Diagnostic value of integrated 18F-PSMA-1007 PET/MRI compared with that of biparametric MRI for the detection of prostate cancer.

Objective: To assess the diagnostic value of fluorine 18 (18F)-labeled prostate-specific membrane antigen (PSMA)-1007 Positron emission tomography/Magnetic resonance imaging (PET/MRI) and compared with that of biparametric MRI (bpMRI) for the detection of prostate cancer (PCa). Materials and methods: The study enrolled 29 patients with suspected PCa preoperatively who underwent 18F-PSMA-1007 PET/MRI and subsequent targeted biopsy for suspected PCa lesions. Two readers independently assessed the images of each suspected PCa lesion and determined their overall assessment category on bpMRI and 18F-PSMA-1007 PET/MRI. By using biopsy histopathology as the reference standard, the accuracies of 18F-PSMA-1007 PET/MRI and bpMRI for the detection of PCa lesion were determined. Furthermore, the receiver-operating characteristic (ROC) curves of their semi-quantitative parameters of the optimal standardized uptake value (SUVmax) and apparent diffusion coefficient (ADC) for detecting PCa lesions were derived, and their correlations with the International Society of Urological Pathology (ISUP) grade were reported. Results: Of the 48 suspected PCa lesions in 29 patients, 38 were pathologically diagnosed with clinically significant PCa and 10 with nonprostate cancer (non-PCa) lesions. Compared with the pathological results, 18F-PSMA-1007 PET/MRI demonstrated much greater diagnostic accuracy (area under the curve, AUC), sensitivity, specificity, positive predictive value, and negative predictive value than bpMRI: 0.974 versus 0.711, 94.74% versus 92.11%, 100% versus 50%, 100% versus 87.50%, and 83.33% versus 62.50%, respectively. The semi-quantitative parameters of SUVmax demonstrated a higher AUC of 0.874 than that of ADC with 0.776 for detecting PCa. The ISUP grade was positively associated with SUVmax at spearman's rho correlation coefficient (Rho) = 0.539, p = 0), but not associated with ADC (Rho = -0.105, p = 0.529). Conclusion: The diagnostic value of 18F-PSMA-1007 PET/MRI for the detection of PCa is better than that of bpMRI, and a high SUVmax may indicate a lesion with a high ISUP grade.

Pelvic Plexiform Schwannoma on 18F-FDG PET/MRI.

ABSTRACT: Plexiform schwannoma (PS), a subtype of schwannoma, is a rare benign nerve sheath tumor characterized by a multinodular plexiform growth pattern. It is usually confined to the head and neck or skin. Pelvic PS is an extremely rare occurrence and signifies a challenge for the imaging diagnosis. In this work, we present a 42-year-old woman with pelvic PS, who was initially suspected of malignant tumor on 18F-FDG PET/MRI but confirmed as PS by postoperative pathology. We consider that this case would contribute to the literature and provide a further insight into diagnosing this kind of rare tumor.

Imaging Diagnosis of Epithelioid Hemangioendothelioma in Thoracic Vertebrae and Liver.

Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor of uncertain biologic behavior. Most cases come out as a single lesion of the soft tissue but also may appear in the lung, liver, and other locations. EHE in bone, especially in thoracic vertebrae, is an extremely rare occurrence and signifies a challenge for the imaging diagnosis. This paper presents a rare case of EHE occurring in thoracic vertebrae and liver revealed by fluoride-18-fluorodeoxyglucose-positron emission tomography and magnetic resonance imaging to provide a better understanding of its clinical application and further insight into diagnosing a rare thoracic tumor.

T1 ρ and T2 mapping for the determination of articular cartilage denaturalization with osteonecrosis of the femoral head: A prospective controlled trial.

BACKGROUND: In the future, biochemical MRI might provide a valuable noninvasive quantitative analysis of the biochemical composition of cartilage in osteonecrosis of the femoral head (ONFH). PURPOSE: To investigate the diagnostic performance of T1 ρ and T2 mapping in cartilage denaturalization with ONFH and to determine the correlation between T1 ρ and T2 mapping and the Association Research Circulation Osseous (ARCO) stage. STUDY TYPE: Prospective. SUBJECTS: Forty-seven patients with ONFH (stage I to III according to the ARCO criteria) and 24 volunteers (control group) were recruited for the prospective study. SEQUENCE: Conventional MRI, multiple echo recalled gradient echo (MERGE), and T1 ρ and T2 mapping sequences. ASSESSMENT: Pseudocolor images and MERGE images were combined in the AW4.5 workstation. The region of interest (ROI) of the hip cartilage was 4-6 mm². The sagittal T1 ρ and T2 mapping values were calculated by the two first authors. STATISTICAL TESTS: One-way analysis of variance (ANOVA), LSD t-tests, Pearson correlation analysis, and receiver operator characteristic (ROC) curves. The significance level was set at P < 0.05. RESULTS: The T1 ρ and T2 mapping values of the ONFH group were significantly higher than the values of the control group (P = 0.000). Regarding the assessment of the severity of ARCO staging, both T1 ρ (r = 0.66, P = 0.004) and T2 mapping (r = 0.501, P = 0.002) were positively associated with disease severity. The T1 ρ values were positively correlated with the T2 mapping values (r = 0.381, P = 0.000). The areas under the curve (AUC) for the T1 ρ and T2 mapping values were 0.822 and 0.791, respectively. The diagnostic sensitivity and specificity were 72.34% and 70.83% for T1 ρ mapping and 72.34% and 58.33%, respectively, for T2 mapping. DATA CONCLUSION: Both T1 ρ and T2 mapping performed well in diagnosing the cartilage denaturalization in ARCO stage I-III ONFH patients. T1 ρ mapping had a higher diagnostic sensitivity and specificity than T2 mapping. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:760-767.

Resveratrol increases nucleus pulposus matrix synthesis through activating the PI3K/Akt signaling pathway under mechanical compression in a disc organ culture.

Disc nucleus pulposus (NP) matrix homeostasis is important for normal disc function. Mechanical overloading seriously decreases matrix synthesis and increases matrix degradation. The present study aims to investigate the effects of resveratrol on disc NP matrix homeostasis under a relatively high-magnitude mechanical compression and the potential mechanism underlying this process. Porcine discs were perfusion-cultured and subjected to a relatively high-magnitude mechanical compression (1.3 MPa at a frequency of 1.0 Hz for 2 h once per day) for 7 days in a mechanically active bioreactor. The non-compressed discs were used as controls. Resveratrol was added along with culture medium to observe the effects of resveratrol on NP matrix synthesis under mechanical load respectively. NP matrix synthesis was evaluated by histology, biochemical content (glycosaminoglycan (GAG) and hydroxyproline (HYP)), and expression of matrix macromolecules (aggrecan and collagen II). Results showed that this high-magnitude mechanical compression significantly decreased NP matrix content, indicated by the decreased staining intensity of Alcian Blue and biochemical content (GAG and HYP), and the down-regulated expression of NP matrix macromolecules (aggrecan and collagen II). Further analysis indicated that resveratrol partly stimulated NP matrix synthesis and increased activity of the PI3K/Akt pathway in a dose-dependent manner under mechanical compression. Together, resveratrol is beneficial for disc NP matrix synthesis under mechanical overloading, and the activation of the PI3K/Akt pathway may participate in this regulatory process. Resveratrol may be promising to regenerate mechanical overloading-induced disc degeneration.