Ultrasound features

The maximum diameter of the mass ranged from 1.2 to 13.9 cm, with an average of (4.45 ± 2.02) cm. There were 85 lesions with maximum diameter ≤ 3 cm and 59 lesions > 3 cm. 62 on the left and 82 on the right; There were 92 hypoechoic, 18 isoechoic and 24 hyperechoic. 61 had clear boundaries and 83 had unclear boundaries.

Pathological results

Among 144 solid renal masses, 51 were benign lesions, including 46 angiomyolipomas, 4 eosinophilic adenomas, and 1 inflammatory pseudotumor. There were 93 malignant lesions, including 68 clear cell carcinoma of the kidney, 13 chromophobe cell carcinoma, 10 papillary renal cell carcinoma, 1 mucinous carcinoma, and 1 nephroblastic carcinoma.

The consistency of blood flow grade and vascular architecture of renal lesions

According to two single ultrasound radiologists’ results, the Kappa coefficients of renal mass blood flow grading in CDFI, SMI and MFI modes were 0.731, 0.856 and 0.865, respectively, and the Kappa coefficients of blood vessel architecture were 0.772, 0.819 and 0.793, respectively.

Blood flow grading analysis of 144 renal lesions based on CDFI, SMI and MFI

The blood flow detection rates of CDFI, SMI and MFI were 78.5% (113/144), 88.9% (128/144) and 93.8% (135/144), respectively. The blood flow grading results were shown in Table 2. Based on CDFI, SMI and MFI, Blood flow grading from 0 to 1 was 56.3% (81/144), 42.3% (61/144) and 37.5% (54/144), respectively. Blood flow grade 2 to 3 were 43.8% (63/144), 57.6% (83/144), and 62.5% (90/144), respectively. Using MFI images in clearance period as a reference, the coincidence rates of CDFI and SMI blood flow grading were 64.58% (93/144) and 81.25% (117/144), respectively. MFI and SMI can detect small, low-speed blood flow signals which CDFI cannot display (Figs. 1 and 2).

Table 2 Blood flow grade of 144 renal lesions based on CDFI, SMI and MFI
Fig. 1
figure 1

A solid mass of left kidney A ultrasound imaging of CDFI, hyperechoic mass with clear boundary, regular shape, and inhomogeneous internal echo B SMI show point-line blood flow signal in the tumor, blood flow grade 1. C MFI show point-line blood flow signal in the tumor, blood flow grade 1, pathological result was hamartoma

Fig. 2
figure 2

A solid tumor of the right kidney A ultrasound imaging, hypoechoic mass with unclear boundary, regular shape, and inhomogeneous internal echo B SMI show multiple large vessels and their dot and linear blood flow branches around and inside the tumor, blood flow grade 3 C MFI ultrasonography showed more clearly vascular branches than SMI, and it could show the branch shape. blood flow grade 3. The pathological result was clear cell renal cell carcinoma

CDFI was significantly different from SMI vascular architecture, 2 to 3 was significantly lower than SMI (x2 = 5.557, P = 0.018). Using the blood flow grading shown by MFI images in the clearance period as a reference, there was a statistically significant difference between CDFI and MFI in evaluating the blood flow grading of renal masses (x2 = 10.165, P = 0.001). There was no statistical significance in blood flow grading between SMI and MFI (x2 = 2.372, P = 0.499).

Vascular architecture analysis of 144 renal lesions based on CDFI, SMI and MFI

In Table 3, CDFI, SMI and MFI were used to examine renal masses, vascular architecture of type I, II and III accounted for 75% (108/144), 50.7% (73/144) and 43.1% (62/144), respectively. Type IV and V vascular architecture accounted for 25% (36/144), 49.3% (71/144) and 56.9% (82/144). SMI could display low-speed blood flow signals, thus showed more detailed and accurate delineation of vascular architecture (Figs. 3 and 4). Using the vascular architecture shown in MFI images during clearance period as a reference, the coincidence rates of CDFI and SMI vascular architecture classification were 56.25% (81/144) and 75.69% (109/144), respectively.

Table 3 Vascular architecture of 144 renal lesions based on CDFI, SMI and MFI
Fig. 3
figure 3

A solid tumor of the right kidney A ultrasound imaging, hyperechoic mass with clear boundary, regular shape, and inhomogeneous internal echo B SMI show a small blood vessels can be seen in the mass, the blood vessel architecture for type II C MFI showed peripheral and internal contorts the blood vessels, blood vessel vascular architecture for type III, pathological results of hamartoma

Fig. 4
figure 4

A solid tumor of the right kidney A ultrasound imaging, isoechoic mass with unclear boundary, regular shape, and inhomogeneous internal echo, with hypoecho and echoless area and small fluid area B SMI the growth from the periphery to the interior was tortuous and disorderly, with multiple branching vessels, and the vascular architecture was type V C MFI images showed the tortuous and disorderly growth of multi-branched vessels from the periphery to the interior. The vascular architecture was type V. Pathological results showed clear cell renal cell carcinoma

CDFI was significantly different from SMI vascular architecture, IV and V was significantly lower than SMI(x2 = 18.217, P < 0.001). Using the vascular architecture of MFI images in the clearance period as a reference, there was a statistically significant difference between CDFI and MFI in the evaluation of renal tumor vascular architecture (x2 = 29.518, P < 0.001). There was no statistically significant difference between SMI and MFI in the evaluation of renal tumor vascular architecture (x2 = 3.048, P = 0.550).

The diagnostic performance of CDFI, SMI and MFI

The diagnosis of benign lesions was based on blood flow grade 0, grade 1, and vascular architecture pattern type I, II and III. The diagnosis of malignant lesions was based on blood flow grade 2, 3 and vascular architecture type IV, V. The diagnostic results of CDFI, SMI and MFI were shown in Table 4. The sensitivity, specificity, 95% confidence interval and area under the ROC curve of SMI and MFI for the diagnosis of benign and malignant renal lesions were calculated respectively, as shown in Table 5. The areas under the ROC curves(AUC) of the three groups were 0.757, 0.839, and 0.862, respectively. Z test results showed that there was a statistically significant difference in the diagnostic efficiency between CDFI and MFI in benign and malignant diagnosis of renal masses (Z = 3.687, P = 0.0002). The diagnostic efficacy of SMI and MFI in the diagnosis of benign and malignant kidney was not statistically significant (Z = 1.167, P = 0.2431), Fig. 5.

Table 4 CDFI, SMI and MFI in the diagnosis result of benign and malignant renal tumors
Table 5 The diagnostic performance of CDFI, SMI, MFI
Fig. 5
figure 5

The ROC curves of identify benign and malignant renal lesions in CDFI. SMI and MFI

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Disclaimer:

This article is autogenerated using RSS feeds and has not been created or edited by OA JF.

Click here for Source link (https://www.biomedcentral.com/)