Months Of MRI Research Articles

Medial temporal lobe gray matter microstructure in preclinical Alzheimer's disease.

Typical MRI measures of neurodegeneration have limited sensitivity in early disease stages. Diffusion MRI (dMRI) microstructural measures may allow for detection in preclinical stages. Participants had dMRI and either beta-amyloid PET or plasma biomarkers of Alzheimer's pathology within 18 months of MRI. Microstructure was measured in portions of the medial temporal lobe (MTL) with high neurofibrillary tangle (NFT) burden based on a previously developed post mortem 3D-map. Regressions examined relationships between microstructure and markers of Alzheimer's pathology in preclinical disease and then across disease stages. There was higher isometric volume fraction in amyloid-positive compared to amyloid-negative cognitively unimpaired individuals in high tangle MTL regions. Similarly, plasma biomarkers and 18F-flortaucipir were associated with microstructural changes in preclinical disease. Additional microstructural effects were seen across disease stages. Combining a post mortem atlas of NFT pathology with microstructural measures allows for detection of neurodegeneration in preclinical Alzheimer's disease. Highlights Typical markers of neurodegeneration are not sensitive in preclinical Alzheimer's. dMRI measured microstructure in regions with high NFT. Microstructural changes occur in medial temporal regions in preclinical disease. Microstructural changes occur in other typical Alzheimer's regions in later stages. Combining post mortem pathology atlases with in vivo MRI is a powerful framework.

Quantitative Characterization of Respiratory Patterns on Dynamic Higher Temporal Resolution MRI to Stratify Postacute Covid-19 Patients by Cardiopulmonary Symptom Burden.

Postacute Covid-19 patients commonly present with respiratory symptoms; however, a noninvasive imaging method for quantitative characterization of respiratory patterns is lacking. To evaluate if quantitative characterization of respiratory pattern on free-breathing higher temporal resolution MRI stratifies patients by cardiopulmonary symptom burden. Prospective analysis of retrospectively acquired data. A total of 37 postacute Covid-19 patients (25 male; median [interquartile range (IQR)] age: 58 [42-64] years; median [IQR] days from acute infection: 335 [186-449]). 0.55 T/two-dimensional coronal true fast imaging with steady-state free precession (trueFISP) at higher temporal resolution. Patients were stratified into three groups based on presence of no (N = 11), 1 (N = 14), or ≥2 (N = 14) cardiopulmonary symptoms, assessed using a standardized symptom inventory within 1 month of MRI. An automated lung postprocessing workflow segmented each lung in each trueFISP image (temporal resolution 0.2 seconds) and respiratory curves were generated. Quantitative parameters were derived including tidal lung area, rates of inspiration and expiration, lung area coefficient of variability (CV), and respiratory incoherence (departure from sinusoidal pattern) were. Pulmonary function tests were recorded if within 1 month of MRI. Qualitative assessment of respiratory pattern and lung opacity was performed by three independent readers with 6, 9, and 23 years of experience. Analysis of variance to assess differences in demographic, clinical, and quantitative MRI parameters among groups; univariable analysis and multinomial logistic regression modeling to determine features predictive of patient symptom status; Akaike information criterion to compare the quality of regression models; Cohen and Fleiss kappa (κ) to quantify inter-reader reliability. Two-sided 5% significance level was used. Tidal area and lung area CV were significantly higher in patients with two or more symptoms than in those with one or no symptoms (area: 15.4 cm2 vs. 12.9 cm2 vs. 12.8 cm2 ; CV: 0.072, 0.067, and 0.058). Respiratory incoherence was significantly higher in patients with two or more symptoms than in those with one or no symptoms (0.05 vs. 0.043 vs. 0.033). There were no significant differences in patient age (P = 0.19), sex (P = 0.88), lung opacity severity (P = 0.48), or pulmonary function tests (P = 0.35-0.97) among groups. Qualitative reader assessment did not distinguish between groups and showed slight inter-reader agreement (κ = 0.05-0.11). Quantitative respiratory pattern measures derived from dynamic higher-temporal resolution MRI have potential to stratify patients by symptom burden in a postacute Covid-19 cohort. 3 TECHNICAL EFFICACY: Stage 3.

High field brain proton magnetic resonance spectroscopy and volumetry in children with chronic, compensated liver disease – A pilot study

BackgroundThere is increasing evidence that children or young adults having acquired liver disease in childhood display neurocognitive impairment which may become more apparent as they grow older. The molecular, cellular and morphological underpinnings of this clinical problem are incompletely understood. AimTherefore, we used the advantages of highly-resolved proton magnetic resonance spectroscopy at ultra-high magnetic field to analyze the neurometabolic profile and brain morphometry of children with chronic, compensated liver disease, hypothesizing that with high field spectroscopy we would identify early evidence of rising brain glutamine and decreased myoinositol, such as has been described both in animals and humans with more significant liver disease. MethodsPatients (n = 5) and age-matched controls (n = 19) underwent 7T MR scans and short echo time 1H MR spectra were acquired using the semi-adiabatic SPECIAL sequence in two voxels located in gray and white matter dominated prefrontal cortex, respectively. A 3D MP2RAGE sequence was also acquired for brain volumetry and T1 mapping. Liver disease had to have developed at least 6 months before entering the study. Subjects underwent routine blood analysis and neurocognitive testing using validated methods within 3 months of MRI and MRS. ResultsFive children aged 8–16 years with liver disease acquired in childhood were included. Baseline biological characteristics were similar among patients. There were no statistically significant differences between subjects and controls in brain metabolite levels or brain volumetry. Finally, there were minor neurocognitive fluctuations including attention deficit in one child, but none fell in the statistically significant range. ConclusionChildren with chronic, compensated liver disease did not display an abnormal neurometabolic profile, neurocognitive abnormalities, or signal intensity changes in the globus pallidus. Despite the absence of neurometabolic changes, it is an opportunity to emphasize that it is only by developing the use of 1H MRS at high field in the clinical arena that we will understand the significance and generalizability of these findings in children with CLD. Healthy children displayed neurometabolic regional differences as previously reported in adult subjects.

Quantitative myocardial T2 mapping adds value to Japanese circulation society diagnostic criteria for active cardiac sarcoidosis.

Noninvasive identification of active myocardial inflammation in patients with cardiac sarcoidosis plays a key role in management but remains elusive. T2 mapping is a proposed solution, but the added value of quantitative myocardial T2 mapping for active cardiac sarcoidosis is unknown. Retrospective cohort analysis of 56 sequential patients with biopsy-confirmed extracardiac sarcoidosis who underwent cardiac MRI for myocardial T2 mapping. The presence or absence of active myocardial inflammation in patients with CS was defined using a modified Japanese circulation society criteria within one month of MRI. Myocardial T2 values were obtained for the 16 standard American Heart Association left ventricular segments. The best model was selected using logistic regression. Receiver operating characteristic curves and dominance analysis were used to evaluate the diagnostic performance and variable importance. Of the 56 sarcoidosis patients included, 14 met criteria for active myocardial inflammation. Mean basal T2 value was the best performing model for the diagnosis of active myocardial inflammation in CS patients (pR2 = 0.493, AUC = 0.918, 95% CI 0.835-1). Mean basal T2 value > 50.8ms was the most accurate threshold (accuracy = 0.911). Mean basal T2 value + JCS criteria was significantly more accurate than JCS criteria alone (AUC = 0.981 vs. 0.887, p = 0.017). Quantitative regional T2 values are independent predictors of active myocardial inflammation in CS and may add additional discriminatory capability to JCS criteria for active disease.

Association of pancreatic fat on imaging with pediatric metabolic co-morbidities.

The relationship between pancreatic fat on imaging and metabolic co-morbidities has not been established in pediatrics. We sought to investigate the relationship between pancreatic fat measured by MRI and endocrine/exocrine dysfunctions along with the metabolic co-morbidities in a cohort of children. To investigate relationships between pancreatic fat quantified by MRI and endocrine and exocrine conditions and metabolic co-morbidities in a cohort of children. MATERIALS ANDMETHODS: This was a retrospective review of pediatric patients (n = 187) who had a clinically indicated MRI examination between May 2018 and February 2020. After 51 patients without useable imaging data were excluded, the remaining 136 subjects comprised the study sample. Laboratory studies were assessed if collected within 6months of MRI and patient charts were reviewed for demographic and clinical information. MRI proton density fat fraction (PDFF) sequence had been acquired according to manufacturer's specified parameters at a slice thickness of 3mm. Two blinded radiologists independently collected PDFF data. The median age at MRI was 12.1 (IQR: 9.0-14.8) years and the majority of patients were Caucasian (79%), followed by African American and Hispanic at 12% and 11% respectively. There was a higher median pancreas fat fraction in patients with exocrine conditions (chronic pancreatitis or exocrine insufficiency) compared to those without (3.5% vs 2.2%, p = 0.03). There was also a higher median fat fraction in the head of pancreas in patients with endocrine insufficient conditions (insulin resistance, pre-diabetes, type 1 and type 2 diabetes) compared to those without endocrine insufficiency when excluding patients with active acute pancreatitis (3.5% vs 2.0%, p = 0.04). Patients with BMI > 85% had higher mean fat fraction compared to patients with BMI ≤ 85% (head: 3.8 vs 2.4%, p = 0.01; body: 3.8 vs 2.5%, p = 0.005; tail: 3.7 vs 2.7%, p = 0.049; overall pancreas fat fraction: 3.8 vs 2.6%, p = 0.002). Pancreas fat is elevated in patients with BMI > 85% and in those with exocrine and endocrine insufficiencies.

Predicting the aggressiveness of peripheral zone prostate cancer using a fractional order calculus diffusion model

PurposeTo evaluate the performance of parameters D, β, μ from the Fractional Order Calculus (FROC) model at differentiating peripheral zone (PZ) prostate cancer (PCa) Material and Methods75 patients who underwent targeted MRI-guided TRUS prostate biopsy within 6 months of MRI were reviewed retrospectively. Regions of interest (ROI) were placed on suspicious lesions on MRI scans. ROIs were then correlated to pathological results based on core biopsy location. The final tumor count is a total: 23 of GS 6 (3 + 3), 36 of GS 7 (3 + 4), 18 of GS 7 (4 + 3), and 19 of GS ≥ 8. Diffusion-weighted imaging (DWI) scans were fitted into the FROC and monoexponential model to calculate ADC and FROC parameters: anomalous diffusion coefficient D, intravoxel diffusion heterogeneity β, and spatial parameter μ. The performance of FROC parameters and ADC at differentiating PCa grade was evaluated with receiver operating characteristic (ROC) analysis. ResultsIn differentiating low (GS 6) vs. intermediate (GS 7) risk PZ PCa, combination of (D, β) provides the best performance with AUC of 0.829 with significance of p = 0.018 when compared to ADC (AUC of 0.655). In differentiating clinically significant (GS 6) vs. clinically significant (GS ≥ 7) PCa, combination of (D, β, μ) provides highest AUC of 0.802 when compared to ADC (AUC of 0.671) with significance of p = 0.038. Stratification of intermediate (GS 7) and high (GS ≥ 8) risk PCa with FROC did not reach a significant difference when compared to ADC. ConclusionCombination of FROC parameters shows greater performance than ADC at differentiating low vs. intermediate risk and clinically insignificant vs. significant prostate cancers in peripheral zone lesions. The FROC diffusion model holds promise as a quantitative imaging technique for non-invasive evaluation of PZ PCa.

Outcomes Following Negative Screening MRI Results in Korean Women with a Personal History of Breast Cancer: Implications for the Next MRI Interval.

Background There are limited data on outcomes following screening breast MRI in women with a personal history of breast cancer (PHBC). Purpose To investigate outcomes and factors associated with subsequent cancers following a negative screening MRI study in women with a PHBC. Materials and Methods Consecutive women with a PHBC and a negative prevalence screening breast MRI result between August 2014 and December 2016 were retrospectively identified. Inclusion criteria were prevalence screening MRI performed as part of routine surveillance protocol (1-3 years after treatment) and follow-up data for at least 12 months. The incidence and characteristics of subsequent cancers were reviewed. Logistic regression analysis was used to investigate associations between clinical-pathologic characteristics and subsequent cancers. Performance metrics were compared among screening MRI, mammography, and US. Results A total of 993 women (mean age ± standard deviation, 53 years ± 10) were evaluated. Ten second in-breast cancers (ie, ipsilateral or contralateral) occurred at a median interval of 31.8 months (range, 13.3-44.8 months) after MRI, of which eight (80%) were ductal carcinoma in situ (DCIS) or node-negative T1 cancers. Only one node-negative T1mi (tumor ≤1 mm) second in-breast cancer visible on a mammogram was detected within 24 months of MRI. Of second in-breast cancers, 40% (four of 10) were detected only at subsequent screening MRI, which was performed a median of 30.5 months after negative prevalence screening MRI. Ten local-regional recurrences occurred at a median interval of 16.9 months (range, 6-35 months). Previous treatment for DCIS was associated with second in-breast cancers (odds ratio, 3.73; 95% CI: 1.04, 13.38; P = .04). In 1048 women who underwent prevalence screening MRI (including all Breast Imaging Reporting and Data System categories), MRI showed a lower abnormal interpretation rate and higher specificity than mammography or US (P < .001 for all). Conclusion After a negative screening MRI result, 90% of subsequent cancers were detected at intervals longer than 24 months and there was a low second in-breast cancer rate (1%). © RSNA, 2021 Supplemental material is available for this article. See also the editorial by Chang in this issue.

Using qualitative descriptors of chronic liver disease on MRI: A practice prone to error

PurposeAssess accuracy of qualitative descriptors for chronic liver disease (CLD) in radiology reports compared to histopathological staging. MethodsDatabase search for patients with hepatitis B/C (HBV/HCV) CLD, abdominal MRI during 2009–2016, and liver biopsy within 6 months of MRI or prior biopsy showing cirrhosis. Reports reviewed for mention of CLD and associated descriptors. Findings stratified into categories: normal/no mention of CLD; changes of CLD without qualitative descriptor; mild/early; moderate; severe/advanced and cirrhosis. Descriptive ranges categorized to the lesser degree. Percent concordance/discordance of descriptors and Scheuer stage (F0-F4), false positive (FP), false negative (FN) and sensitivity/specificity calculated. Results309 patients, median age 54 (24–74). 91% had HCV (282/309), 7% HBV and 2% both HBV/HCV. Biopsy showed 19% without CLD/F0; 8% F1, 15% F2, 15% F3 and 43% F4. 188 MRI reports (61%) stated CLD was present; however, 16 had no fibrosis on histopathology (9% FP). 39% (121/309) did not mention or stated no CLD; however, 78 had CLD on histopathology (64% FN). 59% of FN were early fibrosis (F1 or F2), 27% F3 and 11% F4. Overall sensitivity and specificity was 69% and 73%, respectively. 77% (145/188) of MRI reports used a descriptive qualifier when describing CLD. 10% were concordant with exact histopathology staging. Of discordant reports, 90% identified CLD but under-called severity. ConclusionAbdominal radiologists can detect CLD on MRI but degree of CLD is often under-called compared to histopathology suggesting radiologists should refrain from qualitative descriptors in assessing CLD on MRI and reaffirms the need for quantitative imaging.

Efficacy of Fluoroscopy-Guided Lumbar Facet Joint Synovial Cyst Rupture with Intra-Articular Steroid Injection after Laminectomy.

PurposeWe retrospectively evaluated the technical success rate and long-term efficacy of fluoroscopy-guided synovial cyst rupture followed by an intra-articular steroid injection at the post-laminectomy lumbar facet.Materials and MethodsWe selected subjects who had undergone a fluoroscopy-guided synovial cyst rupture with simultaneous intra-articular steroid injection within 6 months of MRI and demonstrated a symptomatic facet joint synovial cyst at the level of a previous lumbar laminectomy. Fourteen patients were enrolled, and we determined whether cyst rupture and symptom improvement were achieved after each procedure. The degrees of symptom improvement were categorized into 4: 1) symptoms improved (30% or more reduction, based on pre-procedural and post-procedural Numerical Pain Rating Scale scores), 2) symptoms not improved, 3) patient underwent surgery after injection, and 4) loss of follow-up.ResultsThe success rate of percutaneous synovial cyst rupture decreased with repeated procedures (62.5% for the first procedure and 0% to 33.3% for additional procedures). However, 80% of the patients had symptom improvement with the procedures, overall. The surgery rate was 14.3% in 14 patients.ConclusionFor patients with post-laminectomy symptomatic lumbar facet joint synovial cysts, fluoroscopy-guided synovial cyst rupture with intra-articular steroid injection may be an effective and less invasive treatment before considering a surgical approach.

Comparison of PSA-density of the transition zone and whole gland for risk stratification of men with suspected prostate cancer: A retrospective MRI-cohort study

PurposeTo compare the correlation of transition zone prostate-specific antigen density (TZPSAD) versus whole gland (WG) density (PSAD) with Gleason score. MethodsIn this single-center, retrospective cohort study, men undergoing MRI of the prostate in 2015 and 2016 who had a transperineal template saturation biopsy within 6 months of MRI were included (n = 178; median age 64 y, interquartile range [IQR] 58–68 y; PSA 6.6 ng/ml, 4.6–9.7 ng/ml). The WG and TZ were segmented voxel-wise on T2-weighted transverse planes. The volumes and corresponding PSA-densities were calculated. Correlations with the Gleason score were assessed with Spearman’s rho. Optimal thresholds of the PSA densities were computed using the Youden Index of the receiver-operating-characteristics curve. A p-value of ≤ 0.05 was considered statistically significant. ResultsMedian WG volume was 45 ml (IQR: 33.9–58.7 ml, range: 17.2–165.3 ml), median volume of the TZ was 27.3 ml (IQR: 19.2–39.3 ml, range: 9.0–141.1 ml). Both PSA density values, PSAD and TZPSAD, correlated significantly with the Gleason score: The PSAD (rho = 0.39) showed significantly weaker correlation than the TZPSAD (rho = 0.44, p = 0.05). ROC analysis revealed an ideal cut-off of 0.15 ng/ml2 for PSAD (95%-CI: 0.09–0.16 ng/ml2) and 0.22 ng/ml2 for the TZPSAD (0.15-0.32 ng/ml2) for discrimination between Gleason 3 + 4 and 4 + 3. ConclusionThe TZPSAD exhibited a stronger correlation with cancer dedifferentiation than PSAD and may thus be a better surrogate marker for cancer aggressiveness than PSAD. Moreover, the TZPSAD threshold of 0.22 ng/ml2 may help in risk stratification of men with suspected PCa.

Does intravoxel incoherent motion reliably stage hepatic fibrosis, steatosis, and inflammation?

To investigate the usefulness of intravoxel incoherent motion (IVIM) in determining the severity of hepatic fibrosis, steatosis, and inflammation in patients with chronic liver disease. Forty-nine patients who had liver MRI with IVIM sequence and liver biopsy within three months of MRI were enrolled. A reviewer, blinded to histology, placed regions of interest of 1-2cm2 in the right liver lobe. In addition, the first twenty patients were assessed with a second reviewer. Perfusion fraction (f), pseudodiffusion coefficient (D fast), true diffusion coefficient (D slow), and apparent diffusion coefficient (ADC) were calculated from normalized signal intensities that were fitted into a biexponential model. Errors in the model were minimized with global stochastic optimization using Simulated Annealing. ANOVA with post hoc Tukey-Kramer test and multivariate generalized linear model analysis were performed, using histological findings as the gold standard. The most common etiologies for liver disease were hepatitis C and alcohol, accounting together for 76% (37/49) of patients. Low-grade fibrosis (F0, F1), hepatic steatosis, and inflammation were seen in 24% (12/49), 31% (15/49), and 29% (14/49) of patients, respectively. The interobserver correlation was poor for D fast and D slow (0.105, 0.173) and moderate for f and ADC (0.461, 0.418). ANOVA showed a strong inverse association between D fast and liver fibrosis grade (p=0.001). A weak inverse association was seen between ADC and hepatic steatosis (p=0.059). Multivariate general linear model revealed that the only significant association between IVIM parameters and pathological features was between D fast and fibrosis. On ROC curve analysis, D fast<23.4×10-3 mm2/s had a sensitivity of 82.8% and a specificity of 64.3% in predicting high-grade fibrosis. D fast has the strongest association with hepatic fibrosis but has weak interobserver correlation. IVIM parameters were not significantly associated with hepatic inflammation or steatosis.

MRI AND EVOKED POTENTTIALS IN DIFFERENTIAL DIAGNOSIS OF ENCEPHALITIS, DISSEMINATED ENCEPHALOMYELITIS AND MULTIPLE SCLEROSIS IN CHILDREN

Last years are characterized by the growth of encephalitis (Ef) frequency and demyelination diseases of CNS in children, especially, among teenagers. The diseases are characterized by similar of clinical features of the disease onset, absence of differential diagnostical criteria and frequency of the disease chronisation and possibility of transformation in multiple sclerosis (MS), all this determines the problem of differential diagnosis. The aim is to determine differential-diagnostical features of Ef, disseminated encephalomyelitis (DEM) and MS in children by analysis of structure MRI and brain multi-modal evoked potentials (MEP). We observed 35 children with Ef, 40 with DEM and 40 with MS. All patients were from 3 to 17 years old. All patients were diagnosed clinically in acute period and in catamnesis — after 3 and 6 months. MS diagnosis was based on McDonald criteria, 2010 year. ADEM diagnosis was also based on international criteria. We analyzed brain MRI, spinal MRI and MEP in all patients during the first day of hospitalization and after 3 and 6 months later. The analysis of the MRI of the brain and spinal cord in encephalitis (EF, n=35), disseminated encephalomyelitis (ADEM, n=60) and multiple sclerosis (MS, n=60) of children on admission to hospital, and then — after 3 and 6 months. Up to 85% of foci with ADEM and EF had irregular shapes, accompanied by swelling phenomena, and mass effect and in 2⁄3 cases were localized in the gray or white and gray matter of the CNS. In 60% of cases in patients with EF and ADEM based on the localization of foci could suggest the etiology of the disease. In MS 67,5% were detected multifocal white matter lesions (more than 10 lesions), and most of the foci had a size of up to 1 cm and the correct round-oval and the absence of signs of inflammation. The presence of lesions in the gray matter at EF, ADEM and MS respectively observed in 82,5%, 40% and 7,5% of cases. After 3–6 months of MRI in the majority of EF and DEM foci regressed, and in MS were reduced in size, but not completely disappeared. According to the study of evoked potentials (EP) of the brain in children with MS and ADEM often increased latency of the responses, while the EF decreased cortical or brainstem response amplitude. The majority of patients with MS have changed the parameters both 3–4 different EP (somatosensory from the upper and lower limbs, acoustic stem and/or visual), while ADEM and EF-1–2 evoked potentials. Chronic EF, and the progression of neurological symptoms was not associated with the advent of the «new» lesion, and up to 75% of the foci can regress completely after 3–6 months. Chronic EF characterized by increase of only brain atrophy, which involves communication of these changes only with neuronal process. Whereas in MS and multiphase ADEM appeared «new» foci accumulating contrast agent that allows you to talk about preserving the pathogenesis of vascular component in their progression. Study of MEP and MRI in children with Ef, DEM and MS in dynamics can be useful for differential diagnosis and monitoring of therapy efficacy.

PD06-05 THE MRI-INVISIBLE PROSTATE CANCER: INCIDENCE AND SIGNIFICANCE

You have accessJournal of UrologyImaging/Radiology: Uroradiology II1 Apr 2016PD06-05 THE MRI-INVISIBLE PROSTATE CANCER: INCIDENCE AND SIGNIFICANCE Jason Wu, Daniel Margolis, Shyam Natarajan, Alan Priester, Jiaoti Huang, Maria Luz Macairan, Patricia Lieu, Devi Sharma, Frederick Dorey, and Leonard Marks Jason WuJason Wu More articles by this author , Daniel MargolisDaniel Margolis More articles by this author , Shyam NatarajanShyam Natarajan More articles by this author , Alan PriesterAlan Priester More articles by this author , Jiaoti HuangJiaoti Huang More articles by this author , Maria Luz MacairanMaria Luz Macairan More articles by this author , Patricia LieuPatricia Lieu More articles by this author , Devi SharmaDevi Sharma More articles by this author , Frederick DoreyFrederick Dorey More articles by this author , and Leonard MarksLeonard Marks More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.2625AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Targeted prostate biopsy using multi-parametric MRI (mpMRI) guidance results in increased detection of clinically significant prostate cancers (csCaP). However, optimal sensitivity of the new method employs both targeted and systematic template biopsies, as some csCaP lies outside of MRI targets, i.e., is not visualized on MRI. Herein, we examine incidence and significance of the MRI-invisible csCaP. METHODS 322 (23%) of 1385 men with no suspicious lesion on mpMRI (UCLA Grade <3) from 2010-2015 were included in this study. The median age was 65±8, median PSA was 5.15 ng/mL (0.11-67.6) and mean prostate volume was 58.5±33.5 cc. All patients underwent MRI/US fusion biopsy using the 12-point mapping template of the Artemis device within 3 months of MRI. MRI was 3T body coil and interpreted by an expert reader (D.M.); biopsy was performed by an experienced fusion-device operator (L.M.). csCaP was defined as Gleason 3+3 with maximal cancer core length ≥ 4mm or ≥ Gleason 3+4. RESULTS 128 patients (40%) were found to have CaP in their biopsies: 61 patients (19%) had insignificant CaP and 67 patients (21%) had csCaP. 52 (78%) of 67 patients with missed csCaP had ≥ Gleason 3+4=7. 105 patients (32%) were in Active Surveillance at the time of their biopsies. Of these, 27 patients (26%) had csCaP with negative mpMRI. Logistic regression indicated that patients with high PCA3, high PSA density, a prior positive biopsy and smaller prostate volume are directly related to having csCaP in the presence of negative mpMRI (p<0.05). CONCLUSIONS Despite recent advancement of MRI technology, negative mpMRI cannot rule out csCaP completely. 40% of men with negative mpMRI were diagnosed with CaP. Of these, 21% of men harbored csCaP. All clinical factors should be considered before eliminating a systematic biopsy because the MRI is unrevealing. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e175-e176 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Jason Wu More articles by this author Daniel Margolis More articles by this author Shyam Natarajan More articles by this author Alan Priester More articles by this author Jiaoti Huang More articles by this author Maria Luz Macairan More articles by this author Patricia Lieu More articles by this author Devi Sharma More articles by this author Frederick Dorey More articles by this author Leonard Marks More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Utility of Transient Elastography (Fibroscan) in Estimating Hepatic Iron Concentration in Comparison to MRI in Patients with Transfusion Dependent Hemoglobinopathies

BackgroundPatients with severe hereditary anemias (e.g. β-Thalassemia Major) are transfusion-dependent for survival. Current guidelines suggest monitoring serum ferritin every three months and annual MRI to assess hepatic and cardiac iron load1. However, MRI, particularly the R2 sequence (FerriScan) which has high specificity and sensitivity in estimating the liver iron concentration, is expensive and not always readily available. Transient elastography (FibroScan) measures liver’s stiffness and predicts fibrosis. Previous studies have suggested its utility in other conditions that increase liver stiffness, such as amyloidosis2and perhaps iron overload.AimTo determine if FibroScan value correlates with hepatic iron concentration estimated using R2 MRI (FerriScan), and/or serum ferritin level.MethodsA prospective cross-sectional study was conducted at a university-affiliated tertiary care center (St. Paul’s Hospital, Vancouver, BC) in 2013 and 2014. Inclusion criteria: Age ≥ 19 years with transfusion-dependent hereditary anemias. Exclusion criteria: liver cirrhosis, primary liver disease (e.g. Wilson’s disease, hereditary hemochromatosis), and chronic viral hepatitis (e.g. Hepatitis B, C and HIV). In addition to having annual MRI and ferritin levels monitored every three months, subjects underwent FibroScan within six months of MRI in 2013. In 2014, participants were invited to undergo repeat FibroScan within three months of the annual MRI. Linear regression analysis was used to determine if there is any correlation/linear fit between FibroScan result, MRI result, and ferritin levels. This study was approved by the University of British Columbia Research Ethics Board.Results20 subjects have been recruited as of August 1, 2014, with 35 and 33 complete FibroScan and MRI results, respectively. 14 (70%) were female. Mean age was 30.7±9.8 years. Most common primary diagnosis was transfusion-dependent beta-thalassemia (Major and intermedia) (n=17).Linear regression analysis showed a weakly positive correlation between hepatic iron concentrations estimated with R2 MRI (FerriScan) and ferritin levels (R2=0.29; p=0.004), when they are performed within four weeks apart. The correlation remained statistically significant when all subjects were included regardless of time lapse between the two investigations (R2=0.30; p=0.001). However, FibroScan values did not appear to correlate with MRI, regardless of whether the scans are performed within six months (R2=0.011; p=0.58) or three months apart (R2=0.035; p=0.44). Similarly, there was no correlation between FibroScan and Ferritin (R2=0.022; p=0.49) when the investigations were performed within 4 weeks part.ConclusionInterim analysis did not demonstrate any correlation between FibroScan result and MRI-estimated hepatic iron concentration. A final analysis will be performed upon complete formal evaluation of the remaining MRI and FibroScan data.

Quantitative MRI analysis in children with multiple sclerosis: a multicenter feasibility pilot study.

BackgroundPediatric multiple sclerosis (MS) is a rare disorder with significant consequences. Quantitative MRI measurements may provide significant insights, however multicenter collaborative studies are needed given the small numbers of subjects. The goal of this study is to demonstrate feasibility and evaluate lesion volume (LV) characteristics in a multicenter cohort of children with MS.MethodsA common MRI-scanning guideline was implemented at six member sites of the U.S. Network of Pediatric MS Centers of Excellence. We included in this study the first ten scans performed at each site on patients meeting the following inclusion criteria: pediatric RRMS within 3 years of disease onset, examination within 1 month of MRI and no steroids 1 month prior to MRI. We quantified T2 number, T2-LV and individual lesion size in a total of 53 MRIs passing quality control procedures and assessed gadolinium-enhancing lesion number and LV in 55 scans. We studied MRI measures according to demographic features including age, race, ethnicity and disability scores, controlling for disease duration and treatment duration using negative binomial regression and linear regression.ResultsThe mean number of T2 lesions was 24.30 ± 19.68 (range:1–113) and mean gadolinium-enhancing lesion count was 1.85 ± 5.84, (range:0–32). Individual lesion size ranged from 14.31 to 55750.60 mm3. Non-white subjects had higher T2–LV (unadjusted pT2-LV = 0.028; adjusted pT2-LV = 0.044), and maximal individual T2-LV (unadjusted pMax = 0.007; adjusted pMax = 0.011) than white patients. We also found a trend toward larger mean lesion size in males than females (p = 0.07).ConclusionAssessment of MRI lesion LV characteristics is feasible in a multicenter cohort of children with MS.

Comparison of 4D flow and 2D PC MRI blood flow quantification in children and young adults with congenital heart disease

Background Echocardiography (echo) is the primary imaging modality for assessment of aortic and pulmonary blood flow velocities. 2D phase contrast (PC) MRI provides better access to all segments of the aortic and pulmonary system and is considered the standard for evaluating blood flow. Both techniques are limited by velocity analysis in 2D planes and by single-direction velocity measurement which may be inadequate to characterize the complex 3D hemodynamics in congenital heart disease (CHD). 4D flow MRI provides simultaneous assessment of 3D blood flow characteristics of all vessels within a 3D volume and offers the ability to retrospectively quantify blood flow parameters at selectable regions of interest. The aim of this study is to test the potential of 4D flow for accuracy of quantification of aortic and pulmonary flow parameters compared to the reference standards echo and 2D PC MRI in children and young adults with CHD. Methods 32 patients with CHD who underwent simultaneous 4D flow and 2D PC MRI and echo within 9 months of MRI were retrospectively included. 2D PC MRI flow quantification in the aortic root (Ao), pulmonary trunk (PT), and right and left pulmonary arteries (RPA, LPA) was analyzed using Medis (Medis, Leiden, The Netherlands). 4D flow data analysis included calculation of a 3D-PC-angiogram which was used to position analysis planes in the Ao, PT, LPA and RPA (EnSight, CEI, Apex, NC) for quantification of net flow, regurgitant fraction, Qp:Qs, and peak velocities. Ao peak velocities were assessed by echo. Linear regression analysis was performed. Pearson’ sc orrelation coefficient (r) was calculated. A correlation with p<0.05 was considered significant. Results

The Incremental Value of Contrast-Enhanced MRI in the Detection of Biopsy-Proven Local Recurrence of Prostate Cancer After Radical Prostatectomy: Effect of Reader Experience

The purpose of this study is to retrospectively assess the incremental value of contrast-enhanced MRI (CE-MRI) to T2-weighted MRI in the detection of postsurgical local recurrence of prostate cancer by readers of different experience levels, using biopsy as the reference standard. Fifty-two men with biochemical recurrence after prostatectomy underwent 1.5-T endorectal MRI with multiphase contrast-enhanced imaging and had biopsy within 3 months of MRI. Two radiologists (reader 1 had 1 year and reader 2 had 6 years of experience) independently reviewed each MRI study and classified the likelihood of recurrent cancer on a 5-point scale. Areas under receiver operating characteristic curves (A(z)) were calculated to assess readers' diagnostic performance with T2-weighted MRI alone and combined with CE-MRI. Interobserver agreement was assessed using Cohen kappa statistics. Thirty-three patients (63%) had biopsy-proven local recurrence of prostate cancer. With the addition of CE-MRI to T2-weighted imaging, the A(z) for cancer detection increased significantly for reader 1 (0.77 vs 0.85; p = 0.0435) but not for reader 2 (0.86 vs 0.88; p = 0.7294). The use of CE-MRI improved interobserver agreement from fair (κ = 0.39) to moderate (κ = 0.58). CE-MRI increased interobserver agreement and offered incremental value to T2-weighted MRI in the detection of locally recurrent prostate cancer for the relatively inexperienced reader.

Serum Ferritin Predicts Liver but Not Cardiac Iron Burden by Noninvasive MRI in Sickle Cell Disease (SCD.

BACKGROUND: Assumptions about iron loading as well as the utility of ferritin to predict transfusional iron overload among individuals with sickle cell disease (SCD) are largely based on extrapolation from data generated in patients with thalassemia major (TM). Yet recent studies suggest the natural history of iron overload in patients with SCD differs significantly from chronically transfused patients with TM. We sought to evaluate the extent of myocardial and hepatic siderosis using noninvasive imaging in chronically transfused patients with SCD and examine its clinical associations, including relationship to long-term trends in serum ferritin, transfusion history, chelation status and markers of hemolysis and inflammation.METHODS: We evaluated 17 subjects (mean age 15±3.6 yrs, range 9 to 20). The mean transfusion duration was 7.3±3.6 yrs (range 2 to 15). Thirteen (76%) patients were on chelation with deferasirox at the time of screening; 4 were not on chelation Rx. MRI T2*/R2* of the heart and liver using a multiple gradient echo sequence was performed on a single 1.5T GE scanner. Hepatic iron concentration (HIC) values were predicted from liver R2* values. RESULTS: Mean HIC in subjects was 9.9±6.7 mg/gm liver dry weight (range 2.5 to 20.8) and was ≥15 mg/gm in 6/17 (35%) subjects. The mean long-term serum ferritin (past 5 yrs, or duration of transfusion if < 5yrs) was 2318±1122 ng/mL (range 541 to 4225). Using Pearson's correlation coefficient, we observed a significant relationship between HIC and ferritin (r=0.765, p=<0.001). We generated a receiver operator characteristic (ROC) curve to assess the utility of ferritin as a predictor of elevated HIC, using a threshold HIC thought to predict serious iron-related complications. A ferritin cut-off value ≥2164 ng/mL correctly identified 80% of cases of HIC ≥15 mg/gm (AUC 0.96, p=0.003) in our subjects with 83% sensitivity and 73% specificity. Despite markedly elevated HIC and ferritin values in some subjects, none had myocardial siderosis. All 17 subjects had cardiac MRI T2* values in the normal range > 25 ms. Cardiac iron load measured by T2* did not correlate with HIC or serum ferritin. We examined C-reactive protein (CRP) and B-type natriuretic peptide (BNP) as markers for inflammation and myocardial strain, respectively, in our subjects but neither demonstrated a significant relationship to ferritin or MRI findings. BNP, however, did correlate modestly with both age (r=−0.574, p=0.013) and left ventricular ejection fraction on cardiac MRI (r=0.510, p=0.036). A subset of subjects (n=8) had histologic iron measurements by percutaneous liver biopsy (LBx) within 6 months of MRI. While liver iron content by LBx correlated significantly with HIC by MRI (r=0.759, p=0.03), liver iron content by LBx did not correlate with ferritin (r=0.312, p=0.452). CONCLUSION: We found that serum ferritin is a good predictor of liver iron by MRI R2*, and that long term ferritin values ≥2164 ng/mL predict significant hepatic iron overload as assessed by this noninvasive method. We did not observe appreciable cardiac iron loading in our subjects with SCD, which otherwise might have been predicted by elevated HIC alone, as in individuals with TM. These data suggest that reliable, long term surveillance of transfusion-induced iron overload in SCD may be achieved using serum ferritin and HIC by MRI R2* as surrogate markers of hepatic siderosis rather than relying on liver iron content measured invasively by LBx. Also, previously determined thresholds for significant cardiac iron loading in TM, based on degree of hepatic siderosis, may not be applicable in SCD. Further investigation into alternative mechanisms of iron loading or distribution in these related but distinct disorders is warranted.

Reproducibility of image interpretation in MRI of the prostate: application of the sextant framework by two different radiologists

The aim of this study was to reproduce prostate cancer (PCA) localization by MRI based on prostatic sextants (right and left base, middle, and apex) with minimal systematic error. Combined endorectal/body-phased-array-coil MRI of the prostate at 1.5 T was retrospectively evaluated twice, with an interval of more than 1 month, by each of two independent radiologists (R1 readings R11 and R12, and R2 readings R21 and R22) in 23 patients (age 51-75 years) who had radical prostatectomy within 1 month of MRI. PCA stage was pT2 in 14 patients, and pT3 in nine. Median Gleason score was 7 (range 5-9). Histopathology showed 83 sextants with PCA and 55 without. Reproducibility of sextant positions was within one MRI slice (3 mm) in over 80% of cases. For PCA localization, ROC analysis (AUC=0.584+/-0.048-0.724+/-0.043) yielded no significant intra-reader differences. R11 and R21 differed slightly (P=0.035). Intra-observer agreement (kappa=0.52-0.58) exceeded inter-observer agreement (kappa=0.35-0.45). Intra-observer Spearman correlation (r=0.72-0.74) exceeded inter-observer correlation (r=0.43-0.51) for sextants with PCA, but not for sextants without (r=0.69-0.74). Per-sextant localization and reporting provides a highly reliable framework in MRI of the prostate. MRI of the prostate should be followed up by the same radiologists to minimize systematic error of interpretation.

The spectrum of fatty liver in obese children and the relationship of serum aminotransferases to severity of steatosis.

Non-alcoholic fatty liver disease is an emerging diagnosis in the pediatric population. Previously, ultrasonography and serum aminotransferases have been used to estimate prevalence of the disorder. A lack of concordance has been noted between these two diagnostic tests. To better understand the spectrum of fatty liver in obese children and the relationship of serum aminotransferases to the severity of steatosis, hepatic MRI was used to quantitate fat content. Twenty-two children, ages 6 to 18 years, with obesity (BMI > 95th percentile for age) and hepatomegaly (liver edge more than 2 cm below the right costal margin) underwent hepatic MRI for fat quantitation. Hepatic MRI was performed using a modification of the Dixon method that used a fast gradient echo sequence rather than traditional spin echo. Scan times were sufficiently brief to allow completion within a single breath hold. Serum aminotransferases were obtained within one month of MRI. Twenty-one of 22 subjects had an elevated hepatic fat fraction. Seven of 7 subjects with a fat fraction of < or =18% had a normal serum ALT. Twelve of 13 subjects with fat fraction of >18% had an elevated serum ALT. Hepatic fat fraction correlated with serum ALT but did not correlate with age, BMI, or serum AST. The spectrum of fatty liver is larger than detected by screening for abnormal serum aminotransferases alone. Abnormalities in serum ALT occur exclusively in more severe cases of fatty liver.