- Are Gadolinium-Enhanced MR Sequences Needed in Simultaneous 18F-FDG-PET/MRI for Tumor Delineation in Head and Neck Cancer?
Consecutive patients who underwent simultaneous head and neck 18F-FDG-PET/MR imaging staging or restaging followed by surgery were retrospectively included in this study. Local tumor invasion and lymph node extension were assessed by 2 rater groups in 45 head and neck anatomic regions using 18F-FDG-PET/MR imaging. Two reading sessions were performed, one without contrast-enhanced sequences (using only T1WI, T2WI, and PET images) and a second with additional T1-weighted postcontrast sequences. The k concordance coefficient between the reading sessions and sensitivity and specificity for each region were calculated. There was excellent agreement between the contrast-free and postgadolinium reading sessions in delineating precise tumor extension in the 45 anatomic regions studied. The diagnostic accuracy did not differ between contrast-free and postgadolinium reading sessions, being 0.97 for both groups and both reading sessions. The authors conclude that gadolinium-based contrast administration showed no added value for accurate characterization of head and neck primary tumor extension and could possibly be avoided in the PET/MR imaging head and neck workflow.
- Olfactory Bulb Signal Abnormality in Patients with COVID-19 Who Present with Neurologic Symptoms
This retrospective case-control study compared the olfactory bulb and olfactory tract signal intensity on thin-section T2WI and postcontrast 3D T2 FLAIR images in patients with COVID-19 and neurologic symptoms, and age-matched controls imaged for olfactory dysfunction. Olfactory bulb 3D T2-FLAIR signal intensity was greater in the patients with COVID-19 and neurologic symptoms compared with an age-matched control group with olfactory dysfunction, and this was qualitatively apparent in 4 of 12 patients with COVID-19. Analysis of these preliminary findings suggests that olfactory apparatus vulnerability to COVID-19 might be supported on conventional neuroimaging and may serve as a noninvasive biomarker of infection.
- Tentorial Venous Anatomy: Variation in the Healthy Population
The authors retrospectively reviewed tentorial venous anatomy of the head using CTA/CTV performed for routine care or research purposes in 238 patients. Tentorial vein development was related to the ring configuration of the tentorial sinuses. There were 3 configurations: Groups 1A and 1B had ring configuration, while group 2 did not. Group 1A had a medialized ring configuration, and group 1B had a lateralized ring configuration. Measurements of skull base development were predictive of these groups. The ring configuration of group 1 was related to the presence of a split confluens, which correlated with a decreased internal auditory canal-petroclival fissure angle. Configuration 1A was related to the degree of petrous apex pneumatization.