BACKGROUND: Neurofibromatosis type 1 (NF1) is a highly heterogeneous autosomal genetic disorder characterized by a broad spectrum of clinical and molecular manifestations. The correlations between genotype and phenotype in NF1 remain elusive. This study aimed to elucidate genotype-phenotype associations in a large Chinese cohort of NF1 patients.
METHODS: We included NF1 patients from our center who underwent genetic testing for NF1 variants and systemic examination. Genotype-phenotype correlation analyses were performed, focusing on variation types and involved neurofibromin domains.
RESULTS: A total of 195 patients were enrolled, comprising 105 males and 90 females, with a median age of 18 years. Truncating variants, single amino acid variations, and splicing variants accounted for 139/195 (71.3%), 23/195 (11.8%), and 33/195 (16.9%), respectively. Patients with splicing variants exhibited a significantly higher prevalence of spinal plexiform neurofibromas (spinal PNF) than those with truncating variants (76.4% vs. 51.8%; p = 0.022). Variations affecting the PKC domain were associated with higher rates of cutaneous neurofibromas (CNF) (100% vs. 64.9%, p < 0.001), Lisch nodules (100% vs. 61.2%, p < 0.001), plexiform neurofibromas (PNF) (100% vs. 95.7%, p = 0.009), and psychiatric disorders (11.8% vs. 1.6%, p = 0.042). Patients with mutations in the CSRD had an elevated risk of secondary primary malignancies (11.6% vs. 2.8%, p = 0.015). GRD involvement might enhance the risk of Lisch nodules (76.9% vs. 53.7%, p = 0.044). Variations in the Sec14-PH domain were correlated with a higher rate of CNF (76.8% vs. 58.6%, p = 0.014). Additionally, we found that the p.R1748* variants carry a high risk of malignancy.
CONCLUSIONS: Our study suggested some novel genotype-phenotype correlations within a Chinese cohort, providing innovative insights into this complex field that may contribute to genetic counseling, risk stratification, and clinical management for the NF1 population.

To determine the distribution and diagnostic value of peripheral enthesitis detected by whole-body MRI (WBMRI) in axial spondyloarthritis (axSpA) diagnosis, and to determine the value of the peripheral enthesitis score in axSpA assessment.
Sixty axSpA patients [mean age of 33.2 (24.8-40.6) years] and 50 controls with chronic low back pain (LBP) [mean age of 34.7 (28.3-41.1) years] were enrolled. The gold standard was physician\'s comprehensive diagnosis based on current classification criteria and physical examination. All subjects underwent WBMRI, and 47 peripheral entheses were assessed for each patient with scores of 0-188.
WBMRI identified 155 enthesitis sites in 78.3% (n = 47) patients with axSpA. Meanwhile, 23 enthesitis sites were identified in 32% (n = 16) controls. The pelvis had the maximum number of enthesitis sites (52, 33.5%) in axSpA patients. Pelvic and anterior chest wall enthesitis had the highest sensitivity (51.67%) and specificity (100%) in axSpA diagnosis, respectively. There were different manifestations of enthesitis subtypes between axSpA patients and the control group. Osteitis was more present than soft-tissue inflammation in axSpA patients. The AUC for the number of enthesitis sites was 0.819 (95% CI 0.739-0.899), and that for the enthesitis score was 0.833 (95% CI 0.755-0.910), indicating statistically significant differences (P = 0.025). Based on the Youden index and clinical need, three enthesitis sites (sensitivity of 53.33, specificity of 98, and Youden index of 0.51) and enthesitis score (sensitivity of 58.33, specificity of 98, and Youden index of 0.56) may have the greatest value for axSpA diagnosis.
The distribution of peripheral enthesitis can be adequately assessed by whole-body MRI, which could help diagnose axial spondyloarthritis. The enthesitis score may provide a more accurate assessment and diagnostic tool in axSpA compared with enthesitis site counting.

OBJECTIVE: To evaluate the diagnostic accuracy of whole-body MRI (WB-MRI) for assessment of hematological malignancies\' therapeutic response.
METHODS: PubMed, Embase, and Web of Science were searched up to August 2021 to identify studies reporting the diagnostic performance of WB-MRI for the assessment of hematological malignancies\' treatment response. A bivariate random-effects model was applied for the generation of the pooled diagnostic performance.
RESULTS: Fourteen studies with 457 patients with lymphoma, multiple myeloma, and sarcoma (very small proportion) were analyzed. Overall pooled sensitivity and specificity of WB-MRI were 0.88 (95% CI: 0.73-0.95) and 0.86 (95% CI: 0.73-0.93), respectively. Studies using whole-body diffusion-weighted imaging (WB-DWI) showed higher sensitivity than those that did not (0.94 vs. 0.55, p = 0.02). The pooled concordance rate of WB-MRI to assess hematological malignancies\' treatment response with reference standard was 0.78 (95% CI: 0.59-0.96). WB-MRI and PET/CT showed similar diagnostic performance (sensitivity [0.83 vs. 0.92, p = 0.11] and specificity [0.87 vs. 0.76, p = 0.73]).
CONCLUSIONS: WB-MRI has high diagnostic performance for hematological malignancies\' treatment response assessment. The adding of WB-DWI is strongly associated with increased sensitivity.

OBJECTIVE: A whole-body MRI (WB-MRI) including T1, short time inversion recovery (STIR), diffusion-weighted imaging (high b value) was applied in our center for the detection of bone metastasis in prostate cancer (PCa) patients. We intended to assess the diagnostic performance of this examination.
METHODS: 547 cases of PCa patients with higher risk of metastasis were referred to bone scintigraphy with SPECT/CT (BS + SPECT/CT) and whole-body MRI in Shanghai Changhai Hospital. Best valuable comparator (BVC) was applied for the final diagnosis of metastasis. A panel of radiologists interpreted the results. Decision curve analysis (DCA) and receiver operating characteristic curve (ROC) analysis were applied.
RESULTS: Bone metastasis was diagnosed in 110 cases, and others were non-metastatic by BVC. The area under the receiver operating characteristic curve (AUC) was higher in WB-MRI (0.778) than BS + SPECT/CT (0.634, p < 0.001). A WB-MRI-based prediction model was established with AUC of 0.877. Internal validation showed that the predictive model was well-calibrated. The DCA demonstrated that the model had higher net benefit than the BS + SPECT/CT-based model.
CONCLUSIONS: WB-MRI is more effective in identifying metastasis in PCa patients than BS + SPECT/CT. The prediction model combined WB-MRI with clinical parameters may be a promising approach to the assessment of metastasis.

OBJECTIVE. The purpose of this study is to evaluate the diagnostic performance of whole-body (WB) DWI with background body suppression (DWIBS) combined with calculation of the apparent diffusion coefficient (ADC) value at 3 T compared with the diagnostic performance of 18F-FDG PET/CT for detecting bone metastases in patients with malignant tumors. SUBJECTS AND METHODS. Thirty-nine consecutive patients with suspected bone metastases underwent both WB DWIBS and FDG PET/CT. Imaging findings were independently interpreted using qualitative and quantitative analyses. Pathologic findings or clinical or radiologic follow-up data were used as the diagnostic reference standard. The sensitivity, specificity, overall accuracy, positive predictive value, and negative predictive value of both modalities were calculated. The ADCs of benign lesions and metastases were compared. RESULTS. A total of 213 metastatic bone segments were confirmed among 39 patients. The sensitivity, specificity, overall accuracy, positive predictive value, and negative predictive value were 93.0%, 87.8%, 89.6%, 79.8%, and 96.0%, respectively, for WB DWIBS and 92.5%, 92.0%, 92.1%, 85.7% and 95.9%, respectively, for FDG PET/CT. The specificity of WB DWIBS in detecting bone metastases was significantly lower than that of FDG PET/CT (p < 0.05), whereas the sensitivity, overall accuracy, positive predictive value, and negative predictive value in detecting bone metastases were not significantly different between WB DWIBS and FDG PET/CT (p > 0.05). The ADCs for benign lesions were significantly higher than those for metastases (p < 0.001). In ROC curve analysis, the AUC value was 0.901. A cutoff ADC value of 920.5 × 10-6 mm2s-1 distinguished benign lesions from bone metastases with a sensitivity of 92.9% and a specificity of 73.4%. CONCLUSION. WB DWIBS coupled with ADC analysis at 3 T is effective for detecting bone metastases.

OBJECTIVE: To determine the clinical value of multiparametric whole-body (WBMRI) over whole-spine magnetic resonance imaging (WSMRI) in patients with neurofibromatosis type 1 (NF1).
METHODS: A consecutive series of 30 patients with known NF1 underwent WBMRI screening using anatomic, diffusion, and contrast imaging over a 30-month period. Thirteen of 30 patients also had WSMRI. Tumors were classified per location and morphology and were software segmented to determine numbers and volumes. Extra tumor burden detected by WBMRI was assessed. The comparison was made between WBMRI and WSMRI in 13 patients who had both types of scans. Enhancement characteristics were noted and 2 readers recorded apparent diffusion coefficient (ADC) in 30 patients with WBMRI scans. Interobserver performance was assessed using intraclass correlations. A 2-sample test was used for testing mean differences between tumors.
RESULTS: The age of 30 patients with WBMRI and 13 patients with WSMRI were 39.4 ± 14.4 and 41.54 ± 10.79 years (mean ± standard deviation) and male/female ratio was 1:1.73 and 1:2.25, respectively. Only 1 patient was found to have a heterogeneously enhancing lumbar paraspinal malignant peripheral nerve sheath tumor, seen on both WBMRI and WSMRI. The additional total number of tumors on WBMRI was 2766 and 2602 tumors were missed on WSMRI. The volume of tumors was 16,053 cm3 and 15,614 cm3 of tumor burden was incrementally detected on WBMRI. Mean ADC of superficial tumors was significantly lower than that of deep tumors (1.93 ± 0.39 × 10-3 mm2/second and 2.26 ± 0.56 × 10-3 mm2/second, respectively; P = 0.009), whereas no ADC differences were seen in plexiform versus discrete tumors (P = 0.64). Interobserver performance for ADC was excellent (intraclass correlation, 0.84).
CONCLUSIONS: Multiparametric WBMRI provides superior determination of tumor burden and should be considered as a preferred method for evaluation of patients with NF1.

OBJECTIVE: We performed a meta-analysis to investigate and compare diagnostic performance of whole-body MRI and skeletal scintigraphy for detection of bone metastatic tumors.
METHODS: PubMed and Embase were searched for relevant articles. We calculated sensitivities, specificities, diagnostic odds ratios (DOR), positive likelihood ratios (PLR), negative likelihood ratios (NLR), and constructed summary receiver operating characteristic curves using bivariate models for whole-body MRI and skeletal scintigraphy, respectively.
RESULTS: Across 7 studies (332 patients), whole-body MRI have similar patient-based sensitivity (0.84 vs 0.83), specificity (0.96 vs 0.94), DOR (137.0 vs 70.2), PLR (23.3 vs 13.0) and NLR (0.17 vs 0.19) with skeletal scintigraphy. Area under curves for whole-body MRI and skeletal scintigraphy was 0.94 and 0.89, respectively.
CONCLUSIONS: Both whole-body MRI and skeletal scintigraphy have good diagnostic performance for detecting bone metastatic tumors. It remains inconclusive whether whole-body MRI or bone scintigraphy is superior in detecting bone metastatic tumors.