Accuracy of contrast-enhanced ultrasound in the detection of bladder cancer

Bladder Cancer and Artificial Intelligence: Emerging Applications

Bladder cancer is a common and heterogeneous disease that poses a significant burden to the patient and health care system. Major unmet needs include effective early detection strategy, imprecision of risk stratification, and treatment-associated morbidities. The existing clinical paradigm is imprecise, which results in missed tumors, suboptimal therapy, and disease progression. Artificial intelligence holds immense potential to address many unmet needs in bladder cancer, including early detection, risk stratification, treatment planning, quality assessment, and outcome prediction. Despite recent advances, extensive work remains to affirm the efficacy of artificial intelligence as a decision-making tool for bladder cancer management.

Contrast-enhanced Ultrasound Combined With Elastography for the Evaluation of Muscle-invasive Bladder Cancer in Rats

OBJECTIVES

By comparing with the control group, we evaluated the usefulness of contrast-enhanced ultrasound (CEUS) combined with elastography for the assessment of muscle invasion by bladder cancer (MIBC) in a Sprague-Dawley (SD) rat model.

METHODS

In the experimental group, 40 SD rats developed in situ bladder cancer (BLCA) in response to N-methyl-N-nitrosourea treatment, whereas 40 SD rats were included in the control group for comparison. We compared PI, Emean , microvessel density (MVD), and collagen fiber content (CFC) between the two groups. In the experimental group, Bland-Altman test was used to assess the relationships between various parameters. The largest Youden value was used as the cut-off point, and binomial logistic regression analysis was performed to analyze the PI and Emean . Receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic power of parameters, individually and in combination.

RESULTS

The PI, Emean , MVD, and CFC were significantly lower in the control group than in the experimental group (P < .05). The PI, Emean , MVD, and CFC were significantly higher for MIBC than for non-muscle-invasive bladder cancer (P < .05). There were significant correlations between PI and MVD, and between Emean and CFC. The diagnostic efficiency analysis showed PI had the highest sensitivity, CFC had the highest specificity, and PI + Emean had the highest diagnostic efficacy.

CONCLUSION

CEUS and elastography can distinguish lesions from normal tissue. PI, MVD, Emean , and CFC were useful for the detection of BLCA myometrial invasion. The comprehensive utilization of PI and Emean improved diagnostic accuracy and have clinical application.

LC-MS based urine untargeted metabolomic analyses to identify and subdivide urothelial cancer

Introduction

Urine metabolomics has been a promising technique in the liquid biopsy of urothelial cancer (UC). The comparison of upper tract urothelial cancer (UTUC), lower tract urothelial cancer (BCa), and healthy controls (HCs) need to be performed to find related biomarkers.

Methods

In our investigation, urine samples from 35 UTUCs, 44 BCas, and 53 gender- and age-matched HCs were analyzed using liquid chromatography-high resolution mass spectrometry (LC-HRMS). In different groups, the differential metabolites and the disturbed metabolism pathways were explored. Transcriptomics and urine metabolomics are combined to identify the probably disturbed gene in BCa.

Results

With an area under the curve (AUC) of 0.815, the panel consisting of prostaglandin I2, 5-methyldeoxycytidine, 2,6-dimethylheptanoyl carnitine, and deoxyinosine was able to discriminate UC from HCs. With an AUC of 0.845, the validation group also demonstrated strong predictive ability. UTUC and BCa without hematuria could be distinguished using the panel of 5'-methylthioadenosine, L-beta-aspartyl-L-serine, dehydroepiandrosterone sulfate, and N'-formylkynurenine (AUC=0.858). The metabolite panel comprising aspartyl-methionine, 7-methylinosine, and alpha-CEHC glucuronide could discriminate UTUC from BCa with hematuria with an AUC of 0.83. Fatty acid biosynthesis, purine metabolism, tryptophan metabolism, pentose and glucuronate interconversions, and arachidonic acid metabolism were dysregulated when comparing UC with HCs. PTGIS and BCHE, the genes related to the metabolism of prostaglandin I2 and myristic acid respectively, were significantly associated with the survival of BCa.

Discussion

Not only could LC-HRMS urine metabolomic investigations distinguish UC from HCs, but they could also identify UTUC from BCa. Additionally, urine metabolomics combined with transcriptomics can find out the potential aberrant genes in the metabolism.

Incidental Diagnosis of Urothelial Bladder Cancer: Associations with Overall Survival

BACKGROUND

We investigated whether an incidental diagnosis (ID) of bladder cancer (BC) was associated with improved survival.

METHODS

We retrospectively reviewed data of consecutive patients with no prior diagnosis of urothelial cancer who underwent a primary transurethral resection of bladder tumor (pTURBT) between January 2013 and February 2021 and were subsequently diagnosed with urothelial BC. The type of diagnosis (incidental or non-incidental) was identified. Overall, relative, recurrence-free, and progression-free survival rates (OS, RS, RFS, and PFS) after pTURBT were evaluated using the Kaplan-Meier curves and long-rank tests. A multivariable Cox regression model for the overall mortality was developed.

RESULTS

A total of 435 patients were enrolled. The median follow-up was 2.7 years. ID cases were more likely to be low-grade (LG) and non-muscle-invasive. ID vs. non-ID was associated with a trend toward an improved 7-year OS (66% vs. 49%, p = 0.092) and a significantly improved 7-year OS, if incidental cases were limited to ultrasound-detected tumors (75% vs. 49%, p = 0.013). ID was associated with improved survival among muscle-invasive BC (MIBC) patients (3-year RS: 97% vs. 23%, p < 0.001), but not among other subgroups stratified according to disease stage or grade. In multivariable analysis, only age, MIBC, and high-grade (HG) cancer demonstrated an association with mortality. PFS and RFS among non-MIBC patients did not differ in regard to the type of diagnosis.

CONCLUSIONS

Incidental diagnosis may contribute to an improved survival in BC patients, most probably in the mechanism of the relative downgrading of the disease, including the possible overdiagnosis of LG tumors. Nevertheless, in the subgroup analyses, we noted marked survival benefits in MIBC cases. Further prospective studies are warranted to gain a deeper understanding of the observed associations.

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.

Contrast-enhanced ultrasound features of focal pancreatic lesions in dogs

BACKGROUND

Contrast-enhanced ultrasound (CEUS) features of pancreatic lesions are poorly reported in veterinary literature.

METHODS

Qualitative and quantitative features of pancreatic benign (nodular hyperplasia [NH], cyst and abscess) and malignant (adenocarcinoma and insulinoma) lesions during B-mode and CEUS examinations are described in 75 dogs.

RESULTS

Adenocarcinomas (n = 23) had mixed echogenicity at B-mode, and they were hypoenhancing or non-enhancing at CEUS, with a non-homogeneous and cystic enhancement pattern. Insulinomas (n = 23) appeared as hypoechoic lesions at B-mode, and as hyperenhancing, homogeneous and solid lesions at CEUS. NH (n = 17) had an constant appearance, being hypoechoic at ultrasound (US) and isoenhancing at CEUS. Cysts (n = 7) were all anechoic, with acoustic enhancement clearly detectable at US, but were non-enhancing at CEUS. Lastly, abscesses (n = 5) had mixed echogenicity, and they showed both hyperenhancement and non-enhancement at CEUS. Hypoenhancement and non-homogeneous appearance had a moderate diagnostic accuracy in the detection of adenocarcinomas. In particular, hyperenhancement was evident only in malignant lesions (adenocarcinomas and insulinomas).

CONCLUSION

CEUS, in combination with B-mode US features, is a valuable tool for distinction of benign and malignant abnormalities of the pancreas and can potentially differentiate insulinomas from adenocarcinomas.

Advances in Transversal Topics Applicable to the Care of Bladder Cancer Patients in the Real-World Setting

Simple Summary

There are a number of scientific questions that are novel or controversial, which are clinically relevant in the real-world setting for patients diagnosed with bladder cancer, independently of the stage of disease or the histological type and grade of the tumors. These transversal topics have been discussed by a panel of expert specialists who participated in the Genitourinary Alliance Project, aimed to develop actions focused on the integration of relevant information into clinical practice. Advances in radiological imaging techniques have the potential of improving accuracy of staging methods, resulting in a more personalized planning and therapeutic option. The use of liquid biopsy will undoubtedly contribute to an increase in the efficiency of the evaluation of the clinical response and outcome of the disease. It is important to consider specific conditions of elderly people with bladder cancer, as well as the implementation of appropriate measures to enhance safe drug administration.

Abstract

Recommendations regarding transversal topics applicable to bladder cancer patients independent of tumor grade and stage were established by members of the Spanish Oncology Genitourinary Multidisciplinary Working Group (SOGUG). Liquid biopsy in urine and blood samples is useful in the surveillance of non-muscle-invasive and muscle-invasive bladder cancer, respectively. Multiparametric MRI is an accurate, faster and non-invasive staging method overcoming the understaging risk of other procedures. The combination of FDG-PET/MRI could improve diagnostic reliability, but definite criteria for imaging interpretation are still unclear. Hospital oncology pharmacists as members of tumor committees improve the safety of drug use. Additionally, safety recommendations during BCG preparation should be strictly followed. The initial evaluation of patients with bladder cancer should include a multidimensional geriatric assessment. Orthotopic neobladder reconstruction should be offered to motivated patients with full information of self-care requirements. Bladder-sparing protocols, including chemoradiation therapy and immune checkpoints inhibitors (ICIs), should be implemented in centers with well-coordinated multidisciplinary teams and offered to selected patients. The optimal strategy of treatment with ICIs should be defined from the initial diagnostic phase with indications based on scientific evidence. Centralized protocols combined with the experience of professional groups are needed for the integral care of bladder cancer patients.

Head-to-Head Comparison between High-Resolution Microultrasound Imaging and Multiparametric MRI in Detecting and Local Staging of Bladder Cancer: The BUS-MISS Protocol

BACKGROUND: MRI has been proposed as a new staging tool for bladder cancer (BC), but use is limited by its high costs and low availability. 29-MHz high-resolution micro-ultrasound (mUS) technology has been suggested as an alternative to detect BC and distinguish between muscle-invasive and non-muscle invasive BC. OBJECTIVE: The aim was to compare the diagnostic accuracy of mUS vs. magnetic resonance imaging (MRI) in differentiating NMIBC and MIBC at definitive pathological examination. METHODS: This is a prospective study of patients with a primary diagnosis of BC with either positive urine cytology (UC) or negative UC and a tumor size >  25 mm from a tertiary care high volume center. mUS, with the ExactVu system with an EV29L 29 MHz side-fire transducer, and a 3-Tesla MRI were performed before transurethral resection of bladder tumor (TURBT) in every patient before undergoing TURBT. We compared the imaging results with pathological reports. RESULTS: The analyzed population consisted of 58 individuals. The reported mUS and MRI sensitivity, specificity, positive, and negative predictive values were 85.0%, 76.3%, 65.4%, and 90.6%, versus 85.0%, 50.0%, 47.2%, and 86.4%, respectively. In accuracy analysis, the AUC for mUS and MRI were respectively 0.807 and 0.675. CONCLUSIONS: In our population mUS seems to have a better performance in distinguishing NMIBC from MIBC. The main limitation of mUS is the probe shape that makes its use problematic in cases with a large prostate and inadequate rectal preparation. Further studies with a larger population are ongoing to compare and validate these techniques in this setting.

Fall time may be a reliable discriminator between neoplastic and non-neoplastic urinary bladder lesions in dogs undergoing contrast-enhanced ultrasound: a pilot study

Contrast-enhanced ultrasound (CEUS) can provide quantitative information on enhancement patterns and perfusion of lesions, based on time-intensity curves (TICs). No published studies have compared CEUS parameters in neoplastic and non-neoplastic urinary bladder lesions in dogs. The aim of the current prospective, pilot study was to quantitatively characterize the CEUS pattern of neoplastic and non-neoplastic urinary bladder lesions in dogs, assessing the influence of contrast arrival time (CAT) on the final appearance of the curves. Fourteen dogs with cyto-histopathological diagnoses were included (seven malignant and seven inflammatory lesions). B-mode ultrasound was performed followed by CEUS examination after an intravenous bolus injection of 0.04 mL/kg of contrast medium, and TICs were elaborated by dedicated software. Receiver operating characteristic curves (ROC) for each TIC parameter were obtained. Neoplastic lesions had subjectively shorter rise time (RT), time to peak (TTP) and fall time (FT) than inflammatory lesions. Based on ROC curve analyses, fall time ≥ 10.49 s was the most reliable parameter for diagnosing non-neoplastic disease in this small sample of dogs (area under the curve [AUC] 0.75, sensitivity 83.33%, specificity 66.67%). No difference was found between ROCs calculated for each parameter of TICs by adding or removing CAT. Results of the current study provide background for future, larger scale studies evaluating use of a CEUS FT threshold of 10.49 s as a possible discriminator for urinary bladder neoplastic lesions in dogs.

Contrast-enhanced ultrasonography promotes differential diagnosis of ureteral neoplasms

OBJECTIVE

To compare the diagnostic value of contrast-enhanced ultrasonography (CEUS) with baseline ultrasound (B-US) in ureteral neoplasms.

METHODS

Retrospective analysis, comprising clinical presentation, image appearances, and diagnostic results on B-ultrasound and CEUS, considering pathological result as a gold-standard, was conducted on the clinical information of 39 patients with ureteral neoplasms. CT urography was used to detect and confirm the presence of ureteral neoplasms. Both B-ultrasound and CEUS investigations of those 39 patients under study were performed by a senior radiologist.

RESULTS

Pathological outcomes established 27 ureteral malignancies and 12 ureteral benignancies. Ureteral malignancies were observed to occur in older patients than benignancies (p = 0.002). Only the morphological indicator of the ureteric wall on B-ultrasound was different in ureteral malignancies and benignancies (p = 0.030). Tumors with hyperenhancement, larger width, and hyperenhanced ureteric wall were easily diagnosed as malignant on CEUS, whereas iso-/hypoenhanced, narrower, and iso-/hypoenhanced ureteric wall indicated benign tumors. Moreover, the lesion widths, enhanced morphologies of the ureteric wall, and the ureteral wall's linear boundaries on CEUS were different between high- and low-stage ureteral urothelial carcinomas (p = 0.012, 0.002, 0.001, respectively).

CONCLUSION

The display of microvessels in ureteral neoplasms was significantly enhanced by CEUS, thus contributing to the differential diagnosis of ureteral neoplasms while assisting the staging of ureteral urothelial carcinoma.

ADVANCES IN KNOWLEDGE

The imaging features of different ureteral neoplasms on CEUS were analyzed in this study. The diagnostic performances of CEUS and B-ultrasound in ureteral urothelial carcinomas were also explored.

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.

Shiga Toxins: An Update on Host Factors and Biomedical Applications

Shiga toxins (Stxs) are classic bacterial toxins and major virulence factors of toxigenic Shigella dysenteriae and enterohemorrhagic Escherichia coli (EHEC). These toxins recognize a glycosphingolipid globotriaosylceramide (Gb3/CD77) as their receptor and inhibit protein synthesis in cells by cleaving 28S ribosomal RNA. They are the major cause of life-threatening complications such as hemolytic uremic syndrome (HUS), associated with severe cases of EHEC infection, which is the leading cause of acute kidney injury in children. The threat of Stxs is exacerbated by the lack of toxin inhibitors and effective treatment for HUS. Here, we briefly summarize the Stx structure, subtypes, in vitro and in vivo models, Gb3 expression and HUS, and then introduce recent studies using CRISPR-Cas9-mediated genome-wide screens to identify the host cell factors required for Stx action. We also summarize the latest progress in utilizing and engineering Stx components for biomedical applications.

Estadificación clínica como factor pronóstico en cáncer de vejiga músculo-invasor

El cáncer de vejiga músculo invasor (CV-MI), requiere de una adecuada estadificación clínica y patológica, ya que eso determina las estrategias terapéuticas y el pronóstico de la enfermedad, caracterizada por una alta morbimortalidad. Este articulo tiene como objetivo realizar una revisión de la literatura sobre la exactitud diagnóstica de las técnicas de imagen disponibles para la estadificación clínica de los pacientes con CV-MI y cómo se debería realizar el seguimiento radiológico en los pacientes llevados a cirugía. Para eso se realizó una búsqueda en la base de datos Pubmed de artículos en inglés y en español, se incluyeron artículos de revisión, metanálisis, guías clínicas, estudios retrospectivos y prospectivos de pronóstico y diagnóstico desde el año 1988 hasta el año 2020.

Application of contrast-enhanced ultrasonography for large cell neuroendocrine carcinoma in the urinary bladder: a case report

Background

Large cell neuroendocrine carcinoma (LCNEC) of the urinary bladder is an uncommon malignant bladder tumor, and the overall prognosis is poor. Contrast-enhanced ultrasound (CEUS) provides a new effective modality for tumor detection and diagnosis.

Case presentation

A 30-year-old man complained of repeated painless gross haematuria for half a month. Conventional ultrasound demonstrated a hypoechoic solitary lesion with hyperechoic margins measuring 3.4 × 3.1 cm in the anterior wall of the bladder. Superb microvascular imaging (SMI) showed a strong flow signal in the mass. CEUS revealed that the lesion was characterized by hyper-enhancement in the early phase and hypo-enhancement in the late phase. The entire bladder wall was disrupted by homogeneous hyper-enhanced tumor tissue on CEUS. Time-intensity curves (TICs) showed a rapid wash-in with a high maximum signal intensity (SI) and quick wash-out. Finally, partial cystectomy was performed and the pathological examination confirmed the diagnosis of LCNEC with invasion into the whole layer of the bladder wall.

Conclusion

This case suggested that CEUS was a valuable imaging method to detect and diagnose LCNEC in the bladder, and that CEUS can provide information related to the depth of wall invasion and the microvasculature.

Imaging in Localized Bladder Cancer: Can Current Diagnostic Modalities Provide Accurate Local Tumor Staging?

PURPOSE OF REVIEW

Local tumor staging is paramount in the evaluation and management of bladder cancer. While neoadjuvant chemotherapy (NAC) followed by radical cystectomy and urinary diversion remains the gold standard for management of muscle-invasive bladder cancer, bladder-sparing regimens involving systemic chemotherapy and pelvic radiotherapy remain a viable option for select patients. Moreover, pre-cystectomy identification of patients with a complete response to NAC may obviate the need for radical cystectomy, but accurate post-therapy staging can be difficult to achieve. Contemporary imaging techniques may provide additional benefit in local tumor staging beyond standard imaging and cystoscopic biopsy. Our purpose is to summarize the ability of different imaging modalities to accurately stage bladder cancer patients in the treatment-naïve and post-chemotherapy settings.

RECENT FINDINGS

Contemporary investigations have been studying multiparametric magnetic resonance imaging (mp-MRI) in the evaluation of bladder cancer. Its recent incorporation into bladder cancer staging is mainly being assessed in treatment-naïve patients; however, different sequences are being studied to assess their accuracy after the introduction of chemotherapy and possibly radiation. Multiple recent studies incorporating cystoscopy and biopsy are proving to be less accurate than originally predicted. Imaging has generally had a very limited role in guiding therapy in localized bladder cancer, but with the incorporation of newer sequences and techniques, imaging is poised to become vital in decision-making strategies of this cancer. Reliable local tumor staging through improved imaging may help better select patients for bladder-sparing treatments while maintaining optimized oncologic outcomes and allow this paradigm to become more acceptable in the urologic oncology community.

Prospective evaluation of 4-D contrast-enhanced-ultrasound (CEUS) imaging in bladder tumors

PURPOSE

The evaluation of the potential clinical benefit of four-dimensional ultrasound (4D-US) in the assessment of bladder cancer (BC).

MATERIAL AND METHODS

20 patients with indication for cystoscopy for suspicion of bladder cancer were prospectively included in this study. All patients underwent two-dimensional ultrasound (2D-US), contrast enhanced ultrasound (CEUS) and real-time four-dimensional ultrasound (4D-US). All acquisitions were compared to each other in regard to image quality. This assessment was done using a 6 point scale (1 = best). All patients underwent subsequently cystoscopy with resection of the tumor (TURB), due a histopathological analysis was possible.

RESULTS

All examinations were performed successfully and no patient had to be excluded from the study. Patients acceptance of 4D-US was consistently good. No adverse events occurred. Image quality of real time 4D-US (score: 1.27±0.46) was significantly superior (p < 0.001) to both, conventional 2D-US (score: 2.33±0.62) and also to 2D-CEUS (score: 2.00±0.53). In terms of tumor detection no superiority was evident for 4D-US compared to 2D-US or in utilization of CEUS (sensitivity = 0.89; specificity = 1.00; positive predictive value = 1.00; negative predictive value = 0.50; AUC = 0.944; (95% CI: 07.43-0.998)).

CONCLUSION

The assessment of bladder cancer using real time 4D-US is feasible and improves the image quality and therefore also the precise anatomical consistency of intravesical tumor masses.

Role of imaging techniques in the diagnosis and follow-up of muscle-invasive bladder carcinoma

INTRODUCTION

Muscle-invasive bladder malignancies represent 20-30% of all bladder cancers. These patients require imaging tests to determine the regional and distant staging.

OBJECTIVE

To describe the role of various imaging tests in the diagnosis, staging and follow-up of muscle-invasive bladder cancer. To assess recent developments in radiology aimed at improving the sensitivity and specificity of local staging and treatment response.

ACQUISITION OF EVIDENCE

We conducted an updated literature review.

SYNTHESIS OF THE EVIDENCE

Computed tomography and magnetic resonance imaging (MRI) are the tests of choice for performing proper staging prior to surgery. Computed tomography urography is currently the most widely used technique, although it has limitations in local staging. Ultrasonography still has a limited role. Recent developments in MRI have improved its capacity for local staging. MRI has been suggested as the test of choice for the follow-up, with promising results in assessing treatment response. Positron emission tomography could improve the detection of adenopathies and extrapelvic metastatic disease.

CONCLUSIONS

Imaging tests are essential for the diagnosis, staging and follow-up of muscle-invasive bladder cancer. Recent technical developments represent important improvements in local staging and have opened the possibility of assessing treatment response.

Quantitative evaluation of canine urinary bladder transitional cell carcinoma using contrast-enhanced ultrasonography

Background

In veterinary medicine, contrast-enhanced ultrasonography allowed the accurate quantification of liver, splenic and kidney vascularization in healthy dogs and the differentiation between malignant and benign hepatic, renal, and splenic nodules in dogs and cats based on perfusion patterns. The utility of contrast-enhanced ultrasonography in other applications is still under study.

The aim of this study was to develop diagnostic criteria by contrast-enhanced ultrasonography in 8 client-owned adult dogs affected by urinary bladder transitional cell carcinoma with definitive diagnosis made by cytopathologic evaluation after suction biopsy. The contrast enhancement pattern and the quantification of blood flow parameters of this tumor were reported.

Results

Examinations with B-mode, Doppler ultrasonography and contrast-enhanced ultrasonography were performed in all not sedated dogs. Assessments of bladder masses and bladder wall infiltration were performed. Each dog received 2 bolus injections of sulfur hexafluoride during the contrast-enhanced ultrasonography. Quantitative analysis of the contrast-enhanced ultrasonography images were performed. For each dog, one region of interest was manually drawn around the entire tumor. Software analysis of contrast-enhanced time-intensity curves was used to identify peak enhancement, time to peak enhancement, regional blood volume, regional blood flow, and mean transit time.

Contrast-enhanced ultrasonography showed an avid enhancement of the tumour tissue, with a heterogeneous or homogeneous pattern. The exam also showed the loss of planes between the lesion and the muscular layer. The presence of vascularized tissue through the bladder wall confirms the infiltrative feature of the tumour. Post-processing quantitative analysis showed a time-intensity curve with a rapid wash-in, a low level of signal intensity and a slow wash-out.

Conclusions

Contrast-enhanced ultrasonography provided useful clinical information and defined a vascular enhancement patterns and calculated parameters associated with TCC. It may be a useful, noninvasive and reproducible tool for detecting these tumors in dogs.

Contrast-enhanced ultrasound of small cell carcinoma in urinary bladder: a case report and review of literature

BACKGROUND

Small cell carcinoma of the urinary bladder (SCCB) is a relatively rare malignant bladder tumor, and few reports have investigated the microvasculature of SCCB imaged using contrast-enhanced ultrasound (CEUS).

CASE PRESENTATION

A 63-year-old female was admitted to our hospital after experiencing painless gross hematuria for one week. The gray-scale ultrasound (US) demonstrated a 4.8 × 3.4 × 3.6-cm³ hypoechoic mass in the apex of the urinary bladder with a wide base and an irregular surface; the mass did not move with changes in body position. Color Doppler flow imaging (CDFI) showed rich blood flow in the mass. CEUS with low mechanical index (MI) of 0.06 confirmed a highly enhanced 5.0 × 3.3 × 3.8 cm³ mass within the bladder at the apex wall. The time-intensity curves (TICs) showed a wash-in time of 10 s, a time to peak (TTP) of 33 s, a signal intensity (SI) of 62.7% and a wash-out time > 60 s. Finally, the transurethral resection of the bladder tumor (TURBT) was performed, and the pathological examination proved the diagnosis of SCCB.

CONCLUSION

CEUS can provide valuable information related to the rich microvasculature of SCCB, which may be helpful in its diagnosis.

Differentiation between high- and low-grade urothelial carcinomas using contrast enhanced ultrasound

Purpose

To evaluate the value of contrast-enhanced ultrasonography (CEUS) in the differentiation of high and low grade urothelial carcinoma.

Materials and Methods

192 with 192 bladder lesions, including 110 high grade urothelial carcinoma and 82 low grade urothelial carcinoma were examined by CEUS. Among 192 tumors, enhancement patterns of 96 tumors between August 2010 and December 2012 were analyzed retrospectively. Then from January 2013 to April 2015, compared with CEUS was performed on 96 tumors for prospective differential diagnosis. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value were assessed.

Results

With the CEUS view, dominant enhancement patterns were revealed as fast wash-in and slow wash-out for high grade urothelial carcinoma, fast wash-in and fast wash-out for low grade urothelial carcinoma, respectively. At CEUS, the prospective differentiation of bladder tumors showed sensitivity 86% , specificity 90%, accuracy 88%, positive predictive value 92%, and negative predictive value 82% for high grade tumors, while sensitivity 85% , specificity 89%, accuracy 88%, positive predictive value 85% and negative predictive value 89% for low grade tumors, respectively.

Conclusions

Our study demonstrates the great potential of CEUS in the differentiation of high and low grade urothelial carcinoma. Since CEUS is an effective, inexpensive, and non-invasive method. It could be a reliable tool in the evaluation of patients with bladder tumors.

Biocompatible astaxanthin as novel contrast agent for biomedical imaging

Photoacoustic imaging (PAI) is a hybrid imaging modality with high resolution and sensitivity that can be beneficial for cancer staging. Due to insufficient endogenous photoacoustic (PA) contrast, the development of exogenous agents is critical in targeting cancerous tumors. The current study demonstrates the feasibility of marine-oriented material, astaxanthin, as a biocompatible PA contrast agent. Both silicon tubing phantoms and ex vivo bladder tissues are tested at various concentrations (up to 5 mg/ml) of astaxanthin to quantitatively explore variations in PA responses. A Q-switched Nd : YAG laser (λ = 532 nm) in conjunction with a 5 MHz ultrasound transducer is employed to generate and acquire PA signals from the samples. The phantom results presented that the PA signal amplitudes increase linearly with the astaxanthin concentrations (threshold detection = 0.31 mg/ml). The tissue injected with astaxanthin yields up to 16-fold higher PA signals, compared with that with saline. Due to distribution of the injected astaxanthin, PAI can image the margin of astaxanthin boles as well as quantify their volume in 3D reconstruction. Further investigations on selective tumor targeting are required to validate astaxanthin as a potential biocompatible contrast agent for PAI-assisted bladder cancer detection.

Feasibility of quantitative contrast ultrasound imaging of bladder tumors in dogs

The purpose of this pilot study was to assess the feasibility of Cadence contrast pulse sequencing ultrasound to predict clinical and angiogenic tumor response in dogs undergoing chemotherapy. Contrast ultrasound facilitated visualization of bladder tumors but failed to identify a straightforward relationship between ultrasound measures and clinical outcome.

Molecular targets in urothelial cancer: detection, treatment, and animal models of bladder cancer

Bladder cancer remains one of the most expensive cancers to treat in the United States due to the length of required treatment and degree of recurrence. In order to treat bladder cancer more effectively, targeted therapies are being investigated. In order to use targeted therapy in a patient, it is important to provide a genetic background of the patient. Recent advances in genome sequencing, as well as transcriptome analysis, have identified major pathway components altered in bladder cancer. The purpose of this review is to provide a broad background on bladder cancer, including its causes, diagnosis, stages, treatments, animal models, as well as signaling pathways in bladder cancer. The major focus is given to the PI3K/AKT pathway, p53/pRb signaling pathways, and the histone modification machinery. Because several promising immunological therapies are also emerging in the treatment of bladder cancer, focus is also given on general activation of the immune system for the treatment of bladder cancer.

The utility and limitations of contrast-enhanced ultrasound for the diagnosis and treatment of prostate cancer

In association with the widespread use of prostate specific antigen (PSA) screening, the numbers of men identified with early-stage prostate cancer (PCa) are increasing in the developed countries, including Japan. However, the accurate localization of PCa lesions in diagnostic imaging is still difficult because PCa has a tendency to be multifocal in the prostate gland. Contrast-enhanced ultrasound (CEUS) improves the detection of PCa by visualizing cancerous lesions in order to target a needle biopsy. CEUS has the potential to enable not only accurate diagnoses but also novel treatments such as focal therapy. The combination of CEUS and other modalities is expected to improve the diagnosis of PCa and its treatment.

Improving bladder cancer imaging using 3-T functional dynamic contrast-enhanced magnetic resonance imaging

OBJECTIVES

The objective of this study was to assess the capability of T2-weighted magnetic resonance imaging (T2W-MRI) and the additional diagnostic value of dynamic contrast-enhanced MRI (DCE-MRI) using multitransmit 3 T in the localization of bladder cancer.

MATERIALS AND METHODS

This prospective study was approved by the local institutional review board. Thirty-six patients were included in the study and provided informed consent. Magnetic resonance imaging scans were performed with T2W-MRI and DCE-MRI on a 3-T multitransmit system. Two observers (with 12 and 25 years of experience) independently interpreted T2W-MRI before DCE-MRI data (maps of pharmacokinetic parameters) to localize bladder tumors. The pathological examination of cystectomy bladder specimens was used as a reference criteria standard. The McNemar test was performed to evaluate the differences in sensitivity, specificity, and accuracy. Scores of κ were calculated to assess interobserver agreement.

RESULTS

The sensitivity, specificity, and accuracy of the localization with T2W-MRI alone were 81% (29/36), 63% (5/8), and 77% (34/44) for observer 1 and 72% (26/36), 63% (5/8), and 70% (31/44) for observer 2. With additional DCE-MRI available, these values were 92% (33/36), 75% (6/8), and 89% (39/44) for observer 1 and 92% (33/36), 63% (5/8), and 86% (38/44) for observer 2. Dynamic contrast-enhanced MRI significantly (P<0.01) improved the sensitivity and accuracy for observer 2. For the 23 patients treated with chemotherapy, DCE-MRI also significantly (P<0.02) improved the sensitivity and accuracy of bladder cancer localization with T2W-MRI alone for observer 2. Scores of κ were 0.63 for T2W-MRI alone and 0.78 for additional DCE-MRI. Of 7 subcentimeter malignant tumors, 4 (57%) were identified on T2W images and 6 (86%) were identified on DCE maps. Of 11 malignant tumors within the bladder wall thickening, 6 (55%) were found on T2W images and 10 (91%) were found on DCE maps.

CONCLUSIONS

Compared with conventional T2W-MRI alone, the addition of DCE-MRI improved interobserver agreement as well as the localization of small malignant tumors and those within bladder wall thickening.

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.

Advances in bladder cancer imaging

The purpose of this article is to review the imaging techniques that have changed and are anticipated to change bladder cancer evaluation. The use of multidetector 64-slice computed tomography (CT) and magnetic resonance imaging (MRI) remain standard staging modalities. The development of functional imaging such as dynamic contrast-enhanced MRI, diffusion-weighted MRI and positron emission tomography (PET)-CT allows characterization of tumor physiology and potential genotypic activity, to help stratify and inform future patient management. They open up the possibility of tumor mapping and individualized treatment solutions, permitting early identification of response and allowing timely change in treatment. Further validation of these methods is required however, and at present they are used in conjunction with, rather than as an alternative to, conventional imaging techniques.

How much dose can be saved in three-phase CT urography? A combination of normal-dose corticomedullary phase with low-dose unenhanced and excretory phases

OBJECTIVE

The purpose of this study was to investigate the degree to which the total radiation dose for CT urography can be lowered by selective reduction of the dose in the unenhanced and excretory phases when images in these phases are systematically evaluated alongside normal-dose corticomedullary phase images.

SUBJECTS AND METHODS

Twenty-seven patients (mean age, 74±9 years) underwent single-bolus CT urography with acquisition in the unenhanced, corticomedullary, and 5-minute excretory phases. The scanning parameters for normal-dose CT urography were as follows: 16×0.75 mm, 120 kV, and automatic exposure control technique reference tube loads of 100, 120, and 100 effective mAs (mAseff). The patients also underwent low-dose unenhanced and excretory phase scanning, in which the dose was escalated stepwise from a volume CT dose index (CTDIvol) of 1.7 to 6.6 mGy (reference 20-40-60-80 mAseff). Images were analyzed for quality and diagnostic confidence. If low-dose scans of three patients were inadequate, the study continued to the next dose level. When 20 patients were successfully included in the unenhanced and excretory phase groups, the study ended. Doses were calculated with a CT patient dosimetry calculator.

RESULTS

Combined with the normal dose for corticomedullary phase scanning, doses of CTDIvol 1.5 mGy for the unenhanced phase and CTDIvol 2.7 mGy for the excretory phase were sufficient. The effective dose for three-phase CT urography was lowered from 16.2 to 9.4 mSv, a decrease of 42%. Diagnostic confidence in low-dose images was equal to that in normal-dose images when low-dose unenhanced and excretory phase images were read along-side normal-dose corticomedullary phase images.

CONCLUSION

With a three-phase CT urographic protocol, significant dose reductions in the unenhanced and excretory phases can be achieved when these phases are combined with a normal-dose corticomedullary phase.

[The impact of ultrasound in urology]

Ultrasound is of great importance in the diagnosis of acute and chronic diseases in urology, such as kidney colic, testicular torsion, low-grade kidney trauma or for follow-up of vesicoureteral reflux, evaluation of infertility, measurement of residual urinary volume and the detection of cancer. An ultrasound examination is time and cost-effective without exposure to ionizing radiation and is routinely performed by practitioners as well as in the clinical daily routine. With technical innovations, such as contrast-enhanced ultrasound or real time elastography, it would for instance be possible to extend the application field of ultrasound. However, in some fields of investigation ultrasound still lacks accuracy and despite its many advantages the validity of ultrasound findings sometimes has to be verified with computed tomography (CT) or magnetic resonance imaging (MRI).

Delay in diagnosis of cancer as a patient safety issue - a root cause analysis based on a representative case report

Background

It is well known in the literature that imaging has almost no value for diagnosis of superficial bladder cancer. However, wide gap exists between knowledge on diagnosis of bladder cancer and actual clinical practice.

Case presentation

Delay in diagnosis of bladder cancer in a male person with tetraplegia occurred because of reliance on negative flexible cystoscopy and single biopsy, negative ultrasound examination of urinary bladder, and computerised tomography of pelvis. Difficulties in scheduling cystoscopy also contributed to a delay of nearly ten months between the onset of haematuria and establishing a histological diagnosis of vesical malignancy in this patient. The time interval between transurethral resection and cystectomy was 42 days. This delay was mainly due to scheduling of surgery.

Conclusion

We learn from this case that doctors should be aware of the limitations of negative flexible cystoscopy and single biopsy, cytology of urine, ultrasound examination of urinary bladder, and computed tomography of pelvis for diagnosis of bladder cancer in spinal cord injury patients. Random bladder biopsies must be considered under general anaesthesia when there is high suspicion of bladder cancer. Spinal cord injury patients with lesions above T-6 may develop autonomic dysreflexia; therefore, one should be extremely well prepared to prevent or manage autonomic dysreflexia when performing cystoscopy and bladder biopsy. Spinal cord injury patients, who pass blood in urine, should be accorded top priority in scheduling of investigations and surgical procedures.

Contrast-enhanced sonography in pediatrics

Microbubble US contrast agents are composed of an outer shell of protein, phospholipid or polymer that encase air or perfluorocarbon gas. These contrast agents have been widely used in adult cardiology patients to improve endocardial border delineation and have been proved safe and well tolerated in this patient population. There is also a growing body of literature elucidating the value of contrast-enhanced sonography to distinguish benign from malignant liver lesions in adults and to characterize non-hepatic adult malignancies. Because these agents have not been approved for pediatric use in many countries, less is known of the value of contrast-enhanced sonography in children. In this review I will discuss several proven and potential pediatric applications of contrast-enhanced sonography.