Body MRI Scans Research Articles

An unusual cause of osteomalacia in a young lady

Abstract Oncogenic osteomalacia is a rare entity, caused by excessive secretion of fibroblast growth factor-23 (FGF-23) from the peripherally located benign tumours of mesenchymal origin. Patients usually present with chronic widespread pain and fatigue. Diagnostic approach involves demonstration of excessive urinary loss of phosphate and the high plasma level of FGF-23. Whole of PET-CT scan or whole body MRI scan are used to detect the tumour. PET/CT Ga-68 dotatate scan is required often when the other imaging modalities fail to detect the neoplasm. Here we present the case of a 32year old lady who presented to us with chronic low back pain and thorough evaluation helped us to diagnose this rare disease.

Safety and efficacy of salvage high-dose rate brachytherapy for prostate-bed recurrences following radical prostatectomy and external beam radiotherapy.

This retrospective study aims to evaluate the efficacy and safety of salvage HDR brachytherapy in second local recurrences of prostate cancer after applying radical prostatectomy (RP) and post-operative external beam radiotherapy (EBRT). Fifteen patients with locally recurrent prostate cancer after RP and EBRT were salvaged with HDR brachytherapy. Patients had no nodal or distant metastasis evidence on imaging findings, including whole body bone scan, CT scan, and MRI or PSMA PET scan. HDR brachytherapy was applied with 36Gy in four fractions, in two implantations with 1week apart. We followed the patients for a control visit every 3months for 2years, and every 6months thereafter. Fifteen patients with the mean age of 64years (ranged 51-79) underwent salvage HDR brachytherapy. The mean baseline level of PSA was calculated 2.26ng/ml (ranged from 0.21 to 9, SD = 2.33), which has been significantly decreased in all patients. Hence, two of our patients experienced a biochemical failure during the follow-up period. Our results showed that 86.6% (n = 13) of patients had never experienced a significant increment in PSA level after a median follow-up of 48months (ranging from 12 to 132months). Besides, salvage HDR brachytherapy did not induce any significant side effects such as acute or late rectal complications, despite causing urinary complication. HDR brachytherapy could be considered as a treatment in well-selected patients with the second recurrence in their prostatic bed after the former EBRT allowing for dose escalating to the second nodular recurrence.

Biometric analysis of the foetal meconium pattern using T1 weighted 2D gradient echo MRI.

Objectives:Foetal MRI is used to assess abnormalities after ultrasonography. Bowel anomalies are a significant cause of neonatal morbidity, however there are little data concerning its normal appearance on antenatal MRI. This study aims to investigate the pattern of meconium accumulation throughout gestation using its hyperintense appearance on T1 weighted scans and add to the current published data.Methods:This was a retrospective cohort study in a tertiary referral clinical MRI centre. Foetal body MRI scans of varying gestational ages were obtained dating between October 2011 and March 2018. The bowel was visualised on T1 weighted images. The length of the meconium and the width of the meconium at the rectum, sigmoid colon, splenic flexure and hepatic flexure was measured. Presence or absence of meconium in the small bowel was noted. Inter- and intrarater reliability was assessed.Results:181 foetal body scans were reviewed. 52 were excluded and 129 analysed. Visualisation of the meconium in the large bowel became increasingly proximal with later gestations, and small bowel visualisation was greater at earlier gestations. There was statistically significant strong (r = 0.6–0.8) or very strong (r = 0.8–1.0) positive correlation of length and width with increasing gestation. Interrater reliability was moderate to excellent (r = 0.4–1.0).Conclusion:This study provides new information regarding the pattern of meconium accumulation throughout gestation. With care, the results can be used in clinical practice to aid diagnosis of bowel pathology.Advances in knowledge:The findings of this study provide further information concerning the normal accumulation of foetal meconium on MR imaging, an area where current research is limited.

Artificial intelligence for interpretation of segments of whole body MRI in CNO: pilot study comparing radiologists versus machine learning algorithm

BackgroundTo initiate the development of a machine learning algorithm capable of comparing segments of pre and post pamidronate whole body MRI scans to assess treatment response and to compare the results of this algorithm with the analysis of a panel of paediatric radiologists.MethodsWhole body MRI of patients under the age of 16 diagnosed with CNO and treated with pamidronate at a tertiary referral paediatric hospital in United Kingdom between 2005 and 2017 were reviewed. Pre and post pamidronate images of the commonest sites of involvement (distal femur and proximal tibia) were manually selected (n = 45). A machine learning algorithm was developed and tested to assess treatment effectiveness by comparing pre and post pamidronate scans. The results of this algorithm were compared with the results of a panel of radiologists (ground truth).ResultsWhen tested initially the machine algorithm predicted 4/7 (57.1%) examples correctly in the multi class model, and 5/7 (71.4%) correctly in the binary group. However when compared to the ground truth, the machine model was able to classify only 33.3% of the samples correctly but had a sensitivity of 100% in detecting improvement or worsening of disease.ConclusionThe machine learning could detect new lesions or resolution of a lesion with good sensitivity but failed to classify stable disease accurately. However, further validation on larger datasets are required to improve the specificity and accuracy of the machine model.

Multi-compartment mesenchymal tissue segmentation in pelvic MRI examinations of women: Anthropomorphic and clinical correlations

AimTo investigate the reliability of multicompartmental volumetric mesenchymal segmentations on MRI and their correlations with anthropomorphic and clinical parameters. Materials and methodsA consecutive series of middle-age (35–50 year old) female volunteers with variable body mass index (BMI) and MRI scans performed as a part of the Dallas Heart Study were included. A semi-automatic segmentation tool was used to partition different mesenchymal tissues- fat, muscle, and bone on MRI of pelvis. Total volumes of each compartment were calculated and compared between overweight/obese (BMI> = 25 kg/m2) and non-obese (BMI < 25 kg/m2) groups, and with physical performance measurements, i.e. mean activity counts per minute (MVPA) and cardiorespiratory fitness (CRF) estimated by submaximal treadmill test (TT). Kruskal Wallis, Mann-Whitney U test, intraclass correlation coefficient (ICC) and Spearman correlations were used. P value <0.05 was considered statistically significant. ResultsThere were statistically significant positive correlations between fat volume and BMI (p < 0.0001), muscle volume and height (p = 0.03), and bone volume and height (p < 0.0001). Significant inverse correlations were found between bone volume and BMI (p = 0.002). Fair to good interobserver reliability was seen with muscle and fat volumes (ICC = 0.43–0.64) and excellent reliability was seen with bone volumes (ICC = 0.78–0.79). Statistically significant inverse correlations were found between MVPA and age (p = 0.01), and TT with BMI and weight (p = 0.01, 0.03). ConclusionMulti-compartment mesenchymal tissue volume quantification on pelvic MRI is reliable in females. Inverse correlation of bone volume with BMI has potential implications for future risk of fracture.

The role of post-mortem MRI in the neonatal intensive care unit.

ObjectivePost-mortem examination can provide important information about the cause of death and play a significant role in the bereavement process. Autopsies reveal previous unknown medical problems approximately 20–30% of the time. A non-invasive MRI-based post-mortem examination (PM-MRI) may provide an alternative for families who do not consent to an autopsy.Study DesignThis study was a prospective observational study of recently expired neonates and infants. Subjects underwent a full body MRI scan (brain, chest, abdomen and pelvis) followed by conventional autopsy if the family desired to have one. MRI results were compared to autopsy findings and the ante mortem clinical diagnosis. A follow-up survey was conducted to investigate family perceptions of the PM-MRI process.ResultThirty-one infants underwent full PM-MRI. 19/31 (61%) of infants had complete agreement between the clinician’s impression and PM-MRI. Twenty-four infants also had conventional autopsy, with 14/24 (58%) infants having PM-MRI results consistent with autopsy findings. PM-MRI was superior at detection of free intraperitoneal/intrathoracic air and hepatic iron overload. Whole body PM-MRI did not have the resolution to detect focal/microscopic injury, vascular remodeling and some forms of brain injury. Of those families who remembered the PM-MRI findings, the majority felt that the information was useful.ConclusionPM-MRI studies may provide an important adjunct to conventional autopsy and a substitute when the latter is not possible for personal or religious reasons. Clinicians should be aware of, and communicate with the family, the resolution limits of the whole body PM-MRI to detect certain types of injury.

Application of standards and models in body composition analysis.

The aim of this review is to extend present concepts of body composition and to integrate it into physiology. In vivo body composition analysis (BCA) has a sound theoretical and methodological basis. Present methods used for BCA are reliable and valid. Individual data on body components, organs and tissues are included into different models, e.g. a 2-, 3-, 4- or multi-component model. Today the so-called 4-compartment model as well as whole body MRI (or computed tomography) scans are considered as gold standards of BCA. In practice the use of the appropriate method depends on the question of interest and the accuracy needed to address it. Body composition data are descriptive and used for normative analyses (e.g. generating normal values, centiles and cut offs). Advanced models of BCA go beyond description and normative approaches. The concept of functional body composition (FBC) takes into account the relationships between individual body components, organs and tissues and related metabolic and physical functions. FBC can be further extended to the model of healthy body composition (HBC) based on horizontal (i.e. structural) and vertical (e.g. metabolism and its neuroendocrine control) relationships between individual components as well as between component and body functions using mathematical modelling with a hierarchical multi-level multi-scale approach at the software level. HBC integrates into whole body systems of cardiovascular, respiratory, hepatic and renal functions. To conclude BCA is a prerequisite for detailed phenotyping of individuals providing a sound basis for in depth biomedical research and clinical decision making.

Cyclin-dependent kinase 5 contributes to adipose tissue inflammation in obesity through suppression of Treg differentiation (HUM7P.288)

Abstract Homeostatic imbalance of regulatory and conventional T cells is linked with obesity-induced inflammation and insulin resistance. A decline in the number of both circulating and locally residing T regulatory (Treg) cells in adipose tissues is hallmark of adiposity, inflammation, and glucose intolerance. Recently, the signal transducer and activator of transcription 3 (Stat3) has been implicated as a critical mediator in this process; however, the factors that initiate this inflammatory cascade remain largely unclear. We recently reported a previously unknown function for Cyclin-dependent kinase 5 (Cdk5) in T cells, a kinase renowned otherwise for its role in regulating the development and function of cells in the neuronal lineage. Here we report for the first time that the mice lacking Cdk5 in T cells (Cdk5TKO-mice) are lean compared to their wild type littermates as confirmed by their body mass index, histopathological analysis of adipose tissue as well as complete body MRI scans measuring adiposity index. Moreover we observed a significant increase in circulating CD4+ CD25+ Foxp3+ Treg cells along with a marked decrease in Ser-727 phosphorylation of Stat3. Finally, both pharmacologic and genetic deletion of Cdk5 abrogates the IL6-mediated suppression of TGF-β-induced Treg differentiation. These results further solidify the role of Cdk5 as an essential regulator of T cell function and implicate Cdk5 as a potential therapeutic target for prevention and treatment of obesity.

New soft tissue correction factors for stature estimation: Results from magnetic resonance imaging

In stature reconstruction using Fully's method, it is essential that a soft tissue correction factor be added to skeletal height in order to obtain an estimate of living stature. While some anthropologists consider Fully's method to be the most reliable for stature estimation, others consider it to be inadequate as it seems to be underestimating living stature, possibly due to an error in the magnitude of Fully's soft tissue factors. A recent study by Raxter and co-workers revised Fully's technique and also presented a new "universally applicable" soft tissue correction factor. The present study examines the reliability of soft tissue correction factors of Fully and Raxter et al. on a living sample of indigenous South African males. The current study is based on data collected from 28 indigenous South African (ISA) male volunteers. Standing height of each subject was measured using a stadiometer. Fully's method was used in the calculation of total skeletal height from a full body MRI scan of each subject. Subsequent analyses of the acquired data revealed that the previously derived soft tissue correction factors are not applicable to the studied sample, and why they are not applicable. The correction factors of Fully and Raxter et al. both significantly underestimate living stature in a living sample of indigenous South African males. Consequently, a new correction factor was calculated based on the prediction of living stature from TSH using regression analysis.

94th RSNA Annual Meeting

Whole body MRI scans are more effective for assessing cancer in pediatric patients than whole body PET scans. Hyun Goo (Seoul, South Korea) and colleagues analysed 26 pairs of MRI and PET scans in 19 patients (mean age 8 years, range 2–17 years) with various oncological diseases. On the basis of pathological proofs, clinical, and imaging data, five of the 26 pairs of scans were in agreement. MRI gave more accurate information about the tumours than did PET in 18 studies, and less accurate information than PET in six studies.

Identification of a desmin gene mutation in scapuloperoneal syndrome

Background: In 1965, one of the authors reported a kindred with 12 affected members in 5 generations following autosomal dominant inheritance. Age at onset was between 30 and 50 years and followed a slowly progressive course. Histological exmination at autopsy in 1 patient suggested a neurogenic origin, similar to Kugelberg-Welander muscular atrophy. Scapuloperoneal syndrome is a descriptive term comprising various myopathies and muscular atrophies. We examined two affected descendants of the original kindred diagnosed as scapuloperoneal syndrome. The 60-years-old index patient showed pronounced atrophy and weakness of the lower limb and shoulder girdle muscles as well as a slight involvement of the facial muscles and dysphagia, whole body MRI scan showed marked atrophy and fatty degeneration of proximal and distal muscles, only biceps brachii was relatively spared. CK levels were slightly elevated. There was cardiac involvement with mild arrhythmia. Electromyography showed myogenic findings in various muscles as well as subtle neurogenic changes in the distal lower extremities.