Dual-source computed tomography coronary angiography: influence of obesity, calcium load, and heart rate on diagnostic accuracy

Aims To prospectively investigate the diagnostic accuracy of dual-source computed tomography coronary angiography (CTCA) to diagnose coronary stenoses in relation to body mass index (BMI), Agatston score (AS), and heart rate (HR) as compared with catheter coronary angiography (CCA). Methods and results Hundred and fifty consecutive patients (47 female, mean age 62.9 ± 12.1 years) underwent dual-source CTCA without HR control. Patients were divided into subgroups depending on the median of their BMI (26.0 kg/m2), AS (194), and HR (66 b.p.m.). CCA was considered the standard of reference. Mean BMI was 26.5 ± 4.2 kg/m2 (range 18.3-39.1 kg/m2), mean AS was 309 ± 408 (range 0-4387), and HR was 68.5 ± 12.6 b.p.m. (range 35-102 b.p.m.). Diagnostic image quality was found in 98.1% of all segments (2020/2059). Considering not-evaluative segments at CTCA as false-positive, overall per-patient sensitivity, specificity, positive, and negative predictive value were 96.6%, 86.8%, 82.6%, and 97.5%, respectively. High HR did not deteriorate diagnostic accuracy of CTCA. High BMI and AS were associated with a decrease in per-patient specificity to 84.1% and 77.8%, respectively, while sensitivity and negative predictive value remained high. Conclusion Dual-source CTCA provides high diagnostic accuracy irrespective of the HR and serves as a modality to rule-out coronary artery stenoses even in patients with high BMI and A

Pain reduction after lumbar epidural injections using particulate versus non-particulate steroids: intensity of the baseline pain matters

Objectives To compare pain relief after CT-guided lumbar epidural steroid injections (ESI) using particulate (triamcinolone) and non-particulate (dexamethasone) steroids, and to explore factors affecting the effectiveness of both steroid types. Methods This retrospective observational study included 806 patients with lumbar radiculopathy and corresponding MRI or CT abnormalities of the lumbar spine, who were matched using the propensity score method, yielding two cohorts of 209 patients each. Pain intensity was evaluated prior to the procedure using a pain numerical rating scale (NRS) with range 0–10. Reevaluation took place 1 day and 4 weeks post-injection. Logistic regression analysis and cubic splines applied to generalized additive models were implemented to assess the differences in pain reduction after ESI in the analyzed patient groups. Results Four weeks post-injection, the overall chance of ≥ 50% pain reduction was lower in the dexamethasone group than that in the triamcinolone group (odds ratio [OR] = 0.55; p < 0.012). In the dexamethasone cohort, the intensity of baseline pain and the presence of a herniated intervertebral disc in the infiltrated segment were both significant and independent predictors of ≥ 50% pain relief. Patients with baseline NRS score ≥ 7 points had markedly less chance of ≥ 50% pain relief than patients with NRS score < 7 (OR = 0.53; p < 0.032), whereas disc herniation increased the chances more than twofold (OR = 2.29; p < 0.044). There was no significant correlation between the effectiveness of triamcinolone and any analyzed concomitant variables. Conclusions Triamcinolone was superior for lumbar radiculopathy of severe intensity. For mild to moderate pain, no benefit of using triamcinolone over dexamethasone was found. The effectiveness of dexamethasone was lower for stenotic spinal lesions than for disc herniation

FDG PET and PET/CT for the detection of the primary tumour in patients with cervical non-squamous cell carcinoma metastasis of an unknown primary

In patients with a neck metastasis from an unknown primary with non-squamous cell cancer (non-SCC) histology, the primary is often located outside the head and neck area. We retrospectively evaluated 326 patient records and found 14 patients with non-SCC neck lymph node metastasis from an unknown primary undergoing whole body F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) with or without coregistered computed tomography (PET/CT). The PET or PET/CT findings were verified by pathological work-up, additional imaging tests, and clinical follow-up. PET detected pathological FDG uptake suspicious for the primary in eight patients. PET or PET/CT findings were true positive in seven patients, true negative in 4, false positive in 1, and false negative in two patients. In one patient PET/CT revealed a synchronous ovarian carcinoma. The results suggest that whole body imaging with FDG PET and PET/CT can be useful to identify unknown primaries of non-SCC origin. However, the work-up of patients undergoing PET or PET/CT in our study was very heterogeneous and the primary was more likely found in patients without extensive imaging before PET scanning. Further studies should evaluate if the histology of a neck nodal metastasis should influence the choice of the imaging method and the role of PET and PET/CT imaging for the work up of patients with a non-SCC neck lymph node metastasis of an unknown primar

Increased 18F-FDG uptake mimicking thyroid cancer in a patient with Hashimoto's thyroiditis

We report the case of a 68-year-old patient with a known paravertebral malignant schwannoma, sent to us for postoperative staging. A combined whole-body PET/CT scan showed only poor 18F-fluorodeoxyglucose uptake in the region of the primary tumor but distinct increased fluorodeoxyglucose uptake in the left and right thyroid gland. Thyroid sonography showed two hypoechogenic nodules. Ultrasound-guided fine-needle aspiration biopsy of one nodule showed oxyphil transformed cells, compatible with malignancy. Based on these findings, the patient underwent a subtotal thyroidectomy. Histopathology of the specimen revealed a chronic follicular Hashimoto's thyroiditis. This case demonstrates that Hashimoto's thyroiditis can mimic thyroid cancer in PET but also in sonography and fine-needle aspiration biops

Accuracy of image coregistration of pulmonary lesions in patients with non-small cell lung cancer using an integrated PET/CT system

UNLABELLED The purpose of this study was to evaluate the accuracy of image coregistration of PET and CT (PET/CT) images in patients with lung lesions and the influence of the breathing protocol during CT. METHODS Seventy-five patients with a solitary and well-circumscribed pulmonary lesion (non-small cell lung cancer; size, 10-30 mm) underwent PET/CT on a combined scanner. CT was acquired during shallow breathing in 37 patients and during normal expiration (i.e., the level reached when the patient exhaled without forcing expiration and then held the breath) in 38 patients. The volume of interest of each lesion was defined separately on PET and CT images, and the geometric center of gravity (COG) was assessed. The distance of COGs between the PET image and the CT image was measured. All lesions were classified according to 4 lung regions: apical, peripheral, central, and lung base. The mismatch between COG(PET) and COG(CT) was compared between regions and patient groups using a 2-way ANOVA with the Bonferroni-Dunn test for post hoc comparisons. RESULTS The range of COG distance between PET and CT was 1.7-5.4 mm in the apex, 0.5-14.7 mm in the periphery, 0.7-5.9 mm centrally, and 2.9-11.3 mm in the lung base. The match between PET and CT was significantly better in patients who had the CT scan obtained during normal expiration than in patients who performed shallow breathing during CT scanning (P = 0.024). No reciprocal effects were found (interaction P = 0.76). The mismatch of lesions depends significantly on lung region (P < 0.0001). Post hoc analysis showed a significant difference between the upper 2 regions and the lower 2 regions (all P < or = 0.002) but not between the apex and the central region (P = 0.95) and between the peripheral region and the lung base (P = 0.15). The lesion size had no influence on the COG mismatch. CONCLUSION The match of lung lesions in coregistered PET/CT images is better when acquiring the CT scan during normal expiration. The coregistration accuracy is better in the upper and central parts of the lung. The normal expiration protocol is suggested to be superior to shallow breathing during CT scanning