Marrow Fat-Cortical Bone Relationship in ß-Thalassemia: A Study Using MRI.

BACKGROUND: Growing evidence suggests that marrow adipocytes play an active role in the regulation of bone metabolism and hematopoiesis. However, research on the relationship between bone and fat in the context of hematological diseases, particularly ß-thalassemia, remains limited. PURPOSE: To investigate the relationship between marrow fat and cortical bone thickness in ß-thalassemia and to identify key determinants influencing these variables. STUDY TYPE: Prospective. SUBJECTS: Thirty-five subjects in four subject groups of increasing disease severity: 6 healthy control (25.0 ± 5.3 years, 2 male), 4 ß-thalassemia minor, 13 intermedia, and 12 major (29.1 ± 6.4 years, 15 male). FIELD STRENGTH/SEQUENCE: 3.0 T, 3D fast low angle shot sequence and T1-weighted turbo spin echo. ASSESSMENT: Analyses on proton density fat fraction (PDFF) and R2* values in femur subregions (femoral head, greater trochanter, intertrochanteric, diaphysis, distal) and cortical thickness (CBI) of the subjects' left femur. Clinical data such as age, sex, body mass index (BMI), and disease severity were also included. STATISTICAL TESTS: One-way analysis of variance (ANOVA), mixed ANOVA, Pearson correlation and multiple regression. P-values <0.05 were considered significant. RESULTS: Bone marrow PDFF significantly varied between the femur subregions, F(2.89,89.63) = 44.185 and disease severity, F(1,3) = 12.357. A significant interaction between subject groups and femur subregions on bone marrow PDFF was observed, F(8.67,89.63) = 3.723. Notably, a moderate positive correlation was observed between PDFF and CBI (r = 0.33-0.45). Multiple regression models for both PDFF (R2 = 0.476, F(13,151) = 10.547) and CBI (R2 = 0.477, F(13,151) = 10.580) were significant. Significant predictors for PDFF were disease severity (ßTMi = 0.36, ßTMa = 0.17), CBI (ß = 0.24), R2* (ß = -0.32), and height (ß = -0.29) while for CBI, the significant determinants were sex (ß = -0.27), BMI (ß = 0.55), disease severity (ßTMi = 2.15), and PDFF (ß = 0.25). DATA CONCLUSION: This study revealed a positive correlation between bone marrow fat fraction and cortical bone thickness in ß-thalassemia with varying disease severity, potentially indicating a complex interplay between bone health and marrow composition. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 3.

Opportunistic Extraction of Quantitative CT Biomarkers: Turning the Incidental Into Prognostic Information.

The past two decades have seen a significant increase in the use of CT, with a corresponding rise in the mean population radiation dose. This rise in CT use has caused improved diagnostic certainty in conditions that were not previously routinely evaluated using CT, such as headaches, back pain, and chest pain. Unused data, unrelated to the primary diagnosis, embedded within these scans have the potential to provide organ-specific measurements that can be used to prognosticate or risk-profile patients for a wide variety of conditions. The recent increased availability of computing power, expertise and software for automated segmentation and measurements, assisted by artificial intelligence, provides a conducive environment for the deployment of these analyses into routine use. Data gathering from CT has the potential to add value to examinations and help offset the public perception of harm from radiation exposure. We review the potential for the collection of these data and propose the incorporation of this strategy into routine clinical practice.

Marrow Fat Content and Composition in ß-Thalassemia: A Study using 1 H-MRS.

BACKGROUND: ß-thalassemia is a genetic disease that causes abnormal production of red blood cells (ineffective erythropoiesis, IE). IE is a condition known to change bone marrow composition. PURPOSE: To evaluate the effect of IE on the marrow fat content and fat unsaturation levels in the proximal femur using 1 H-MRS. STUDY TYPE: Prospective. SUBJECTS: Twenty-three subjects were included in this study, seven control and 16 ß-thalassemia subjects. FIELD STRENGTH/SEQUENCE: 3.0T; stimulated echo acquisition Mode (STEAM); magnetic resonance spectroscopy (MRS) sequence. ASSESSMENT: Multiecho MRS scans were performed in four regions of the proximal left femur of each subject, that is, diaphysis, femoral neck, femoral head, and greater trochanter. The examined regions were grouped into red (diaphysis and femoral neck) and yellow marrow regions (femoral head and greater trochanter). STATISTICAL TESTS: The Jonckheere-Terpstra test was used to evaluate the impact of increasing disease severity on bone marrow fat fraction (BMFF), marrow conversion index, and fat unsaturation index (UI). Pairwise comparison analysis was performed when a significant trend (P < 0.05) was found. K-means clustering analysis was used to examine the clusters observed when BMFF in the red and yellow regions were studied (diaphysis against greater trochanter). RESULTS: BMFF showed a significant decreasing trend with increasing disease severity in both red (TJT = 109.00, z = -4.414, P < 0.05) and yellow marrow regions (TJT = 108.00, z = -4.438, P < 0.05). The opposite trend was observed in UI in both bone marrow regions (red marrow: TJT = 180.5, z = 3.515, P < 0.05; yellow marrow: TJT = 155.0, z = 2.282, P = 0.05). Three distinct forms of marrow adipogenesis were found when plotting BMFF diaphysis against BMFF greater trochanter: 1) normal (centroid: 80.4%, 66.6%), 2) partial disruption (centroid: 51.1%, 16.6%), and 3) total disruption (centroid: 2.6%, 1.6%). DATA CONCLUSION: ß-thalassemia is associated with decreased marrow fat, and increased marrow fat unsaturation level. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3.

Challenges in the Management of Childhood Intracranial Germ Cell Tumors in Middle-Income Countries: A 20-Year Retrospective Review From a Single Tertiary Center in Malaysia.

BACKGROUND: A higher incidence of pediatric intracranial germ cell tumors (iGCTs) in Asian countries compared with Western countries has been reported. In Malaysia, the literature regarding pediatric iGCTs have been nonexistent. The aim of this study was to review the management, survival, and long-term outcomes of pediatric iGCTs at a single tertiary center in Malaysia. PATIENTS AND METHODS: We retrospectively reviewed data from patients below 18 years of age with iGCTs treated at the University Malaya Medical Center (UMMC) from 1998 to 2017. RESULTS: Thirty-four patients were identified, with a median follow-up of 3.54 years. Sixteen (47%) patients had pure germinoma tumors (PGs), and the remaining patients had nongerminomatous germ cell tumors (NGGCTs). The median age was 12 years, with a male:female ratio of 4.7:1. Abnormal vision, headache with vomiting, and diabetes insipidus were the commonest presenting symptoms. Twenty-eight patients received initial surgical interventions, 24 were treated with chemotherapy, and 28 received radiotherapy. Eight patients experienced relapses. The 5- and 10-year event-free survival rates were similar at 61.1%±12.6% and 42.9%±12.1% for PG and NGGCT, respectively. The 5- and 10-year overall survival rates were the same at 75.5%±10.8% and 53.3%±12.3% for PG and NGGCT, respectively. Four patients died of treatment-related toxicity. Most of the survivors experienced good quality of life with satisfactory neurologic status. CONCLUSIONS: The survival rate of childhood iGCTs in UMMC was inferior to that reported in developed countries. Late diagnosis, poor adherence to treatment, and treatment-related complications were the contributing factors. Although these results highlight a single institution experience, they most likely reflect similar treatment patterns, outcomes, and challenges in other centers in Malaysia.

Conduct of neuro-oncology multidisciplinary team meetings and closing the "gaps" in the clinical management of childhood central nervous system tumors in a middle-income country.

PURPOSE: Multidisciplinary team meetings (MDTMs) are essential in the clinical management of pediatric central nervous system (CNS) tumors. Evaluations of the impact of MDTMs on childhood CNS tumors and clinicians' perspectives on their effectiveness are scarce. METHODS: We retrospectively reviewed the clinical data of pediatric patients (aged <18 years) with CNS tumors diagnosed and treated in the Pediatric Hematology-Oncology Division at the University Malaya Medical Center from 2008 to 2019. We also conducted a web-based survey of the core members of the multidisciplinary team to evaluate the impact of the MDTMs. RESULTS: During the pre-MDTM era (2008-2012), 29 CNS tumors were diagnosed and treated, and during the MDTM era (2014-2019), 49 CNS tumors were diagnosed and treated. The interval for histologic diagnosis was significantly shorter during the MDTM era (p=0.04), but the interval from diagnosis to chemotherapy or radiotherapy and the 5-year overall survival of the 78 patients did not improve (62.1% ± 9.0% vs. 68.8% ± 9.1%; p=0.184). However, the 5-year overall survival of patients with medulloblastoma or rare tumors significantly improved in the MDTM era (p=0.01). Key factors that contributed to delayed treatment and poor outcomes were postoperative complications, the facility's lack of infrastructure, poor parental education about early treatment, cultural beliefs in alternative medicine, and infection during chemotherapy. Eighteen clinicians responded to the survey; they felt that the MDTMs were beneficial in decision-making and enhanced the continuity of coordinated care. CONCLUSION: MDTMs significantly reduced the diagnostic interval and improved the overall outcomes. However, delayed treatment remains a major challenge that requires further attention.

Innovations in detecting skull fractures: A review of computer-aided techniques in CT imaging.

BACKGROUND/INTRODUCTION: Traumatic brain injury (TBI) remains a leading cause of disability and mortality, with skull fractures being a frequent and serious consequence. Accurate and rapid diagnosis of these fractures is crucial, yet current manual methods via cranial CT scans are time-consuming and prone to error. METHODS: This review paper focuses on the evolution of computer-aided diagnosis (CAD) systems for detecting skull fractures in TBI patients. It critically assesses advancements from feature-based algorithms to modern machine learning and deep learning techniques. We examine current approaches to data acquisition, the use of public datasets, algorithmic strategies, and performance metrics RESULTS: The review highlights the potential of CAD systems to provide quick and reliable diagnostics, particularly outside regular clinical hours and in under-resourced settings. Our discussion encapsulates the challenges inherent in automated skull fracture assessment and suggests directions for future research to enhance diagnostic accuracy and patient care. CONCLUSION: With CAD systems, we stand on the cusp of significantly improving TBI management, underscoring the need for continued innovation in this field.

Bone Marrow Fat Distribution in Patients With ß-Thalassemia: A Study Using Chemical Shift-Based Water-Fat MRI.

RATIONALE AND OBJECTIVES: Molecular studies have shown the changes in bone marrow fat in relation to altered hematopoiesis. This study aims to investigate the changes in the bone marrow fat in patients affected by ß-thalassemia by using chemical shift-encoded (CSE)-MRI. MATERIALS AND METHODS: Twenty-three subjects, comprising of six healthy (17-31 years old) and 17 ß-thalassemia subjects (19-39 years old), were scanned using a multiecho fast low angle shot sequence (0.94 × 0.94 × 3.00 mm3) and a stimulated echo acquisition mode sequence using 3T MRI. Bone marrow proton density fat fraction (PDFF) was quantified in the left femur of each subject. Regression and Bland-Altman analysis were used to analyze agreement between CSE-MRI and 1H-MRS. PDFF distribution was analyzed using Hartigan's dip test and the computed Wasserstein distances. Jonckheere-Terpstra trend analysis was performed to evaluate the effect of disease severity on PDFF distribution. RESULTS: An excellent agreement was found between PDFF measured using CSE-MRI with 1H-MRS (R2 = 0.91; bias =-1.41%). Healthy subjects showed left-skewed or bimodal PDFF distribution while ß-thalassemia subjects showed bimodal, normal or right-skewed distribution. Jonckheere-Terpstra test shows that PDFF distribution was increasingly different from the norm as disease severity increased (TJT = 166.0, z = 3.806, p < 0.05). Increase in variability of PDFF distribution within each subject group was also seen with increasing disease severity (TJT = 169.0, z = 3.971, p < 0.05). CONCLUSION: CSE-MRI is a promising tool to demonstrate spatial changes and variability in marrow fat distribution, resulting from ineffective erythropoiesis.

Radiation Safety in Emergency Medicine: Balancing the Benefits and Risks.

The use of computed tomography (CT) in emergency departments has increased over several decades, as physicians increasingly depend on imaging for diagnoses. Patients and medical personnel are put at risk due to frequent exposure to and higher levels of radiation, with very little evidence of improvements in outcomes. Here, we explore why CT imaging has a tendency to be overused in emergency departments and the obstacles that medical personnel face in ensuring patient safety. The solution requires cooperation from all emergency care stakeholders as well as the continuous education of doctors on how CT scans help in particular cases.

Measurement of coronary bifurcation angle with coronary CT angiography: A phantom study.

PURPOSE: Accurate determination of the bifurcation angle and correlation with plaque buildup may lead to the prediction of coronary artery disease (CAD). This work evaluates two techniques to measure bifurcation angles in 3D space using coronary computed tomography angiography (CCTA). MATERIALS AND METHODS: Nine phantoms were fabricated with different bifurcation angles ranging from 55.3° to 134.5°. General X-ray and CCTA were employed to acquire 2D and 3D images of the bifurcation phantoms, respectively. Multiplanar reformation (MPR) and volume rendering technique (VRT) were used to measure the bifurcation angle between the left anterior descending (LAD) and left circumflex arteries (LCx). The measured angles were compared with the true values to determine the accuracy of each measurement technique. Inter-observer variability was evaluated. The two techniques were further applied on 50 clinical CCTA cases to verify its clinical value. RESULTS: In the phantom setting, the mean absolute differences calculated between the true and measured angles by MPR and VRT were 2.4°±2.2° and 3.8°±2.9°, respectively. Strong correlation was found between the true and measured bifurcation angles. Furthermore, no significant differences were found between the bifurcation angles measured using either technique. In clinical settings, large difference of 12.0°±10.6° was found between the two techniques. CONCLUSION: In the phantom setting, both techniques demonstrated a significant correlation to the true bifurcation angle. Despite the lack of agreement of the two techniques in the clinical context, our findings in phantoms suggest that MPR should be preferred to VRT for the measurement of coronary bifurcation angle by CCTA.

Sex determination from carpal bone volumes: A Multi Detector Computed Tomography (MDCT) study in a Malaysian population.

PURPOSE: The use of Multi Detector Computed Tomography (MDCT) volume measurements of bones for sex determination allows fragile, fragmented human remains to be assessed without compromising the specimen. We set out to assess the ability of MDCT carpal bone volume measurement in determining sex in a Malaysian population. MATERIALS AND METHODS: 52 healthy volunteers were scanned in a 16-slice MDCT, and the volume of 104 sets of carpal bones was measured using a Syngo workstation (Both CT and workstation-Siemens Healthcare, Erlangen, Germany). RESULTS: Male carpal bones were of higher volume compared to the female carpal bones (p<0.001). Area under the curve (AUC) assessment of responder-operator characteristics curves showed that the trapezium bone was best able to predict sex with an AUC of 0.986. At a trapezium bone volume of ⩾1.94cm(3), there was a 93.5% probability that the subject was male. Binary logistic regression analysis found that the highest accuracy was derived using the pisiform, trapezium and capitate bones. There was a strong relationship between sex prediction and grouping of the carpal bone volumes (Nagelkerke R(2)=0.923) with an overall prediction accuracy of 97%. CONCLUSION: All 8 carpal bones exhibit sexual dimorphism to varying degrees. A binary regression analysis combining the 5 carpal bones with the highest predictive values for sex produces an accurate predictive model.