Evaluating the perfusion of occupying lesions of kidney and bladder with contrast-enhanced ultrasound

The comparison between contrast-enhanced ultrasound and contrast-enhanced magnetic resonance imaging in diagnosing bladder urothelial carcinoma

PURPOSE

The surgical treatment of bladder urothelial carcinoma depends on whether the tumor has invaded the bladder muscular layer. Normal ultrasound and contrast-enhanced magnetic resonance imaging (contrast-enhanced MRI) are widely used in patients bear bladder tumors; the latter is also widely used in estimating the muscularis invasion of bladder cancer (BC). However, contrast-enhanced ultrasound (CEUS) is rarely used in this aspect. As the gold standard in diagnosing muscularis invasion remains being pathological examination, this study was set to find out whether there are differences between CEUS and contrast-enhanced MRI in diagnosing bladder malignant tumors and in diagnosing the muscularis invasion of the bladder urothelial carcinoma under the guide of the pathological results.

METHODS

160 patients from Yongchuan Hospital of Chongqing Medical University and The Second Affiliated Hospital of Chongqing Medical University were recruited from July 1st, 2021, to June 30th, 2022. Patients are arranged to undergo CEUS, contrast-enhanced MRI and then take a surgery. After surgery, we compare the results of CEUS, MRI and the pathological results, using software to run the statistical examinations.

RESULTS

The accuracies of CEUS and contrast-enhanced MRI in diagnosing malignant bladder tumors were 85.90 and 84.62%, and they had no differences (P > 0.05). While the accuracies of CEUS and contrast-enhanced MRI in diagnosing the muscularis invasion were 84.62 and 76.92%, in which CEUS had a better sensitivity (P < 0.05).

CONCLUSIONS

We found that CEUS and contrast-enhanced MRI had no differences in diagnosing the different pathological types (benign or malignant) of BC, but CEUS holds a better sensitivity in diagnosing muscularis invasions of bladder urothelial carcinoma than the contrast-enhanced MRI.

Highlights of the development in ultrasound during the last 70 years: A historical review

This review looks at highlights of the development in ultrasound, ranging from interventional ultrasound and Doppler to the newest techniques like contrast-enhanced ultrasound and elastography, and gives reference to some of the valuable articles in Acta Radiologica. Ultrasound equipment is now available in any size and for any purpose, ranging from handheld devices to high-end devices, and the scientific societies include ultrasound professionals of all disciplines publishing guidelines and recommendations. Interventional ultrasound is expanding the field of use of ultrasound-guided interventions into nearly all specialties of medicine, from ultrasound guidance in minimally invasive robotic procedures to simple ultrasound-guided punctures performed by general practitioners. Each medical specialty is urged to define minimum requirements for equipment, education, training, and maintenance of skills, also for medical students. The clinical application of contrast-enhanced ultrasound and elastography is a topic often seen in current research settings.

Contrast-Enhanced Ultrasound in the Bladder: Critical Features to Differentiate Occupied Lesions

Objective

To study the clinical diagnostic value of contrast-enhanced ultrasound (CEUS) in bladder occupied lesions.

Methods

38 cases of conventional-ultrasound-found bladder occupied lesions did color Doppler flow imaging (CDFI) and CEUS checks. By comparing the difference between two types of blood flow imaging technologies in displaying the flow of bladder occupied lesions and observing the perfusion modes of contrast agents to enter lesions, the perfusion characteristics of CEUS were analyzed. Finally, they were contrasted with the surgical pathology results.

Results

Of all the 38 cases, there were 51 bladder occupied lesions, including 43 bladder malignant tumors, 2 bladder inverted papillomas, and 6 glandular cystitis lesions. The blood flow display rate of bladder occupied lesions was 100% using CEUS. Apparently, it was higher than that of CDFI (62.7%), and the result of these showed a statistically significant difference (P < 0.05). Using CEUS, 46 malignant lesions and 5 glandular cystitis lesions were indicated, and the diagnostic accuracy rate was 86.3%.

Conclusion

CEUS can improve the blood flow display rate of bladder occupied lesions, and it can also observe the real-time blood flow of these lesions. It can help judge their nature and has a higher clinical value in differentiating the benign from the malignant.

ACR Appropriateness Criteria® Hematuria

Hematuria is a common reason for patients to be referred for imaging of the urinary tract. All patients diagnosed with hematuria should undergo a thorough history and physical examination, urinalysis, and serologic testing prior to any initial imaging. Ultrasound, CT, and MRI are the most common imaging modalities used to evaluate hematuria. This document discusses the following clinical scenarios for hematuria: initial imaging of microhematuria without risk factors or history of recent vigorous exercise, or presence of infection, or viral illness, or present or recent menstruation; initial imaging of microhematuria in patients with known risk factors and no history of recent vigorous exercise, or presence of infection, or viral illness, or present or recent menstruation or renal parenchymal disease; initial imaging of microhematuria in the pregnant patient and initial imaging of gross hematuria. Follow-up of normal or abnormal findings is beyond the scope of this review. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Contrast-Enhanced Ultrasound Characteristics of Renal Pelvis Urothelial Carcinoma and Its Relationship with Microvessel Density

We studied the characteristics of contrast-enhanced ultrasound (CEUS) in renal pelvic urothelial carcinomas and explored its performance in assessing microvessel density (MVD) of tumor tissues. We retrospectively analyzed the characteristics of 125 cases, which were confirmed pathologically to be renal pelvic urothelial carcinomas using CEUS. We performed CEUS and found that most tumors presented with an enhanced mode of "slow-in (mean = 16.7 ± 2.6 s, range: 12-25 s), hypo-enhancement and fast-out (mean = 69.3 ± 16.2 s, range: 42-113 s)." However, the wash-in pattern, homogeneity and wash-out pattern observed with CEUS was not correlated with pT stage and grade (p > 0.05). But advanced-pT-stage and high-grade tumors had a higher peak enhancement than early-pT-stage and low-grade tumors (p < 0.01). Peak enhancement obtained with CEUS can be used to evaluate the pT stage and grade of renal pelvic urothelial carcinomas more effectively. The MVD of those tissues was observed using immunohistochemical staining of cluster of differentiation 34 (CD34). MVD in the advanced-pT-stage and high-grade groups was significantly higher than that in the early-pT-stage and low-grade groups (p < 0.01). As tumor pT stage and grade improved, CEUS peak enhancement intensity and MVD of tumors also exhibited an upward trend. CEUS peak enhancement intensity has the potential to determine MVD of renal pelvic urothelial carcinomas.

Staging, surveillance, and evaluation of response to therapy in renal cell carcinoma: role of MDCT

Renal cell carcinoma is the most common malignant renal tumor in the adults. Significant advances have been made in the management of localized and advanced renal cell carcinoma. Surgery is the standard of care and accurate pre-operative staging based on imaging is critical in guiding appropriate patient management. Besides staging, imaging plays a key role in the post-operative surveillance and evaluation of response to systemic therapies. Both CT and MR are useful in the staging and follow up of renal cell carcinoma, but CT is more commonly used due to its lower costs and wider availability. In this article, we discuss and illustrate the role of multi-detector CT in pre-operative staging, post-operative surveillance, and evaluation of response to systemic therapy in renal cell carcinoma.

Diagnostic accuracy of contrast-enhanced ultrasound for renal cell carcinoma: a meta-analysis

This meta-analysis aimed to identify the accuracy of contrast-enhanced ultrasonography (CEUS) for the diagnosis of renal cell carcinoma (RCC). We searched PubMed, Web of Science, Google Scholar, Cochrane Library, CISCOM, CINAHL, EBSCO, and CBM databases from inception through August 1, 2013 without language restrictions. Meta-analysis was conducted using STATA version 12.0 and Meta-Disc version 1.4 softwares. We calculated the summary statistics for sensitivity (Sen), specificity (Spe), positive and negative likelihood ratio (LR+/LR-), diagnostic odds ratio (DOR), and receiver operating characteristic (SROC) curve. Eleven studies that met all inclusion criteria were included in this meta-analysis. A total of 567 RCC patients and 313 patients with benign renal tumors were assessed. All renal lesions were histologically confirmed after CEUS. The pooled Sen was 0.88 (95 %CI = 0.85 ∼ 0.90); the pooled Spe was 0.80 (95 %CI = 0.75 ∼ 0.85). The pooled LR+ was 4.30 (95 %CI = 2.65 ∼ 6.99); the pooled negative LR- was 0.11 (95 %CI = 0.05 ∼ 0.22). The pooled DOR of CEUS in the diagnosis of RCC was 46.97 (95 % CI = 16.72 ∼ 131.97). The area under the SROC curve was 0.922 (standard error [SE] = 0.039). We found no evidence for publication bias (t = -1.00, P = 0.342). Our meta-analysis indicates that CEUS may have high diagnostic accuracy in differential diagnosis between benign and malignant renal tumors. Thus, CEUS may be a good tool for the diagnosis of RCC.

CEUS in the study of bladder, method, administration and evaluation, a technical note

PURPOSE

Contrast-enhanced ultrasound (CEUS) is the application of ultrasound contrast agents (UCAs) to traditional medical sonography. The development of UCAs allowed to overcome some of the limitations of conventional B-mode and Doppler ultrasound techniques and enabled the display of the parenchymal microvasculature. Purpose of this paper is to delineate the elements of a solid and science-based technique in the execution of urinary bladder CEUS.

METHODS

We describe the technical execution of urinary bladder CEUS and the use of perfusion softwares to perform contrast enhancement quantitative analysis with generation of time-intensity curves from regions of interest.

RESULTS

During CEUS, normal bladder wall shows a wash-in time of 13 s, a time to peak (TTP) >40 s, a signal intensity (SI) <45 % and a wash-out time >80 s; Low-grade urothelial cell carcinoma (UCC) shows a wash-in time of 13 s, a time to peak TTP >28 s, a SI <45 % and a wash-out time of 40 s; High-grade UCC shows a wash-in time of 13 s, a TTP >28 s, a SI >50 % and a wash-out time of 58 s.

CONCLUSIONS

CEUS is a useful tool for an accurate characterization of bladder UCC although it has some drawbacks. To avoid misunderstandings, a widely accepted classification and a standardized terminology about the most significant parameters of this application should be adopted in the immediate future.

Evaluation of renal urothelial carcinoma by contrast-enhanced ultrasonography

PURPOSE

To observe ultrasonographic features of urothelial carcinoma in renal pelvis and evaluate contrast-enhanced ultrasound (CEUS) in diagnosis.

MATERIALS AND METHODS

Fifty-two patients with urothelial carcinoma underwent preoperative conventional US, colour Doppler flow imaging (CDFI) and CEUS.

RESULTS

Of 52 total lesions, 41 (78.8%) could be clearly identified by US, and 49 (94.2%) were enhanced by CEUS. Among US-imaged lesions, 39 (95.1%) were solid tumours, and two (4.9%) were mixed solid-cystic; 25 (61.0%) were isoechoic, 11 (26.8%) hypoechoic, and five (12.2%) hyperechoic. Analysis of tumour blood flow by CDFI characterised 17 avascular lesions (41.5% of total), 16 hypovascular (39.0%), and 8 hypervascular (19.5%). The resistance index ranged from 0.65 to 0.88 (mean of 0.71). Enhancement was seen in 49 lesions after injection of SonoVue. A slow enhancement pattern was observed in 36 lesions (73.5%) relative to renal cortex, and 13/49 (26.5%) showed simultaneous enhancement. At peak enhancement, 38 lesions (77.6%) were hypo-enhanced, six (12.2%) iso-enhanced, and five (10.2%) hyper-enhanced. There were 12 lesions with intertumoural necrosis or haemorrhage (24.5%) that were heterogeneously enhanced, and 37 (75.5%) were homogeneously enhanced. A fast washout pattern was observed in 46 lesions (93.9%), synchronous washout in two (4.08%), and slow washout in one (2.04%).

CONCLUSIONS

Slow-in, fast-out, and hypo-enhancement properties are associated with renal urothelial carcinoma and may thus have diagnostic value. We found that CEUS is able to identify tumours that are ambiguous by conventional US, and it thus significantly improves the confidence of diagnosis.