Dynamic Contrast-enhanced Perfusion Research Articles

MRI Detection of Changes in Tissue Sodium Concentration in Brain Metastases after Stereotactic Radiosurgery: A Feasibility Study.

To date, treatment response to stereotactic radiosurgery (SRS) in brain metastases (BM) can only be determined by MRI evaluation of contrast-enhancing lesions in a long-time follow-up. Sodium MRI has been a subject of immense interest in imaging research as the measure of tissue sodium concentration (TSC) can give valuable quantitative information on cell viability. We aimed to analyze the longitudinal changes of TSC in BM measured with 23 Na MRI before and after SRS for assessment of early local tumor effects. Seven patients with a total of 12 previously untreated BM underwent SRS with 22 Gy. In addition to a standard MRI protocol including dynamic susceptibility-weighted contrast-enhanced perfusion, a 23 Na MRI was performed at three time points: (I) 2 days before, (II) 5 days, and (III) 40 days after SRS. Nine BMs were evaluated. The absolute TSC in the BM, the respective peritumoral edemas, and the normal-appearing corresponding contralateral brain area were assessed and the relative TSC were correlated to the changes in BM longest axial diameters. TSC was elevated in nine BM at baseline before SRS with a mean of 73.4±12.3 mM. A further increase in TSC was observed 5 days after SRS in all the nine BM with a mean of 86.9±13 mM. Eight of nine BM showed a mean 60.6±13.3% decrease in the longest axial diameter 40 days after SRS; at this time point, the TSC also had decreased to a mean 65.1± 7.9 mM. In contrast, one of the nine BM had a 13.4% increase in the largest axial diameter at time point III. The TSC of this BM showed a further TSC increase of 80.1 mM 40 days after SRS. Changes in TSC using 23 Na MRI shows the possible capability to detect radiobiological changes in BM after SRS.

Clinical value of high-resolution dynamic contrast-enhanced (DCE) MRI in diagnosis of cutaneous squamous cell carcinoma.

While uncomplicated cases of skin squamous cell carcinoma (cSCC) can be treated with surgery topical therapy alone, more objective and non-invasive examination methods are needed to guide clinicians to make more detailed biopsy and surgical plans for lesions with atypical or subcutaneous growth. High-resolution magnetic resonance imaging (HR-MRI) is a novel skin imaging method. Prospective collection of 19 patients with clinically suspected cSCC. All patients underwent high-resolution DCE-MRI using a 70-mm microscopy coil before operation. The imaging features and results of surgical pathology were recorded. Ktrans , Kep , Ve values, and the time-signal curve (TIC) types were determined using DCE images. 16 cases of cSCC, 3 cases of acanthoma. The subcutaneous invasion of all lesions was clearly displayed, of which 8 lesions invaded the subcutaneous fat layer, 5 invaded the muscle layer, 1 invaded the periosteum, 2 invaded the cap fascia, and the layer of all lesions invasion judged by HR-MR imaging was consistent with the postoperative pathology. The main manifestations of cSCC were ill-defined margin, obvious inhomogeneous enhancement, higher perfusion parameters value and type-III TIC, while acanthoma showed well-defined and type-I TIC. Some imaging findings (such as boundary, enhancement) and DCE perfusion parameters of the two groups overlap. High-resolution DCE-MRI can fully and directly display the subcutaneous invasion of cSCC, and more work needs to be done to prove its value. Next, we will expand the sample size, and further explore its value in the differential diagnosis and prognosis evaluation of cSCC from acanthoma or other skin tumors.

Added-value of advanced magnetic resonance imaging to conventional morphologic analysis for the differentiation between benign and malignant non-fatty soft-tissue tumors.

To evaluate the added value of DWI, qualitative proton MR spectroscopy (H-MRS) and dynamic contrast-enhanced perfusion (DCE-P) to conventional MRI in differentiating benign and malignant non-fatty soft tissue tumors (NFSTT). From November 2009 to August 2017, 288 patients with NFSTT that underwent conventional and advanced MRI were prospectively evaluated. The study was approved by the local ethics committee. All patients signed an informed consent. A musculoskeletal (R1) and a general (R2) radiologist classified all tumors as benign, malignant, or indeterminate according to morphologic MRI features. Then, DWI, H-MRS, and DCE-P data of indeterminate tumors were analyzed by two additional radiologists (R3 and R4). Advanced techniques were considered individually and in combination for tumor benign-malignant differentiation using histology as the gold standard. There were 104 (36.1%) malignant and 184 (63.9%) benign tumors. Conventional MRI analysis classified 99 tumors for R1 and 135 for R2 as benign or malignant, an accuracy for the identification of malignancy of 87.9% for R1 and 83.7% for R2, respectively. There were 189 indeterminate tumors for R1. For these tumors, the combination of DWI and H-MRS yielded the best accuracy for malignancy identification (77.4%). DWI alone provided the best sensitivity (91.8%) while the combination of DCE-P, DWI, and H-MRS yielded the best specificity (100%). The reproducibility of the advanced imaging parameters was considered good to excellent (Kappa and ICC > 0.86). An advanced MRI evidence-based evaluation algorithm was proposed allowing to characterize 28.1 to 30.1% of indeterminate non-myxoid tumors. The prioritized use of advanced MRI techniques allowed to decrease by about 30% the number of non-myxoid NFSTT deemed indeterminate after conventional MRI analysis alone. • When morphological characterization of non-fatty soft tissue tumors is possible, the diagnostic performance is high and there is no need for advanced imaging techniques. • Following morphologic analysis, advanced MRI techniques reduced by about 30% the number of non-myxoid indeterminate tumors. • DWI is the keystone of advanced imaging techniques yielding the best sensitivity (91.8%). Optimal specificity (> 90%) is obtained by a combination of advanced techniques.

Value of Diffusion-Weighted and Perfusion-Weighted MR Imaging in Differentiation of Recurrent Tongue Carcinoma from Post-Treatment Changes

Abstract Background: Tongue carcinoma is characterized by high recurrence rate. Thus, post-treatment follow-up imaging is critically important. Advanced Magnetic Resonance Imaging (MRI) techniques can be employed for this purpose due to the limited accuracy of conventional MRI. Aim of Study: Evaluation of the value of Diffusion Weight-ed (DW) and perfusion weighted MRI implementation in the post-treatment follow-up of tongue carcinoma. Patients and Methods: This study was conducted on 23 patients on post-treatment follow-up of tongue carcinoma. They underwent DW-MRI and Dynamic Contrast Enhanced (DCE) perfusion T1-weighted MRI to differentiate between recurrent tumor and post-treatment changes. Apparent Diffu-sion Coefficient (ADC) was estimated, perfusion MR quali-tative and semiquantitative assessment was performed. Re-sulting data were compared to histopathologic characterization (n=18) and further clinical and radiological follow-up (n=5) which were considered as the reference standards. Results: The mean ADC value of recurrent tongue carci-noma (1.029±0.207 X 10–3mm2/s) was significantly lower (p < 0.001) than the mean ADC value of post-treatment changes (1.425±0.238 X 10–3mm2/s). The ADC threshold used for differentiating recurrent tumor from post-treatment changes was 1.175 X 10–3mm2/s with Area Under the Curve (AUC) of 0.938 and diagnostic accuracy of 82.6%. Among the DCE perfusion weighted MR parameters, the wash in rate and Area Under Gadolinium Curve (AUGC) displayed the highest diagnostic accuracy (73.9%) with thresholds of 18.65a.u/s and 126826.7m.M.s respectively. The combined use of both DW-MRI and perfusion weighted MRI showed the highest diagnostic accuracy. Conclusion: The DW MRI is a non-invasive technique providing accurate post-treatment follow-up assessment of tongue carcinoma. The perfusion weighted MRI provides lower diagnostic accuracy than DWI. The combined use of both techniques provides superior differentiation of tumor recurrence from post-treatment changes.

Advanced Imaging in Musculoskeletal Oncology: Moving Away From RECIST and Embracing Advanced Bone and Soft Tissue Tumor Imaging (ABASTI) - Part I - Tumor Response Criteria and Established Functional Imaging Techniques

According to the Revised Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, the majority of bone metastases are considered to be nonmeasurable disease. Traditional response criteria rely on physical measurements. New criteria would be valuable if they incorporated newly developed imaging features in order to provide a more comprehensive assessment of oncological status. Advanced magnetic resonance imaging (MRI) sequences such as diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) with dynamic contrast-enhanced (DCE) perfusion imaging are reviewed in the context of the initial and post-therapeutic assessment of musculoskeletal tumors. Particular attention is directed to the pseudoprogression phenomenon in which a successfully treated tumor enlarges from the pretherapeutic baseline, followed by regression without a change in therapy.

Feasibility of free-breathing quantitative myocardial perfusion using multi-echo Dixon magnetic resonance imaging

Dynamic contrast-enhanced quantitative first-pass perfusion using magnetic resonance imaging enables non-invasive objective assessment of myocardial ischemia without ionizing radiation. However, quantification of perfusion is challenging due to the non-linearity between the magnetic resonance signal intensity and contrast agent concentration. Furthermore, respiratory motion during data acquisition precludes quantification of perfusion. While motion correction techniques have been proposed, they have been hampered by the challenge of accounting for dramatic contrast changes during the bolus and long execution times. In this work we investigate the use of a novel free-breathing multi-echo Dixon technique for quantitative myocardial perfusion. The Dixon fat images, unaffected by the dynamic contrast-enhancement, are used to efficiently estimate rigid-body respiratory motion and the computed transformations are applied to the corresponding diagnostic water images. This is followed by a second non-linear correction step using the Dixon water images to remove residual motion. The proposed Dixon motion correction technique was compared to the state-of-the-art technique (spatiotemporal based registration). We demonstrate that the proposed method performs comparably to the state-of-the-art but is significantly faster to execute. Furthermore, the proposed technique can be used to correct for the decay of signal due to T2* effects to improve quantification and additionally, yields fat-free diagnostic images.

Validity and Reproducibility of the ADNEX MR Scoring System in the Diagnosis of Sonographically Indeterminate Adnexal Masses.

The diagnosis of sonographically indeterminate adnexal masses (AM) signifies a major challenge in clinical practice. Early detection and characterization have increased the need for accurate imaging evaluation before treatment. To assess the validity and reproducibility of the ADNEX MR Scoring system in the diagnosis of sonographically indeterminate AM. A prospective multicenter study. In all, 531 women (mean age, 44 ± 11.2 years; range, 21-79 years) with 572 sonographically indeterminate AM. 1.5T/precontrast T1 -weighted imaging (WI) fast spin echo (FSE) (in-phase and out-of-phase, with and without fat suppression); T2 -WI FSE; diffusion-WI single-shot echo planner with b-values of 0 and 1000 s/mm2 ; and dynamic contrast-enhanced perfusion T1 -WI liver acquisition with volume acceleration (LAVA). All MRI examinations were evaluated by three radiologists, and the AM were categorized into five scores based on the ADNEX MR Scoring system. Score 1: no AM; 2: benign AM; 3: probably benign AM; 4: indeterminate AM; 5: probably malignant AM. Histopathology and imaging follow-up were used as the standard references for evaluating the validity of the ADNEX MR Scoring system for detecting ovarian malignancy. Four-fold table test, kappa statistics (κ), and receiver operating characteristic (ROC) curve. In all, 136 (23.8%) AM were malignant, and 436 (76.2%) were benign. Of the 350 AM classified as score 2, one (0.3%) was malignant; of the 62 AM classified as score 3, six (9.7%) were malignant; of the 73 AM classified as score 4, 43 (58.9%) were malignant; and of the 87 AM categorized as score 5, 86 (98.9%) were malignant. The best cutoff value for predicting malignant AM was score >3 with sensitivity and specificity of 92.9% and 94.9%, respectively. The interreader agreement of the ADNEX MR Scoring was very good (κ = 0.861). The current study supports the high validity and reproducibility of the ADNEX MR Scoring system for the diagnosis of sonographically indeterminate AM. 1 TECHNICAL EFFICACY STAGE: 2.

The utility of multiparametric MRI to characterize hypoxic tumor subvolumes in comparison to FMISO PET/CT. Consequences for diagnosis and chemoradiation treatment planning in head and neck cancer

Background and PurposeHypoxia is an essential metabolic marker that determines chemo- and radiation resistance in head-and-neck squamous cell carcinoma (HNSCC) patients. Our exploratory analysis aimed to identify multiparametric MRI (mpMRI) parameters linked to hypoxia that might be used as surrogate for [18F]FMISO-PET in diagnosis and chemoradiation treatment (CRT) of HNSCC. Materials and Methods21 patients undergoing definitive CRT for HNSCC were prospectively imaged with serial [18F]FMISO-PET and 3 Tesla mpMRI for T1- and T2-weighted and dynamic contrast-enhanced perfusion and diffusion-weighted measurements (ktrans, ve, kep, ADC) in weeks 0, 2 and 5 and FDG-PET in week 0. [18F]FMISO-PET-derived hypoxic subvolumes (HSV) and complementary non-hypoxic subvolumes (nonHSV) were created for tumor and lymph nodes and projected on the mpMRI scans after PET/MRI co-registration. MpMRI and [18F]FMISO-PET parameters within HSVs and nonHSVs were statistically compared. ResultsFMISO-PET-based HSVs of the primary tumors on MRI were characterized by lower ADC at all time points (p = 0.012 at baseline; p = 0.015 in week 2) and reduced interstitial space volume fraction ve and perfusion ktrans at baseline (p = 0.006, p = 0.047) compared to nonHSVs. Hypoxic lymph nodes were characterized by significantly lower ADC values at baseline (p = 0.039), but not at later time points and a reduction in ktrans-based perfusion at week 2 (p = 0.018). ConclusionMpMRI parameters differ significantly between hypoxic and non-hypoxic tumor regions, defined on FMISO-PET/CT as gold standard and might represent surrogate markers for tumor hypoxia. These findings suggest that mpMRI may be useful in the future as a surrogate modality for hypoxia imaging in order to personalize CRT.

Multiparametric Renal MRI: An Intrasubject Test-Retest Repeatability Study.

BackgroundRenal multiparametric magnetic resonance imaging (MRI) is a promising tool for diagnosis, prognosis, and treatment monitoring in kidney disease.PurposeTo determine intrasubject test–retest repeatability of renal MRI measurements.Study TypeProspective.PopulationNineteen healthy subjects aged over 40 years.Field Strength/SequencesT1 and T2 mapping, R2* mapping or blood oxygenation level‐dependent (BOLD) MRI, diffusion tensor imaging (DTI), and intravoxel incoherent motion (IVIM) diffusion‐weighted imaging (DWI), 2D phase contrast, arterial spin labelling (ASL), dynamic contrast enhanced (DCE) MRI, and quantitative Dixon for fat quantification at 3T.AssessmentSubjects were scanned twice with ~1 week between visits. Total scan time was ~1 hour. Postprocessing included motion correction, semiautomated segmentation of cortex and medulla, and fitting of the appropriate signal model.Statistical TestTo assess the repeatability, a Bland–Altman analysis was performed and coefficients of variation (CoVs), repeatability coefficients, and intraclass correlation coefficients were calculated.ResultsCoVs for relaxometry (T1, T2, R2*/BOLD) were below 6.1%, with the lowest CoVs for T2 maps and highest for R2*/BOLD. CoVs for all diffusion analyses were below 7.2%, except for perfusion fraction (FP), with CoVs ranging from 18–24%. The CoV for renal sinus fat volume and percentage were both around 9%. Perfusion measurements were most repeatable with ASL (cortical perfusion only) and 2D phase contrast with CoVs of 10% and 13%, respectively. DCE perfusion had a CoV of 16%, while single kidney glomerular filtration rate (GFR) had a CoV of 13%. Repeatability coefficients (RCs) ranged from 7.7–87% (lowest/highest values for medullary mean diffusivity and cortical FP, respectively) and intraclass correlation coefficients (ICCs) ranged from −0.01 to 0.98 (lowest/highest values for cortical FP and renal sinus fat volume, respectively).Data ConclusionCoVs of most MRI measures of renal function and structure (with the exception of FP and perfusion as measured by DCE) were below 13%, which is comparable to standard clinical tests in nephrology.Level of Evidence2Technical EfficacyStage 1

Quantitative dynamic contrast-enhanced MRI blood perfusion in Hoffa’s fatpad signal abnormalities in patients with and without osteoarthritis

Purpose: Infrapatellar fat pad (IPFP) T2FS-hyperintense regions are an important imaging feature of knee osteoarthritis (OA) and are thought to represent inflammation. These regions are very common also in non-OA subjects, and may not always be linked to inflammation.The aim of this study was to evaluate quantitative blood perfusion parameters, as surrogate measure of inflammation, within T2FS-hyperintense regions in patients with OA, with patellofemoral pain (PFP) (supposed OA precursor), and control subjects.

Differentiation of progressive disease from pseudoprogression using 3D PCASL and DSC perfusion MRI in patients with glioblastoma.

To use 3D pseudocontinuous arterial spin labeling (3D PCASL) and dynamic susceptibility contrast-enhanced (DSC) perfusion MRI to differentiate progressive disease from pseudoprogression in patients with glioblastoma (GBM). Thirty-two patients with GBM who developed progressively enhancing lesions within the radiation field following resection and chemoradiation were included in this retrospective, single-institution study. The updated modified RANO criteria were used to establish progressive disease or pseudoprogression. Following 3D PCASL and DSC MR imaging, perfusion parameter estimates of cerebral blood flow (ASL-nCBF and DSC-nrCBF) and cerebral blood volume (DSC-nrCBV) were calculated. Additionally, contrast enhanced volumes were measured. Mann-Whitney U tests were used to compare groups. Linear discriminant analysis (LDA) and area under receiver operator characteristic curve (AUC) analyses were used to evaluate performance of each perfusion parameter and to determine optimal cut-off points. All perfusion parameter measurements were higher in patients with progressive disease (mean, 95% CI ASL-nCBF 2.48, [2.03, 2.93]; DSC-nrCBF = 2.27, [1.85, 2.69]; DSC-nrCBV = 3.51, [2.37, 4.66]) compared to pseudoprogression (mean, 95% CI ASL-nCBF 0.99, [0.47, 1.52]; DSC-nrCBF = 1.05, [0.36, 1.74]; DSC-nCBV = 1.19, [0.34, 2.05]), and findings were significant at the p < 0.0125 level (p = 0.001, 0.003, 0.002; effect size: Cohen's d = 1.48, 1.27, and 0.92). Contrast enhanced volumes were not significantly different between groups (p > 0.447). All perfusion parameters demonstrated high AUC (0.954 for ASL-nCBF, 0.867 for DSC-nrCBF, and 0.891 for DSC-nrCBV), however, ASL-nCBF demonstrated the highest AUC and misclassified the fewest cases (N = 6). Lesions correctly classified by ASL but misclassified by DSC were located along the skull base or adjacent to large resection cavities with residual blood products, at areas of increased susceptibility. Both 3D PCASL and DSC perfusion MRI techniques have nearly equivalent performance for the differentiation of progressive disease from pseudoprogression in patients with GBM. However, 3D PCASL is less sensitive to susceptibility artifact and may allow for improved classification in select cases.

Quantitative evaluation of Crohn's disease using dynamic contrast-enhanced MRI in children and young adults.

To evaluate the clinical usefulness of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in children and young adults with Crohn's disease. From August 2017 to October 2018, 30 patients with Crohn's disease (21 males and 9 females; mean age 15.1 ± 2.5years) underwent DCE-MRI with MRI enterography. We assessed the endoscopic finding, pediatric Crohn's disease activity index (PCDAI), C-reactive protein (CRP) level (mg/dL), Crohn's disease MR index (CDMI) score, and the perfusion parameters of DCE-MRI (Ktrans, Kep, and Ve) at the ileocecal region between the inactive and active groups based on the histopathologic status. The active Crohn's disease group showed higher PCDAI, CRP, and CDMI scores than the inactive group (22.2 ± 18.8 vs. 6.3 ± 6.4, p = 0.027; 1.32 ± 1.79 vs. 0.10 ± 0.13, p = 0.005; 7.4 ± 3.9 vs. 4.5 ± 3.0, p = 0.047, respectively). The active Crohn's disease group showed a higher Ktrans value than the inactive group (0.31 ± 0.12 vs. 0.16 ± 0.46min-1, p = 0.002). Endoscopic finding; PCDAI, CRP, and CDMI scores; and Ktrans value were significant parameters in the identification of the active Crohn's disease (p = 0.002, p < 0.001, p = 0.029, p = 0.006, and p < 0.001, respectively). Ktrans value was the most significant value for identifying active Crohn's disease in the multivariate logistic regression analysis (p = 0.013). Ktrans value could discriminate between inactive and active Crohn's diseases. Ktrans value may have the potential to monitor the pediatric Crohn's disease activity. • With dynamic contrast-enhanced MRI, we can quantitatively monitor the Crohn's disease status in pediatric patients and provide proper management plans to clinicians. • The Ktransvalue of dynamic contrast-enhanced MRI perfusion parameter, as well as the clinical pediatric Crohn's disease activity index, C-reactive protein level, the endoscopic score, and the Crohn's disease MR index, was higher in the active Crohn's disease than in the inactive group based on the histopathologic status. • The Ktransvalue among the dynamic contrast-enhanced MRI perfusion parameters was the most significant differentiating parameter for the active Crohn's disease from inactive status among those parameters (p=0.013).

Abstract 37: Increased Mean Transit Time and Blood Brain Permeability in Asymptomatic White Matter Lesions of Ischemic Origin

Introduction: White matter lesions of presumed ischemic origin (WMH) have been associated with increased risk of stroke, cognitive and motor decline, and are a subject of public health research. Engineering new MRI pipelines allowing for determination of mean transit time (MTT), and blood brain barrier permeability (BBBP), within WMH lesions is required for long-term population-based studies of lesion progression in patients with dementia and vascular cognitive impairment. Methods: WMH lesion volumes in 24 asymptomatic individuals was determined using an automated segmentation methodology, S3DL, with manual correction to remove false positives. A double contrast injection scheme was used to measure both K trans using dynamic contrast enhanced (DCE) imaging and K 2 using dynamic susceptibility contrast (DSC) imaging which also provided perfusion-related measures. BBBP was measured as k 2 within segmented WMH lesions and compared with normal white and gray matter. Results: The mean transit time (MTT) was found to be significantly prolonged (8.11, p&lt;0.001Wilcoxon Signed-Rank Test) in WMH lesions when compared to normal appearing white and gray matter. There was no significant difference in DCE-K trans (0.018, p=0.351) between the lesions and the white/gray matter. Permeability measured in the WMH lesions using the DSC-K 2 method was increased and was correlated withincreasing total WMH lesion volume (spearman correlation 0.44; p&lt; 0.046). Conclusion: In this first study using an advanced WMH lesion automated segmentation pipeline, we measured DCE and DSC perfusion and permeability variables within WMH lesions and compared them to normal white and grey matter in healthy people. We observed increasing MTT, within WMH lesions as compared to unaffected white and gray matter. Using the DSC-K 2 method, BBBP was higher within WMH lesions in these asymptomatic people, and correlated with increasing total lesion volume.

Abstract TMP115: Common Transcriptomic and Biomarker Signatures in the Aging Brain and in Mendelian Neurovascular Disease, Cerebral Cavernous Malformation

Background: Cellular senescence is associated with gene expression dysregulation affecting endothelial barrier function as well as angiogenic and inflammatory processes. These pathological changes occur in cerebral cavernous malformations (CCMs), a neurovascular anomaly predisposing patients to hemorrhagic stroke. We hypothesize common transcriptomic and biomarker signatures between the aging brain and CCMs. Method: Brain specific genes dysregulate in Younger (age &lt; 30) and Older (age &gt; 50) human brain parenchyma were identified using the Genotype-Tissue Expression database, and compared with differential transcriptome in microdissected neurovascular units of human CCM lesions. Brain white matter vascular permeability in areas devoid of lesions was measured in non-CCM (23 Younger, 27 Older), Sporadic-CCM (S-CCM) (26 Younger, 37 Older) and Familial-CCM (F-CCM) (41 Younger, 17 Older) using dynamic contrast-enhanced quantitative perfusion MRI. Plasma levels of 6 proteins with reported roles in CCMs were quantified, including VEGF, angiopoietin (ANG 1 &amp; 2), CRP, thrombospondin 2 (THBS 2), and endoglin (ENG). All reported correlations were significant at P&lt; 0.05, FDR corrected. Result: We identified 320 genes (absolute fold change≥1.5) commonly dysregulated in aging brain and CCM, related to inflammation and extracellular matrix organization pathways. Brain permeability was greater in Older non-CCM and S-CCM compared to Younger subjects. Brain permeability was higher in Younger F-CCM harboring germ line CCM mutations, than in both Younger non-CCM (p&lt;0.001) and S-CCM (p&lt;0.05) lacking those mutations. No difference was observed in Younger or Older F-CCM and Older S-CCM or controls. Plasma levels of VEGF, ANG-2 and CRP were greater in both Older non-CCM and S-CCM compared to Younger. No difference was found in Older or Younger F-CCM. No differences were observed in THBS2, ENG and ANG1. Conclusion: There are common transcriptomic, and brain permeability and plasma biomarker signatures in the aging brain and CCM, suggesting common dysregulated pathways. Biomarkers and potential therapies identified in a well characterized Mendelian neurovascular disease may be applicable to mitigate the same mechanistic aberrations in the aging brain.

Differentiation between benign and malignant ovarian masses using multiparametric MRI

PurposeTo investigate the capabilities of multiparametric MRI including dynamic contrast enhanced (DCE) perfusion and diffusion-weighted imaging (DWI) to discriminate between benign and malignant ovarian masses. MethodsA total of 43 women with a total of 43 ovarian masses were retrospectively included. They had a mean age of 51.26±18.05 (SD) years (range: 20–88years). Twenty women had benign and 23 had malignant ovarian tumors. All women had multiparametric MRI examinations including DWI (b50-b800) and DCE perfusion imaging at 1–5T. Results of DWI (apparent diffusion coefficient [ADC], b-800) and DCE imaging (volume transfer coefficient [Ktrans], rate constant [Kep], interstitial volume [Ve], initial area under the curve [iAUC]) were compared between benign and malignant ovarian masses. ResultsMean ADC was significantly lowed in malignant tumors (0.92±0.25 [SD]×10−3 mm2/s (range: 0.6–1.6×10−3 mm2/s) than in benign tumors (1.37±0.69 [SD]×10−3 mm2/s; range: 0.4–2.9×10−3 mm2/s) (P=0.011). B-800 was significantly greater in malignant tumors (80.61±24.73 [SD] s/mm2; range: 24–110 s/mm2) than in benign ones (61.15±22.17 [SD] s/mm2; range: 38–155 s/mm2) (P=0.010). Ktrans was lower in benign tumors (0.13±0.06 [SD] min−1; range: 0–0.2min−1) than in malignant ones (0.25±0.16 [SD] min−1; range: 0.1–0.8min−1) (P=0.002). Kep was significantly greater in malignant tumors (0.55±0.19 [SD] min−1; range: 0.1–1.9min−1) than in benign ones (0.44±0.38 [SD] min−1; range: 0.2–1.1min−1) (P=0.003). iAUC was greater in malignant tumors (15.59±7.98 [SD] mM/min; range: 6.6–42.1mM/min) than in benign ones (7.98±5.06 [SD] mM/min; range: 0.2–17.7mM/min) (P=0.001). No differences in Ve were found between benign and malignant masses (P=0.084). The area under the ROC curve was significant for all parameters but Ve. Logistic regression analysis revealed 5.590 and 11.637 times higher malignancy risk for an ADC≤0.93×10−3 mm2/s and an iAUC≥13.88mM/min, respectively. ConclusionMultiparametric MRI has high accuracy in discrimination between benign and malignant ovarian masses. Therefore, adding these methods to the more common MRI protocol can help select the best treatment option in women with ovarian mass.

Multinodular and Vacuolating Neuronal Tumor in the Brain Depth - Atypical Presentation of a New Tumor: A Case Report

Introduction: Multinodular and Vacuolating Neuronal Tumors (MVNTs) are clinically benign lesions and was recently included in the last World Health Organization Classification of Tumors of the Central Nervous System (WHO – 2016). Recent studies have discovered specific immunomarkers that classifies the MVNTs as a new neoplasm group placed within the section covering "Neuronal and mixed neuronal-glial tumors” as a WHO grade I lesion. Case report: We present a case of a probable MVNT in a 55-year old woman, who presented with chronic pattern seizures. Conventional MRI revealed an infiltrative and multinodular pattern lesion localized in the deep left cerebral hemisphere compromising the ventral posteromedial and pulvinar surfaces of thalamus, lateral geniculate body, choroidal fissure, mammillothalamic tract, fornix and septum pellucidum, anterior commissure, extending to contralateral globus pallidus and internal capsule. Dynamic susceptibility contrast-enhanced MR perfusion and Arterial Spin Labeling (ASL) technique didn’t show any abnormalities. MR spectroscopy demonstrated a mild increase in Choline (Cho) and mild reduction in N-acetyl aspartate (NAA). No substantial difference both clinically and radiologically was observed on five years follow up. Conclusion: The diagnosis of MVNT was made considering the extremally benign biological behavior of this tumor and the typical imaging features, despite of deep localization of the lesion, and once this kind of lesion was previously described as a “don’t touch lesion” the histological, biopsy was not performed.

Advanced neuroimaging in traumatic brain injury: an overview.

Traumatic brain injury (TBI) is a common condition with many potential acute and chronic neurological consequences. Standard initial radiographic evaluation includes noncontrast head CT scanning to rapidly evaluate for pathology that might require intervention. The availability of fast, relatively inexpensive CT imaging has fundamentally changed the clinician's ability to noninvasively visualize neuroanatomy. However, in the context of TBI, limitations of head CT without contrast include poor prognostic ability, inability to analyze cerebral perfusion status, and poor visualization of underlying posttraumatic changes to brain parenchyma. Here, the authors review emerging advanced imaging for evaluation of both acute and chronic TBI and include QuickBrain MRI as an initial imaging modality. Dynamic susceptibility-weighted contrast-enhanced perfusion MRI, MR arterial spin labeling, and perfusion CT are reviewed as methods for examining cerebral blood flow following TBI. The authors evaluate MR-based diffusion tensor imaging and functional MRI for prognostication of recovery post-TBI. Finally, MR elastography, MR spectroscopy, and convolutional neural networks are examined as future tools in TBI management. Many imaging technologies are being developed and studied in TBI, and some of these may hold promise in improving the understanding and management of TBI. ABBREVIATIONS ASL = arterial spin labeling; CNN = convolutional neural network; CTP = perfusion CT; DAI = diffuse axonal injury; DMN = default mode network; DOC = disorders of consciousness; DTI = diffusion tensor imaging; FA = fractional anisotropy; fMRI = functional MRI; GCS = Glasgow Coma Scale; MD = mean diffusivity; MRE = MR elastography; MRS = MR spectroscopy; mTBI = mild TBI; NAA = N-acetylaspartate; SWI = susceptibility-weighted imaging; TBI = traumatic brain injury; UHF = ultra-high field.

Noninvasive Monitoring of the Response of Human Lungs to Low-Dose Lipopolysaccharide Inhalation Challenge Using MRI: A Feasibility Study.

Development of antiinflammatory drugs for lung diseases demands novel methods for noninvasive assessment of inflammatory processes in the lung. To investigate the feasibility of hyperpolarized 129 Xe MRI, 1 H T1 time mapping, and dynamic contrast-enhanced (DCE) perfusion MRI for monitoring the response of human lungs to low-dose inhaled lipopolysaccharide (LPS) challenge compared to inflammatory cell counts from induced-sputum analysis. Prospective feasibility study. Ten healthy volunteers underwent MRI before and 6 hours after inhaled LPS challenge with subsequent induced-sputum collection. 1.5T/hyperpolarized 129 Xe MRI: Interleaved multiecho imaging of dissolved and gas phase, ventilation imaging, dissolved-phase spectroscopy, and chemical shift saturation recovery spectroscopy. 1 H MRI: Inversion recovery fast low-angle shot imaging for T1 mapping, time-resolved angiography with stochastic trajectories for DCE MRI. Dissolved-phase ratios of 129 Xe in red blood cells (RBC), tissue/plasma (TP) and gas phase (GP), ventilation defect percentage, septal wall thickness, surface-to-volume ratio, capillary transit time, lineshape parameters in dissolved-phase spectroscopy, 1 H T1 time, blood volume, flow, and mean transit time were determined and compared to cell counts. Wilcoxon signed-rank test, Pearson correlation. The percentage of neutrophils in sputum was markedly increased after LPS inhalation compared to baseline, P = 0.002. The group median RBC-TP ratio was significantly reduced from 0.40 to 0.31, P = 0.004, and 1 H T1 was significantly elevated from 1157.6 msec to 1187.8 msec after LPS challenge, P = 0.027. DCE MRI exhibited no significant changes in blood volume, P = 0.64, flow, P = 0.17, and mean transit time, P = 0.11. Hyperpolarized 129 Xe dissolved-phase MRI and 1 H T1 mapping may provide biomarkers for noninvasive assessment of the response of human lungs to LPS inhalation. By its specificity to the alveolar region, hyperpolarized 129 Xe MRI together with 1 H T1 mapping adds value to sputum analysis. 1 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1669-1676.

Can Dynamic Contrast-Enhanced CT Quantify Perfusion in a Stimulated Muscle of Limited Size? A Rat Model.

AbstractBackgroundMuscle injury may result in damage to the vasculature, rendering it unable to meet the metabolic demands of muscle regeneration and healing. Therefore, therapies frequently aim to maintain, restore, or improve blood supply to the injured muscle. Although there are several options t

Automatic myocardial segmentation in dynamic contrast enhanced perfusion MRI using Monte Carlo dropout in an encoder-decoder convolutional neural network

Background and ObjectiveCardiac perfusion magnetic resonance imaging (MRI) with first pass dynamic contrast enhancement (DCE) is a useful tool to identify perfusion defects in myocardial tissues. Automatic segmentation of the myocardium can lead to efficient quantification of perfusion defects. The purpose of this study was to investigate the usefulness of uncertainty estimation in deep convolutional neural networks for automatic myocardial segmentation. MethodsA U-Net segmentation model was trained on the cardiac cine data. Monte Carlo dropout sampling of the U-Net model was performed on the dynamic perfusion datasets frame-by-frame to estimate the standard deviation (SD) maps. The uncertainty estimate based on the sum of the SD values was used to select the optimal frames for endocardial and epicardial segmentations. DCE perfusion data from 35 subjects (14 subjects with coronary artery disease, 8 subjects with hypertrophic cardiomyopathy, and 13 healthy volunteers) were evaluated. The Dice similarity scores of the proposed method were compared with those of a semi-automatic U-Net segmentation method, which involved user selection of an image frame for segmentation in the cardiac perfusion dataset. ResultsThe proposed method was fully automatic and did not require manual labeling of the cardiac perfusion image data for model development. The mean Dice similarity score of the proposed automatic method was 0.806 (±0.096), which was comparable to the 0.808 (±0.084) Dice score of the semi-automatic U-Net segmentation method (intraclass correlation coefficient = 0.61, P < 0.001). ConclusionsOur study demonstrated the feasibility of applying an existing model trained on cardiac cine data to dynamic cardiac perfusion data to achieve robust and automatic segmentation of the myocardium. The uncertainty estimates can be used for screening purposes, which would facilitate the cases with high endocardial and epicardial uncertainty estimates to be sent for further evaluation and correction by human experts.