Hongliang Zhao

Dynamic contrast-enhanced MRI of benign prostatic hyperplasia and prostatic carcinoma : correlation with angiogenesis

AIM To investigate the diagnostic and differential diagnostic values of dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) in prostatic diseases, and to investigate the correlation between the parameters of SI-T curves and angiogenesis. MATERIALS AND METHODS Twenty-one patients with proven prostatic carcinoma (Pca) and 29 patients with proven benign prostatic hyperplasia (BPH) were examined using DCE MRI. Diagnostic characteristics for differentiation were examined using threshold values for maximum peak time, enhancement degree, and enhancement rate. Then, the signal intensity-time curves (SI-T curves) were analysed, and the correlations between the parameters of SI-T curves and the expression levels of vascular endothelial growth factor (VEGF) and microvascular density (MVD) were investigated. All patents underwent prostatectomy. DCE MRI and histological findings were correlated. RESULTS Pca showed stronger enhancement with an earlier peak time, higher enhancement, and enhancement rate (p<0.05). Regarding the type of SI-T curves, in the BPH group six were type A, 10 were type B, and 13 were type C, whereas in the Pca group, 14 were type A, six were type B, and only one was type C (Chi-square test, chi2=13.57, P<0.005). The VEGF and MVD expression levels of Pca were higher than those of BPH. Peak time was negatively correlated with the expression levels of VEGF and MVD, whereas the enhancement degree and enhancement rate showed positive correlations (Pearson correlation, p<0.05). CONCLUSION Based on T2-weighted imaging, DCE MRI curves can help to differentiate benign from malignant prostate tissue. In the present study the type C curve was rarely seen with malignant disease, but these results need confirmation.

Low concentration contrast medium for dual-source computed tomography coronary angiography by a combination of iterative reconstruction and low-tube-voltage technique: Feasibility study

OBJECTIVES To assess the impact of low-concentration contrast medium on vascular enhancement, image quality and radiation dose of coronary CT angiography (cCTA) by using a combination of iterative reconstruction (IR) and low-tube-voltage technique. MATERIALS AND METHODS One hundred patients were prospectively randomized to two types of contrast medium and underwent prospective electrocardiogram-triggering cCTA (Definition Flash, Siemens Healthcare; collimation: 128 mm × 0.6mm; tube current: 300 mAs). Fifty patients received Iopromide 370 were scanned using the conventional tube setting (100 kVp or 120 kVp if BMI ≥ 25 kg/m(2)) and reconstructed with filtered back projection (FBP). Fifty patients received Iodixanol 270 were scanned using the low-tube-voltage (80 kVp or 100 kVp if BMI ≥ 25 kg/m(2)) technique and reconstructed with IR. CT attenuation was measured in coronary artery and other anatomical regions. Noise, image quality and radiation dose were compared. RESULTS Compared with two Iopromide 370 subgroups, Iomeprol 270 subgroups showed no significant difference in CT attenuation (576.63 ± 95.50 vs. 569.51 ± 118.93 for BMI< 25 kg/m(2), p=0.647 and 394.19 ± 68.09 vs. 383.72 ± 63.11 for BMI ≥ 25 kg/m(2), p=0.212), noise (in various anatomical regions of interest) and image quality (3.5 vs. 4.0, p=0.13), but significantly (0.41 ± 0.17 vs. 0.94 ± 0.45 for BMI< 25 kg/m(2), p<0.001 and 1.14 ± 0.24 vs. 2.37 ± 0.69 for BMI ≥ 25 kg/m(2), p<0.001) lower radiation dose, which reflects dose saving of 56.4% and 51.9%, respectively. CONCLUSIONS Combined IR with low-tube-voltage technique, a low-concentration contrast medium of 270 mg I/ml can still maintain the contrast enhancement without impairing image quality, as well as significantly lower the radiation dose.

Accuracy, image quality, and radiation dose of prospectively ECG-triggered high-pitch dual-source CT angiography in infants and children with complex coarctation of the aorta.

RATIONALE AND OBJECTIVES To evaluate the diagnostic accuracy, image quality, and radiation dose of prospective electrocardiogram (ECG)-triggered high-pitch dual-source computed tomography (DSCT) in infants and young children with complex coarctation of the aorta (CoA). MATERIALS AND METHODS Forty pediatric patients aged < 4 years with suspected CoA underwent prospective ECG-triggered high-pitch DSCT angiography and transthoracic echocardiography (TTE). Surgery and/or conventional cardiac angiography (CCA) were performed in all patients. The diagnostic accuracy of DSCT angiography and TTE was compared to the surgical and/or CCA findings. The causes of misdiagnosis and miss were analyzed, and the advantages and limitation of both imaging modalities were evaluated. Image quality of DSCT was evaluated, and effective radiation dose was calculated. RESULTS The sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy of DSCT in evaluation of complex CoA were 92.37%, 98.51%, 97.32%, 93.57%, and 96.25%, respectively. There was a significant difference in the accuracy between DSCT and TTE (χ² = 9.9, P＜.05). For a total of 80 extracardiac anomalies, the sensitivity (98.8%, 79/80) of DSCT was greater than that of TTE (62.5%; 50 of 80). On the contrary, for 38 cardiac anomalies, the sensitivity (78.9%, 30 of 38) of DSCT was lesser than that of TTE (100%; 38 of 38). The mean score of image quality was 4.27 ± 0.73. The mean effective radiation dose was 0.20 ± 0.09 mSv. CONCLUSIONS Prospective ECG-triggered high-pitch DSCT may be a clinical feasible modality in the evaluation of pediatric patients with complex CoA, providing adequate image quality, high diagnostic accuracy, and low radiation dose.

Identification of CTA-Based Predictive Findings for Temporary and Permanent Neurological Dysfunction after Repair in Acute Type A Aortic Dissection

The aim of this study was to determine CT risk findings predictive of temporary neurological dysfunction (TND) and permanent neurological dysfunction (PND) after surgical repair for acute type A aortic dissection (ATAAD). A total of 255 patients (41 ± 16 years, 79% male) with ATAAD underwent aortic CT angiography (CTA) and surgical repair consecutively from January 2013 to June 2016. The CTA findings of the 255 patients for the thoracic aorta and carotid artery were analysed to identify risk factors predictive of TND and PND. Thirty-eight patients (15%) suffered TND, and 18 (7%) exhibited PND. Common carotid artery (CCA) dissection (OR = 4.63), lower enhancement of unilateral ICA (OR = 3.02) and aortic arch tears (OR = 2.83) were predictors of postoperative TND, while PND was best predicted by retrograde ascending aorta (aAO) dissection (OR = 5.62) and aortic arch tears (OR = 6.74). In CCA dissection, the extent of the entire CCA and proximal ICA (P = 0.014), a low-enhancement false lumen with re-entry (P = 0.000) and a severely narrowed true lumen without re-entry (P = 0.005) significantly increased the risk of postoperative TND. In patients with ATAAD, specific CT findings allow the individual risk of postoperative TND and PND to be identified and may guide subsequent surgical management.

The effect of without using anisodamine during CT enterography on image quality, diagnostic performance and latent side effects

OBJECTIVE To examine whether no anisodamine injection before CTE was feasible without impairing image quality and diagnostic performance. MATERIALS The change of mural thickness and luminal diameter were compared between using and no using anisodamine. The diagnostic performance of small-bowel disease was analyzed and compared. RESULTS No motion artifact was detected in two groups. There was no significant difference regarding the change of luminal diameter and mural thickness (all P>0.05). The diagnostic accuracy of small-bowel disease was no significant difference (P=0.63). CONCLUSION Lack of anisodamine injection before CTE did not impair image quality and diagnostic performance compared with CTEs performed with anisodamine injection.

Combined CT angiography of the aorta and craniocervical artery: a new imaging protocol for assessment of acute type A aortic dissection

Background To investigate the feasibility of combined computed tomography angiography (CTA) of the aorta and craniocervical artery in acute type A aortic dissection (ATAAD) and the value of incremental craniocervical information. Methods Combined CTA of head, neck and aorta was performed in patients with suspected aortic dissection and 243 ATAAD patients were analyzed. The image quality and radiation dose were assessed. Valuable craniocervical CTA findings were determined for further surgical analysis. Results The mean dose-length product (DLP) was 314.11±29.31 mGy.cm. The image quality of craniocervical arteries were 100% diagnostic. Intimal flap involving carotid arteries was detected in 47% of patients, and significant stenosis of true lumen was observed in 60% of common carotid arteries (CCAs). Hypodensity and hypoplasia/occlusion of carotid arteries were also detected and apprised surgeons. The tortuosity of carotid artery was found in 90.9% of patients. Bilateral antegrade selective cerebral perfusion (ASCP) was performed in 21.1% of aortic arch surgery based on 7 hemodynamic variation types of the circle of Willis (CW) determined by cranial CTA information. Conclusions A combined CTA of head, neck and aorta is feasible with low radiation dose and diagnostic image quality. Incremental information on craniocervical pathology and anatomy may be useful for surgery repair of ATAAD.