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1.
Radiology ; 311(2): e232329, 2024 May.
Article in English | MEDLINE | ID: mdl-38742975

ABSTRACT

Background High rates of provider burnout and turnover, as well as staffing shortages, are creating crises within radiology departments. Identifying ways to support health care workers, such as the Positively Energizing Leadership program, is important during these ongoing crises. Purpose To identify the relationship between leadership behaviors and workplace climate and health care worker outcomes (ie, burnout, intent to leave, and engagement) and to determine whether the positive leadership program could improve workplace climate and health care worker outcomes. Materials and Methods This prospective study involved two parts. First, a web-based survey was administered to faculty and staff in a breast imaging unit of a large academic medical center in February 2021 to identify relationships between leadership behaviors and workplace climate and health care worker outcomes. Second, a web-based survey was administered in February 2023, following the implementation of a positive leadership program, to determine improvement in engagement and reduction of burnout and intent to leave since 2021. Multiple regression, the Sobel test, Pearson correlation, and the t test were used, with a conservative significance level of P < .001. Results The sample consisted of 88 respondents (response rate, 95%) in 2021 and 85 respondents (response rate, 92%) in 2023. Leadership communication was associated with a positive workplace climate (ß = 0.76, P < .001) and a positive workplace climate was associated with improved engagement (ß = 0.53, P < .001), reduction in burnout (ß = -0.42, P < .001), and reduction in intent to leave (ß = -0.49, P < .001). Following a 2-year positive leadership program, improved perceptions were observed for leadership communication (pretest mean, 4.59 ± 1.51 [SD]; posttest mean, 5.80 ± 1.01; t = 5.97, P < .001), workplace climate (pretest mean, 5.09 ± 1.43; posttest mean, 5.77 ± 1.11; t = 3.35, P < .001), and engagement (pretest mean, 5.27 ± 1.20, posttest mean, 5.68 ± 0.96; t = 2.50, P < .01), with a reduction in burnout (pretest mean, 2.69 ± 0.94; posttest mean, 2.18 ± 0.74; t = 3.50, P < .001) and intent to leave (pretest mean, 3.12 ± 2.23; posttest mean, 2.56 ± 1.84; t = 1.78, P < .05). Conclusion After implementation of a positive leadership program in a radiology department breast imaging unit, burnout and intention to leave decreased among health care workers, while engagement increased. © RSNA, 2024 See also the editorial by Thrall in this issue.


Subject(s)
Burnout, Professional , Leadership , Humans , Burnout, Professional/psychology , Female , Prospective Studies , Surveys and Questionnaires , Radiology Department, Hospital/organization & administration , Adult , Male , Job Satisfaction , Intention , Personnel Turnover/statistics & numerical data , Workplace/psychology , Middle Aged
2.
Acad Radiol ; 2024 Feb 05.
Article in English | MEDLINE | ID: mdl-38320946

ABSTRACT

RATIONALE AND OBJECTIVES: This study aims to assess the quality of abdominal MR images acquired on a commercial 0.55T scanner and compare these images with those acquired on conventional 1.5T/3T scanners in both healthy subjects and patients. MATERIALS AND METHODS: Fifteen healthy subjects and 52 patients underwent abdominal Magnetic Resonance Imaging at 0.55T. Images were also collected in healthy subjects at 1.5T, and comparison 1.5/3T images identified for 28 of the 52 patients. Image quality was rated by two radiologists on a 4-point Likert scale. Readers were asked whether they could answer the clinical question for patient studies. Wilcoxon signed-rank test was used to test for significant differences in image ratings and acquisition times, and inter-reader reliability was computed. RESULTS: The overall image quality of all sequences at 0.55T were rated as acceptable in healthy subjects. Sequences were modified to improve signal-to-noise ratio and reduce artifacts and deployed for clinical use; 52 patients were enrolled in this study. Radiologists were able to answer the clinical question in 52 (reader 1) and 46 (reader 2) of the patient cases. Average image quality was considered to be diagnostic (>3) for all sequences except arterial phase FS 3D T1w gradient echo (GRE) and 3D magnetic resonance cholangiopancreatography for one reader. In comparison to higher field images, significantly lower scores were given to 0.55T IP 2D GRE and arterial phase FS 3D T1w GRE, and significantly higher scores to diffusion-weighted echo planar imaging at 0.55T; other sequences were equivalent. The average scan time at 0.55T was 54 ± 10 minutes vs 36 ± 11 minutes at higher field strengths (P < .001). CONCLUSION: Diagnostic-quality abdominal MR images can be obtained on a commercial 0.55T scanner at a longer overall acquisition time compared to higher field systems, although some sequences may benefit from additional optimization.

3.
JAMA Netw Open ; 6(11): e2344856, 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-38019516

ABSTRACT

Importance: Magnetic resonance imaging (MRI) and potential MRI-guided biopsy enable enhanced identification of clinically significant prostate cancer. Despite proven efficacy, MRI and potential MRI-guided biopsy remain costly, and there is limited evidence regarding the cost-effectiveness of this approach in general and for different prostate-specific antigen (PSA) strata. Objective: To examine the cost-effectiveness of integrating annual MRI and potential MRI-guided biopsy as part of clinical decision-making for men after being screened for prostate cancer compared with standard biopsy. Design, Setting, and Participants: Using a decision analytic Markov cohort model, an economic evaluation was conducted projecting outcomes over 10 years for a hypothetical cohort of 65-year-old men in the US with 4 different PSA strata (<2.5 ng/mL, 2.5-4.0 ng/mL, 4.1-10.0 ng/mL, >10 ng/mL) identified by screening through Monte Carlo microsimulation with 10 000 trials. Model inputs for probabilities, costs in 2020 US dollars, and quality-adjusted life-years (QALYs) were from the literature and expert consultation. The model was specifically designed to reflect the US health care system, adopting a federal payer perspective (ie, Medicare). Exposures: Magnetic resonance imaging with potential MRI-guided biopsy and standard biopsy. Main Outcomes and Measures: Incremental cost-effectiveness ratios (ICERs) using a willingness-to-pay threshold of $100 000 per QALY was estimated. One-way and probabilistic sensitivity analyses were performed. Results: For the 3 PSA strata of 2.5 ng/mL or greater, the MRI and potential MRI-guided biopsy strategy was cost-effective compared with standard biopsy (PSA 2.5-4.0 ng/mL: base-case ICER, $21 131/QALY; PSA 4.1-10.0 ng/mL: base-case ICER, $12 336/QALY; PSA >10.0 ng/mL: base-case ICER, $6000/QALY). Results varied depending on the diagnostic accuracy of MRI and potential MRI-guided biopsy. Results of probabilistic sensitivity analyses showed that the MRI and potential MRI-guided biopsy strategy was cost-effective at the willingness-to-pay threshold of $100 000 per QALY in a range between 76% and 81% of simulations for each of the 3 PSA strata of 2.5 ng/mL or more. Conclusions and Relevance: This economic evaluation of a hypothetical cohort suggests that an annual MRI and potential MRI-guided biopsy was a cost-effective option from a US federal payer perspective compared with standard biopsy for newly eligible male Medicare beneficiaries with a serum PSA level of 2.5 ng/mL or more.


Subject(s)
Prostate , Prostatic Neoplasms , United States , Aged , Male , Humans , Prostate/diagnostic imaging , Prostate-Specific Antigen , Cost-Benefit Analysis , Medicare , Image-Guided Biopsy , Prostatic Neoplasms/diagnostic imaging , Magnetic Resonance Imaging
4.
Mult Scler Relat Disord ; 79: 105024, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37783196

ABSTRACT

BACKGROUND: In this cross sectional study, we used MRF to investigate tissue properties of normal-appearing white matter, gray matter, and lesions in relapsing remitting MS (n = 21), secondary progressive MS (n = 16) and healthy controls (n = 9). A FISP-based MRF sequence was used for acquisition, imaging time 5 min 15 s. MRF T1 and T2 relaxation times were measured from lesional tissue, normal-appearing frontal white matter, corpus callous, thalamus, and caudate. Differences between healthy controls and MS were examined using ANCOVA adjusted for age and sex. Spearman rank correlations were assessed between T1 and T2 relaxation times and clinical measures. OBJECTIVES: To examine brain T1 and T2 values using magnetic resonance fingerprinting (MRF) in healthy controls and MS. METHODS: The subjects included 21 relapsing-remitting (RR) MS, 16 secondary progressive (SP) MS, and 9 age- and sex-matched HC without manifest neurological disease participating in a longitudinal MRI study. A 3T/ FISP-based MRF sequence was acquired. Regions of interest were drawn for lesions and normal appearing white matter. ANCOVA adjusted for age and sex were used to compare the groups with significance set at 0.05. RESULTS: A step-wise increase in T1 and T2 relaxation times was found between healthy controls, relapsing remitting MS, and secondary progressive MS. Significant differences were found in T1 and T2 between MS and healthy controls in the frontal normal-appearing white matter, corpus callosum, and thalamus (p < 0.04 for all). Significant differences in T1 and T2 between RR and SPMS were found in the frontal normal-appearing white matter and T2 lesions (p < 0.02 for all). T1 relaxation from the frontal normal-appearing white matter correlated with the Expanded Disability Status Scale [ρ = 0.62, p < 0.001], timed 25 foot walk (ρ = 0.45, p = 0.01), 9 hole peg test (ρ = 0.62, p < 0.001), and paced auditory serial addition test (ρ = -0.4, p = 0.01). CONCLUSION: These results suggest that MRF may be a clinically feasible quantitative approach for characterizing tissue damage in MS.


Subject(s)
Multiple Sclerosis, Relapsing-Remitting , Multiple Sclerosis , Humans , Multiple Sclerosis/diagnostic imaging , Multiple Sclerosis/pathology , Cross-Sectional Studies , Magnetic Resonance Imaging/methods , Magnetic Resonance Spectroscopy , Brain/diagnostic imaging , Brain/pathology , Multiple Sclerosis, Relapsing-Remitting/diagnostic imaging , Multiple Sclerosis, Relapsing-Remitting/pathology
5.
NMR Biomed ; : e5017, 2023 Aug 31.
Article in English | MEDLINE | ID: mdl-37654047

ABSTRACT

The purpose of this study was to assess the quality of clinical brain imaging in healthy subjects and patients on an FDA-approved commercial 0.55 T MRI scanner, and to provide information about the feasibility of using this scanner in a clinical workflow. In this IRB-approved study, brain examinations on the scanner were prospectively performed in 10 healthy subjects (February-April 2022) and retrospectively derived from 44 patients (February-July 2022). Images collected using the following pulse sequences were available for assessment: axial DWI (diffusion-weighted imaging), apparent diffusion coefficient maps, 2D axial fluid-attenuated inversion recovery images, axial susceptibility-weighted images (both magnitude and phase), sagittal T1 -weighted (T1w) Sampling Perfection with Application Optimized Contrast images, sagittal T1w MPRAGE (magnetization prepared rapid gradient echo) with contrast enhancement, axial T1w turbo spin echo (TSE) with and without contrast enhancement, and axial T2 -weighted TSE. Two readers retrospectively and independently evaluated image quality and specific anatomical features in a blinded fashion on a four-point Likert scale, with a score of 1 being unacceptable and 4 being excellent, and determined the ability to answer the clinical question in patients. For each category of image sequences, the mean, standard deviation, and percentage of unacceptable quality images (<2) were calculated. Acceptable (rating ≥ 2) image quality was achieved at 0.55 T in all sequences for patients and 85% of the sequences for healthy subjects. Radiologists were able to answer the clinical question in all patients scanned. In total, 50% of the sequences used in patients and about 60% of the sequences used in healthy subjects exhibited good (rating ≥ 3) image quality. Based on these findings, we conclude that diagnostic quality clinical brain images can be successfully collected on this commercial 0.55 T scanner, indicating that the routine brain imaging protocol may be deployed on this system in the clinical workflow.

6.
Cancers (Basel) ; 15(17)2023 Sep 01.
Article in English | MEDLINE | ID: mdl-37686647

ABSTRACT

Accurate survival prediction for bladder cancer patients who have undergone radical cystectomy can improve their treatment management. However, the existing predictive models do not take advantage of both clinical and radiological imaging data. This study aimed to fill this gap by developing an approach that leverages the strengths of clinical (C), radiomics (R), and deep-learning (D) descriptors to improve survival prediction. The dataset comprised 163 patients, including clinical, histopathological information, and CT urography scans. The data were divided by patient into training, validation, and test sets. We analyzed the clinical data by a nomogram and the image data by radiomics and deep-learning models. The descriptors were input into a BPNN model for survival prediction. The AUCs on the test set were (C): 0.82 ± 0.06, (R): 0.73 ± 0.07, (D): 0.71 ± 0.07, (CR): 0.86 ± 0.05, (CD): 0.86 ± 0.05, and (CRD): 0.87 ± 0.05. The predictions based on D and CRD descriptors showed a significant difference (p = 0.007). For Kaplan-Meier survival analysis, the deceased and alive groups were stratified successfully by C (p < 0.001) and CRD (p < 0.001), with CRD predicting the alive group more accurately. The results highlight the potential of combining C, R, and D descriptors to accurately predict the survival of bladder cancer patients after cystectomy.

7.
Invest Radiol ; 58(8): 561-577, 2023 08 01.
Article in English | MEDLINE | ID: mdl-37026802

ABSTRACT

ABSTRACT: Magnetic resonance fingerprinting (MRF) is an approach to quantitative magnetic resonance imaging that allows for efficient simultaneous measurements of multiple tissue properties, which are then used to create accurate and reproducible quantitative maps of these properties. As the technique has gained popularity, the extent of preclinical and clinical applications has vastly increased. The goal of this review is to provide an overview of currently investigated preclinical and clinical applications of MRF, as well as future directions. Topics covered include MRF in neuroimaging, neurovascular, prostate, liver, kidney, breast, abdominal quantitative imaging, cardiac, and musculoskeletal applications.


Subject(s)
Brain , Image Processing, Computer-Assisted , Male , Humans , Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Magnetic Resonance Spectroscopy , Heart/diagnostic imaging , Phantoms, Imaging
8.
Eur Radiol ; 33(2): 836-844, 2023 Feb.
Article in English | MEDLINE | ID: mdl-35999374

ABSTRACT

OBJECTIVES: To test the feasibility of using 3D MRF maps with radiomics analysis and machine learning in the characterization of adult brain intra-axial neoplasms. METHODS: 3D MRF acquisition was performed on 78 patients with newly diagnosed brain tumors including 33 glioblastomas (grade IV), 6 grade III gliomas, 12 grade II gliomas, and 27 patients with brain metastases. Regions of enhancing tumor, non-enhancing tumor, and peritumoral edema were segmented and radiomics analysis with gray-level co-occurrence matrices and gray-level run-length matrices was performed. Statistical analysis was performed to identify features capable of differentiating tumors based on type, grade, and isocitrate dehydrogenase (IDH1) status. Receiver operating curve analysis was performed and the area under the curve (AUC) was calculated for tumor classification and grading. For gliomas, Kaplan-Meier analysis for overall survival was performed using MRF T1 features from enhancing tumor region. RESULTS: Multiple MRF T1 and T2 features from enhancing tumor region were capable of differentiating glioblastomas from brain metastases. Although no differences were identified between grade 2 and grade 3 gliomas, differentiation between grade 2 and grade 4 gliomas as well as between grade 3 and grade 4 gliomas was achieved. MRF radiomics features were also able to differentiate IDH1 mutant from the wild-type gliomas. Radiomics T1 features for enhancing tumor region in gliomas correlated to overall survival (p < 0.05). CONCLUSION: Radiomics analysis of 3D MRF maps allows differentiating glioblastomas from metastases and is capable of differentiating glioblastomas from metastases and characterizing gliomas based on grade, IDH1 status, and survival. KEY POINTS: • 3D MRF data analysis using radiomics offers novel tissue characterization of brain tumors. • 3D MRF with radiomics offers glioma characterization based on grade, IDH1 status, and overall patient survival.


Subject(s)
Brain Neoplasms , Glioblastoma , Glioma , Adult , Humans , Feasibility Studies , Magnetic Resonance Imaging , Brain Neoplasms/pathology , Glioma/pathology , Magnetic Resonance Spectroscopy , Isocitrate Dehydrogenase/genetics , Mutation , Neoplasm Grading
9.
NMR Biomed ; 36(3): e4846, 2023 03.
Article in English | MEDLINE | ID: mdl-36259628

ABSTRACT

Magnetic resonance imaging (MRI) technology has profoundly transformed current healthcare systems globally, owing to advances in hardware and software research innovations. Despite these advances, MRI remains largely inaccessible to clinicians, patients, and researchers in low-resource areas, such as Africa. The rapidly growing burden of noncommunicable diseases in Africa underscores the importance of improving access to MRI equipment as well as training and research opportunities on the continent. The Consortium for Advancement of MRI Education and Research in Africa (CAMERA) is a network of African biomedical imaging experts and global partners, implementing novel strategies to advance MRI access and research in Africa. Upon its inception in 2019, CAMERA sets out to identify challenges to MRI usage and provide a framework for addressing MRI needs in the region. To this end, CAMERA conducted a needs assessment survey (NAS) and a series of symposia at international MRI society meetings over a 2-year period. The 68-question NAS was distributed to MRI users in Africa and was completed by 157 clinicians and scientists from across Sub-Saharan Africa (SSA). On average, the number of MRI scanners per million people remained at less than one, of which 39% were obsolete low-field systems but still in use to meet daily clinical needs. The feasibility of coupling stable energy supplies from various sources has contributed to the growing number of higher-field (1.5 T) MRI scanners in the region. However, these systems are underutilized, with only 8% of facilities reporting clinical scans of 15 or more patients per day, per scanner. The most frequently reported MRI scans were neurological and musculoskeletal. The CAMERA NAS combined with the World Health Organization and International Atomic Energy Agency data provides the most up-to-date data on MRI density in Africa and offers a unique insight into Africa's MRI needs. Reported gaps in training, maintenance, and research capacity indicate ongoing challenges in providing sustainable high-value MRI access in SSA. Findings from the NAS and focused discussions at international MRI society meetings provided the basis for the framework presented here for advancing MRI capacity in SSA. While these findings pertain to SSA, the framework provides a model for advancing imaging needs in other low-resource settings.


Subject(s)
Magnetic Resonance Imaging , Humans , Africa South of the Sahara , Surveys and Questionnaires
10.
AJR Am J Roentgenol ; 220(4): 604-605, 2023 04.
Article in English | MEDLINE | ID: mdl-36129225

ABSTRACT

Radiology has been identified as a subspecialty with exceptionally high rates of incivility among colleagues. Such behaviors are detrimental to the well-being, productivity, and retention of health care practitioners and to the quality of patient care. Addressing incivility has become imperative given current and anticipated staff shortages, yet research from positive organizational scholarship suggests a greater opportunity to be had. Going forward, we need not only to address incivility but also to build purpose-driven, compassionate, and supportive workplaces.


Subject(s)
Incivility , Radiology , Humans , Organizational Culture , Workplace
11.
Magn Reson Med ; 88(4): 1818-1827, 2022 10.
Article in English | MEDLINE | ID: mdl-35713379

ABSTRACT

PURPOSE: To evaluate multicenter repeatability and reproducibility of T1 and T2 maps generated using MR fingerprinting (MRF) in the International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology MRI system phantom and in prostatic tissues. METHODS: MRF experiments were performed on 5 different 3 Tesla MRI scanners at 3 different institutions: University Hospitals Cleveland Medical Center (Cleveland, OH), Brigham and Women's Hospital (Boston, MA) in the United States, and Diagnosticos da America (Rio de Janeiro, RJ) in Brazil. Raw MRF data were reconstructed using a Gadgetron-based MRF online reconstruction pipeline to yield quantitative T1 and T2 maps. The repeatability of T1 and T2 values over 6 measurements in the International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology MRI system phantom was assessed to demonstrate intrascanner variation. The reproducibility between the 4 clinical scanners was assessed to demonstrate interscanner variation. The same-day test-retest normal prostate mean T1 and T2 values from peripheral zone and transitional zone were also compared using the intraclass correlation coefficient and Bland-Altman analysis. RESULTS: The intrascanner variation of values measured using MRF was less than 2% for T1 and 4.7% for T2 for relaxation values, within the range of 307.7 to 2360 ms for T1 and 19.1 to 248.5 ms for T2 . Interscanner measurements showed that the T1 variation was less than 4.9%, and T2 variation was less than 8.1% between multicenter scanners. Both T1 and T2 values in in vivo prostatic tissue demonstrated high test-retest reliability (intraclass correlation coefficient > 0.92) and strong linear correlation (R2  > 0.840). CONCLUSION: Prostate MRF measurements of T1 and T2 are repeatable and reproducible between MRI scanners at different centers on different continents for the above measurement ranges.


Subject(s)
Magnetic Resonance Imaging , Prostate , Brazil , Female , Humans , Image Processing, Computer-Assisted , Male , Phantoms, Imaging , Prostate/diagnostic imaging , Reproducibility of Results
12.
MAGMA ; 35(4): 557-571, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35419668

ABSTRACT

Multiparametric magnetic resonance imaging (mpMRI) has been adopted as the key tool for detection, localization, characterization, and risk stratification of patients suspected to have prostate cancer. Despite advantages over systematic biopsy, the interpretation of prostate mpMRI has limitations including a steep learning curve, leading to considerable interobserver variation. There is growing interest in clinical translation of quantitative imaging techniques for more objective lesion assessment. However, traditional mapping techniques are slow, precluding their use in the clinic. Magnetic resonance fingerprinting (MRF) is an efficient approach for quantitative maps of multiple tissue properties simultaneously. The T1 and T2 values obtained with MRF have been validated with phantom studies as well as in normal volunteers and patients. Studies have shown that MRF-derived T1 and T2 along with ADC values are all significant independent predictors in the differentiation between normal prostate tissue and prostate cancer, and hold promise in differentiating low and intermediate/high-grade cancers. This review seeks to introduce the basics of the prostate MRF technique, discuss the potential applications of prostate MRF for the characterization of prostate cancer, and describes ongoing areas of research.


Subject(s)
Multiparametric Magnetic Resonance Imaging , Prostatic Neoplasms , Biopsy , Humans , Magnetic Resonance Imaging/methods , Male , Phantoms, Imaging , Prostate/diagnostic imaging , Prostate/pathology , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/pathology
13.
J Magn Reson Imaging ; 55(5): 1322-1339, 2022 05.
Article in English | MEDLINE | ID: mdl-34927776

ABSTRACT

The COVID-19 pandemic highlighted the challenges delivering face-to-face patient care across healthcare systems. In particular the COVID-19 pandemic challenged the imaging community to provide timely access to essential diagnostic imaging modalities while ensuring appropriate safeguards were in place for both patients and personnel. With increasing vaccine availability and greater prevalence of vaccination in communities worldwide we are finally emerging on the other side of the COVID-19 pandemic. As we learned from our institutional and healthcare system responses to the pandemic, maintaining timely access to MR imaging is essential. Radiologists and other imaging providers partnered with their referring providers to ensure that timely access to advanced MR imaging was maintained. On behalf of the International Magnetic Resonance in Medicine (ISMRM) Safety Committee, this white paper is intended to serve as a guide for radiology departments, imaging centers, and other imaging specialists who perform MR imaging to refer to as we prepare for the next pandemic. Lessons learned including strategies to triage and prioritize MR imaging research during a pandemic are discussed. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 5.


Subject(s)
COVID-19 , Pandemics , Humans , Magnetic Resonance Imaging/adverse effects , Pandemics/prevention & control
14.
J Imaging ; 7(12)2021 Dec 14.
Article in English | MEDLINE | ID: mdl-34940741

ABSTRACT

Image-guided cardiovascular interventions are rapidly evolving procedures that necessitate imaging systems capable of rapid data acquisition and low-latency image reconstruction and visualization. Compared to alternative modalities, Magnetic Resonance Imaging (MRI) is attractive for guidance in complex interventional settings thanks to excellent soft tissue contrast and large fields-of-view without exposure to ionizing radiation. However, most clinically deployed MRI sequences and visualization pipelines exhibit poor latency characteristics, and spatial integration of complex anatomy and device orientation can be challenging on conventional 2D displays. This work demonstrates a proof-of-concept system linking real-time cardiac MR image acquisition, online low-latency reconstruction, and a stereoscopic display to support further development in real-time MR-guided intervention. Data are acquired using an undersampled, radial trajectory and reconstructed via parallelized through-time radial generalized autocalibrating partially parallel acquisition (GRAPPA) implemented on graphics processing units. Images are rendered for display in a stereoscopic mixed-reality head-mounted display. The system is successfully tested by imaging standard cardiac views in healthy volunteers. Datasets comprised of one slice (46 ms), two slices (92 ms), and three slices (138 ms) are collected, with the acquisition time of each listed in parentheses. Images are displayed with latencies of 42 ms/frame or less for all three conditions. Volumetric data are acquired at one volume per heartbeat with acquisition times of 467 ms and 588 ms when 8 and 12 partitions are acquired, respectively. Volumes are displayed with a latency of 286 ms or less. The faster-than-acquisition latencies for both planar and volumetric display enable real-time 3D visualization of the heart.

15.
AJR Am J Roentgenol ; 217(4): 908-918, 2021 10.
Article in English | MEDLINE | ID: mdl-33336582

ABSTRACT

BACKGROUND. In-gantry MRI-guided biopsy (MRGB) of the prostate has been shown to be more accurate than other targeted prostate biopsy methods. However, the optimal number of cores to obtain during in-gantry MRGB remains undetermined. OBJECTIVE. The purpose of this study was to assess the diagnostic yield of obtaining an incremental number of cores from the primary lesion and of second lesion sampling during in-gantry MRGB of the prostate. METHODS. This retrospective study included 128 men with 163 prostate lesions who underwent in-gantry MRGB between 2016 and 2019. The men had a total of 163 lesions sampled with two or more cores, 121 lesions sampled with three or more cores, and 52 lesions sampled with four or more cores. A total of 40 men underwent sampling of a second lesion. Upgrade on a given core was defined as a greater International Society of Urological Pathology (ISUP) grade group (GG) relative to the previously obtained cores. Clinically significant prostate cancer (csPCa) was defined as ISUP GG 2 or greater. RESULTS. The frequency of any upgrade was 12.9% (21/163) on core 2 versus 10.7% (13/121) on core 3 (p = .29 relative to core 2) and 1.9% (1/52) on core 4 (p = .03 relative to core 3). The frequency of upgrade to csPCa was 7.4% (12/163) on core 2 versus 4.1% (5/121) on core 3 (p = .13 relative to core 2) and 0% (0/52) on core 4 (p = .07 relative to core 3). The frequency of upgrade on core 2 was higher for anterior lesions (p < .001) and lesions with a higher PI-RADS score (p = .007); the frequency of upgrade on core 3 was higher for apical lesions (p = .01) and lesions with a higher PI-RADS score (p = .01). Sampling of a second lesion resulted in an upgrade in a single patient (2.5%; 1/40); both lesions were PI-RADS category 4 and showed csPCa. CONCLUSION. When performing in-gantry MRGB of the prostate, obtaining three cores from the primary lesion is warranted to optimize csPCa diagnosis. Obtaining a fourth core from the primary lesion or sampling a second lesion has very low yield in upgrading cancer diagnoses. CLINICAL IMPACT. To reduce patient discomfort and procedure times, operators may refrain from obtaining more than three cores or second lesion sampling.


Subject(s)
Biopsy, Large-Core Needle/methods , Image-Guided Biopsy/methods , Magnetic Resonance Imaging, Interventional/methods , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/pathology , Aged , Humans , Male , Middle Aged , Neoplasm Grading , Retrospective Studies
16.
Eur Radiol ; 31(3): 1336-1346, 2021 Mar.
Article in English | MEDLINE | ID: mdl-32876839

ABSTRACT

OBJECTIVES: To explore the associations between T1 and T2 magnetic resonance fingerprinting (MRF) measurements and corresponding tissue compartment ratios (TCRs) on whole mount histopathology of prostate cancer (PCa) and prostatitis. MATERIALS AND METHODS: A retrospective, IRB-approved, HIPAA-compliant cohort consisting of 14 PCa patients who underwent 3 T multiparametric MRI along with T1 and T2 MRF maps prior to radical prostatectomy was used. Correspondences between whole mount specimens and MRI and MRF were manually established. Prostatitis, PCa, and normal peripheral zone (PZ) regions of interest (ROIs) on pathology were segmented for TCRs of epithelium, lumen, and stroma using two U-net deep learning models. Corresponding ROIs were mapped to T2-weighted MRI (T2w), apparent diffusion coefficient (ADC), and T1 and T2 MRF maps. Their correlations with TCRs were computed using Pearson's correlation coefficient (R). Statistically significant differences in means were assessed using one-way ANOVA. RESULTS: Statistically significant differences (p < 0.01) in means of TCRs and T1 and T2 MRF were observed between PCa, prostatitis, and normal PZ. A negative correlation was observed between T1 and T2 MRF and epithelium (R = - 0.38, - 0.44, p < 0.05) of PCa. T1 MRF was correlated in opposite directions with stroma of PCa and prostatitis (R = 0.35, - 0.44, p < 0.05). T2 MRF was positively correlated with lumen of PCa and prostatitis (R = 0.57, 0.46, p < 0.01). Mean T2 MRF showed significant differences (p < 0.01) between PCa and prostatitis across both transition zone (TZ) and PZ, while mean T1 MRF was significant (p = 0.02) in TZ. CONCLUSION: Significant associations between MRF (T1 in the TZ and T2 in the PZ) and tissue compartments on corresponding histopathology were observed. KEY POINTS: • Mean T2 MRF measurements and ADC within cancerous regions of interest dropped with increasing ISUP prognostic groups (IPG). • Mean T1 and T2 MRF measurements were significantly different (p < 0.001) across IPGs, prostatitis, and normal peripheral zone (NPZ). • T2 MRF showed stronger correlations in the peripheral zone, while T1 MRF showed stronger correlations in the transition zone with histopathology for prostate cancer.


Subject(s)
Deep Learning , Prostatic Neoplasms , Prostatitis , Diffusion Magnetic Resonance Imaging , Epithelium , Humans , Magnetic Resonance Imaging , Male , Prostatic Neoplasms/diagnostic imaging , Prostatitis/diagnostic imaging , Retrospective Studies
17.
Eur J Nucl Med Mol Imaging ; 48(3): 683-693, 2021 03.
Article in English | MEDLINE | ID: mdl-32979059

ABSTRACT

PURPOSE: This is a radiomics study investigating the ability of texture analysis of MRF maps to improve differentiation between intra-axial adult brain tumors and to predict survival in the glioblastoma cohort. METHODS: Magnetic resonance fingerprinting (MRF) acquisition was performed on 31 patients across 3 groups: 17 glioblastomas, 6 low-grade gliomas, and 8 metastases. Using regions of interest for the solid tumor and peritumoral white matter on T1 and T2 maps, second-order texture features were calculated from gray-level co-occurrence matrices and gray-level run length matrices. Selected features were compared across the three tumor groups using Wilcoxon rank-sum test. Receiver operating characteristic curve analysis was performed for each feature. Kaplan-Meier method was used for survival analysis with log rank tests. RESULTS: Low-grade gliomas and glioblastomas had significantly higher run percentage, run entropy, and information measure of correlation 1 on T1 than metastases (p < 0.017). The best separation of all three tumor types was seen utilizing inverse difference normalized and homogeneity values for peritumoral white matter in both T1 and T2 maps (p < 0.017). In solid tumor T2 maps, lower values in entropy and higher values of maximum probability and high-gray run emphasis were associated with longer survival in glioblastoma patients (p < 0.05). Several texture features were associated with longer survival in glioblastoma patients on peritumoral white matter T1 maps (p < 0.05). CONCLUSION: Texture analysis of MRF-derived maps can improve our ability to differentiate common adult brain tumors by characterizing tumor heterogeneity, and may have a role in predicting outcomes in patients with glioblastoma.


Subject(s)
Brain Neoplasms , Glioblastoma , Glioma , Adult , Brain Neoplasms/diagnostic imaging , Glioblastoma/diagnostic imaging , Humans , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy
19.
Tomography ; 8(1): 10-21, 2021 12 23.
Article in English | MEDLINE | ID: mdl-35076600

ABSTRACT

The purpose of this work is to evaluate the feasibility of performing magnetic resonance fingerprinting (MRF) on older and lower-performance MRI hardware as a means to bring advanced imaging to the aging MRI install base. Phantom and in vivo experiments were performed on a 1.5T Siemens Aera (installed 2015) and 1.5T Siemens Symphony (installed 2002). A 2D spiral MRF sequence for simultaneous T1/T2/M0 mapping was implemented on both scanners with different gradient trajectories to accommodate system specifications. In phantom, for T1/T2 values in a physiologically relevant range (T1: 195-1539 ms; T2: 20-267 ms), scanners had strong correlation (R2 > 0.999) with average absolute percent difference of 8.1% and 10.1%, respectively. Comparison of the two trajectories on the newer scanner showed differences of 2.6% (T1) and 10.9% (T2), suggesting a partial explanation of the observed inter-scanner bias. Inter-scanner agreement was better when the same trajectory was used, with differences of 6.0% (T1) and 4.0% (T2). Intra-scanner coefficient of variation (CV) of T1 and T2 estimates in phantom were <2.0% and in vivo were ≤3.5%. In vivo inter-scanner white matter CV was 4.8% (T1) and 5.1% (T2). White matter measurements on the aging scanner after two months were consistent, with differences of 1.9% (T1) and 3.9% (T2). In conclusion, MRF is feasible on an aging MRI scanner and required only changes to the gradient trajectory.


Subject(s)
Magnetic Resonance Imaging , Feasibility Studies , Magnetic Resonance Imaging/methods , Magnetic Resonance Spectroscopy , Phantoms, Imaging
20.
J Magn Reson Imaging ; 53(5): 1311-1317, 2021 05.
Article in English | MEDLINE | ID: mdl-32808391

ABSTRACT

Historically, the presence of cardiac implantable electronic devices (CIEDs), including pacemakers and implantable cardioverter defibrillators (ICDs), was widely considered an absolute contraindication to magnetic resonance imaging (MRI). The recent development of CIEDs with MR Conditional labeling, as well as encouraging results from retrospective studies and a prospective trial on the safety of MRI performed in patients with CIEDs without MR Conditional labeling, have led to a reevaluation of this practice. The purpose of this report is to provide a concise summary of recent developments, including practical guidelines that an institution could adopt for radiologists who choose to image patients with CIEDs that do not have MR Conditional labeling. This report was written on behalf of and approved by the International Society for Magnetic Resonance in Medicine (ISMRM) Safety Committee. LEVEL OF EVIDENCE: 3. TECHNICAL EFFICACY STAGE: 1.


Subject(s)
Defibrillators, Implantable , Pacemaker, Artificial , Electronics , Humans , Magnetic Resonance Imaging , Prospective Studies , Retrospective Studies
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