18F-FDG positron emission tomography scanning in systemic sclerosis-associated interstitial lung disease: a pilot study

Background Interstitial lung disease is a common complication of systemic sclerosis (SSc-ILD), and it remains difficult to accurately predict its course. Progressing ILD could be more metabolically active, suggesting that the 18F-FDG tracer could be a tool in the managing of SSc-ILD. Methods In our center, SSc patients and controls (non-Hodgkin lymphoma cured after first-line regimen) who had received a PET/CT were screened retrospectively. The FDG uptake (visual intensity, pattern, SUVmax) was systematically recorded in > 30 regions of interest (ROIs) linked to SSc in a blind reviewing by 2 independent nuclear medicine physicians using a standardized form. Results Among the 545 SSc patients followed up in our center, 36, including 22 SSc-ILDs, had a PET/CT, whose indication was cancer screening in most cases. The mean ± SD age was 57.9 ± 13.0 years with 20/36 females. Fourteen patients had a disease duration of less than 2 years. A third had anti-centromere antibodies and 27.8% had anti-topoisomerase antibodies. Pulmonary FDG uptakes were higher in SSc patients than in controls (n = 89), especially in those with ILD compared with those without ILD. Pulmonary FDG uptakes were positively correlated with the ILD severity (fibrosis extent, %FVC, and %DLCO). No significant difference was found in the FDG uptakes from extrathoracic ROIs. Progressing SSc-ILDs within the 2 years after PET/CT (n = 9) had significant higher pulmonary FDG uptakes at baseline than stable SSc-ILDs (n = 13). Conclusion PET/CT could be a useful tool in the assessment of the severity and the prediction of pulmonary function outcome of SSc-ILD.

Restrictive lung defects: parenchymal, chest wall and neuromuscular

Sarcoidosis is a multisystem condition which may affect a number of organs and, within the cardiopulmonary system, most commonly manifests as parenchymal, airway-centred, nodal, vascular or cardiac disease. Pleural involvement is rare, but well described, and often presents as pleural effusions or pleural thickening. Here, we present the first case of active sarcoidosis manifesting as bilateral pleural calcification. We highlight the importance of a nuanced understanding of pulmonary physiology when dissecting coexistent extrathoracic and intrathoracic pulmonary restriction. We demonstrate the value of positron emission tomography scanning for identification of sites of sarcoid activity, in this case the pleura, to ensure tissue confirmation of this rare but functionally important manifestation of disease. Sarcoidosis should be considered within the differential diagnosis for patients with pleural calcification, not explained by more common causes.

Radioisotopes in urology

Ever since the first discovery of radioactivity, the medical applications of radioactive isotopes have been at the forefront of developments. There are two broad categories of medical radioisotopes; those that are predominantly diagnostic in purpose and those that are used for therapeutic benefit. Nuclear medicine studies play a key role in the imaging of the renal tracts. Due to the different physiological functions that can be assessed by different radiopharmaceuticals, the choice of a particular radioisotope test can sometimes challenge one’s thinking and thought processes. The routine functions that can be assessed by isotope renography are covered and a table to guide clinical decision-making is also provided. Positron emission tomography scanning represents a big leap in functional imaging, as it not only enables visualization of metabolism and other physiological processes at a molecular level, it also frequently provides a better quality of image compared with conventional nuclear medicine images.

The use of PET/CT in pregnancy: A case report of malignant parathyroid carcinoma and a review of the literature

Positron emission tomography scanning is not commonly performed in pregnancy but can be done if required. Fetal doses of radiation can be minimized, and our case exemplifies the safe application of positron emission tomography/computed tomography in pregnancy. A 38-year-old woman in her first ongoing pregnancy presented at 28 weeks’ gestation with symptomatic hypercalcemia. Given a history of parathyroid carcinoma, recurrence was suspected. Ultrasound and magnetic resonance imaging failed to locate the lesion. However, positron emission tomography/computed tomography identified a culprit supraclavicular lymph node. This was excised under local anesthesia resulting in normalization of parathyroid hormone and calcium levels. A term, healthy baby was delivered. The literature provides support that the use of positron emission tomography/computed tomography is acceptable when indicated, and there are modifications to protocols that can further limit risk.