Quantitative biomarkers for distinguishing bone metastasis and benign bone marrow lesions using turbo spin echo T1- and T2-weighted Dixon imaging at 3.0 T.

Objective: To assess the diagnostic performance and calculate the optimal threshold for quantitative biomarkers to differentiate bone metastasis and benign bone marrow lesions using turbo spin echo (TSE) Dixon images with a 3.0 T scanner. Materials and methods: Each 100 patients diagnosed with bone metastases and variable benign bone marrow lesions on spine MRI were included retrospectively. Images included in-phase (IP), opposed-phase (OP), water images (WI), and fat images (FI) by the TSE Dixon technique with T1WI and T2WI using a 3.0 T scanner. Regions of interest (ROI) of the lesions were manually drawn by two musculoskeletal radiologists independently, and the average signal intensity was recorded. The signal reduction rate from IP to OP (%drop) and a fat fraction (%fat) were calculated. Results: All biomarkers showed a significant difference between metastatic and benign lesions (P < 0.001). When comparing the AUCs, the %drop of T1WI had the highest AUC (0.934). Although the AUC of %fat from T2WI was significantly lower than that of other biomarkers, the %drop of T2WI was not significantly different from the %drop of T1WI (p = 0.339). The optimal threshold of %drop to differentiate metastatic and benign lesions was 22.0 in T1WI and 15.9 in T2WI. The inter-reader agreement was excellent for all biomarkers (0.82-0.86). Conclusion: While %drop of T1WI showed the highest diagnostic performance to differentiate bone metastasis from benign lesions, the %drop of T2WI showed a comparable ability using a threshold 15.9.

Comparison of the axillary lymph node between rheumatoid arthritis and psoriatic arthritis with computed tomography.

Backgrounds: There is a lack of universally available biomarker to differentiate rheumatoid arthritis (RA) and psoriatic arthritis (PsA). Purpose: to see if the size of the axillary lymphnodes (ALNs) and the frequency of lymphadenopathy are useful biomarker to differentiate RA and PsA. Material and Methods: Forty RA and 19 PsA patients without previous biologics usage were retrospectively included. Chest CT was assessed for the presence of lymphadenopathy and the size of the largest ALN. Frequency of lymphadenopathies was statistically compared between RA and PsA. The short axis and the long axis of the largest ALN were also compared and receiver operating characteristic (ROC) curve analysis was performed. Results: Frequency of axillary lymphadenopathy was significantly higher in RA than in PsA (80% vs 31.6%, p < .001). Number of lymphadenopathies in each patient was also significantly higher in RA than in PsA (3.0 vs 1.2 per patient, p = .005). Sensitivity and specificity for differentiating RA from PsA by the presence of at least one axillary lymphadenopathy were 0.8 and 0.68, respectively.The short axis of the largest ALNs in RA was significantly longer than in PsA (6.5 ± 1.6 mm vs 4.7 ± 1.7 mm, p < .001). ROC curve analysis of the short axis showed AUC of 0.75 (p = .002) and the cutoff value of 5.1 mm with a sensitivity of 0.83 and specificity of 0.74, when differentiating RA and PsA. Conclusion: Presence of ALN lymphadenopathy and the short axis of the largest ALN may have a potential utility in differentiating RA and PsA.

Anatomical analysis of inflammation in hand psoriatic arthritis by Dual-Energy CT Iodine Map.

OBJECTIVE: This study aimed to identify the detailed location of inflammatory lesions and its frequency of hand PsA on DECT Iodine Map with referring the cadaveric specimen. MATERIALS AND METHODS: Thirty-eight anatomical landmarks were selected as a potential inflammatory sites in the thumb and middle finger. We included 22 symptomatic PsA patients who underwent contrast enhanced DECT of the hand. MR images and macroscopic specimens of thumb and middle finger were prepared from a cadaver. Two musculoskeletal radiologists evaluated DECT with referring the cadaveric images to determine the precise location of inflammatory sites and its frequency. RESULTS: The frequently observed inflammation sites of active PsA patients were either classical or functional entheses, and coincide with the well-known hypothesis that primary inflammatory sites of PsA are enthesis. We have noticed that there was remarkable enhancement around DIP joints (13.6 %-45.5 %). CONCLUSION: DECT could assess the detailed anatomical sites of the inflammatory lesion in hand psoriatic arthritis, which coincided with enthesis.

Quantitative analysis of therapeutic response in psoriatic arthritis of digital joints with Dual-energy CT iodine maps.

The aim of this study was to investigate the feasibility of quantitative assessment of the therapeutic response in psoriatic arthritis (PsA) by measuring iodine uptake using a Dual-energy CT (DECT) iodine map. The study included 74 symptomatic and 74 matching non-symptomatic joints of 26 consecutive PsA patients who underwent two contrast enhanced DECTs of the hand or foot, pre and post medical interventions. Symptomatic and matched non-symptomatic control joints were scored with the PsA DECT Scoring System (PsADECTS), which was derived by modifying the PsA MRI Scoring System (PsAMRIS), a recently validated scoring system that assesses PsA changes on MRI. Quantified iodine uptake measured using the DECT iodine map was compared to the PsADECTS score. Efficacy of PsA treatment was confirmed by the improved clinical findings. Both PsADECTS and iodine uptake also showed significant improvement after treatment (Wilcoxon signed-rank test: z = 7.38, p < 0.005; z = 6.20, p < 0.005, respectively). The treatment effects of PsADECTS score and iodine uptake showed a good correlation with each other (Spearman's ρ = 0.58 p < 0.005). Inter-reader agreement for PsADECTS score and iodine uptake were either moderate or good. In conclusion, our study showed that the DECT iodine map is a valid tool for quantitative assessment of the therapeutic response of PsA.

Diagnostic value of ultrasonography and TI-201/Tc-99m dual scintigraphy in differentiating between benign and malignant thyroid nodules.

PURPOSE: To evaluate the performance of ultrasonography (US) and TI-201/Tc-99m dual (Tl/Tc) scintigraphy in differentiating between benign and malignant thyroid nodules. METHODS: Eighty-six patients diagnosed to have a thyroid tumor on postoperative histopathologic examination between June 2009 and February 2017 were included in this retrospective study. A radiologist reviewed the US and Tl/Tc scintigraphy reports along with all available clinical and histopathologic information. On Tl/Tc scintigraphy, a nodule in which uptake was higher in the delayed phase than in the surrounding parenchyma was defined as a delayed accumulation pattern and a nodule in which uptake was higher in the delayed phase than in the early phase was defined as a persistent pattern. The Tl/Tc scintigraphy images were evaluated in a blinded manner to assess reproducibility. A statistical analysis was performed to identify features associated with malignancy. Interobserver variability was calculated using the κ statistic. RESULTS: US had higher sensitivity (81.2%), specificity (88.2%), and positive (96.6%) and negative (53.6%) predictive values than Tl/Tc scintigraphy. An ill-defined margin and microcalcification were independent predictors of a malignant thyroid nodule on multivariate logistic regression (P = 0.003 and P = 0.014, respectively). The persistent pattern had high specificity (85.7%) equivalent to that of US but had lower sensitivity (34.7%). The κ values for the delayed accumulation and persistent patterns were 0.66-0.78 and 0.32-0.50, respectively. CONCLUSIONS: An ill-defined margin and microcalcification on US were independent predictors of a malignant thyroid nodule. A persistent pattern seen on Tl/Tc scintigraphy could contribute to the differential diagnosis.