ADC Values Research Articles

Utility of clinical and MR imaging parameters for prediction and monitoring of response to capecitabine and temozolomide (CAPTEM) therapy in patients with liver metastases of neuroendocrine tumors.

This study explores the predictive and monitoring capabilities of clinical and multiparametric MR parameters in assessing capecitabine and temozolomide (CAPTEM) therapy response in patients with neuroendocrine tumors (NET). This retrospective study (n = 44) assessed CAPTEM therapy response in neuroendocrine liver metastases (NELM) patients. Among 33 monitored patients, as a subgroup of the overall study cohort, pretherapeutic and follow-up MRI data (size, apparent diffusion coefficient [ADC] values, and signal intensities), along with clinical parameters (chromogranin A [CgA] and Ki-67%), were analyzed. Progression-free survival (PFS) served as the reference. Responders were defined as those with PFS ≥ 6 months. Most patients were male (75%) and had G2 tumors (76%) with a pancreatic origin (84%). Median PFS was 5.7 months; Overall Survival (OS) was 25 months. Non-responders (NR) had higher Ki-67 in primary tumors (16.5 vs. 10%, p = 0.01) and increased hepatic burden (20% vs. 5%, p = 0.007). NR showed elevated CgA post-treatment, while responders (R) exhibited a mild decrease. ADC changes differed significantly between groups, with NR having decreased ADCmin (-23%) and liver-adjusted ADCmean/ADCmean liver (-16%), compared to R's increases of ADCmin (50%) and ADCmean/ADCmean liver (30%). Receiver operating characteristic (ROC) analysis identified the highest area under the curve (AUC) (0.76) for a single parameter for ∆ ADC mean/liver ADCmean, with a cut-off of < 6.9 (76% sensitivity, 75% specificity). Combining ∆ Size NELM and ∆ ADCmin achieved the best balance (88% sensitivity, 60% specificity) outperforming ∆ Size NELM alone (69% sensitivity, 65% specificity). Kaplan-Meier analysis indicated significantly longer PFS for ∆ ADCmean/ADCmean liver < 6.9 (p = 0.024) and ∆ Size NELM > 0% + ∆ ADCmin < -2.9% (p = 0.021). Survival analysis emphasizes the need for adapted response criteria, involving combined evaluation of CgA, ADC values, and tumor size for monitoring CAPTEM response in hepatic metastasized NETs.

Identification of Multiclass Pediatric Low-Grade Neuroepithelial Tumor Molecular Subtype with ADC MR Imaging and Machine Learning.

Molecular biomarker identification increasingly influences the treatment planning of pediatric low-grade neuroepithelial tumors (PLGNTs). We aimed to develop and validate a radiomics-based ADC signature predictive of the molecular status of PLGNTs. In this retrospective bi-institutional study, we searched the PACS for baseline brain MRIs from children with PLGNTs. Semiautomated tumor segmentation on ADC maps was performed using the semiautomated level tracing effect tool with 3D Slicer. Clinical variables, including age, sex, and tumor location, were collected from chart review. The molecular status of tumors was derived from biopsy. Multiclass random forests were used to predict the molecular status and fine-tuned using a grid search on the validation sets. Models were evaluated using independent and unseen test sets based on the combined data, and the area under the receiver operating characteristic curve (AUC) was calculated for the prediction of 3 classes: KIAA1549-BRAF fusion, BRAF V600E mutation, and non-BRAF cohorts. Experiments were repeated 100 times using different random data splits and model initializations to ensure reproducible results. Two hundred ninety-nine children from the first institution and 23 children from the second institution were included (53.6% male; mean, age 8.01 years; 51.8% supratentorial; 52.2% with KIAA1549-BRAF fusion). For the 3-class prediction using radiomics features only, the average test AUC was 0.74 (95% CI, 0.73-0.75), and using clinical features only, the average test AUC was 0.67 (95% CI, 0.66-0.68). The combination of both radiomics and clinical features improved the AUC to 0.77 (95% CI, 0.75-0.77). The diagnostic performance of the per-class test AUC was higher in identifying KIAA1549-BRAF fusion tumors among the other subgroups (AUC = 0.81 for the combined radiomics and clinical features versus 0.75 and 0.74 for BRAF V600E mutation and non-BRAF, respectively). ADC values of tumor segmentations have differentiative signals that can be used for training machine learning classifiers for molecular biomarker identification of PLGNTs. ADC-based pretherapeutic differentiation of the BRAF status of PLGNTs has the potential to avoid invasive tumor biopsy and enable earlier initiation of targeted therapy.

Second-Order Motion-Compensated Echo-Planar Cardiac Diffusion-Weighted MRI: Usefulness of Compressed Sensitivity Encoding.

Cardiac diffusion-weighted imaging (DWI) using second-order motion-compensated spin echo (M2C) can provide noninvasive in-vivo microstructural assessment, but limited by relatively low signal-to-noise ratio (SNR). Echo-planar imaging (EPI) with compressed sensitivity encoding (EPICS) could address these issues. To combine M2C DWI and EPCIS (M2C EPICS DWI), and compare image quality for M2C DWI. Prospective. Ten ex-vivo hearts, 10 healthy volunteers (females, 5 [50%]; mean ± SD of age, 25 ± 4 years), and 12 patients with diseased hearts (female, 1 [8.3%]; mean ± SD of age, 44 ± 16 years; including coronary artery heart disease, congenital heart disease, dilated cardiomyopathy, amyloidosis, and myocarditis). 3-T, M2C EPICS DWI, and M2C DWI. The apparent SNR (aSNR) and the rating scores were used to evaluate and compared image quality of all three groups. The aSNR was calculated using , and the myocardium was segmented manually. Three observers independently rated subjective image quality using a 5-point Likert scale. Bland-Altman analysis and paired t-tests. The threshold for statistical significance was set at P < 0.05. In healthy volunteers, the aSNR with a b-value of 450 s/mm2 acquired by M2C EPICS DWI was significantly higher than M2C DWI at in-plane resolutions of 3.0 × 3.0, 2.5 × 2.5, and 2.0 × 2.0 mm2. In patients with diseased hearts, the aSNR ofM2C EPICS DWI was also significantly higher than that for M2C DWI (bias of M2C EPICS-M2C = 1.999, 95% limits of agreement, 0.362 to 3.636; mean ± SD, 7.80 ± 1.37 vs. 5.80 ± 0.81). The ADC values of M2C EPICS was significantly higher than M2C DWI in in-vivo hearts. Over 80% of the images with rating scores for M2C EPICS DWI were higher than M2C DWI in in-vivo hearts. Cardiac imaging by M2C EPICS DWI may demonstrate better overall image quality and higher aSNR than M2C DWI. 2 TECHNICAL EFFICACY: Stage 1.

Impact of Radiotherapy on Radiation-Induced Brain Injury in Patients with Nasopharyngeal Carcinoma Using Nano-Magnetic Resonance Imaging

This study investigate the changes of white matter injury induced by radiation after radiotherapy in patients with nasopharyngeal carcinoma (NPC) and its association with cognitive dysfunction using multiple MRI methods. A total of 42 patients with NPC who underwent radiotherapy at xxx Hospital between December 2018 and June 2021 were included. The patients were randomly divided into 4 groups based on the timing of radiotherapy. Superparamagnetic iron oxide nanoparticles were used as MRI contrast agents. DTI and MRS scans were conducted to measure FA, ADC, NAA/Cho, Cho/Cr, and NAA/Cr ratios in the hippocampus of both temporal lobes. A cognitive assessment was performed using the MoCA and MMSE scales. After radiotherapy, patients experienced a decline in cognitive scores, which stabilized after 6 months. White matter changes were observed in the hippocampus, with decreased FA and increased ADC values that gradually returned to normal levels. Cho value increased and NAA value decreased initially but eventually returned to pre-treatment levels. No significant changes occurred in the Cr value. Metabolite ratios decreased within 3 months post-radiotherapy but gradually increased thereafter, remaining lower than pre-treatment levels at 6 months. Higher radiation doses did not significantly affect FA and ADC values but decreased white matter metabolite ratios. In conclusion, we reveal that the dosage and duration of radiotherapy can influence the degree of brain injury in patients with NPC and highlights the cognitive decline, white matter changes, and changes in metabolite ratios after radiotherapy for NPC, providing insights into the effects of radiation on brain structure and function.

472 Utility of [89Zr]Trastuzumab-PET/MRI Imaging for Quantitative Assessment of Tumor Heterogeneity In HER2+ Breast Cancer

OBJECTIVES/GOALS: This study was performed to explore the capabilities of simultaneous [89 Zr]trastuzumab-PET/MRI acquisition in a cohort of metastatic HER2+ breast cancer. The insights derived provide additional noninvasive characterization and precise intratumoral analysis tools for healthcare providers. METHODS/STUDY POPULATION: A total of 13 patients, aged between 40 and 70, diagnosed with HER2-positive breast cancer, were selected to participate in this study. Whole-body [89 Zr]trastuzumab-PET/MR imaging was performed 5 ± 1 days post-injection of the radiopharmaceutical during ongoing HER2-directed therapy. Concurrently acquired T1-weighted MRI facilitated the identification of normal organ and tumor regions of interest, which were further analyzed for mean ADC and mean standardized uptake value. Multiparametric intratumoral habitat analysis was performed. Utilizing the median metric values, tumors were evaluated for heterogeneity, specifically assessing high and low HER2 expression through an image processing framework in conjunction with ADC metrics. Long-term treatment response evaluation is ongoing. RESULTS/ANTICIPATED RESULTS: Initial analysis indicate all tumors exhibited higher overall uptake of [89 Zr]trastuzumab across various sites including the bone (p=0.019), brain (p=0.014), and breast (p=0.069), when compared to corresponding normal organs. Additionally, increased ADCmean values were observed in all regions besides brain tumors (bone: p=0.002, brain: p=0.5, breast: p=0.03, juxtapulmonary: p=0.037), indicating distinct patterns of cellularity. Notably, one of five patients with a breast lesion, who exhibited a complete response to HER2-targeted therapy, exhibited the highest breast lesion SUVmean. Brain and lymph node lesions demonstrated intratumoral heterogeneity of HER2 expression. Qualification of multi parametric maps is anticipated to inform on intratumoral heterogeneity DISCUSSION/SIGNIFICANCE: Despite limitation in clinical applications of quantitative approaches due to lack of standardization of processing, initial investigations, in combining molecular imaging of HER2 and quantitative MRI demonstrate potential in characterizing metastatic HER2+ breast cancer for intratumoral classification and therapeutic stratification.

THE ROLE OF DIFFUSION-WEIGHTED IMAGING IN THE DIFFERENTIAL DIAGNOSIS OF LIVER LESIONS

Introduction: Diffusion-weighted imaging [DWI] plays a significant role in distinguishing liver lesions. This study focuses on the significance of apparent diffusion coefficient [ADC] values in distinguishing between benign and malignant liver lesions.&#x0D; Methods: A retrospective evaluation was conducted on patients who underwent liver MRI examinations at our clinic, and 378 liver lesions were found. The study comprised 141 women, 80 men, and 221 patients with liver lesions. The measured ADC values between benign and malignant lesions were compared. In addition, the lesion ADC value/CSF ADC value ratio was measured, and the relative ADC value was named.&#x0D; Results: 118 hemangiomas, 59 simple cysts, 67 hydatid cysts, 3 focal nodular hyperplasias, 9 abscesses, 28 hepatocellular carcinomas, 88 metastases, and 6 lymphomas were evaluated. Simple cysts and hemangiomas had the most elevated ADC values compared to all other liver lesions. The ADC values for liver lesions classified as benign had a mean of 2.10 x 10-3 mm2/s, while malignant ones had a lower mean of 0.75 x 10-3 mm2/s. The ADC values of malignant liver lesions were lower compared to the benign lesions.&#x0D; Conclusion: Using DWI combined with ADC values could be valuable in discerning between benign and malignant liver lesions. Besides, relative ADC values may also contribute to more objective results.

Multiparametric arterial spin-labeling and diffusion-weighted imaging of phenotyping of polycystic ovaries

BackgroundPolycystic ovarian syndrome [PCO] is a worldwide endocrine disorder affecting women of reproductive age. Diagnosis and differentiation of PCO phenotypes are crucial for disease prognosis, fertility outcome, and treatment planning. This study aims to assess arterial spin labeling perfusion (ASL) and diffusion-weighted imaging (DWI) derived metrics in the diagnosis of PCO, differentiation of its phenotypes, and correlation of these metrics with laboratory measurements.ResultsASL and DWI of the pelvis were performed on 72 PCO patients and another 20 age-matched control group. Two observers measured the blood flow (BF) and ADC in the ovarian stroma. Serum levels of testosterone, dehydroepiandrosterone sulfate (DHEAS), and body mass index (BMI) were calculated. BF values were significantly higher in PCO patients than in control cases (P = 0.001), with area under the curve (AUC) of (0.94 and 0.89) and accuracy of (96% and 92%) for both observers, respectively. Also, BF values were significantly higher in classic than in non-classic PCO cases (P = 0.001), with AUC of (0.92 and 0.90) and accuracy of (91%) for both observers, respectively. ADC values were significantly lower in PCO patients than in control cases (P = 0.001), with AUC of (0.85 and 0.84) for the first observer and second observer, respectively. ADC values were significantly lower in classic PCO patients than in non-classic patients (P = 0.001), with AUC of (0.85 and 0.84) and accuracy of (77% and 81%) for both observers, respectively. Combined values of BF and ADC showed an accuracy of 91% and 86% for differentiating patient from control cases for both observers, respectively, and an accuracy of 92% for differentiating classic from non-classic PCO phenotypes. A significant correlation was found between ADC, BF metrics, and both serum testosterone and DHEAS levels (P < 0.05).ConclusionsCombination of ASL and ADC can be used in PCO diagnosis and can help in the differentiation of its phenotypes. Serum levels of testosterone and DHEAS have a significant correlation with ADC and BF metrics.

Differentiation of salivary gland tumors using diffusion-weighted image-based virtual MR elastography: A pilot study.

Differentiation among benign salivary gland tumors, Warthin tumors, and malignant salivary gland tumors is crucial to treatment planning and predicting patient prognosis. However, differentiation of those tumors using imaging findings remains difficult. This study evaluated the usefulness of elasticity determined from Diffusion-weighted image (DWI)-based virtual MR elastography (MRE) compared with conventional MRI findings in differentiating the tumors. This study included 17 benign salivary gland tumors, six Warthin tumors, and 11 malignant salivary gland tumors scanned on neck MRI. The long and short diameters, T1 and T2 signal intensities, tumor margins, ADC values, and elasticity from DWI-based virtual MRE of the tumors were evaluated. The interobserver agreement in measuring tumor elasticity and the ROC curves were also assessed. The long and short diameters and the T1 and T2 signal intensities showed no significant difference among the three tumor groups. Tumor margins and the mean ADC values showed significant differences among some tumor groups. The elasticity from virtual MRE showed significant differences among all three tumor groups and the interobserver agreement was excellent. The area under the ROC curves of the elasticity were higher than those of tumor margins and mean ADC values. Elasticity values based on DWI-based virtual MRE of benign salivary gland tumors, Warthin tumors, and malignant salivary gland tumors were significantly different. The elasticity of Warthin tumors was the highest and that of benign tumors was the lowest. The elasticity from DWI-based virtual MRE may aid in the differential diagnosis of salivary gland tumors.

ComBating inter-site differences in field strength: harmonizing preclinical traumatic brain injury MRI data.

Integrating datasets from multiple sites and scanners can increase statistical power for neuroimaging studies but can also introduce significant inter-site confounds. We evaluated the effectiveness of ComBat, an empirical Bayes approach, to combine longitudinal preclinical MRI data acquired at 4.7 or 9.4 T at two different sites in Australia. Male Sprague Dawley rats underwent MRI on Days 2, 9, 28, and 150 following moderate/severe traumatic brain injury (TBI) or sham injury as part of Project 1 of the NIH/NINDS-funded Centre Without Walls EpiBioS4Rx project. Diffusion-weighted and multiple-gradient-echo images were acquired, and outcomes included QSM, FA, and ADC. Acute injury measures including apnea and self-righting reflex were consistent between sites. Mixed-effect analysis of ipsilateral and contralateral corpus callosum (CC) summary values revealed a significant effect of site on FA and ADC values, which was removed following ComBat harmonization. Bland-Altman plots for each metric showed reduced variability across sites following ComBat harmonization, including for QSM, despite appearing to be largely unaffected by inter-site differences and no effect of site observed. Following harmonization, the combined inter-site data revealed significant differences in the imaging metrics consistent with previously reported outcomes. TBI resulted in significantly reduced FA and increased susceptibility in the ipsilateral CC, and significantly reduced FA in the contralateral CC compared with sham-injured rats. Additionally, TBI rats also exhibited a reversal in ipsilateral CC ADC values over time with significantly reduced ADC at Day 9, followed by increased ADC 150 days after injury. Our findings demonstrate the need for harmonizing multi-site preclinical MRI data and show that this can be successfully achieved using ComBat while preserving phenotypical changes due to TBI.

Correlation between MRI (DWI and DCE) and cellularity of parotid gland pleomorphic adenomas.

Parotid pleomorphic adenomas present a risk of recurrence, higher when the tumour is a hypocellular subtype. The aim of the study was to determine whether it is possible to characterize this histological subtype with diffusion and perfusion sequences of the preoperative MRI. This retrospective study included 97 patients operated between 2010 and 2020. Histologic slides review was performed to classify tumours into three histologic subtypes: hypocellular, classical and hypercellular. Univariate and multivariate analyses studied the correlation between histology and diffusion and perfusion MRI parameters obtained with OleaSphere® software. The hypocellular subtype had higher apparent diffusion coefficient values than the other two subtypes: 2.13 ± 0.23, 1.83 ± 0.42, and 1.61 ± 0.4 × 10-3mm2/s for hypocellular, classical and hypercellular subtype respectively (p < 0.0001). Multivariate analysis showed that an ADCmean > 1.88 × 10-3mm2/s was suggestive of a hypocellular pleomorphic adenoma in 79% of the cases, with a specificity and PPV of 94 and 96% (p < 0.001), respectively. The histological subtype of a pleomorphic adenoma can be predicted preoperatively with ADC values. A prospective and multicentric study on a larger cohort is needed to confirm our results.

Correlation of clinical and radiological scores for evaluation of activity in patients having thyroid-associated orbitopathy: A prospective observational study.

To find a correlation between the clinical (vision-inflammation-strabismus-appearance [VISA] score) and radiological (apparent diffusion coefficient [ADC] values) scores for evaluating disease activity in patients with thyroid-associated orbitopathy. A prospective comparative study. Our study was performed for consecutively diagnosed thyroid-associated orbitopathy (TAO) patients. Clinical evaluation included the VISA classification system with the basic thyroid workup. An inflammatory score of <4/8 was considered inactive and ≥4/8 as an active disease. Every included patient underwent a diffusion-weighted magnetic resonance imaging (DW-MRI) scan of the orbits. The orbital parameters evaluated on imaging included the proptosis, thickness, as well as the ADC values of extraocular muscles. We studied 33 consecutive patients (23 females, 69.7%) with a mean age of 41.8 years. The majority (n = 27, 81.8%) were hyperthyroid, four were hypothyroid, and two were euthyroid. In the VISA classification, nine patients had active TAO (≥4/8 inflammation score), while 24 had inactive disease. There was a positive correlation between the inflammation score and ADC values of medial rectus (MR), inferior rectus (IR) and lateral rectus (LR). We had nine patients with inflammation scores ≥4. With receiver operating characteristic (ROC) curve analysis, we found that the ADC value of IR can predict disease activity with 68% sensitivity and MR-ADC can predict active TAO with 87% sensitivity. The ADC parameters of DW-MRI are objective and less operator dependent than the clinical TAO activity scores like VISA classification. A randomized control trial may provide robust data on this correlation.

Diagnostic contribution of diffusion-weighted imaging in liver hemangiomas

Objective: To evaluate the contribution of diffusion-weighted imaging (DWI) and measure apparent diffusion coefficient values (ADC) in hepatic hemangiomas.&#x0D; Material and Methods: Seventy patients with liver hemangiomas were evaluated with DWI with a b value of 800 s/mm2. ADC map was created and ADC values were measured for 70 liver masses and normal liver tissue following DWI. ADC measurements of 70 normal liver parenchyma and mean ADC values of 80 hemangiomas are performed.&#x0D; Results: Eighty hemangiomas of 70 patients (50 female and 20 male) were evaluated. The mean age of the patients was 49.61±10.96 years. Hemangiomas were most frequently demonstrated at segment 7 (%28.8), segment 6 (%21.3), and least demonstrated at segment 5 (%5). While the mean ADC measurements of normal livers were 1.06±0.11 x 10-3 mm2/sn, the mean ADC values of hemangiomas were measured as 1.70±0.29 x 10-3 mm2/sn.&#x0D; Conclusion: DWI and the ADC measurements seem to be useful for the diagnosis of liver hemangiomas. DWI should be routinely added to conventional magnetic resonance imaging sequences.

Diffusion weighted imaging combining respiratory triggering and navigator echo tracking in the upper abdomen.

To evaluate a new motion correction method, named RT + NV Track, for upper abdominal DWI that combines the respiratory triggering (RT) method using a respiration sensor and the Navigator Track (NV Track) method using navigator echoes. To evaluate image quality acquired upper abdominal DWI and ADC images with RT, NV, and RT + NV Track in 10 healthy volunteers and 35 patients, signal-to-noise efficiency (SNRefficiency) and the coefficient of variation (CV) of ADC values were measured. Five radiologists independently performed qualitative image-analysis assessments. RT + NV Track showed significantly higher SNRefficiency than RT and NV (14.01 ± 4.86 vs 12.05 ± 4.65, 10.05 ± 3.18; p < 0.001, p < 0.001). RT + NV Track was superior to RT and equal or better quality than NV in CV and visual evaluation of ADC values (0.033 ± 0.018 vs 0.080 ± 0.042, 0.057 ± 0.034; p < 0.001, p < 0.001). RT + NV Track tends to acquire only expiratory data rather than NV, even in patients with relatively rapid breathing, and can correct for respiratory depth variations, a weakness of RT, thus minimizing image quality degradation. The RT + NV Track method is an efficient imaging method that combines the advantages of both RT and NV methods in upper abdominal DWI, providing stably good images in a short scan time.

Clinical, qualitative imaging biomarkers, and tumor oxygenation imaging biomarkers for differentiation of midline-located IDH wild-type glioblastomas and H3 K27-altered diffuse midline gliomas in adults

PurposeTo compare the clinical, qualitative and quantitative imaging phenotypes, including tumor oxygenation characteristics of midline-located IDH-wildtype glioblastomas (GBMs) and H3 K27-altered diffuse midline gliomas (DMGs) in adults. MethodsPreoperative MRI data of 55 adult patients with midline-located IDH-wildtype GBM or H3 K27-altered DMG (32 IDH-wildtype GBM and 23 H3 K27-altered DMG patients) were included. Qualitative imaging assessment was performed. Quantitative imaging assessment including the tumor volume, normalized cerebral blood volume, capillary transit time heterogeneity (CTH), oxygen extraction fraction (OEF), relative cerebral metabolic rate of oxygen values, and mean ADC value were performed from the tumor mask via automatic segmentation. Univariable and multivariable logistic analyses were performed. ResultsOn multivariable analysis, age (odds ratio [OR] = 0.92, P = 0.015), thalamus or medulla location (OR = 10.48, P = 0.013), presence of necrosis (OR = 0.15, P = 0.038), and OEF (OR = 0.01, P = 0.042) were independent predictors to differentiate H3 K27-altered DMG from midline-located IDH-wildtype GBM. The area under the curve, accuracy, sensitivity, and specificity of the multivariable model were 0.88 (95 % confidence interval: 0.77–0.95), 81.8 %, 82.6 %, and 81.3 %, respectively. ConclusionsAlong with younger age, tumor location, less frequent necrosis, and lower OEF may be useful imaging biomarkers to differentiate H3 K27-altered DMG from midline-located IDH-wildtype GBM. Tumor oxygenation imaging biomarkers may reflect the less hypoxic nature of H3 K27-altered DMG than IDH-wildtype GBM and may contribute to differentiation.

Values of multiparametric and biparametric MRI in diagnosing clinically significant prostate cancer: a multivariate analysis

BackgroundTo investigate the value of semi-quantitative and quantitative parameters (PI-RADS score, T2WI score, ADC, Ktrans, and Kep) based on multiparametric MRI (mpMRI) or biparametric MRI (bpMRI) combined with prostate specific antigen density (PSAD) in detecting clinically significant prostate cancer (csPCa).MethodsA total of 561 patients (276 with csPCa; 285 with non-csPCa) with biopsy-confirmed prostate diseases who underwent preoperative mpMRI were included. Prostate volume was measured for calculation of PSAD. Prostate index lesions were scored on a five-point scale on T2WI images (T2WI score) and mpMRI images (PI-RADS score) according to the PI-RADS v2.1 scoring standard. DWI and DCE-MRI images were processed to measure the quantitative parameters of the index lesion, including ADC, Kep, and Ktrans values. The predictors of csPCa were screened by logistics regression analysis. Predictive models of bpMRI and mpMRI were established. ROC curves were used to evaluate the efficacy of parameters and the model in diagnosing csPCa.ResultsThe independent diagnostic accuracy of PSA density, PI-RADS score, T2WI score, ADCrec, Ktrans, and Kep for csPCa were 80.2%, 89.5%, 88.3%, 84.6%, 58.5% and 61.6%, respectively. The diagnostic accuracy of bpMRI T2WI score and ADC value combined with PSAD was higher than that of PI-RADS score. The combination of mpMRI PI‑RADS score, ADC value with PSAD had the highest diagnostic accuracy.ConclusionsPI-RADS score according to the PI-RADS v2.1 scoring standard was the most accurate independent diagnostic index. The predictive value of bpMRI model for csPCa was slightly lower than that of mpMRI model, but higher than that of PI-RADS score.

Quantitative fetal MRI with diffusion tensor imaging in cases with 'short' corpus callosum.

It has been suggested previously that the presence of Probst bundles (PB) in cases with a short corpus callosum (SCC) on diffusion tensor imaging (DTI) may help to differentiate between corpus callosal (CC) dysplasia and a variant of normal CC development. The objectives of this study were to compare DTI parameters between cases of SCC vs normal CC and between cases of SCC with PB (SCC-PB+) vs SCC without PB (SCC-PB-). This was a retrospective study of patients referred to the Necker Hospital in Paris, France, for magnetic resonance imaging (MRI) evaluation of an apparently isolated SCC detected by sonography between November 2016 and December 2022 (IRB: 00011928). MRI was performed using a 1.5-Tesla Signa system. T2-weighted axial and sagittal sequences of the fetal brain were used to measure the length and thickness of the CC. 16-direction DTI axial brain sequences were performed to identify the presence of PB and to generate quantitative imaging parameters (fractional anisotropy (FA) and apparent diffusion coefficient (ADC)) of the entire CC, genu, body and splenium. Cases in which other associated brain abnormalities were detected on MRI were excluded. Cases were matched for fetal gender and gestational age with controls in a 1:3 ratio. Control cases were normal fetuses included in the LUMIERE on the FETUS trial (NCT04142606) that underwent the same DTI evaluation of the brain. Comparisons between SCC and normal CC cases, and between SCC-PB+ and SCC-PB- cases were performed using ANOVA and adjusted for potential confounders using ANCOVA. Twenty-two SCC cases were included and compared with 66 fetuses with a normal CC. In 10/22 (45.5%) cases of SCC, PB were identified. As expected, dimensions of the CC were significantly smaller in SCC compared with normal CC cases (all P < 0.01). In SCC-PB+ vs SCC-PB- cases, FA values were significantly lower in the entire CC (median, 0.21 (range, 0.19-0.24) vs 0.24 (range, 0.22-0.28); P < 0.01), genu (median, 0.21 (range, 0.15-0.29) vs 0.24 (range, 0.17-0.29); P = 0.04), body (median, 0.21 (range, 0.18-0.23) vs 0.23 (range, 0.21-0.27); P = 0.04) and splenium (median, 0.22 (range, 0.16-0.30) vs 0.25 (range, 0.20-0.29); P = 0.03). ADC values were significantly higher in the entire CC, genu and body in SCC-PB+ vs SCC-PB- cases (all P < 0.05). In SCC-PB+ cases, all FA values were significantly lower, and ADC values in the CC body were significantly higher compared with normal CC cases (all P < 0.05). In SCC-PB- cases, there was no significant difference in FA and ADC compared with normal CC cases (all P > 0.05). Fetal DTI evaluation of the CC showed that FA values were significantly lower and ADC values tended to be significantly higher in SCC-PB+ compared with normal CC cases. This may highlight alterations of the white matter microstructure in SCC-PB+. In contrast, isolated SCC-PB- did not demonstrate significant changes in DTI parameters, strengthening the possibility that this is a normal CC variant. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Collision tumours: a meningioma and not oedema, but an oligodendroglioma

BackgroundIntracranial collision tumours represent a very rare entity. We hereby report a case involving the coexistence of a meningioma and an underlying oligodendroglioma in the adjacent brain, which could be misdiagnosed as oedema if not carefully examined for atypical changes. This study aimed to shed light on the diagnostic challenges associated with intracranial collision tumours, specifically the coexistence of meningioma and oligodendroglioma.Case presentationA 54-year-old woman presented to the emergency department with seizures and vertigo. Brain CT revealed an expansile extra-axial left frontal lesion with calcifications and homogeneous enhancement after contrast administration, interpreted as a meningioma, with underlying vasogenic oedema. Two months later, MRI revealed a heterogeneous area in the underlying compressed brain with high intensity at T2/FLAIR sequences, initially misconceived as oedema. However, atypical features such as cortex involvement, lower ADC values (compared to vasogenic oedema), an inversion of the choline/NAA ratio, and high rCBV values led to the hypothesis of an underlying oligodendroglioma, later confirmed by histology.ConclusionsThe coexistence of histologically different tumours in the same anatomical location is extremely rare and makes the diagnosis more challenging, requiring cautious evaluation and a high suspicion from the radiologist. The look for atypical findings, described in detail in this study, and the use of additional sequences, such as spectroscopy and perfusion, might be the key to the correct diagnosis.

Prognostic Value of Apparent Diffusion Coefficient (ADC) in Patients with Diffuse Gliomas.

This study aimed to evaluate potential posttreatment changes in ADC values within the tissue surrounding the enhancing lesion, particularly in areas not exhibiting MRI characteristics of involvement. Additionally, the objective was to investigate the correlations among ADC values, treatment response, and survival outcomes in individuals diagnosed with gliomas. This retrospective study included a total of 49 patients that underwent either stereotactic biopsy or maximal surgical resection. Histologically confirmed as Grade III or IV gliomas, all cases adhered to the 2016 and 2021 WHO classifications, with subsequent radio-chemotherapy administered post-surgery. Patients were divided into two groups: short and long survival groups. Baseline and follow-up MRI scans were obtained on a 1.5 T MRI scanner. Two ROI circles were positioned near the enhancing area, one ROI in the NAWM ipsilateral to the neoplasm and another symmetrically in the contralateral hemisphere on ADC maps. At follow-up there was a significant difference in both ipsilateral and contralateral NAWM between the two groups, -0.0857 (p = 0.004) and -0.0607 (p = 0.037), respectively. There was a weak negative correlation between survival and ADC values in ipsilateral and contralateral NAWM at the baseline with the correlation coefficient -0.328 (p = 0.02) and -0.302 (p = 0.04), respectively. The correlation was stronger at the follow-up. The findings indicate that ADC values in normal-appearing white matter (NAWM) may function as a prognostic biomarker in patients with diffuse gliomas.

Abstract WP219: Diffusion Weighted Imaging Characteristics in Deep White and Gray Matter Structures in Pediatric Patients With Moyamoya Disease

Background: Moyamoya Disease (MMD) is a steno-occlusive arteriopathy associated with transient ischemic attacks, stroke, and cognitive impairments. In adult MMD, normal-appearing deep gray and white matter structures (NADWM) show diffusion changes that are associated with cognitive impairments. Apparent diffusion coefficient [ADC] measures the mean diffusion and is sensitive to these changes. The association of ADC changes in NADWM in pediatric MMD is not clear. Our objective is to determine whether ADC is elevated in NADWM in pediatric MMD patients. Hypothesis: ADC values in NADWM will be elevated in MMD patients compared to controls. Methods: Twenty-nine MMD patients and no stroke and 7 healthy controls (HC) were included in a single center, retrospective study. Diffusion and T1-weighted images were analyzed. We constructed a script implementing a convolutional neural network (CNN) based approach to segment and binarize cortical regions of interest (ROI) and allow extraction of ADC values (units =[x10 -6 mm 2 /s]). Segmented ROIs included: 1) all white matter (WM), and NADWM including: 2) thalamus, 3) caudate, 4) putamen, 5) globus pallidus, 6) hippocampus. Mean ADC values were compared for: 1) all ROIs between MMD and controls, and 2) all ROIs in the MMD affected and the contralateral hemispheres within the MMD group. Results: Patients were on average 7.7 + 5.4 years at MMD diagnosis. In all WM, MMD patients had significantly higher ADC values than controls in the left (mean= 865.7 + 101.6 versus 762.4 + 21.6, p=0.01) and right hemispheres (mean= 869.9 + 104.9 versus 761.0 + 21.3, p=.01), respectively. In NADGM, there were no significant differences found between the MMD and control groups in any of the NADGM ROIs. In the NADGM of MMD patients, higher ADC values were found in the putamen (mean= 778.2 + 46.0, p=0.041), hippocampus (mean=1009.5 + 58.6, p=0.005) and all NAWM (mean= 860.3 + 57.0, p&lt;0.0001) in the MMD affected compared to the contra-lesional hemisphere. Conclusions: In pediatric patients with MMD, we found elevated ADC values in deep gray and white matter structures in the diseased hemisphere indicating alterations in the underlying microstructure. Our future analysis will integrate hemodynamic profiles and cognitive outcomes.

Mean ADC values and arterial phase hyperintensity discriminate small (≤ 3cm) well-differentiated hepatocellular carcinoma from dysplastic nodule.

This research endeavor sought to distinguish small (≤ 3cm) well-differentiated hepatocellular carcinoma (WD-HCC) from dysplastic nodules (DN) by employing traditional imaging features and mean apparent diffusion coefficient (mADC) values derived from diffusion-weighted imaging (DWI). In this retrospective analysis, we assessed a cohort of ninety patients with confirmed dysplastic nodules (DNs) (n = 71) or well-differentiated hepatocellular carcinoma (WD-HCC) (n = 41) who had undergone dynamic contrast-enhanced magnetic resonance imaging between March 2018 and June 2021. Multivariable logistic regression analyses were executed to pinpoint characteristics that can effectively differentiate histologic grades. A region-of-interest (ROI) encompassing all lesion voxels was delineated on each slice containing the mass in the ADC map. Subsequently, the whole-lesion mean ADC (mADC) were computed from these delineations. A receiver operating characteristic (ROC) curve was generated to assess the discriminatory efficacy of the mADC values in distinguishing between WD-HCC and DN. Among the histopathological types from benign to malignant, mADC showed a significant decrease (P < 0.001). The mADCs were effective in distinguishing WD-HCC from DN [AUC, 0.903 (95% CI 0.849-0.958)]. The best cutoffs for theYoudenindexwere 0.0012mm2/s for mADC, with moderate sensitivity (70.7%) and high specificity (94.4%). MRI features including hyperintensity at arterial phase (odds ratio, 21.2; P = 0.009), mADC < 0.0012mm2/s (odds ratio, 52.2; P < 0.001) were independent predictors for WD-HCC at multivariable analysis. The AUC value of hyperintensity at arterial phase was 0.857 (95% CI 0.786-0.928). The composite diagnostic criterion of arterial hyperintensity + mADC < 0.0012mm2/s showed good performance [AUC, 0.926 (95% CI 0.878-0.975)], displaying increased sensitivity compared to individual assessments involving arterial hyperintensity (P = 0.013), mADC < 0.0012mm2/s (P = 0.004), or LR-5 (P < 0.001), with similar specificity compared to LR-5 (P = 0.193). DN and WD-HCC displayed contrasting diffusion characteristics, attainable to distinguish with satisfactory accuracy. The utilization of arterial phase hyperintensity and mADC < 0.0012 on MRI facilitated the differentiation of WD-HCC from DN.