OBJECTIVE: Liver resection is currently considered the most effective treatment for patients with liver cancer. To the best of our knowledge, no study has investigated the association between gadoxetic acid-enhanced magnetic resonance imaging (MRI) findings and liver regeneration in patients who underwent hemihepatectomy. We aimed to clarify the relationship between the signal intensity (SI) of the liver parenchyma on gadoxetic acid-enhanced MRI and the degree of liver regeneration in patients who underwent hemihepatectomy.
METHODS: Forty-one patients who underwent gadoxetic acid-enhanced MRI before hemihepatectomy were enrolled. We calculated the liver-to-erector spinae muscle SI ratio (LMR) in the hepatobiliary phase and the precontrast images. ΔLMR was calculated using the following equation: ΔLMR = (LMR in the hepatobiliary phase-LMR in the precontrast image)/LMR in the precontrast image. The preoperative and postoperative remnant liver volumes (LVs) were calculated using CT volumetry. We calculated the resection rate (RR) and liver regeneration index (LRI) using the following formulas: RR = Resected LV/Total LV × 100 and LRI = (postoperative remnant LV-preoperative remnant LV)/preoperative remnant LV × 100. The relationships among LRI, imaging, and clinicopathological factors were analyzed.
RESULTS: Univariate analysis showed RR and ΔLMR showed a positive correlation with LRI (ρ = 0.4133, p = 0.0072 and ρ = 0.7773, p < 0.001, respectively). Spleen volume showed a negative correlation with LRI (ρ = -0.3138, p = 0.0486). Stepwise multiple regression analysis showed ΔLMR and RR were independently correlated with LRI (β coefficient = 44.8771, p = 0.0198 and β coefficient = 1.9653, p < 0.001, respectively).
CONCLUSIONS: ΔLMR may serve as a preoperative predictor of liver regeneration in patients undergoing hemihepatectomy.

Along with clinical and laboratory findings, imaging has a significant role in the initial evaluation and treatment follow-up of a wide variety of infectious and non-infectious musculoskeletal (MSK) conditions. The imaging findings of many non-infectious MSK processes, such as inflammatory, metabolic, and degenerative arthropathies, complications of diabetes mellitus, osseous and soft tissue injuries, osteonecrosis, tumors, and tumor-like lesions may be nonspecific and often overlap with those found in MSK infections. In this article, the authors discuss the imaging findings of both frequent and rare mimickers of MSK infections, including potential distinguishing characteristics.

Simple bone cysts (SBCs) are the most common osteolytic lesions in children, often leading to pathological fractures of non-weight-bearing bones. These benign tumors primarily arise in the proximal humerus, femur, or calcaneus. The cystic cavity is filled with serous or serosanguineous fluid and lined by a thin fibrovascular connective tissue membrane. The etiological factors include disturbances in bone growth, local venous obstruction, synovial origin disorders, and genetic predispositions. SBCs are most frequently observed in individuals from birth to 20 years of age. The report presented a case of a 12-year-old male patient who was admitted to the hospital with a history of a mass on his left upper arm. The mass had an acute onset and gradually progressed to its current size over three to four weeks, after which it became nonprogressive. The patient had been healthy until the age of four, after which he experienced frequent fractures of the left arm following trivial trauma. Multiple traumas led to the gradual formation of a diffuse mass over the upper part of the humerus. Radiological imaging modalities, such as X-ray and magnetic resonance imaging, are crucial in diagnosing bone cysts and evaluating their clinical conditions. Treatment can involve the injection of bone marrow or steroids into the cyst to facilitate the healing process.

UNASSIGNED: Metastasis to the spinal column is a common complication of malignancy, potentially causing pain and neurologic injury. An automated system to identify and refer patients with spinal metastases can help overcome barriers to timely treatment. We describe the training, optimization and validation of a natural language processing algorithm to identify the presence of vertebral metastasis and metastatic epidural cord compression (MECC) from radiology reports of spinal MRIs.
UNASSIGNED: Reports from patients with spine MRI studies performed between January 1, 2008 and April 14, 2019 were reviewed by a team of radiologists to assess for the presence of cancer and generate a labeled dataset for model training. Using regular expression, impression sections were extracted from the reports and converted to all lower-case letters with all nonalphabetic characters removed. The reports were then tokenized and vectorized using the doc2vec algorithm. These were then used to train a neural network to predict the likelihood of spinal tumor or MECC. For each report, the model provided a number from 0 to 1 corresponding to its impression. We then obtained 111 MRI reports from outside the test set, 92 manually labeled negative and 19 with MECC to test the model\'s performance.
UNASSIGNED: About 37,579 radiology reports were reviewed. About 36,676 were labeled negative, and 903 with MECC. We chose a cutoff of 0.02 as a positive result to optimize for a low false negative rate. At this threshold we found a 100% sensitivity rate with a low false positive rate of 2.2%.
UNASSIGNED: The NLP model described predicts the presence of spinal tumor and MECC in spine MRI reports with high accuracy. We plan to implement the algorithm into our EMR to allow for faster referral of these patients to appropriate specialists, allowing for reduced morbidity and increased survival.

UNASSIGNED: Myelin oligodendrocyte glycoprotein antibody associated disease (MOGAD) is a relatively new disease entity in the field of demyelinating disorders. Its first diagnostic criteria have recently been published.
UNASSIGNED: We evaluated the positive predictive value (PPV) for MOG-IgG testing and report the clinical and radiologic features with respect to the recently published criteria.
UNASSIGNED: A retrospective study was conducted at three centers in Dallas, Texas. Patients with positive MOG-IgG testing on cell-based assays at any time were included. Positive cases were reviewed by at least two neuroimmunologists for fulfillment of the criteria.
UNASSIGNED: We included 235 patients. The PPV of seropositivity at any time was 78.3% overall, 52.6% for low titer, and 90.1% for high titer. Children had a higher PPV than adults (93.9% versus 67.2%). Positive predictive value was 6.3% in those without a core clinical demyelinating attack. Children more often have the typical imaging features of MOGAD in optic neuritis than adults.
UNASSIGNED: We report a PPV of 78.3% for MOG-IgG testing using the 2023 MOGAD diagnostic criteria. Children had higher PPV and frequency of supporting imaging features. Careful consideration is necessary when assigning patients with no core demyelinating event and low titers a MOGAD diagnosis.

Purpose To clarify the predominant causative plaque constituent for periprocedural myocardial injury (PMI) following percutaneous coronary intervention: (a) erythrocyte-derived materials, indicated by a high plaque-to-myocardium signal intensity ratio (PMR) at coronary atherosclerosis T1-weighted characterization (CATCH) MRI, or (b) lipids, represented by a high maximum 4-mm lipid core burden index (maxLCBI4 mm) at near-infrared spectroscopy intravascular US (NIRS-IVUS). Materials and Methods This retrospective study included consecutive patients who underwent CATCH MRI before elective NIRS-IVUS-guided percutaneous coronary intervention at two facilities. PMI was defined as post-percutaneous coronary intervention troponin T values greater than five times the upper reference limit. Multivariable analysis was performed to identify predictors of PMI. Finally, the predictive capabilities of MRI, NIRS-IVUS, and their combination were compared. Results A total of 103 lesions from 103 patients (median age, 72 years [IQR, 64-78]; 78 male patients) were included. PMI occurred in 36 lesions. In multivariable analysis, PMR emerged as the strongest predictor (P = .001), whereas maxLCBI4 mm was not a significant predictor (P = .07). When PMR was excluded from the analysis, maxLCBI4 mm emerged as the sole independent predictor (P = .02). The combination of MRI and NIRS-IVUS yielded the largest area under the receiver operating curve (0.86 [95% CI: 0.64, 0.83]), surpassing that of NIRS-IVUS alone (0.75 [95% CI: 0.64, 0.83]; P = .02) or MRI alone (0.80 [95% CI: 0.68, 0.88]; P = .30). Conclusion Erythrocyte-derived materials in plaques, represented by a high PMR at CATCH MRI, were strongly associated with PMI independent of lipids. MRI may play a crucial role in predicting PMI by offering unique pathologic insights into plaques, distinct from those provided by NIRS. Keywords: Coronary Plaque, Periprocedural Myocardial Injury, MRI, Near-Infrared Spectroscopy Intravascular US Supplemental material is available for this article. © RSNA, 2024.

Research has found strong evidence for common and distinct morphometric brain abnormality profiles in nonaffective psychosis (NAff-P) and affective psychosis (Aff-P). Due to chronicity and prolonged medication exposure confounds, it is crucial to examine structural morphometry early in the course of psychosis. Using Human Connectome Project-Early Psychosis data, multivariate profile analyses were implemented to examine regional profiles for cortical thickness, cortical surface area, subcortical volume, and ventricular volume in healthy control (HC; n = 56), early illness NAff-P (n = 83), and Aff-P (n = 30) groups after accounting for normal aging. Associations with symptom severity, functioning, and cognition were also examined. Group regional profiles were significantly nonparallel and differed in level for cortical thickness (P < .001), with NAff-P having widespread cortical thinning relative to HC and Aff-P and some regions showing greater deficits than others. Significant nonparallelism of group regional profiles was also evident for cortical surface area (P < .006), with Aff-P and N-Aff-P differing from HC and from each other (P < .001). For subcortical volume, there was significant profile nonparallelism with NAff-P having an enlarged left pallidum and smaller accumbens and hippocampus (P < .028), and Aff-P having a smaller accumbens and amygdala (P < .006), relative to HC. NAff-P also had larger basal ganglia compared to Aff-P. Furthermore, NAff-P had enlarged ventricles (P < .055) compared to HC and Aff-P. Additionally, greater ventricular volume was associated with increased manic symptoms in NAff-P and Aff-P. Overall, this study found common and distinct regional morphometric profile abnormalities in early illness NAff-P and Aff-P, providing evidence for both shared and disease-specific pathophysiological processes.

Hyperpolarization stands out as a technique capable of significantly enhancing the sensitivity of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). Dynamic nuclear polarization (DNP), among various hyperpolarization methods, has gained prominence for its efficacy in real-time monitoring of metabolism and physiology. By administering a hyperpolarized substrate through dissolution DNP (dDNP), the biodistribution and metabolic changes of the DNP agent can be visualized spatiotemporally. This approach proves to be a distinctive and invaluable tool for non-invasively studying cellular metabolism in vivo, particularly in animal models. Biomarkers play a pivotal role in influencing the growth and metastasis of tumor cells by closely interacting with them, and accordingly detecting pathological alterations of these biomarkers is crucial for disease diagnosis and therapy. In recent years, a range of hyperpolarized DNP molecular bioresponsive agents utilizing various nuclei, such as 13C, 15N, 31P, 89Y, etc., have been developed. In this context, we explore how these magnetic resonance signals of nuclear spins enhanced by DNP respond to biomarkers, including pH, metal ions, enzymes, or redox processes. This review aims to offer insights into the design principles of responsive DNP agents, target selection, and the mechanisms of action for imaging. Such discussions aim to propel the future development and application of DNP-based biomedical imaging agents.

UNASSIGNED: To analyse changes in the use of paediatric (≤16 years) CT over the past decade and to evaluate the appropriateness of CT examinations at a tertiary teaching hospital.
UNASSIGNED: Data from 290 paediatric CTs were prospectively collected in 2022 and compared with data from 2017 (358 cases) and 2012 (538 cases). The justification of CTs was evaluated with regard to medical imaging referral guidelines and appropriateness rates were calculated.
UNASSIGNED: Paediatric CTs decreased 39.4% over the 10 years, contrasting with a 27.6% increase in overall CTs. Paediatric CTs as the share of overall CTs dropped from 2.5% in 2012 to 1.1% in 2022 (P < .0001), with a concurrent rise in paediatric MRIs (P < .0001). Notable reductions in CT use occurred for head trauma (P = .0003), chronic headache (P < .0001), epilepsy (P = .037), hydrocephalus (P = .0078), chest tumour (P = .0005), and whole-body tumour (P = .0041). The overall appropriateness of CTs improved from 73.1% in 2017 to 79.0% in 2022 (P = .0049). In 15.4% of the cases, no radiological examination was deemed necessary, and in 8.7% of the cases, another modality was more appropriate. Appropriateness rates were the highest for the head and neck angiography (100%) and the chest (96%) and the lowest for the neck (66%) and the head (67%).
UNASSIGNED: Justification of CT scans can be improved by regular educational interventions, increasing MRI accessibility, and evaluating the appropriateness of the requested CT before the examination. Interventions for a more effective implementation of referral guidelines are needed.
UNASSIGNED: The focus for improvement should be CTs for head and cervical spine trauma, accounting for the majority of inappropriate requests in the paediatric population.

UNASSIGNED: The Accelerating Medicines Partnership Schizophrenia (AMP SCZ) funds a longitudinal study of 43 research sites across 5 continents to develop tools to stratify developmental trajectories of youth at clinical high risk for psychosis (CHR) and identify homogenous targets for future clinical trials. However, there are no sites in Africa, leaving a critical gap in our knowledge of clinical and biological outcomes among CHR individuals.
UNASSIGNED: We describe the development of the Kenya Psychosis-Risk Outcomes Study (KePROS), a 5-year NIH-funded project in Kenya designed to harmonize with AMP SCZ. The study will recruit over 100 CHR and 50 healthy participants and conduct multiple clinical and biomarker assessments over 2 years. Capacity building is a key component of the study, including the construction of an electroencephalography (EEG) laboratory and the upgrading of a local 3 T magnetic resonance imaging (MRI) machine. We detail community recruitment, study methodologies and protocols, and unique challenges with this pioneering research in Africa.
UNASSIGNED: This paper is descriptive only. Planned future analyses will investigate possible predictors of clinical outcomes and will be compared to results from other global populations.
UNASSIGNED: KePROS will provide the research community with a rich longitudinal clinical and biomarker dataset from an African country in the developing Global South, which can be used alongside AMP SCZ data to delineate CHR outcome groups for future treatment development. Training in mental health assessment and investment in cutting-edge biomarker assessment and other technologies is needed to facilitate the inclusion of African countries in large-scale research consortia.