Whole-body Magnetic Resonance Imaging Scans Research Articles

Reliability assessment of the OMERACT whole-body magnetic resonance imaging scoring system for juvenile idiopathic arthritis

Inter-reader reliability of a new scoring system for evaluating joint inflammation and enthesitis in whole body MRI (WBMRI) in juvenile idiopathic arthritis was tested. The scoring system grades 732 item-region combinations of bone marrow and soft tissue changes for commonly involved joints and entheseal sites. Five radiologists rated 17 WBMRI scans through an online rating platform. Item-wise reliability was calculated for 117 items with non-zero scores in >10 % of readings. Interquartile ranges of the five-reader Kappa reliability coefficients were 0.58–0.73 (range: 0.36–0.88) for the joints, 0.65–0.81 (range: 0.39–0.95) for the entheses, and 0.62–0.75 (range: 0.60–0.76) for chronic nonbacterial osteomyelitis-like lesions.

A simple, clinically usable whole-body MRI system of joint assessment in adolescents and young people with juvenile idiopathic arthritis.

To introduce and evaluate a simple method for assessing joint inflammation and structural damage on whole-body MRI (WBMRI) in juvenile idiopathic arthritis (JIA), which is usable in clinical practice. The proposed system utilises post-contrast Dixon WBMRI scans. Joints are assessed for synovitis (grade 0-2) and structural damage (present/absent) at 81 sites. The synovitis grading is based on features including above-normal intensity synovial enhancement, synovial hypertrophy, joint effusion, subarticular bone marrow oedema and peri-articular soft tissue oedema.This system was evaluated in a prospective study of 60 young people (47 patients with JIA and 13 controls with non-inflammatory musculoskeletal pain) who underwent a WBMRI. Three readers (blinded to diagnosis) independently reviewed all images and re-reviewed 20 individual scans. The intra- and inter-reader overall agreement (OA) and the intra- and inter-reader Gwet's agreement coefficients 2 (GAC2) were measured for the detection of a) participants with ≥1 joint with inflammation or structural damage and b) joint inflammation or structural damage for each joint. The inter-reader OA for detecting patients with ≥1 joint with inflammation, defined as grade 2 synovitis (G2), and ≥1 joint with structural damage were 80% and 73%, respectively. The intra-reader OA for readers 1-3 were 80-90% and 75-90% respectively. The inter-reader OA and GAC2 for joint inflammation (G2) at each joint were both ≥85% for all joints but were lower if grade 1 synovitis was included as positive. The intra- and inter-reader agreements of this WBMRI assessment system are adequate for assessing objective joint inflammation and damage in JIA.

Detection of inflammation by whole-body MRI in young people with juvenile idiopathic arthritis.

To assess the frequency of joint inflammation detected by whole-body MRI (WBMRI) in young people (YP) with JIA and controls, and to determine the relationship between WBMRI-detected inflammation and clinical findings. YP aged 14-24 years, with JIA (patients) or arthralgia without JIA (controls), recruited from one centre, underwent a WBMRI scan after formal clinical assessment. Consensus between at least two of the three independent radiologists was required to define inflammation and damage on WBMRI, according to predefined criteria. YP with JIA were deemed clinically active as per accepted definitions. The proportions of YP with positive WBMRI scans for joint inflammation (≥1 inflamed joint) as well as serum biomarkers were compared between active vs inactive JIA patients and controls. Forty-seven YP with JIA (25 active and 22 inactive patients) and 13 controls were included. WBMRI detected joint inflammation in 60% (28/47) patients with JIA vs 15% (2/13) controls (difference: 44%, 95% CI 20%, 68%). More active than inactive JIA patients had WBMRI-detected inflammation [76% (19/25) vs 41% (9/22), difference: 35% (95% CI 9%, 62%)], and this was associated with a specific biomarker signature. WBMRI identified inflammation in ≥ 1 clinically inactive joint in 23/47 (49%) patients (14/25 active vs 9/22 inactive JIA patients). WBMRI's validity in joint assessment was demonstrated by the higher frequency of inflammation in JIA patients vs controls, and in active vs inactive JIA patients. WBMRI found unsuspected joint inflammation in 49% YP with JIA, which needs further investigation of potential clinical implications.

Exercise-Related Physical Activity Relates to Brain Volumes in 10,125 Individuals.

The potential neuroprotective effects of regular physical activity on brain structure are unclear, despite links between activity and reduced dementia risk. To investigate the relationships between regular moderate to vigorous physical activity and quantified brain volumes on magnetic resonance neuroimaging. A total of 10,125 healthy participants underwent whole-body MRI scans, with brain sequences including isotropic MP-RAGE. Three deep learning models analyzed axial, sagittal, and coronal views from the scans. Moderate to vigorous physical activity, defined by activities increasing respiration and pulse rate for at least 10 continuous minutes, was modeled with brain volumes via partial correlations. Analyses adjusted for age, sex, and total intracranial volume, and a 5% Benjamini-Hochberg False Discovery Rate addressed multiple comparisons. Participant average age was 52.98±13.04 years (range 18-97) and 52.3% were biologically male. Of these, 7,606 (75.1%) reported engaging in moderate or vigorous physical activity approximately 4.05±3.43 days per week. Those with vigorous activity were slightly younger (p < 0.00001), and fewer women compared to men engaged in such activities (p = 3.76e-15). Adjusting for age, sex, body mass index, and multiple comparisons, increased days of moderate to vigorous activity correlated with larger normalized brain volumes in multiple regions including: total gray matter (Partial R = 0.05, p = 1.22e-7), white matter (Partial R = 0.06, p = 9.34e-11), hippocampus (Partial R = 0.05, p = 5.96e-7), and frontal, parietal, and occipital lobes (Partial R = 0.04, p≤1.06e-5). Exercise-related physical activity is associated with increased brain volumes, indicating potential neuroprotective effects.

Establishing Normative Values for Acromion Anatomy: A Comprehensive MRI-Based Study in a Healthy Population of 996 Participants.

Shoulder pain is a common issue often linked to conditions such as subacromial impingement or rotator cuff lesions. The role of the acromion in these symptoms remains a subject of debate. This study aims to establish standardized values for commonly used acromion dimensions based on whole-body MRI scans of a large and healthy population and to investigate potential correlations between acromion shape and influencing factors such as sex, age, BMI, dominant hand, and shoulder pain. The study used whole-body MRI scans from the Study of Health in Pomerania, a German population-based study. Acromion index, acromion tilt, and acromion slope were measured. Interrater variability was tested with two independent, trained viewers on 100 MRI sequences before actual measurements started. Descriptive statistics and logistic regression were used to evaluate the results. We could define reference values based on a shoulder-healthy population for each acromion parameter within the 2.5 to 97.5 percentile. No significant differences were found in acromion slope, tilt, and index between male and female participants. No significant correlations were observed between acromion morphology and anthropometric parameters such as height, weight, or BMI. No significant differences were observed in acromion parameters between dominant and non-dominant hands or stated pain intensity. This study provides valuable reference values for acromion-related parameters, offering insight into the anatomy of a healthy shoulder. The findings indicate no significant differences in acromion morphology based on sex, weight, BMI, or dominant hand. Further research is necessary to ascertain the clinical implications of these reference values. The establishment of standardized reference values opens new possibilities for enhancing clinical decision making regarding surgical interventions, such as acromioplasty.

Development of a Semiquantitative Whole-Body MRI Scoring System for Multiple Myeloma.

Background In patients with multiple myeloma (MM), the serum marker β2-microglobulin does not always accurately reflect tumor load. In contrast, whole-body (WB) MRI has shown high sensitivity for detecting bone lesions. Purpose To develop and validate a semiquantitative WB MRI scoring system for newly diagnosed MM and to compare it with the International Staging System (ISS) and Revised ISS (R-ISS). Materials and Methods This study included two retrospective groups (group 1, July 2015 to September 2021; group 2, February 2020 to September 2021) and one prospective group (group 3, October 2021 to February 2022) of patients with newly diagnosed MM. A new scoring system for MM was developed using spine MRI scans in group 1 and WB MRI scans in group 2 that integrated three features: (a) background marrow pattern, (b) number of focal bone lesions, and (c) presence of extramedullary or paramedullary lesions. The summed total score ranged from zero to nine. The interobserver agreement for each feature was assessed using Fleiss or Cohen weighted κ. WB MRI total scores in group 3 were compared across ISS and R-ISS stages using two-way analysis of variance. Results Groups 1, 2, and 3 included 103 patients (mean age, 62.1 years ± 9.1 [SD]; 60 men), 36 patients (mean age 65.4 years ± 11.3 [SD]; 19 women), and 39 participants (mean age, 62.0 years ± 11.7 [SD]; 20 men), respectively. The interobserver agreements for the three features composing the scoring system were substantial (κ range, 0.69-0.80). WB MRI total score increased with increasing ISS stage (mean score for ISS 1, 2, and 3 was 2.2, 4.2, and 5.8, respectively; P = .009) and R-ISS stage (mean score for R-ISS 1, 2, and 3 was 2.1, 3.8, and 5.9, respectively; P = .005). Conclusion The developed WB MRI scoring system for MM demonstrated substantial observer agreement and corresponded well with ISS and R-ISS stages. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Dragan and Messiou in this issue.

MRI Characterization Of Skeletal Muscle Size And Fatty Infiltration In Long-term Trained And Untrained Individuals

PURPOSE: We aimed to investigate various body composition measures in highly trained and untrained men and women using whole-body magnetic resonance imaging (MRI). Additionally, correlations between these measures and skeletal muscle gene expression were performed. METHODS: Thirty-six individuals were included: endurance-trained men (ME, n = 8) and women (FE, n = 7), strength-trained men (MS, n = 7) or untrained control men (MC, n = 8) and women (FC, n = 6). Whole-body MRI scans were performed, and m. vastus lateralis biopsies were collected at rest. Cross-sectional area (CSA) and infiltration of muscular adipose tissue (IMAT) were calculated from Mm. pectoralis, M. erector spinae and M. multifidus combined, Mm. quadriceps, and Mm. triceps surae (TS). RESULTS: ME and FE had significantly lower liver fat fraction, visceral fat volume and total body fat mass relative to body weight than MC and FC, respectively. MS had larger CSA across all four muscle groups and less IMAT in all muscles apart from TS (p = 0.053) compared with MC. ME was found to have less IMAT across all muscle groups and a larger CSA in three of the four muscle groups compared with MC. However, the only difference in IMAT between FE and FC was found in Mm. pectoralis. Functional analysis of muscle gene expression of the top 50 genes that correlated most strongly with IMAT revealed a significant enrichment of the AMPK-pathway. CONCLUSIONS: This study suggests that both regular endurance and resistance training are, over time, appropriate to maintain muscle mass and reduced skeletal muscle infiltration of adipose tissue in male adults. Although a significant relationship between IMAT and the AMPK pathway was found, future studies are needed to determine the mechanism by which infiltration of adipose tissue is regulated in muscle.

Whole-body MR imaging in evaluation of children with juvenile dermatomyositis

PurposeTo evaluate the whole-body MRI (WBMRI) findings in children with juvenile dermatomyositis (JDM) and correlate them with clinical and laboratory results. MethodWe conducted the present prospective study from October 2019 to September 2021. Thirty children (8.2 ± 3.88 years) with a diagnosis of JDM based on EULAR/ACR classification criteria underwent WBMRI using short tau inversion recovery, diffusion-weighted, and T1 modified DIXON (precontrast and postcontrast) sequences. WBMRI scans were analysed independently by two radiologists for abnormal signal intensity and enhancement in the different muscle groups. Radiological findings were correlated with clinical examination, muscle enzymes, and inflammatory markers. ResultsWBMRI revealed abnormal signal intensity and diffusion restriction, predominantly in the thigh (n = 21, 70 % children), calf (n = 18, 60 % children), and hip (n = 16, 53.3 % children) muscles. A significant positive correlation was observed between the serum total creatinine kinase and lactic dehydrogenaselevels, with altered signal intensity and diffusion restriction in the paraspinal and thigh muscles. Diffusion restriction in the hip and calf muscles also showed significant positive correlations with these enzymes. Significant positive correlations were detected between lower limb muscle strength and altered signal intensity and diffusion restriction in the thigh (p = 0.023) and calf (p = 0.002) muscles. Postcontrast images did not yield any additional useful information. ConclusionsWBMRI provided useful information in evaluation of the extent and distribution of findings in children with JDM. There were significant positive correlations between MRI findings and muscle enzymes and clinical examination results. The addition of contrast to the WBMRI protocol did not provide any additional advantage.

Identification of novel genes whose expression in adipose tissue affects body fat mass and distribution: an RNA-Seq and Mendelian Randomization study.

Many studies have shown that abdominal adiposity is more strongly related to health risks than peripheral adiposity. However, the underlying pathways are still poorly understood. In this cross-sectional study using data from RNA-sequencing experiments and whole-body MRI scans of 200 participants in the EPIC-Potsdam cohort, our aim was to identify novel genes whose gene expression in subcutaneous adipose tissue has an effect on body fat mass (BFM) and body fat distribution (BFD). The analysis identified 625 genes associated with adiposity, of which 531 encode a known protein and 487 are novel candidate genes for obesity. Enrichment analyses indicated that BFM-associated genes were characterized by their higher than expected involvement in cellular, regulatory and immune system processes, and BFD-associated genes by their involvement in cellular, metabolic, and regulatory processes. Mendelian Randomization analyses suggested that the gene expression of 69 genes was causally related to BFM and BFD. Six genes were replicated in UK Biobank. In this study, we identified novel genes for BFM and BFD that are BFM- and BFD-specific, involved in different molecular processes, and whose up-/downregulated gene expression may causally contribute to obesity.

Serum levels of perfluoroalkyl substances (PFAS) and body composition – A cross-sectional study in a middle-aged population

BackgroundIt has been suggested that per- and polyfluoroalkyl substances (PFAS) are endocrine disruptors with a potential to influence fat mass. ObjectiveThe primary hypothesis tested was that we would find positive relationships for PFAS vs measures of adiposity. MethodsIn 321 subjects all aged 50 years in the POEM study, five PFAS (perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA)) were measured in serum together with a Dual-energy X-ray absorptiometry (DXA) scan for determination of fat and lean mass. Whole-body magnetic resonance imaging scan was performed and the body was divided into >1 million voxels. Voxel-wise statistical analysis was carried out by a novel method denoted Imiomics. ResultsPFOS and PFHxS, did not show any consistent associations with body composition. However, PFOA, and especially PFNA and PFDA, levels were inversely related to most traditional measures reflecting the amount of fat in women, but not in men. In the Imiomics analysis of tissue volume, PFDA and PFNA levels were inversely related to the volume of subcutaneous fat, mainly in the arm, trunk and hip regions in women, while no such clear relationship was seen in men. Also, the visceral fat content of the liver, the pericardium, and the gluteus muscle were inversely related to PFDA and PFNA in women. DiscussionContrary to our hypothesis, some PFAS showed inverse relationships vs measurements of adiposity. ConclusionPFOS and PFHxS levels in plasma did not show any consistent associations with body composition, but PFOA, and especially PFNA and PFDA were inversely related to multiple measures reflecting the amount of fat, but in women only.

Early diagnosis and response assessment in chronic recurrent multifocal osteomyelitis: changes in lesion volume and signal intensity assessed by whole-body MRI

Objective:To assess the effectiveness of whole-body MRI (WB-MRI) in early diagnosis of chronic recurrent multifocal osteomyelitis (CRMO) and the prediction of clinical response through quantitative MRI features.Methods:20 children (mean age, 10.3 years; range, 5–14 years) with CRMO underwent WB-MRI and were assessed with a clinical score (Jansson) at baseline (median time after first encounter, 8 months) and follow-up (median time after baseline, 11.5 months). Baseline WB-MRI scans were classified as early (within 6 months after first encounter) and late. Clinical responders and non-responders were compared regarding number and localization of bone lesions, lesion volume and T2 signal intensity (SI) ratio (lesion to muscle).Results:Diagnosis of CRMO was made promptly in the early WB-MRI group (n = 10; median, 3 months) compared to the late WB-MRI group (n = 10; 18 months; p = 0.006). Bone lesions were mainly located in the lower extremities (n = 119/223; 53%). No significant difference was detected regarding the number of bone lesions and lesion volume in the subgroups of clinical responders (n = 10) and non-responders (n = 10). Responders showed a higher volume reduction of bone lesions at follow-up compared to non-responders (p = 0.03). Baseline and follow-up SI ratios were lower in responders (5.6 and 5.8 vs 6.1 and 7.2; p = 0.047 and p = 0.005).Conclusion:The use of WB-MRI within 6 months of disease suspicion may serve as a benchmark to support early diagnosis of CRMO. T2 SI ratios and the reduction of lesions’ volume correlate with clinical outcome.Advances in knowledge:WB-MRI at an early stage of suspected CRMO plays a key role for early diagnosis. This is the first study showing that quantitative MRI features are suitable for response assessment and can be used as prognostic markers for the prediction of clinical response.

Oncologically Relevant Findings Reporting and Data System (ONCO-RADS): Guidelines for the Acquisition, Interpretation, and Reporting of Whole-Body MRI for Cancer Screening.

Acknowledging the increasing number of studies describing the use of whole-body MRI for cancer screening, and the increasing number of examinations being performed in patients with known cancers, an international multidisciplinary expert panel of radiologists and a geneticist with subject-specific expertise formulated technical acquisition standards, interpretation criteria, and limitations of whole-body MRI for cancer screening in individuals at higher risk, including those with cancer predisposition syndromes. The Oncologically Relevant Findings Reporting and Data System (ONCO-RADS) proposes a standard protocol for individuals at higher risk, including those with cancer predisposition syndromes. ONCO-RADS emphasizes structured reporting and five assessment categories for the classification of whole-body MRI findings. The ONCO-RADS guidelines are designed to promote standardization and limit variations in the acquisition, interpretation, and reporting of whole-body MRI scans for cancer screening. Published under a CC BY 4.0 license Online supplemental material is available for this article.

Feasibility of magnetic resonance-guided high-intensity focused ultrasound treatment targeting distinct nodular lesions in neurofibromatosis type 1.

BackgroundPatients with Neurofibromatosis Type 1 (NF1) and plexiform neurofibromas (PN) often have radiographically diagnosed distinct nodular lesions (DNL) which can cause pain and weakness. Magnetic resonance-guided high intensity focused ultrasound (MR-HIFU) can precisely and accurately deliver heat to thermally ablate target tissue. The aim of this study is to evaluate whole-body MRIs from patients with NF1 and DNL, applying volumetrics and a consistent treatment planning approach to determine the feasibility of MR-HIFU ablation of DNL.MethodsA retrospective review of whole-body MRI scans from patients with NF1 and PN from CNH and NCI was performed. DNL are defined as lesions >3 cm, distinct from PN and lacking the “central dot” feature. Criteria for MR-HIFU thermal ablation include target location 1–8 cm from skin surface; >1 cm from visible plexus, spinal canal, bladder, bowel, physis; and ability to ablate ≥50% of lesion volume. Lesions in skull and vertebral body were excluded.ResultsIn 26 patients, 120 DNL were identified. The majority of DNL were located in an extremity (52.5%). Other sites included head/neck (7%), chest (13%), and abdomen/pelvis (28%). The predefined HIFU ablation criteria was not met for 47.5% of lesions (n = 57). The main limitation was proximity to a vital structure or organ (79%). Complete and partial HIFU ablation was feasible for 25% and 27.5% of lesions, respectively.ConclusionBased on imaging review of lesion location, technical considerations and ability to target lesions, thermal ablation with MR-HIFU may be a feasible noninvasive alternative for symptom management in patients with NF1 and symptomatic DNL.

Assessment of body composition and association with clinical outcomes in patients with lung and colorectal cancer.

Objectives:To assess body composition in patients with non-small cell lung cancer (NSCLC) and colorectal cancer using whole-body MRI and relate this to clinical outcomes.Methods:53 patients with NSCLC (28 males, 25 females; mean age 66.9) and 74 patients with colorectal cancer (42 males, 32 females; mean age 62.9) underwent staging whole-body MRI scans, which were post-processed to derive fat mass (FM), fat free mass (FFM) and skeletal muscle (SM) indices and SM fat fraction (FF). These were compared between the two cancer cohorts using two-sided t-tests and the chi-squared test. Measurements of body composition were correlated with outcomes including length of hospital stay, metastatic status and mortality.Results:Patients with NSCLC had significantly lower FFM (p = 0.0071) and SM (p = 0.0084) indices. Mean SM FF was greater in patients with NSCLC (p = 0.0124) and was associated with longer hospital stay (p = 0.035). There was no significant relationship between FM, FFM and SM indices and length of hospital stay, metastatic status or mortality.Conclusions:Patients with NSCLC had lower FFM and SM indices than patients with colorectal cancer and greater SMFF, indicating lower SM mass with fatty infiltration. These findings reflect differences in the phenotype of the two groups and suggest patients with lung cancer are more likely to require additional nutritional support.Advances in knowledge:Body composition differs between NSCLC and colorectal cancer. Patients with NSCLC have both a reduced SM mass and greater SM FF suggesting that they are more nutritionally deplete than patients with colorectal cancer.

Whole Body 3.0 T Magnetic Resonance Imaging in Lymphomas: Comparison of Different Sequence Combinations for Staging Hodgkin's and Diffuse Large B Cell Lymphomas.

To investigate the diagnostic value of different whole-body magnetic resonance imaging (WB-MRI) protocols for staging Hodgkin and diffuse-large B-cell lymphomas (HL and DLBCL), twenty-two patients (M/F 12/10, median age 32, range 22–87, HL/DLBCL 14/8) underwent baseline WB-MRI and 18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET) fused with computed tomography (CT) scan 18F-FDG-PET-CT. The 3.0 T WB-MRI was performed using pre-contrast modified Dixon (mDixon), T2-weighted turbo-spin-echo (TSE), diffusion-weighted-imaging (DWI), dynamic-contrast-enhanced (DCE) liver/spleen, contrast-enhanced (CE) lung MRI and CE whole-body mDixon. WB-MRI scans were divided into: (1) “WB-MRI DWI+IP”: whole-body DWI + in-phase mDixon (2) “WB-MRI T2-TSE”: whole-body T2-TSE (3) “WB-MRI Post-C”: whole-body CE mDixon + DCE liver/spleen and CE lung mDixon (4) “WB-MRI All “: the entire protocol. Two radiologists evaluated WB-MRIs at random, independently and then in consensus. Two nuclear-medicine-physicians reviewed 18F-FDG PET-CT in consensus. An enhanced-reference-standard (ERS) was derived using all available baseline and follow-up imaging. The sensitivity and specificity of WB-MRI protocols for nodal and extra-nodal staging was derived against the ERS. Agreement between the WB-MRI protocols and the ERS for overall staging was assessed using kappa statistic. For consensus WB-MRI, the sensitivity and specificity for nodal staging were 75%, 98% for WB-MRI DWI+IP, 76%, 98% for WB-MRI Post-C, 83%, 99% for WB-MRI T2-TSE and 87%, 100% for WB-MRI All. The sensitivity and specificity for extra-nodal staging were 67% 100% for WB-MRI DWI+IP, 89%, 100% for WB-MRI Post-C, 89%, 100% for WB-MRI T2-TSE and 100%, 100% for the WB-MRI All. The consensus WB-MRI All read had perfect agreement with the ERS for overall staging [kappa = 1.00 (95% CI: 1.00-1.00)]. The best diagnostic performance is achieved combining all available WB-MRI sequences.

Magnetic resonance imaging for early pregnancy diagnosis in the laboratory rat.

Pregnancy diagnosis and embryo counting are important end points in reproductive, developmental biology and toxicology studies. The purpose of the present study was to assess the feasibility and efficacy of magnetic resonance imaging (MRI) for early pregnancy diagnosis and embryo counting in the laboratory rat. Female Wistar rats were subjected to whole-body MRI scanning using a 1.5T MRI scanner, employing a isotropic T2-weighted 3D short-tau inversion recovery sequence from day 8 to day 12 post coitum (pc) or without prior mating, under general anaesthesia for pregnancy diagnosis and embryo counting. MRI examination was followed by laparotomy and visual inspection of the uterus to verify MRI findings. By day 8 pc, uterine bulges, characteristic of pregnancy, were depicted as oval-shaped structures of high intensity signal. By day 10 pc, embryonic vesicles were detected at the medial side of the uterine bulges. Pregnancy was diagnosed with 0% false-negative diagnosis and 100% accuracy by day 11 pc, while embryos were counted with 100% accuracy by day 12 pc. In conclusion, MRI proved to be a feasible and reliable non-invasive imaging method of early pregnancy diagnosis and embryo counting in the laboratory rat.

Inductively Coupled RF Coil for Imaging a 40 µm-Thick Histology Sample in a Clinical MRI Scanner

A histology coil is a U-shaped radio-frequency (RF) coil that is designed to provide a high signal-to-noise ratio (SNR) in magnetic resonance imaging (MRI) of microscopically thin samples. In this work, we demonstrate an inductively coupled histology coil that can be easily integrated with a human MRI scanner, providing a simple method to conduct novel, microscopic imaging experiments in a clinical scanner. All experiments were conducted in a 3T whole-body MRI scanner. The coil consisted of a U-shaped copper foil with tuning capacitors shunting the ends of the “U”. This design maximizes the B1-field efficiency and the homogeneity in the coil’s cavity. For inductive coupling, the histology coil was connected to an untuned single-turn pick-up loop via a coaxial cable. A standard 3T receive-only surface coil, connected to the scanner’s standard receive circuitry, was then inductively coupled to the pick-up loop. Separately, the RF pulse transmitted from the MRI body coil inductively drove the histology coil. In gel phantom imaging, we confirmed a higher (threefold) SNR for the histology coil than for the scanner’s standard surface coil, as well as high B1 homogeneity for the histology coil. Gradient echo images of a 40-µm-thick rat brain slice, at an in-plane resolution of 219 × 219 µm2, could be obtained with SNR > 10 (in the cortex) in about 2 hours. Our work demonstrates the feasibility of imaging microscopically thin tissue slices in a clinical MRI scanner using an inductively coupled histology coil. The method can be applied to multi-modality and multi-orientation imaging of ex-vivo and engineered tissue samples.

Whole-body MRI: a powerful alternative to bone scan for bone marrow staging without radiation and gadolinium enhancer.

Whole-body magnetic resonance imaging (WB-MRI) is a radiation-free alternative to the 99mTc-HDP bone scan (BS) for the detection of bone metastasis. The major drawback is the long examination time and application of gadolinium enhancer. The aim of this study is to analyze (i) the performance of WB-MRI versus the BS and (ii) the diagnostic benefit of gadolinium (WB-MRI + Gd) compared to a non-enhanced protocol (NE WB-MRI). 1256 eligible WB-MRI scans were analyzed retrospectively with a single inclusion criterion, a clinical 12-month follow-up or a biopsy as ground truth. N = 285 patients received both a WB-MRI and a BS within 12months. All the patients were imaged with a coronal T1w and a STIR, and n = 528 (42%) received an additional T1w-mDixon with gadoteridol (0.1mmol Gd-DTPA/kg). From 1256 eligible patients, n = 884 (70%) had breast cancer as a primary disease, n = 101(8%) prostate cancer, and n = 77(6%) lung cancer. The sensitivity (Se) and negative predictive value (NPV) of the WB-MRI was 98/99%, significantly higher compared to BS with 82/89%, P < 0.001 Mc Nemar's test. The specificity (Spe) and positive predictive value (PPV) of the WB-MRI and BS was 85/82% and 91/86%, respectively. The interobserver agreement between WB-MRI and BS was 71%, Cohen's kappa 0.42. Analysis of the added diagnostic value of gadolinium revealed Se/Spe/PPV/NPV of 98/93/92/98% for the NE WB-MRI and 99/93/85/100% for the WM-MRI + Gd, P > 0.05 binary logistic regression with Fischer's exact test. WB-MRI exceeds the sensitivity of BS without compromising the specificity, even after omitting the gadolinium enhancer.

Patient deprivation and perceived scan burden negatively impact the quality of whole-body MRI

To evaluate the association between the image quality of cancer staging whole-body magnetic resonance imaging (WB-MRI) and patient demographics, distress, and perceived scan burden. A sample of patients recruited prospectively to multicentre trials comparing WB-MRI with standard scans for staging lung and colorectal cancer were invited to complete two questionnaires. The baseline questionnaire, administered at recruitment, collated data on demographics, distress and co-morbidity. The follow-up questionnaire, completed after staging investigations, measured perceived WB-MRI scan burden (scored 1 low to 7 high). WB-MRI anatomical coverage, and technical quality was graded by a radiographic technician and grading combined to categorise the scan as "optimal", "sub-optimal" or "degraded". A radiologist categorised 30 scans to test interobserver agreement. Data were analysed using the chi-square, Fisher's exact, t-tests, and multinomial regression. One hundred and fourteen patients were included in the study (53 lung, 61 colorectal; average age 65.3 years, SD=11.8; 66 men [57.9%]). Overall, 45.6% (n=52), scans were classified as "optimal" quality, 39.5% (n=45) "sub-optimal", and 14.9% (n=17) as "degraded". In adjusted analyses, greater deprivation level and higher patient-reported scan burden were both associated with a higher likelihood of having a sub-optimal versus an optimal scan (odds ratio [OR]: 4.465, 95% confidence interval [CI]: 1.454 to 13.709, p=0.009; OR: 1.987, CI: 1.153 to 3.425, p=0.013, respectively). None of the variables predicted the likelihood of having a degraded scan. Deprivation and patients' perceived experience of the WB-MRI are related to image quality. Tailored protocols and individualised patient management before and during WB-MRI may improve image quality.

MRI Safety for Patients Implanted With the MRI Ready ICD System

A prospective, multicenter study was performed to assess the safety and efficacy of the Durata and Optisure HV leads and the Ellipse VR implantable cardioverter-defibrillator (ICD) (St. Jude Medical, Sylmar, California) in a 1.5-T magnetic resonance imaging (MRI) environment. The primary safety objective was >90% freedom from MRI scan-related complications. The primary efficacy objectives were absence of change in capture threshold and absence of decrease of sensing amplitude from pre-MRI examination to 1 month after MRI. MRI scanning of patients has been shown to be safe in patients with magnetic resonance-conditional implantable cardioverter-defibrillators (ICD) systems. Patients with a previously implanted magnetic resonance-conditional system underwent a nondiagnostic MRI scan. After the scan, a questionnaire was given to investigators and patients who returned for 1-month follow-up examination. A subset of patients underwent ventricular tachyarrhythmia or ventricular fibrillation (VT/VF) induction testing after the MRI to evaluate defibrillation function. There were 220 patients (81% male; 62.1 ± 11.2 years of age) enrolled who received an MRI scans from 29centers. All primary safety and efficacy endpoints were met (p<0.0001). No significant detection delays were found in 34 patients who had VT/VF episodes after the MRI scan was performed. Most physicians reported easy and acceptable programming and ease of MRI scheduling. The MRI Ready MRI-conditional ICD system is safe, and electrical performance was not affected in patients receiving a 1.5-T whole-body MRI scan. Investigators reported favorable collaboration between cardiologists and radiologists in the MRI Ready IDE clinical trial. (A Clinical Evaluation of the Durata or Optisure High Voltage Leads and Ellipse VR ICD Undergoing MRI, an IDE Study [MRI Ready IDE]; NCT02787291).