Quantitative analysis of MR T2 relaxation times in neck muscles.

T2 relaxation times (T2 times) are different between resting and exercised muscles and between muscles of healthy subjects and subjects with muscle pathology. However, studies specifically focusing on neck muscles are lacking. Furthermore, normative neck muscle T2 times are not well defined and methodology used to analyse T2 times in neck muscles is not robust. We analysed T2 times in key neck muscles and explored factors affecting variability between muscles. 20 healthy subjects were recruited. Two circular regions of interest (ROIs) were drawn in two mutually exclusive regions within neck muscles on T2 weighted images and values averaged. ROI measurements were performed by a co-investigator, supervised by a neuro-radiologist. For the first ten subjects, measurements were done from C1-T1. For the remaining subjects, ROIs were drawn at two pre-determined levels. Two MRIs were repeated at 31 degrees acquisition to evaluate the effect of muscle fibre orientation. ROI values were translated into T2 times. Results showed semispinalis capitis had the longest T2 times (range 46.88-51.42 ms), followed by splenius capitis (range 47.37-48.33 ms), trapezius (range 45.27-47.46 ms), levator scapulae (range 43.17-45.63 ms) and sternocleidomastoid (range 38.45-42.91 ms). T2 times did not vary along length of muscles and were unaffected by muscle fibre orientation (P > 0.05). T2 times of splenius capitis correlated significantly with age at C2/C3 and C5/C6 levels and trapezius at C7/T1 level. Gender did not influence relaxation times (P > 0.05). In conclusion, results of normative neck muscle T2 time values and factors influencing the T2 times could serve as a reference for future MR analysis of neck muscles. The methodology used may also be useful for related studies of neck muscles.

Pregnancy in patients with implantable cardiac defibrillators.

The number of patients of reproductive age with inherited and congenital heart disease receiving implantable cardiac defibrillators (ICD) is steadily increasing. Safely and effectively coordinating pregnancy in this high-risk cohort is important to optimise maternal-foetal outcomes. As members of the multidisciplinary team caring for pregnant patients with indications for ICD, cardiologists and electrophysiologists should be aware of the considerations and nuances involved in managing these patients. This article reviews the pathophysiology of arrhythmias, ICD implantation considerations, novel minimal fluoroscopy techniques and subcutaneous ICD. In addition, antenatal and device management during pregnancy and delivery are discussed.

Diagnostic yield of computed tomography-guided biopsy and aspiration for vertebral osteomyelitis.

INTRODUCTION: The diagnostic yield of and best approaches for imaging-guided percutaneous biopsy for vertebral osteomyelitis is controversial. Early studies suggest yields of up to 90%; however, recent evidence shows lower yields of 30-40%. We aim to determine yield and predictors of yield in percutaneous CT-guided biopsies in vertebral osteomyelitis. METHODS: We conducted a retrospective observational single-centre study cohort study of all patients presenting for vertebral biopsy or aspiration between 2014 and 2018. Only patients undergoing biopsy for suspected infection were included. Patients with malignant indications were excluded. Comprehensive review of medical records was performed for clinical presentation, comorbidities, imaging, biomarkers, microbiology and treatment. RESULTS: Overall, 40 out of 88 biopsies were performed for suspected infection, in 36 patients. Mean age was 59 ± 18 years; 29 (81%) were male. Of the 40 samples, an organism was identified in 14 samples (35%). Gram-positive organisms were most commonly identified; Staphylococcus aureus was cultured in 7 (50%) of samples. Mean admission CRP was significantly higher in patients with identified organisms compared to those without (137 ± 106 vs 54 ± 78, P = 0.008). Aspiration was a strong independent predictor of positive microbiological growth on multivariate analysis (OR 6.52 [1.25-34.02], P = 0.026). Biopsy or aspiration aided clinical decision-making in half of cases. CONCLUSIONS: Percutaneous CT-guided biopsy has a modest yield for identifying the culprit organism in suspected cases of vertebral osteomyelitis. Elevated CRP and aspiration of fluid collections are associated with improved microbiological yield and should be considered in deciding when and where to biopsy.

A rare cause of bowel obstruction in pregnancy.

We present the case of a 30-year-old woman admitted at 38 weeks and 3 days gestation with a rare cause of bowel obstruction. Definitive diagnosis was not made until laparotomy. We present the unique management challenges posed and a review of the literature.