Expression of regional brain amyloid-β deposition with [18F]Flutemetamol in Centiloid scale -a multi-site study

PURPOSE

The Centiloid project helps calibrate the quantitative amyloid-β (Aβ) load into a unified Centiloid (CL) scale that allows data comparison across multi-site. How the smaller regional amyloid converted into CL has not been attempted. We first aimed to express regional Aβ deposition in CL using [18F]Flutemetamol and evaluate regional Aβ deposition in CL with that in standardized uptake value ratio (SUVr). Second, we aimed to determine the presence or absence of focal Aβ deposition by measuring regional CL in equivocal cases showing negative global CL.

METHODS

Following the Centiloid project pipeline, Level-1 replication, Level-2 calibration, and quality control were completed to generate corresponding Centiloid conversion equations to convert SUVr into Centiloid at regional levels. In equivocal cases, the regional CL was compared with visual inspection to evaluate regional Aβ positivity.

RESULTS

14 out of 16 regional conversions from [18F]Flutemetamol SUVr to Centiloid successfully passed the quality control, showing good reliability and relative variance, especially precuneus/posterior cingulate and prefrontal regions with good stability for Centiloid scaling. The absence of focal Aβ deposition could be detected by measuring regional CL, showing a high agreement rate with visual inspection. The regional Aβ positivity in the bilateral anterior cingulate cortex was most prevalent in equivocal cases.

CONCLUSION

The expression of regional brain Aβ deposition in CL with [18F]Flutemetamol has been attempted in this study. Equivocal cases had focal Aβ deposition that can be detected by measuring regional CL.

Prediction of pathological activity in Crohn's disease based on dual-energy CT enterography

PURPOSE

To explore the feasibility of predicting the pathological activity of Crohn's disease (CD) based on dual-energy CT enterography (DECTE).

METHODS

The clinical, endoscopic, imaging and pathological data of 55 patients with CD scanned by DECTE were retrospectively analyzed; the pathological results were used as a reference standard to classify the diseased bowel segments into active and inactive phases. The normalized iodine concentration (NIC), energy-spectrum curve slope K, dual energy index (DEI), fat fraction (FF) of the arterial phases and venous phases were compared. To assess the parameters' predictive ability, receiver-operating characteristic curves were used. The Delong test was used to compare the differences between the diagnostic efficiency of each parameter.

RESULTS

A total of 84 intestinal segments were included in the study, including 54 active intestinal segments and 30 inactive intestinal segments. The NIC, energy-spectrum curve slope K and DEI were significantly different between active and inactive bowel segments in the arterial and venous phases (P < 0.05), while FF were not significantly different (P > 0.05). The largest area under the curve (AUC) of NIC, energy-spectrum curve slope K and DEI were higher in arterial phase than in venous phase. For identifying the intestinal activity of CD, the maximum AUC of NIC in arterial phase was 0.908, with a sensitivity of 0.833 and a specificity of 0.800, and the DEI in arterial phase had the highest sensitivity (0.944).

CONCLUSION

The NIC, energy-spectrum curve slope K and DEI can effectively distinguish the active and inactive phases of the intestinal segments of CD patients and provide good assistance for determining further treatment.

Comparison of the clinical application value of mo-targeted X-ray, color doppler ultrasound and MRI in preoperative comprehensive evaluation of breast cancer

Objective

To investigate the clinical application value of the Mo-targeted X-ray examination, color Doppler ultrasound and magnetic resonance imaging (MRI) in the diagnosis and preoperative comprehensive evaluation of breast cancer.

Methods

Among 170 breast cancer patients, they underwent Mo-targeted X-ray examination, color Doppler ultrasound and MRI before surgery to evaluate the lesions in breast, axillary lymph nodes and the availability of breast-conserving surgery.

Results

The detection rates using color Doppler ultrasound examination and MRI were higher than that in the Mo-targeted X-ray examination, which were 90%, 94% and 82%, respectively (P < 0.01 or 0.05). With the result of pathological examination as the golden criteria, we found that specificities of Mo-targeted X-ray examination, color Doppler ultrasound examination and MRI in evaluating the metastasis in axillary lymph nodes were similar (85.11%, 77.66% and 79.79%; P > 0.05). Before surgery, the sensitivities and accuracies of the color Doppler ultrasound examination and MRI were higher than those using the Mo-targeted X-ray examination, which were 73.21%, 82.14%, and 28.57%, 76.00%, 80.67% and 64.00% (P < 0.01 or 0.05). Before surgery, the accuracy rate of MRI in evaluating the breast-conserving surgery was higher than those of Mo-targeted X-ray examination and color Doppler ultrasound (92.00%, 83.33% and 84.67%; P < 0.05).

Conclusion

Combined application of Mo-targeted X-ray examination, color Doppler ultrasound and MRI shows a higher accuracy in diagnosis of breast cancer and evaluation of axillary lymph node metastasis, which is conducive to the selection of surgical methods.

Combined application of pharamcokinetic DCE-MRI and IVIM-DWI could improve detection efficiency in early diagnosis of ductal carcinoma in situ

PURPOSE

Ductal carcinoma in situ (DCIS) is a precursor of invasive ductal breast carcinoma (IDC). This study aimed to use pharamcokinetic dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) for the early diagnosis of DCIS.

METHODS

Forty-seven patients, including 25 with DCIS (age: 28-70 yr, mean age: 48.7 yr) and 22 with benign disease (age: 25-67 yr, mean age: 43.1 yr) confirmed by pathology, underwent pharamcokinetic DCE-MRI and IVIM-DWI in this study. The quantitative parameters K^trans , K_ep , V_e , V_p , and D, f, D* were obtained by processing of DCE-MRI and IVIM-DWI images with Omni-Kinetics and MITK-Diffusion softwares, respectively. Parameters were analyzed statistically using GraphPad Prism and MedCalc softwares.

RESULTS

All low-grade DCIS lesions demonstrated mass enhancement with clear boundaries, while most middle-grade and high-grade DCIS lesions showed non-mass-like enhancement (NMLE). DCIS lesions were significantly different from benign lesions in terms of K^trans , K_ep , and D (t = 5.959, P < 0.0001; t = 5.679, P < 0.0001; and t = 5.629, P < 0.0001, respectively). The AUC of K^trans , K_ep , D and the combined indicator of K^trans , K_ep, and D were 0.936, 0.902, 0.860, and 0.976, respectively. There was a significant difference in diagnostic efficacy only between D and the combined indicator (Z = 2.408, P = 0.016).

CONCLUSION

DCE-MRI and IVIM-DWI could make for the early diagnosis of DCIS, and reduce the misdiagnosis of DCIS and over-treatment of benign lesions.