Quantitative iron-neuromelanin MRI associates with motor severity in Parkinson's disease and matches radiological disease classification.

Background: Neuromelanin- and iron-sensitive MRI studies in Parkinson's disease (PD) are limited by small sample sizes and lack detailed clinical correlation. In a large case-control PD cohort, we evaluated the diagnostic accuracy of quantitative iron-neuromelanin MRI parameters from the substantia nigra (SN), their radiological utility, and clinical association. Methods: PD patients and age-matched controls were prospectively recruited for motor assessment and midbrain neuromelanin- and iron-sensitive [quantitative susceptibility mapping (QSM) and susceptibility map-weighted imaging (SMWI)] MRI. Quantitative neuromelanin-iron parameters from the SN were assessed for their discriminatory performance in PD classification using ROC analysis compared to those of qualitative visual classification by radiological readers of differential experience and used to predict motor severity. Results: In total, 191 subjects (80 PD, mean age 65.0 years; 111 controls, 65.6) were included. SN masks showed (a) higher mean susceptibility (p < 0.0001) and smaller sizes after thresholding for low susceptibility (p < 0.0001) on QSM and (b) lower contrast range (p < 0.0001) and smaller sizes after thresholding for high-signal voxels (p < 0.0001) on neuromelanin-sensitive MRI in patients than in controls. Quantitative iron and neuromelanin parameters showed a moderate correlation with motor dysfunction (87.5%: 0.4< | r | <0.6, p < 0.0001), respectively. A composite quantitative neuromelanin-iron marker differentiated the groups with excellent performance (AUC 0.94), matching the diagnostic accuracy of the best-performing reader (accuracy 97%) using SMWI. Conclusion: Quantitative neuromelanin-iron MRI is associated with PD motor severity and matched best-performing radiological PD classification using SMWI, with the potential to improve diagnostic confidence in the clinics and track disease progression and response to neuroprotective therapies.

Appropriateness of lumbar spine radiography and factors influencing imaging ordering patterns: paving the path toward value-driven health care.

The demand for diagnostic imaging continues to rise. Against the backdrop of rising health care costs and finite resources, this has prompted a paradigm shift toward value-driven patient care. Inappropriate imaging is a barrier toward achieving this goal, which runs counter to prevailing evidence-based guidelines and contributes to rising healthcare costs. Our objective was to evaluate the appropriateness of lumbar spine X-rays in a tertiary referral Emergency Department (ED) and assess whether physicians' specialization and years of experience influence appropriateness. A total of 1030 lumbar spine radiographs performed in the ED of an academic medical center over a consecutive 3-month period were reviewed retrospectively. Referral indications were reviewed for adherence to 2021 American College of Radiology appropriateness guidelines for lower back pain, and referral patterns were evaluated among physician groups based on specialists' training and years in practice. 63.8% of lumbar spine radiographs were appropriate, with trauma being the most common indication. 36.2% of orders were inappropriate, with lower back pain of <6 weeks duration being the most common indication. Significant differences in inappropriate orders were found (P < .001) across physician groups: qualified Emergency Medicine specialists (20.9% inappropriate orders), specialists in training (27.8%), and non-specialists with ≥3 (60.0%) and <3 (36.9%) years in practice, respectively. Approximately one-third of lumbar spine radiographs performed in the ED were inappropriately ordered by American College of Radiology guidelines; specialists training and years in practice affected referral patterns. Integrating evidence-based appropriateness guidelines into the physician order workflow and targeting older non-specialists may promote more judicious imaging and reduce health care costs.

SingHealth Radiology Archives pictorial essay Part 2: gastroenterology, musculoskeletal, and obstetrics and gynaecology cases.

The Singapore Health Services cluster (SingHealth) radiology film archives are a valuable repository of local radiological cases dating back to the 1950s. Some of the cases in the archives are of historical medical interest, i.e. cerebral angiography in the workup of patients with hemiplegia. Other cases are of historical social interest, being conditions seen during earlier stages of Singapore's development, i.e. bound feet. The archives form a unique portal into the development of local radiology as well as the national development of Singapore. A selection from the archives is published in commemoration of the International Day of Radiology in 2020, as well as the 200th anniversary of the Singapore General Hospital in 2021. This pictorial essay comprises gastroenterology, musculoskeletal and obstetrics and gynaecology cases from the archives.

SingHealth Radiology Archives pictorial essay Part 1: cardiovascular, respiratory and neurological cases.

The Singapore Health Services cluster (SingHealth) radiology film archives are a valuable repository of local radiological cases dating back to the 1950s. Some of the cases in the archives are of historical medical interest, i.e. cerebral angiography in the workup of patients with hemiplegia. Other cases are of historical social interest, being conditions seen during earlier stages of Singapore's development, i.e. bound feet. The archives form a unique portal into the development of local radiology as well as the national development of Singapore. A selection from the archives is published in 2020 in commemoration of the 20th anniversary of the formation of SingHealth, the 55th National Day of Singapore, and the 125th anniversary of the International Day of Radiology. This pictorial essay comprises cardiovascular, respiratory and neurological cases from the archives.

Metronidazole induced encephalopathy: case report and discussion on the differential diagnoses, in particular, Wernicke's encephalopathy.

Metronidazole induced encephalopathy is a rare central nervous system toxicity, which may be completely reversible with prompt cessation of metronidazole usage. We present a case of metronidazole induced encephalopathy in a 59-year-old man with a history of Whipple's procedure for pancreatic neuroendocrine tumour. The characteristic magnetic resonance imaging features of metronidazole induced encephalopathy and its main differential diagnosis, Wernicke's encephalopathy, are discussed.