OBJECTIVEBrown adipose tissue (BAT) is present in adult humans where it may be important in the prevention of obesity, although the main factors regulating its abundance are not well established. BAT demonstrates seasonal variation relating to ambient temperature and photoperiod in mammals. The objective of our study was therefore to determine whether seasonal variation in BAT activity in humans was more closely related to the prevailing photoperiod or temperature.RESEARCH DESIGN AND METHODSWe studied 3,614 consecutive patients who underwent positron emission tomography followed by computed tomography scans. The presence and location of BAT depots were documented and correlated with monthly changes in photoperiod and ambient temperature.RESULTSBAT activity was demonstrated in 167 (4.6%) scans. BAT was demonstrated in 52/724 scans (7.2%) in winter compared with 27/1,067 (2.5%) in summer months (P < 0.00001, χ2 test). Monthly changes in the occurrence of BAT were more closely related to differences in photoperiod (r2 = 0.876) rather than ambient temperature (r2 = 0.696). Individuals with serial scans also demonstrated strong seasonal variation in BAT activity (average standardized uptake value [SUVmax] 1.5 in July and 9.4 in January). BAT was also more common in female patients (female: n = 107, 7.2%; male: n = 60, 2.8%; P < 0.00001, χ2 test).CONCLUSIONSOur study demonstrates a very strong seasonal variation in the presence of BAT. This effect is more closely associated with photoperiod than ambient temperature, suggesting a previously undescribed mechanism for mediating BAT function in humans that could now potentially be recruited for the prevention or reversal of obesity.

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Background Tuberculosis remains a global health challenge, with early diagnosis key to its reduction. Face-mask sampling detects exhaled Mycobacterium tuberculosis. We aimed to investigate bacillary output from patients with pulmonary tuberculosis and to assess the potential of face-mask sampling as a diagnostic method in active casefinding. MethodsWe did a 24-h longitudinal study in patients from three hospitals in Pretoria, South Africa, with microbiologically confirmed pulmonary tuberculosis. Patients underwent 1 h of face-mask sampling eight times over a 24-h period, with contemporaneous sputum sampling. M tuberculosis was detected by quantitative PCR. We also did an active case-finding pilot study in inhabitants of an informal settlement near Pretoria. We enrolled individuals with symptoms of tuberculosis on the WHO screening questionnaire. Participants provided sputum and face-mask samples that were tested with the molecular assay Xpert MTB/RIF Ultra. Sputum-negative and face-mask-positive individuals were followed up prospectively for 20 weeks by bronchoscopy, PET-CT, and further sputum analysis to validate the diagnosis.

Objectives In this article we will give a comprehensive literature review on sedation/general anaesthesia (S/GA) and discuss the international variations in practice and options available for S/GA for imaging children. Methods The key articles were obtained primarily from PubMed, MEDLINE, ERIC, NHS Evidence and The Cochrane Library. Results Recently, paediatric radiology has seen a surge of diagnostic and therapeutic procedures, some of which require children to be still and compliant for up to 1 h. It is difficult and sometimes even impossible to obtain quick and high-quality images without employing sedating techniques in certain children. As with any medical procedure, S/GA in radiological practice is not without risks and can have potentially disastrous consequences if mismanaged. In order to reduce any complications and practice safety in radiological units, it is imperative to carry out pre-sedation assessments of children, obtain parental/guardian consent, monitor them closely before, during and after the procedure and have adequate equipment, a safe environment and a well-trained personnel. Conclusion Although the S/GA techniques, sedative drugs and personnel involved vary from country to country, the ultimate goal of S/GA in radiology remains the same; namely, to provide safety and comfort for the patients. Advances in knowledge Imaging children under general anaesthesia is becoming routine and preferred by operators because it ensures patient conformity and provides a more controlled environment.

The recently devised National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) appears superior to the revised IPI (R-IPI) in delineating outcome in diffuse large B-cell lymphoma. We examined the outcome of a population-based cohort of 223 consecutive patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) or R-CHOP-like immuno-chemotherapy between January 2005 and December 2011 by both the NCCN-IPI and R-IPI, and further stratified outcome by the achievement of both computerized tomography (CT) and positron emission tomography (PET)-CT complete remission (CR), with the latter reassessed using blinded central review by an independent nuclear medicine and radiology specialist. The NCCN-IPI was superior to the R-IPI in identifying patients at very high risk of systemic and/or central nervous system relapse. Notably, both the NCCN-IPI and the R-IPI remained strongly predictive of relapse irrespective of CT or PET-defined remission status following R-CHOP. Patients with high-risk NCCN-IPI scores (≥6) have a dismal outcome following R-CHOP therapy regardless of PET-defined response to R-CHOP. Moreover, such patients appear refractory to salvage chemotherapy and thus require alternative therapeutic approaches, although age and performance status may, for many patients, preclude the safe delivery of a primary intensified regimen. By contrast, patients with NCCN-IPI 1-5 who achieve PET-CR following R-CHOP have excellent outcomes and may merit reduced follow up frequency.

We describe a case of oncogenic osteomalacia secondary to solitary plasmacytoma of the vertebral body of T3. The patient presented with symptoms of hypophosphataemia. Following the initial diagnosis, the lesion was surgically resected with good results, although several follow-up procedures, including bone grafting, were necessary to stabilize the thoracic spine. The lesion recurred almost 15 years after its initial resection, again presenting with hypophosphataemia and neurological symptoms suggestive of local tumour recurrence. A variety of radiological examinations were performed in an attempt to confirm and localize recurrent tumour, including bone scintigraphy, (111)indium octreotide scintigraphy, high-resolution CT and MRI of the thoracic spine, but these yielded only negative or equivocal results owing, in part, to the presence of extensive post-operative changes, and also to a difference in the MR signals of the recurrent and original tumours. Positron emission tomography (PET/CT) demonstrated a solitary focus of intense fluorodeoxyglucose uptake in the T3 vertebral body, enabling a definitive diagnosis of recurrent plasmacytoma. This case illustrates the diagnostic value of PET/CT in the setting of challenging post-operative changes in the surrounding tissue and in the appearance of the tumour itself. Relevant related imaging literature is also reviewed.

With hybrid imaging playing an increasingly important role in nuclear medicine, this article reviews the literature on single-photon emission computed tomography/computed tomography (SPECT/CT) in parathyroid scintigraphy. An understanding of parathyroid and neck anatomy is important for accurate reporting of these scans, as this can have an impact on the surgical approach used. The contribution of SPECT/CT over and above SPECT alone is greatest in terms of localization, particularly for ectopic tumours. There remains controversy on the role of SPECT/CT in eutopic tumours, especially when considering such factors as imaging time and the additional radiation dose.

Primary malignant rhabdoid tumour of the central nervous system is a rare neoplasm affecting children. We present a pathologically proven case, which was initially referred to the paediatric surgeons as a sebaceous cyst, and highlights the importance of imaging prior to surgery of potentially innocuous scalp lesions. Imaging features on CT and MRI are presented, which show bony involvement not previously reported in the literature.