Prediction of Epidermal Growth Factor Receptor Amplification in Isocitrate Dehydrogenase-Wild-Type Lower-Grade Gliomas: A Multicenter Study.

The epidermal growth factor receptor (EGFR) amplification status of isocitrate dehydrogenase-wild-type (IDHwt) lower-grade gliomas (LGGs; grade II/III) is one of the key markers for diagnosing molecular glioblastoma. However, the association between EGFR status and imaging parameters is unclear. To identify noninvasive imaging parameters from diffusion-weighted and dynamic susceptibility contrast imaging for predicting the EGFR amplification status of IDHwt LGGs. A total of 86 IDHwt LGG patients with known EGFR amplification status (62 nonamplified and 24 amplified) from 3 tertiary institutions were included. Qualitative and quantitative imaging features, including histogram parameters from apparent diffusion coefficient (ADC), normalized cerebral blood volume (nCBV), and normalized cerebral blood flow (nCBF), were assessed. Univariable and multivariable logistic regression models were constructed. On multivariable analysis, multifocal/multicentric distribution (odds ratio [OR] = 11.77, P=.006), mean ADC (OR=0.01, P=.044), 5th percentile of ADC (OR=0.01, P=.046), and 95th percentile of nCBF (OR=1.24, P=.031) were independent predictors of EGFR amplification. The diagnostic performance of the model with qualitative imaging parameters increased significantly when quantitative imaging parameters were added, with areas under the curves of 0.81 and 0.93, respectively (P=.004). The presence of multifocal/multicentric distribution patterns, lower mean ADC, lower 5th percentile of ADC, and higher 95th percentile of nCBF may be useful imaging biomarkers for EGFR amplification in IDHwt LGGs. Moreover, quantitative imaging biomarkers may add value to qualitative imaging parameters.

Dynamic contrast-enhanced magnetic resonance imaging for differentiating head and neck paraganglioma and schwannoma.

Morphological assessment with conventional magnetic resonance imaging (MRI) sequences has limited specificity to distinguish between paragangliomas and schwannomas. Assessing the differences in microvascular properties through pharmacokinetic parameters of dynamic contrast-enhanced (DCE)-MRI can provide additional information to aid in this differentiation. A prospective study on MR characterization of neck masses was performed between January 2017 and March 2019 in our department, out of which 40 patients with head and neck paragangliomas (HNPGLs) (33 lesions) and schwannomas (15 lesions) were included in this analysis. MR perfusion using dynamic axial T1WI fat suppressed fast spoiled gradient recalled sequence with parallel imaging was performed in all the patients, in addition to single-shot turbo spin-echo axial diffusion weighted imaging (DWI) and routine MRI. ROI-based method was used to obtain signal-time curves, permeability measurements, and mean apparent diffusion coefficient (ADC) to differentiate paragangliomas from schwannomas. Statistical analysis was done to assess the significance and establish a cutoff to distinguish between the two entities. The available images of DOTANOC PET/CT (34 lesions) were analyzed retrospectively. Correlations between the perfusion, diffusion, and molecular PET/CT parameters were done. Paragangliomas had a higher wash-in rate, wash-out rate, Ktrans, Kep , and Vp (p < 0.001); while schwannomas had a higher relative enhancement (p < 0.012), time to peak, time of onset, brevity of enhancement, and Ve (p < 0.001). Among the perfusion parameters, Kep (area under curve (AUC) 0.994) and Vp (AUC 0.992) were found to have the highest diagnostic value. In diffusion-weighted imaging, paragangliomas had a lower mean ADC compared to schwannomas (p < 0.001). The SUVmax and SUVmean were significantly associated with Ktrans , Kep , and Vp in paragangliomas. DCE-MRI in addition to DWI-MRI can accurately distinguish HNPGL from schwannoma and may replace the need for any additional imaging and preoperative biopsy in most cases.

Clinical and diffusion parameters may noninvasively predict TERT promoter mutation status in grade II meningiomas

Increasing evidence suggests that genomic and molecular markers need to be integrated in grading of meningioma. Telomerase reverse transcriptase promoter (TERTp) mutation is receiving attention due to its clinical relevance in the treatment of meningiomas. The predictive ability of conventional and diffusion MRI parameters for determining the TERTp mutation status in grade II meningiomas has yet been identified. In this study, 63 patients with surgically confirmed grade II meningiomas (56 TERTp wildtype, 7 TERTp mutant) were included. Conventional imaging features were qualitatively assessed. The maximum diameter, volume of the tumors and histogram parameters from the apparent diffusion coefficient (ADC) were assessed. Independent clinical and imaging risk factors for TERTp mutation were investigated using multivariable logistic regression. The discriminative value of the prediction models with and without imaging features was evaluated. In the univariable regression, older age (odds ratio [OR] = 1.13, P = 0.005), larger maximum diameter (OR = 1.09, P = 0.023), larger volume (OR = 1.04, P = 0.014), lower mean ADC (OR = 0.02, P = 0.025), and lower ADC 10th percentile (OR = 0.01, P = 0.014) were predictors of TERTp mutation. In multivariable regression, age (OR = 1.13, P = 0.009) and ADC 10th percentile (OR = 0.01, P = 0.038) were independent predictors of variables for predicting the TERTp mutation status. The performance of the prediction model increased upon inclusion of imaging parameters (area under the curves of 0.86 and 0.91, respectively, without and with imaging parameters). Older age and lower ADC 10th percentile may be useful parameters to predict TERTp mutation in grade II meningiomas.