Surgical Outcomes of Hugo™ RAS Robot-Assisted Partial Nephrectomy for Cystic Renal Masses: Technique and Initial Experience.

Background: The Hugo™ Robot-Assisted Surgery (RAS) system is a new cutting-edge robotic platform designed for clinical applications. Nevertheless, its application for cystic renal tumors has not yet been thoroughly investigated. In this context, we present an initial series of Robot-Assisted Partial Nephrectomy (RAPN) procedures carried out using the Hugo™ RAS system for cystic renal masses. Methods: Between October 2022 and January 2024, twenty-seven RAPN procedures for renal tumors were performed at Fondazione Policlinico Universitario Campus Bio-Medico. Our prospective board-approved dataset was queried for "cystic features" (n = 12). Perioperative data were collected. The eGFR was calculated according to the CKD-EPI formula. Post-operative complications were reported according to the Clavien-Dindo classification. Computed tomography (CT) scans for follow-up were performed according to the EAU guidelines. Trifecta was defined as the coexistence of negative surgical margin status, no Clavien-Dindo grade ≥ 3 complications, and eGFR decline ≤ 30%. Results: All the patients successfully underwent RAPN without the need for conversion or additional port placement. The median docking and console time were 5.5 (IQR, 4-6) and 79.5 min (IQR, 58-91 min), respectively. No intraoperative complications occurred, as well as clashes between instruments or with the bedside assistant. Two minor postoperative complications were recorded (Clavien-Dindo II). At discharge, serum creatinine and eGFR were comparable to preoperative values. Only one patient (8.4%) displayed positive surgical margins. The rate of trifecta achievement was 91.7%. Conclusions: RAPN for cystic renal masses using the novel Hugo™ RAS system can be safely and effectively performed. This robotic system provided satisfactory peri-operative outcomes, preserving renal function and displaying low postoperative complications and a high trifecta rate achievement.

Differentiating mixed epithelial and stromal tumor family from predominantly cystic renal cell carcinoma using magnetic resonance imaging-based Bosniak classification system version 2019.

PURPOSE: To differentiate mixed epithelial and stromal tumor family (MESTF) of the kidney from predominantly cystic renal cell carcinoma (RCC) using the magnetic resonance imaging (MRI)-based Bosniak classification system version 2019 (v2019). MATERIALS AND METHODS: The study included 36 consecutive patients with MESTF and 77 with predominantly cystic RCC who underwent preoperative renal MRI. One radiologist evaluated and documented the clinical and MRI characteristics (age, sex, laterality, R.E.N.A.L. Nephrometry Score [RNS], surgical approach, the signal intensity on T2-weighted imaging, restricted diffusion and enhancement features in corticomedullary phase). Blinded to clinical and pathological information, another two radiologists independently evaluated Bosniak category of all masses. Interobserver agreement based on Bosniak classification system v2019 was measured by the weighted Cohen/Conger's Kappa coefficient. Furthermore, predominantly cystic RCCs and MESTFs were divided into low (categories I, II, and IIF) and high-class (categories III, and IV) tumors. The independent sample t test (Mann-Whitney U test) or Pearson Chi-square test (Fisher's exact probability test) was utilized to compare clinical and imaging characteristics between MESTFs and predominantly cystic RCCs. The performance of the Bosniak classification system v2019 in distinguishing MESTF from predominantly cystic RCC was investigated via receiver operating characteristic curve analysis. RESULTS: MESTF and predominantly cystic RCC groups significantly differed in terms of age, lesion size, RNS, restricted diffusion, and obvious enhancement in corticomedullary phase, but not sex, laterality, surgical approach, and the signal intensity on T2WI. Interobserver agreement was substantially based on the Bosniak classification system v2019. There were 24 low-class tumors and 12 high-class tumors in the MESTF group. Meanwhile, 13 low-class tumors and 64 high-class tumors were observed in the predominantly cystic RCC group. The distribution of low- or high-class tumors significantly differed between the MESTF and predominantly cystic RCC groups. Bosniak classification system v2019 had excellent discrimination (cutoff value = category III), and an area under curve value was 0.81; accuracy, 80.5%; sensitivity, 87.0%; and specificity, 66.7%. CONCLUSION: The MRI-based Bosniak classification system v2019 can effectively distinguish MESTF from predominantly cystic RCC if category III was used as a cutoff reference.

Multiparametric MRI-Based Machine Learning Models for the Characterization of Cystic Renal Masses Compared to the Bosniak Classification, Version 2019: A Multicenter Study.

RATIONALE AND OBJECTIVE: Accurate differentiation between benign and malignant cystic renal masses (CRMs) is challenging in clinical practice. This study aimed to develop MRI-based machine learning models for differentiating between benign and malignant CRMs and compare the best-performing model with the Bosniak classification, version 2019 (BC, version 2019). METHODS: Between 2009 and 2021, consecutive surgery-proven CRM patients with renal MRI were enrolled in this multicenter study. Models were constructed to differentiate between benign and malignant CRMs using logistic regression (LR), random forest (RF), and support vector machine (SVM) algorithms, respectively. Meanwhile, two radiologists classified CRMs into I-IV categories according to the BC, version 2019 in consensus in the test set. A subgroup analysis was conducted to investigate the performance of the best-performing model in complicated CRMs (II-IV lesions in the test set). The performances of models and BC, version 2019 were evaluated using the area under the receiver operating characteristic curve (AUC). Performance was statistically compared between the best-performing model and the BC, version 2019. RESULTS: 278 and 48 patients were assigned to the training and test sets, respectively. In the test set, the AUC and accuracy of the LR model, the RF model, the SVM model, and the BC, version 2019 were 0.884 and 75.0%, 0.907 and 83.3%, 0.814 and 72.9%, and 0.893 and 81.2%, respectively. Neither the AUC nor the accuracy of the RF model that performed best were significantly different from the BC, version 2019 (P = 0.780, P = 0.065). The RF model achieved an AUC and accuracy of 0.880 and 81.0% in complicated CRMs. CONCLUSIONS: The MRI-based RF model can accurately differentiate between benign and malignant CRMs with comparable performance to the BC, version 2019, and has good performance in complicated CRMs, which may facilitate treatment decision-making and is less affected by interobserver disagreements.

Cystic Renal Masses: Old and New Paradigms.

Cystic renal masses describe a spectrum of lesions with benign and/or malignant features. Cystic renal masses are most often identified incidentally with the Bosniak classification system stratifying their malignant potential. Solid enhancing components most often represent clear cell renal cell carcinoma yet display an indolent natural history relative to pure solid renal masses. This has led to an increased adoption of active surveillance as a management strategy in those who are poor surgical candidates. This article provides a contemporary overview of historical and emerging clinical paradigms in the diagnosis and management of this distinct clinical entity.

Ultrasound-based "CEUS-Bosniak"classification for cystic renal lesions: an 8-year clinical experience.

PURPOSE: Renal cysts comprise benign and malignant entities. Risk assessment profits from CT/MRI imaging using the Bosniak classification. While Bosniak-IIF, -III, and -IV cover complex cyst variants, Bosniak-IIF and -III stand out due to notorious overestimation. Contrast-enhanced ultrasound (CEUS) is promising to overcome this deficit but warrants standardization. This study addresses the benefits of a combined CEUS and CT/MRI evaluation of renal cysts. The study provides a realistic account of kidney tumor boards' intricacies in trying to validate renal cysts. METHODS: 247 patients were examined over 8 years. CEUS lesions were graded according to CEUS-Bosniak (IIF, III, IV). 55 lesions were resected, CEUS-Bosniak- and CT/MRI-Bosniak-classification were correlated with histopathological diagnosis. Interobserver agreement between the classifications was evaluated statistically. 105 lesions were followed by ultrasound, and change in CEUS-Bosniak-types and lesion size were documented. RESULTS: 146 patients (156 lesions) were included. CEUS classified 67 lesions as CEUS-Bosniak-IIF, 44 as CEUS-Bosniak-III, and 45 as CEUS-Bosniak-IV. Histopathology of 55 resected lesions revealed benign cysts in all CEUS-Bosniak-IIF lesions (2/2), 40% of CEUS-Bosniak-III and 8% of CEUS-Bosniak-IV, whereas malignancy was uncovered in 60% of CEUS-Bosniak-III and 92% of CEUS-Bosniak-IV. Overall, CEUS-Bosniak-types matched CT/MRI-Bosniak types in 58% (fair agreement, κ = 0.28). CEUS-Bosniak resulted in higher stages than CT/MRI-Bosniak (40%). Ultrasound follow-up of 105 lesions detected no relevant differences between CEUS-Bosniak-types concerning cysts size. 99% of lesions showed the same CEUS-Bosniak-type. CONCLUSION: The CEUS-Bosniak classification is an essential tool in clinical practice to differentiate and monitor renal cystic lesions and empowers diagnostic work-up and patient care.

Diagnostic performance of the Bosniak classification, version 2019 for cystic renal masses: A systematic review and meta-analysis.

Purpose: To systematically assess the diagnostic performance of the Bosniak classification, version 2019 for risk stratification of cystic renal masses. Methods: We conducted an electronic literature search on Web of Science, MEDLINE (Ovid and PubMed), Cochrane Library, EMBASE, and Google Scholar to identify relevant articles between June 1, 2019 and March 31, 2022 that used the Bosniak classification, version 2019 for risk stratification of cystic renal masses. Summary estimates of sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR) were pooled with the bivariate model and hierarchical summary receiver operating characteristic (HSROC) model. The quality of the included studies was assessed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Results: A total of eight studies comprising 720 patients were included. The pooled sensitivity and specificity were 0.85 (95% CI 0.79-0.90) and 0.68 (95% CI 0.58-0.76), respectively, for the class III/IV threshold, with a calculated area under the HSROC curve of 0.84 (95% CI 0.81-0.87). The pooled LR+, LR-, and DOR were 2.62 (95% CI 2.0-3.44), 0.22 (95% CI 0.16-0.32), and 11.7 (95% CI 6.8-20.0), respectively. The Higgins I 2 statistics demonstrated substantial heterogeneity across studies, with an I 2 of 57.8% for sensitivity and an I 2 of 74.6% for specificity. In subgroup analyses, the pooled sensitivity and specificity for CT were 0.86 and 0.71, respectively, and those for MRI were 0.87 and 0.67, respectively. In five studies providing a head-to-head comparison between the two versions of the Bosniak classification, the 2019 version demonstrated significantly higher specificity (0.62 vs. 0.41, p < 0.001); however, it came at the cost of a significant decrease in sensitivity (0.88 vs. 0.94, p = 0.001). Conclusions: The Bosniak classification, version 2019 demonstrated moderate sensitivity and specificity, and there was no difference in diagnostic accuracy between CT and MRI. Compared to version 2005, the Bosniak classification, version 2019 has the potential to significantly reduce overtreatment, but at the cost of a substantial decline in sensitivity.

Assessment of Contrast-Enhanced Ultrasound (CEUS) and Computed Tomography (CT) diagnostic accuracy in the evaluation of challenging cystic renal masses.

PURPOSE: To assess the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) and computed tomography (CT) within Bosniak IIF/III categories. METHODS: After cystic renal mass diagnosis by contrast-enhanced CT, all patients with Bosniak score ≥ II also underwent CEUS between March 2017 and March 2019. Their exams were retrospectively analyzed. One experienced uro-radiologist performed every CEUS and reviewed the exams according to the EFSUMB 2020 Position Statement, while blinded to clinical data. CT Bosniak scores were retrospectively given blindly by two uro-radiologists (CT 1 and CT 2). We compared CEUS, CT 1 and CT 2 scores to clinical findings and histological tests. Clinical performance characteristics and area under the receiver operating characteristic (ROC) curves (AUCs) were determined separately for CEUS and CT, and then compared. RESULTS: 101 cystic masses were analyzed. In Bosniak categories IIF and III, the AUCs were 0.854 for CT 1, 0.779 for CT 2, and 0.746 for CEUS. CONCLUSION: Despite some statistical limitations, this study confirms that among cystic renal masses, those classified as Bosniak IIF and III are the most difficult to assess. The diagnostic performances of CEUS and CT are similar within this group. However, in experienced hands, CEUS could be valuable in further evaluation of ambiguous cystic masses, and in more ductile, safer, and cost-effective surveillance of those classified as Bosniak IIF and III. When challenging cystic renal masses occur, CEUS is a useful tool for clinical management and for the follow-up of non-surgical lesions.

[Usefulness of contrast enhanced ultrasound for evaluation of cystic renal masses.] / Utilidad de la ecografía con contraste en el estudio de las lesiones renales quísticas.

OBJECTIVE: Contrast enhanced ultrasound(CE) consists of the intravenous injection of gasmicrobubbles and their detection within the kidney in differentphases. CE is more accurate than contrast enhancedtomography for detection of septa and wall thicknessvascularization in cystic renal lesions. The purposes ofthis study are to confirm the usefulness of this tool in thecharacterization of complex cystic renal masses and toassess its histological correlation. MATERIALS AND METHODS: Retrospective observationalstudy of 78 patients with complex or indeterminatecystic renal masses who underwent a CE betweenJanuary 2015 - January 2020. RESULTS: Lesions with high suspicion of malignancy(Bosniak III and IV) were identified in 35 patients(45%). A surgical approach was taken in 23 (30%): 18patients with histology of renal cell carcinoma, and onlyin 4 the histology was benign. CE involved a change intherapeutic management due to better definition of thelesion in 48 patients (61.5%). CE has a sensitivity 100%,specificity 91.5%, PPV 81.8%, NPV 100%, and CE hadan important confidence level showed by the area underthe ROC curve (AUC = 0.968). CONCLUSIONS: CE is a useful tool in the characterizationof complex cystic renal lesions. It allows abetter definition of the Bosniak classification for thoseindeterminate or doubtful cases on CT that couldgenerate a change in the therapeutic attitude in manycases. It has a good image - histology relation.

OBJETIVO: La ecografía con contraste(EC) consiste en la inyección intravenosa demicroburbujas de gas y su detección dentro del riñón endistintas fases. En las lesiones renales quísticas la EC esmás sensible que la tomografía con contraste para valorarla vascularización de septos y tabiques. Los objetivosde este trabajo son confirmar la utilidad de esta técnicaen la caracterización de las lesiones renales quísticascomplejas y estudiar su relación anatomo-patológica MATERIAL Y MÉTODOS: Estudio observacionalretrospectivo de 78 pacientes con masas renales quísticascomplejas o dudosas en los que se les realizó una ECentre enero 2015 ­ enero 2020. RESULTADOS: En 35 pacientes (45%) se identificaronlesiones con alta sospecha de malignidad (BosniakIII y IV). En 23 (30%) se tomó una actitud quirúrgica: 18con anatomía patológica de carcinoma de células renalesy 4 con anatomía patológica benigna. En 48 pacientes(61,5%) supuso un cambio de actitud terapéuticadebido a la mejor definición de la lesión. La EC presentóuna sensibilidad 100%, especificidad 91,5%, VPP 81,8%,VPN 100%, con un nivel confianza diagnóstica mostradopor el área bajo la curva ROC (AUC = 0,968).CONCLUSIÓN: La EC es una herramienta útil en lavaloración de quistes renales complejos. Permite unamejor definición de la clasificación Bosniak para aquelloscasos indeterminados o dudosos en TC, que implicóun cambio de actitud terapéutica en muchos casos. Además,presenta una buena relación imagen-histología.

Utilidad de la ecografía con contraste en el estudio de las lesiones renales quísticas / Usefulness of contrast enhanced ultrasound for evaluation of cystic renal masses

OBJETIVO: La ecografía con contraste (EC) consiste en la inyección intravenosa demicroburbujas de gas y su detección dentro del riñón endistintas fases. En las lesiones renales quísticas la EC esmás sensible que la tomografía con contraste para valorar la vascularización de septos y tabiques. Los objetivosde este trabajo son confirmar la utilidad de esta técnicaen la caracterización de las lesiones renales quísticascomplejas y estudiar su relación anatomo-patológicaMATERIAL Y MÉTODOS: Estudio observacionalretrospectivo de 78 pacientes con masas renales quísticas complejas o dudosas en los que se les realizó una ECentre enero 2015 – enero 2020.RESULTADOS: En 35 pacientes (45%) se identificaron lesiones con alta sospecha de malignidad (BosniakIII y IV). En 23 (30%) se tomó una actitud quirúrgica: 18con anatomía patológica de carcinoma de células renales y 4 con anatomía patológica benigna. En 48 pacientes (61,5%) supuso un cambio de actitud terapéuticadebido a la mejor definición de la lesión. La EC presentóuna sensibilidad 100%, especificidad 91,5%, VPP 81,8%,VPN 100%, con un nivel confianza diagnóstica mostradopor el área bajo la curva ROC (AUC = 0,968).CONCLUSIÓN: La EC es una herramienta útil en lavaloración de quistes renales complejos. Permite unamejor definición de la clasificación Bosniak para aquellos casos indeterminados o dudosos en TC, que implicóun cambio de actitud terapéutica en muchos casos. Además, presenta una buena relación imagen-histología. (AU)

OBJECTIVE: Contrast enhanced ultrasound (CE) consists of the intravenous injection of gasmicrobubbles and their detection within the kidney in different phases. CE is more accurate than contrast enhanced tomography for detection of septa and wall thicknessvascularization in cystic renal lesions. The purposes ofthis study are to confirm the usefulness of this tool in thecharacterization of complex cystic renal masses and toassess its histological correlation.MATERIALS AND METHODS: Retrospective observational study of 78 patients with complex or indeterminate cystic renal masses who underwent a CE betweenJanuary 2015 – January 2020.RESULTS: Lesions with high suspicion of malignancy (Bosniak III and IV) were identified in 35 patients(45%). A surgical approach was taken in 23 (30%): 18patients with histology of renal cell carcinoma, and onlyin 4 the histology was benign. CE involved a change intherapeutic management due to better definition of thelesion in 48 patients (61.5%). CE has a sensitivity 100%,specificity 91.5%, PPV 81.8%, NPV 100%, and CE hadan important confidence level showed by the area under the ROC curve (AUC = 0.968). CONCLUSIONS: CE is a useful tool in the characterization of complex cystic renal lesions. It allows abetter definition of the Bosniak classification for those indeterminate or doubtful cases on CT that couldgenerate a change in the therapeutic attitude in manycases. It has a good image – histology relation. (AU)

Ultrasound, CT, and MR Imaging for Evaluation of Cystic Renal Masses.

Cystic renal masses are often encountered during abdominal imaging. Although most of them are benign simple cysts, some cystic masses have malignant characteristics. The Bosniak classification system provides a useful way to classify cystic masses. The Bosniak classification is based on the results of a well-established computed tomography protocol. Over the past 30 years, the classification system has been refined and improved. This paper reviews the literature on this topic and compares the advantages and disadvantages of different screening and classification methods. Patients will benefit from multimodal diagnosis for lesions that are difficult to classify after a single examination.

MRI-based Bosniak version 2019 for Ⅱ, ⅡF and Ⅲ cystic renal masses: improved interobserver agreement by subtraction imaging / 中华放射学杂志

Objective:To investigate the value of MR subtraction images in improving the interobserver agreement for Bosniak Ⅱ, ⅡF, and Ⅲ cystic renal masses (CRMs) with Bosniak classification version 2019.Methods:From January 2009 to August 2020, 323 patients (335 CRMs) with surgical pathology results and complete preoperative MRI examination (T 2WI, T 1WI precontrast images and enhanced MRI in corticomedullary, nephrographic, and excretory phases) were retrospectively collected in the First Medical Center of PLA General Hospital. The CRMs of Bosniak Ⅱ, ⅡF, and Ⅲ were selected and classified by 2 experienced genitourinary radiologists according to the Bosniak classification version 2019. The "Subtraction" function in the American GE ADW 4.4 workstation was used to perform subtraction images reconstruction on the enhanced images in the corticomedullary, nephrographic, and excretory phases. Blinded to pathologic information, the other 2 radiologists independently classified the enrolled CRM cases with and without subtraction MR images, respectively, with an interval of 1 month. Ultimately, by using weighted Kappa value, interobserver agreement was evaluated, and the differences in weighted Kappa value were compared using the Gwet coefficient. Results:A total of 187 patients with 187 CRMs were enrolled in the study. The results of the classification of Bosniak Ⅱ, ⅡF, and Ⅲ CRMs categorized by 2 radiologists without and with subtraction images showed that 119 and 141 cases were consistent, and 68 and 46 were inconsistent, respectively. The weighted Kappa value for interobserver agreement among two radiologists without and with subtraction MR images was 0.60 (95%CI 0.53-0.68) and 0.73 (95%CI 0.66-0.80), respectively. The interobserver agreement was higher with subtraction images than that without subtraction images ( t=-2.56, P=0.011). Conclusion:According to the MRI criteria of Bosniak classification version 2019, the interobserver agreement for Bosniak Ⅱ, ⅡF, and Ⅲ CRMs could be improved using subtraction MR images, which may facilitate the popularization and application of Bosniak classification version 2019.

Risk factors for intraoperative cyst rupture in partial nephrectomy for cystic renal masses.

PURPOSE: To determine the risk factors of intraoperative cyst rupture in partial nephrectomy (PN) for a cystic renal mass (CRM) and their effect on the prognosis of patients. MATERIALS AND METHODS: Patients who underwent partial nephrectomy for CRMs from January 2009 to January 2015 were included. Uni/multivariate Logistic/Cox analysis and Kaplan-Meier analysis were performed. RESULTS: A total of 174 patients were included in this study. There were 27 (15.5%) intraoperative cyst ruptures. The median follow-up time was 60 months. Multivariate logistic analysis showed that the E component (P = 0.018) and N component (P = 0.022) of the R.E.N.A.L. nephrometry score, Bosniak category III (P = 0.044), and surgeon's experience (P = 0.030) were risk factors associated with intraoperative cyst rupture in PN for CRMs. The 5-year recurrence-free survival (RFS), cancer-free survival (CFS) and overall survival (OS) were 92.7%, 90.32% and 94.4%, respectively, in 124 cases of malignant CRM. Kaplan-Meier analysis demonstrated that 5-year RFS and 5-year CFS in patients with cyst rupture was worse than those without cyst rupture (P = 0.006 and 0.003, respectively). Multivariate Cox analysis revealed that intraoperative cyst rupture was independent risk factor for 5-year RFS and 5-year CFS (P = 0.039 and 0.013, respectively). However, there was no significant difference in OS between the two groups (P = 0.275). CONCLUSIONS: The prevalence of intraoperative cyst rupture is relatively high. Higher E and N scores, Bosniak category III, and lacking surgical experience (<20 cases) increase the risk of occurrence of intraoperative cyst rupture.

Approach to Renal Cystic Masses and the Role of Radiology.

Most renal masses are benign cysts; a subset are malignant. Most renal masses are incidental findings. Evaluation of renal cysts has evolved with updates to the Bosniak classification system and other guidelines. The Bosniak classification provides detailed definitions and extends the system from computed tomography to MR imaging. This article provides a simple approach to the evaluation of cystic or potentially cystic renal masses. The radiologist is central to this process. Key elements include confirming that a renal lesion is cystic and not solid, determining the need for further characterization by imaging, and judicious application of the Bosniak classification system.

Multislice computed tomography/contrast-enhanced ultrasound image fusion as a tool for evaluating unclear renal cysts.

Ultrasonography is a generally accepted imaging technique for diagnosing and monitoring cystic renal lesions. The widely used Bosniak classification (I-IV) categorizes renal cystic lesions into five distinctive groups according to ultrasonography and computed tomography (CT) image criteria. For solid renal lesions, determination of vascularity is discriminatory for malignancy in most instances. In indeterminate cases, contrast-enhanced ultrasound (CEUS) and magnetic resonance imaging/CT-ultrasound image fusion are able to detect and characterize difficult pathologies, with superior performance to either technique alone. In contrast to multislice CT (MS-CT), ultrasound image fusion is a real-time imaging technique that can be used in combination with other cross-sectional imaging modalities. This technical note describes state-of-the-art image fusion of CEUS and MS-CT to detect and characterize unclear renal pathologies.

Multislice computed tomography/contrast-enhanced ultrasound image fusion as a tool for evaluating unclear renal cysts

Ultrasonography is a generally accepted imaging technique for diagnosing and monitoring cystic renal lesions. The widely used Bosniak classification (I-IV) categorizes renal cystic lesions into five distinctive groups according to ultrasonography and computed tomography (CT) image criteria. For solid renal lesions, determination of vascularity is discriminatory for malignancy in most instances. In indeterminate cases, contrast-enhanced ultrasound (CEUS) and magnetic resonance imaging/CT-ultrasound image fusion are able to detect and characterize difficult pathologies, with superior performance to either technique alone. In contrast to multislice CT (MS-CT), ultrasound image fusion is a real-time imaging technique that can be used in combination with other cross-sectional imaging modalities. This technical note describes state-of-the-art image fusion of CEUS and MS-CT to detect and characterize unclear renal pathologies.

Comparison of contrast-enhanced ultrasound with MRI in the diagnosis of complex cystic renal masses: a meta-analysis.

Background The differential diagnosis of cystic renal masses still faces great challenges. There has been no systematically assessment to compare the value of contrast-enhanced ultrasound (CEUS) with magnetic resonance imaging (MRI) in the diagnosis of cystic renal masses. Purpose To perform a meta-analysis to compare the diagnostic efficacy of CEUS with that of MRI for cystic renal masses. Material and Methods A systematic search was performed for literature evaluating the diagnostic performance of CEUS or MRI in cystic renal masses. Quality assessment of diagnostic studies 2 (QUADAS-2) was used to evaluate the quality of each study included. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and the areas under the summary receiver operating characteristic (AUCs-SROC) curve for CEUS and MRI were calculated, respectively. Results Seventeen studies with 1142 lesions were included. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for CEUS /MRI were 0.95/0.92, 0.84/0.91, 5.62/6.74, and 0.09/0.13, respectively. The AUCs-SROC curves for the two methods were 95.66% and 94.65%. The subgroup analysis indicated that the scanning slice thickness may influence the diagnostic efficacy of MRI. Conclusion Both CEUS and MRI have good diagnostic performance for cystic renal masses and can provide the reference for clinicians. CEUS is more sensitive but less specific than MRI.

Renal Masses: Imaging Evaluation.

This article illustrates the imaging characteristics of cystic and solid renal masses, along with a summary of identified imaging criteria that may be of use to differentiate masses that are more likely to be benign from those that are more likely to be malignant. In addition, important features of known or suspected renal cancers that should be identified before treatment are summarized, including staging of renal cancer and RENAL nephrometry. Finally, the imaging appearance of patients following treatment of renal cancer, including after partial or total nephrectomy, thermal ablation, or chemotherapy for metastatic disease, is reviewed.