A direct comparison in diagnostic performance of CDUS, FDG-PET/CT and MRI in patients suspected of giant cell arteritis.

OBJECTIVES: This study directly compares diagnostic performance of Colour Duplex Ultrasound (CDUS), Fluor-18-deoxyglucose Positron Emission Tomography Computed Tomography (FDG-PET/CT) and Magnetic Resonance Imaging (MRI) in patients suspected of giant cell arteritis (GCA). METHODS: Patients with suspected GCA were included in a nested-case control pilot study. CDUS, whole body FDG-PET/CT and cranial MRI were performed within 5 working days after initial clinical evaluation. Clinical diagnosis after six months follow-up by experienced rheumatologists in the field of GCA, blinded for imaging, was used as reference standard. Diagnostic performance of the imaging modalities was determined. Stratification for GCA subtype was performed and imaging results were evaluated in different risk stratification groups. RESULTS: In total, 23 patients with GCA and 19 patients suspected of but not diagnosed with GCA were included. Sensitivity was 69.6% (95%CI 50.4%-88.8%) for CDUS, 52.2% (95%CI 31.4%-73.0%) for FDG-PET/CT and 56.5% (95%CI 35.8%-77.2%) for MRI. Specificity was 100% for CDUS, FDG-PET/CT and MRI. FDG-PET/CT was negative for GCA in all isolated cranial GCA patients (n = 8), while MRI was negative in all isolated extracranial GCA patients (n = 4). In 4 GCA patients with false-negative (n = 2; intermediate and high risk) or inconclusive (n = 2; low and intermediate risk) CDUS results, further imaging confirmed diagnosis. CONCLUSIONS: Sensitivity of CDUS was highest, while specificity was excellent in all imaging modalities. Nevertheless, confidence intervals of all imaging modalities were overlapping. Following EULAR recommendations, CDUS can be used as a first test to diagnose GCA. With insufficient evidence for GCA, further testing considering GCA subtype is warranted.

Diagnostic accuracy of dynamic CZT-SPECT in coronary artery disease. A systematic review and meta-analysis.

BACKGROUND: With the appearance of cadmium-zinc-telluride (CZT) cameras, dynamic myocardial perfusion imaging (MPI) has been introduced, but comparable data to other MPI modalities, such as quantitative coronary angiography (CAG) with fractional flow reserve (FFR) and positron emission tomography (PET), are lacking. This study aimed to evaluate the diagnostic accuracy of dynamic CZT single-photon emission tomography (SPECT) in coronary artery disease compared to quantitative CAG, FFR, and PET as reference. MATERIALS AND METHODS: Different databases were screened for eligible citations performing dynamic CZT-SPECT against CAG, FFR, or PET. PubMed, OvidSP (Medline), Web of Science, the Cochrane Library, and EMBASE were searched on the 5th of July 2020. Studies had to meet the following pre-established inclusion criteria: randomized controlled trials, retrospective trails or observational studies relevant for the diagnosis of coronary artery disease, and performing CZT-SPECT and within half a year the methodological references. Studies which considered coronary stenosis between 50% and 70% as significant based only on CAG were excluded. Data extracted were sensitivity, specificity, likelihood ratios, and diagnostic odds ratios. Quality was assessed with QUADAS-2 and statistical analysis was performed using a bivariate model. RESULTS: Based on our criteria, a total of 9 studies containing 421 patients were included. For the assessment of CZT-SPECT, the diagnostic value pooled analysis with a bivariate model was calculated and yielded a sensitivity of 0.79 (% CI 0.73 to 0.85) and a specificity of 0.85 (95% CI 0.74 to 0.92). Diagnostic odds ratio (DOR) was 17.82 (95% CI 8.80 to 36.08, P < 0.001). Positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 3.86 (95% CI 2.76 to 5.38, P < 0.001) and 0.21 (95% CI 0.13 to 0.33, P < 0.001), respectively. CONCLUSION: Based on the results of the current systematic review and meta-analysis, dynamic CZT-SPECT MPI demonstrated a good sensitivity and specificity to diagnose CAD as compared to the gold standards. However, due to the heterogeneity of the methodologies between the CZT-SPECT MPI studies and the relatively small number of included studies, it warrants further well-defined study protocols.

Targeted lymph node biopsy in mediastinoscopy using 3D FDG-PET/CT movies: a feasibility study.

In non-small-cell lung cancer, positive lymph nodes with increased fluorodeoxyglucose (FDG) uptake may be missed by mediastinoscopy. Lack of pathological confirmation may lead to radical, but unnecessary lung surgery. To minimize these false-negative results, the feasibility and potential value of three-dimensional (3D) FDG-PET/computed tomography (CT) movies were investigated to improve targeted lymph node biopsy during mediastinoscopies. PET/CT images were rendered in 3D volumes with multiplanar reconstructions and maximum intensity projections and reviewed in 3D 'fly-through' and 'fly-around' movies. These movies were developed and optimized by the Departments of Surgery and Nuclear Medicine. Twenty-two consecutive patients with non-small-cell lung cancer were included, of whom eight were FDG-PET positive for mediastinal lymph nodes. 3D FDG-PET/CT movies were presented to surgeons before mediastinoscopy. Surgical consequences were investigated, including sensitivity and the negative predictive value of mediastinoscopy. Results were compared with those of a retrospective study in which 3D techniques were not used. During mediastinoscopies, the 3D-PET/CT movies were found to be helpful in the surgical localization of FDG-positive lymph nodes. It led to more confidence in the surgical approach. The sensitivity and negative predictive value were 86 and 94%, respectively. Although not statistically significant, these results were higher compared with those of the retrospective study (75 and 92%, respectively). 3D FDG-PET/CT guidance during mediastinoscopy is feasible. The movies seem to lead to targeted biopsy of lymph nodes. They may reduce false-negative mediastinoscopies and improve staging of lung cancer. 3D FDG-PET/CT can be seen as a promising tool for further implementation of image-guided surgery.