The role of molecular imaging in detecting fibrosis in Crohn's disease

Fibrosis is a pathological process that occurs due to chronic inflammation, leading to the proliferation of fibroblasts and the excessive deposition of extracellular matrix (ECM). The process of long-term fibrosis initiates with tissue hypofunction and progressively culminates in the ultimate manifestation of organ failure. Intestinal fibrosis is a significant complication of Crohn's disease (CD) that can result in persistent luminal narrowing and strictures, which are difficult to reverse. In recent years, there have been significant advances in our understanding of the cellular and molecular mechanisms underlying intestinal fibrosis in inflammatory bowel disease (IBD). Significant progress has been achieved in the fields of pathogenesis, diagnosis, and management of intestinal fibrosis in the last few years. A significant amount of research has also been conducted in the field of biomarkers for the prediction or detection of intestinal fibrosis, including novel cross-sectional imaging modalities such as positron emission tomography (PET) and single photon emission computed tomography (SPECT). Molecular imaging represents a promising biomedical approach that enables the non-invasive visualization of cellular and subcellular processes. Molecular imaging has the potential to be employed for early detection, disease staging, and prognostication in addition to assessing disease activity and treatment response in IBD. Molecular imaging methods also have a potential role to enabling minimally invasive assessment of intestinal fibrosis. This review discusses the role of molecular imaging in combination of AI in detecting CD fibrosis.

Sonographic Assessment of Renal Transplantation in Adult Saudi Patients: A Cross-Sectional Retrospective Study

Kidney transplantation stands as a practical and cost-effective treatment option for end-stage renal disease patients, offering an improved quality of life with reduced morbidity when compared with hemodialysis. To evaluate the status of transplanted kidneys in Saudi patients, we conducted a retrospective single-center study at Jazan, Saudi Arabia, involving 46 adult renal recipients enrolled randomly from 2015 to December 2022. Using high-frequency ultrasound, we performed Duplex ultrasound examinations to assess renal allografts. The study revealed that the renal grafts exhibited normal length, with preserved cortical medullary differentiation (CMD) in 84.8% of cases and poor CMD in 15.2%. The echogenicity of the grafts remained normal in 69.6% of instances. Interestingly, we observed a significant rise in resistance index values as the graft duration increased (P = .04), whereas patients with abnormal creatinine levels displayed decreased peak systolic velocity and end-diastolic velocity. Notably, sonographic graft assessments unveiled complications, including perinephric fluid accumulation (8.7%), simple renal cysts (10.86%), hydronephrosis (8.7%), and one case of graft rejection. Receiver operating characteristics analysis for serum blood creatinine levels and abnormal parenchymal findings yielded fair to poor predictive accuracy, with varying sensitivity and specificity measures that lacked statistical significance. In conclusion, our study revealed that most Saudi renal transplant recipients exhibited grafts with normal echogenicity, preserved CMD, and limited perinephric fluid. This investigation provides valuable insights into sonographic changes and Doppler parameters of renal grafts, potentially aiding in the early detection of graft rejection and facilitating diagnostic and therapeutic planning.

Radiologists' and Radiographers' Perspectives on Artificial Intelligence in Medical Imaging in Saudi Arabia

INTRODUCTION

Artificial intelligence (AI) in medical imaging rapidly expands regarding image processing and interpretation. Therefore, the aim was to explore radiographers' and radiologists' perceptions and attitudes towards AI use in medical imaging technologies in Saudi Arabia.

METHODS

The survey was distributed online, and responses were collected from 173 participants nationwide. Data analysis was performed using SPSS Statistics (version 27).

RESULTS

The participants scored an average of 1.7, 1.6, and 1.8 on a scale of 1-3 for attitudinal perspectives on clinical application and the positive and negative impact of integrating AI technology in diagnostic radiology. Lack of knowledge (43.9%) and perceived cyber threats (37.7%) were the most cited factors hindering AI implementation in Saudi Arabia.

CONCLUSION

The radiographradiology radiologists in this study had a favorable attitude toward AI integration in diagnostic radiology; nonetheless, concerns were raised about data protection, cyber security, AI-related errors, and decision-making challenges.

A Systematic Review of the Relationship between Chest CT Severity Score and Laboratory Findings and Clinical Parameters in COVID-19 Pneumonia

The COVID-19 virus has infected millions of people and became a global pandemic in 2020. The efficacy of laboratory and clinical parameters in the diagnosis and monitoring of COVID-19 has been established. The CT scan has been identified as a crucial tool in the prognostication of COVID-19 pneumonia. Moreover, it has been proposed that the CT severity score can be utilized for the diagnosis and prognostication of COVID-19 disease severity and exhibits a correlation with laboratory findings such as inflammatory markers, blood glucose levels, and clinical parameters such as endotracheal intubation, oxygen saturation, mortality, and hospital admissions. Nevertheless, the correlation between the CT severity score and clinical or laboratory parameters has not been firmly established. The objective of this study is to provide a comprehensive review of the aforementioned association. This review used a systematic approach to collate and assess the existing literature that investigates the correlation between CT severity score and laboratory and clinical parameters. The search was conducted using Embase Ovid, MEDLINE Ovid, and PubMed databases, covering the period from inception to 20 May 2023. This review identified 20 studies involving more than 8000 participants of varying designs. The findings showed that the CT severity score is positively associated with laboratory and clinical parameters in COVID-19 patients. The findings indicate that the CT severity score exhibits a satisfactory level of prognostic accuracy in predicting mortality among patients with COVID-19.

A systemic review of rubidium-82 PET contrasted with 99mTc-MIBI SPECT for imaging coronary artery disease

BACKGROUND

99mTc-sestamibi single photon emission tomography (SPECT) method is widely used for imaging coronary artery disease (CAD). 82-Rubidium-PET is an alternative method that can be used to perform the same purpose.

PURPOSE/AIM

This study aims to determine whether 82-Rubidium-PET can offer extra value over 99mTc-sestamibi SPECT in imaging CAD.

METHODS

To achieve the study aim, a systematic review of the literature for the 2 tracers were conducted. The aim of the systemic review was to find every related previous study that corresponded to well-defined scientific criteria. The analysis of the results was restricted to peer-reviewed papers in order to avoid any selective outcome reports. Besides, extra analysis was carried out to curb or avoid any ascertainment bias. The qualified studies selected for this research were then assessed for the risk of bias. Furthermore, the details of the methods were rechecked to ensure that they were comparable, before synthesizing the results.

RESULTS

Eighteen original studies were selected and included in the final analysis out of 803 articles identified at the initial research. Overall, the mean value of sensitivity and specificity for diagnosis of CAD was 84.3% and 75.4%, respectively for technetium 99m sestamibi (99mTc-MIBI). On the other hand, for 82-Rubidium-PET, the mean value of sensitivity and specificity for diagnosis of CAD was 81% and 81%, respectively. The accuracy of diagnostics of these imaging modalities was dependent on the radiotracers and stress agent used in these studies, with 99mTc-MIBI achieving the highest diagnostic value.

CONCLUSION

This study concludes that 99mTc-MIBI-SPECT has higher diagnostic value for diagnosing CAD compared to 82-Rubidium-PET. This indicates that 99mTc-MIBI-SPECT is a more valuable technique for predicting CAD. Besides, for the stress agents used to stimulate the heart and increase workload, this research/study recommends the use of adenosine for the SPECT and the use of dipyridamole for positron emission tomography. However, it suggests the need for more systemic and theoretical studies to assess the real value of 82-Rubidium-PET and the value of stress agents.

Amygdala and subregion volumes are associated with photoperiod and seasonal depressive symptoms: A cross-sectional study in the UK Biobank cohort

Although seasonal changes in amygdala volume have been demonstrated in animals, seasonal differences in human amygdala subregion volumes have yet to be investigated. Amygdala volume has also been linked to depressed mood. Therefore, we hypothesised that differences in photoperiod would predict differences in amygdala or subregion volumes and that this association would be linked to depressed mood. 10,033 participants ranging in age from 45 to 79 years were scanned by MRI in a single location. Amygdala subregion volumes were obtained using automated processing and segmentation algorithms. A mediation analysis tested whether amygdala volume mediated the relationship between photoperiod and mood. Photoperiod was positively associated with total amygdala volume (p < .001). Multivariate (GLM) analyses revealed significant effects of photoperiod across all amygdala subregion volumes for both hemispheres (p < .001). Post hoc univariate regression analyses revealed significant associations of photoperiod with each amygdala subregion volume (p < .001). PLS showed the highest loadings of amygdala subregions in lateral nucleus, ABN, basal nucleus, CAT, PLN, AAA, central nucleus, cortical nucleus and medial nucleus for left hemisphere and ABN, lateral nucleus, CAT, PLN, cortical nucleus, AAA, central nucleus and medial nucleus for right hemisphere. There were no significant associations between photoperiod and mood nor between mood scores and amygdala volumes, and due to the lack of these associations, the mediation hypothesis was not supported. This study is the first to demonstrate an association between photoperiod and amygdala volume. These findings add to the evidence supporting the role of photoperiod on brain structural plasticity.

Sex differences in the association of photoperiod with hippocampal subfield volumes in older adults: A cross-sectional study in the UK Biobank cohort

INTRODUCTION

Even though seasonal and sex-dependent changes in hippocampal and subfield volumes are well known in animals, little is known about changes in humans. We hypothesized that changes in photoperiod would predict changes in hippocampal subfield volumes and that this association would be different between females and males.

METHODS

A total of 10,033 participants ranging in age from 45 to 79 years were scanned by MRI in a single location as part of the UK Biobank project. Hippocampal subfield volumes were obtained using automated processing and segmentation algorithms using the developmental version of the FreeSurfer v 6.0. Photoperiod was defined as the number of hours between sunrise and sunset on the day of scan.

RESULTS

Photoperiod correlated positively with total hippocampal volume and all subfield volumes across participants as well as in each sex individually, with females showing greater seasonal variation in a majority of left subfield volumes compared with males. ANCOVAs revealed significant differences in rate of change in only left subiculum, CA-4, and GC-ML-DG between females and males. PLS showed highest loadings of hippocampal subfields in both females and males in GC-ML-DG, CA1, CA4, subiculum, and CA3 for left hemisphere and CA1, GC-ML-DG, CA4; subiculum and CA3 for right hemisphere in females; GC-ML-DG, CA1, subiculum, CA4 and CA3 for left hemisphere; CA1, GC-ML-DG, subiculum, CA4 and CA3 for right hemisphere in males.

CONCLUSION

The influence of day length on hippocampal volume has implications for modeling age-related decline in memory in older adults, and sex differences suggest an important role for hormones in these effects.

Brainstem volume mediates seasonal variation in depressive symptoms: A cross sectional study in the UK Biobank cohort

Seasonal differences in mood and depressive symptoms affect a large percentage of the general population, with seasonal affective disorder (SAD) representing the most common presentation. SAD affects up to 3% of the world’s population, and it tends to be more predominant in females than males. The brainstem has been shown to be affected by photoperiodic changes, and that longer photoperiods are associated with higher neuronal density and decreased depressive-like behaviours. We predict that longer photoperiod days are associated with larger brainstem volumes and lower depressive scores, and that brainstem volume mediates the seasonality of depressive symptoms. Participants (N = 9289, 51.8% females and 48.1% males) ranging in age from 44 to 79 years were scanned by MRI at a single location. Photoperiod was found to be negatively correlated with low mood and anhedonia in females while photoperiod was found to be positively correlated with brainstem volumes. In females, whole brainstem, pons and medulla volumes individually mediated the relationship between photoperiod and both anhedonia and low mood, while midbrain volume mediated the relationship between photoperiod and anhedonia. No mediation effects were seen in males. Our study extends the understanding of the neurobiological factors that contribute to the pathophysiology of seasonal mood variations.