Advances in medical imaging for the diagnosis and management of common genitourinary cancers

Medical imaging of the 3 most common genitourinary (GU) cancers—prostate adenocarcinoma, renal cell carcinoma, and urothelial carcinoma of the bladder—has evolved significantly during the last decades. The most commonly used imaging modalities for the diagnosis, staging, and follow-up of GU cancers are computed tomography, magnetic resonance imaging (MRI), and positron emission tomography (PET). Multiplanar multidetector computed tomography and multiparametric MRI with diffusion-weighted imaging are the main imaging modalities for renal cell carcinoma and urothelial carcinoma, and although multiparametric MRI is rapidly becoming the main imaging tool in the evaluation of prostate adenocarcinoma, biopsy is still required for diagnosis. Functional and molecular imaging using 18-fluorodeoxyglucose-PET and sodium fluoride-PET are essential for the diagnosis, and especially follow-up, of metastatic GU tumors. This review provides an overview of the latest advances in the imaging of these 3 major GU cancers.     

Magnetic resonance imaging in the staging of renal cell carcinoma

Correct diagnosis and accurate staging of renal cell carcinoma are critical in the evaluation of prognosis and subsequent treatment planning. Between October 1989 and April 1993, 25 patients with histologically proven renal cell carcinoma (RCC) were studied, comparing magnetic resonance imaging (MRI), computerized tomography (CT), operative findings and histopathological results. Two patients with pT3 tumours were understaged by both methods as T2. Three other patients staged as T4 by CT and T3 by MRI were actually pT3. N and V status were accurately detected by both imaging modalities. One patient with biopsy-proven liver metastasis missed by CT was correctly diagnosed by MRI. We conclude that MRI is complementary to CT and is especially helpful in patients with advanced stage and large sized tumours.     

Magnetic resonance imaging in the diagnosis and staging of renal masses: a critical appraisal and comparison with computed tomography

Summary The purpose of this prospective study was to compare the accuracy of magnetic resonance imaging (MRI) and computed tomography (CT) in the diagnosis and staging of renal masses. MRI was performed with an 0.5 T superconducting MR-scanner using conventional T1- and T2-weighted spin-echo pulse sequences. The results of MRI and CT were compared in 31 patients with a renal mass. In the diagnosis of benign tumors, similar information was obtained by MRI and CT. Regarding malignant tumors, one transitional cell carcinoma, imaged by CT, was not shown by MRI. CT appeared to be slightly more accurate in the determination of perinephric extension of renal cell carcinoma (stage I vs stage II). Similar results were obtained in stage III and stage IV tumors. The main diagnostic limitations which may lead to inaccurate staging of renal cell carcinoma are encountered in MRI as well as CT. They are: the assessment of tumor extension into the intrarenal vein, the differentiation between lymphadenopathy due to reactive hyperplasia and metastatic involvement and the differentiation between tumor extension into adjacent organs and adhesions without tumor spread outside the renal capsule. It is concluded that CT remains the method of choice in the diagnosis and staging of renal masses as long as no substantial improvements in MRI performance have been achieved.     

Impact of magnetic resonance on staging of renal carcinoma

Computerized tomography (CT), ultrasound, and angiography have been used for staging renal cell carcinoma. CT has proven to be the most reliable and sensitive of these techniques. Magnetic resonance (MR) has emerged recently as a viable alternative imaging modality. Five patients with renal cell carcinoma and suspected caval involvement were evaluated by CT, ultrasound, and MR. Caval extension and the differentiation of intra-versus retrocaval tumor was seen with greater clarity on MR scans; perinephric extension was seen equally well with both modalities. The primary tumor itself was better defined with CT. In patients with equivocal findings regarding the renal veins or inferior vena cava, MR is a valuable adjunct in preoperative evaluation. In patients at high risk for contrast administration, MR is the staging modality of choice.     

Contemporary Imaging of the Renal Mass

Renal masses increasingly are detected incidentally in asymptomatic individuals. Accurate characterization of these lesions is important for clinical management, planning intervention, and avoiding unnecessary procedures. Ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) are the mainstays of renal mass detection and characterization. Ultrasonography is useful for distinguishing cystic from solid lesions and can detect lesion vascularity, especially with use of ultrasound contrast agents, but is less sensitive, less specific, and less reproducible than CT and MRI. CT, with and without intravenous contrast, is the primary imaging test for characterization and staging of renal lesions, and is utilized more often than MRI. Current multidetector CT technology provides near isotropic acquisition, with three-dimensional reformatting capabilities. Due to lack of exposure to iodinated contrast and ionizing radiation and superior soft tissue contrast, MRI is being increasingly utilized as a problem-solving tool for diagnosis, staging, and preoperative planning for renal malignancies. Future directions for imaging of primary renal neoplasm include accurate characterization of renal cell cancer subtype, assistance with treatment planning, and evaluation of treatment response.     

Mapping intravascular extension of Wilms' tumor with magnetic resonance imaging

Accurate preoperative diagnosis of renal vein, vena caval, or intracardiac extension of Wilms' tumor allows the surgeon to better plan operative vascular control and assess the potential benefits of preoperative chemotherapy. Magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound were used to study four consecutive patients presenting with Wilms' tumor. Three had vena caval involvement, with one of these having a massive right atrial tumor thrombus. A fourth patient had renal vein involvement only. We found MRI to be superior to both CT and ultrasound for mapping intravascular extension of Wilms' tumor and for delineating nonvascular disease. Because of its noninvasiveness, multiplane imaging capabilities, and image contrast and resolution, MRI is a valuable complimentary imaging modality for the diagnosis and follow-up of patients with Wilms' tumor.     

Präoperatives Staging von Nierenzellkarzinomen mit Kavazapfen: welches diagnostische Verfahren?

To evaluate whether MRI is usefull in staging renal cell carcinomas with caval thrombus the accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in staging renal tumors with caval thrombus were preoperatively examined. Tumor staging by CT and MR imaging were correlated with histopathological tumor stadium. In MRI 4 out of 7 thrombi were correctly diagnosed with high accuracy, in CT none. In advanced renal carcinoma MRI with Gadolinium was superior to CT imaging, especially in diagnosing tumor thrombus. Consequently the extent of tumor thrombus may be assessed by MRI which therefore may replace conventional cavography.     

Advances in musculoskeletal tumor imaging

In the last 2 decades, there has been a dramatic change in the clinical approach to the tumors of the musculoskeletal system. The role of medical imaging in diagnosis, staging,and eventual follow-up of patients who have musculoskeletal neoplasia has expanded.This article presents an overview of the role of imaging, recent advances in technology,and state-of-the-art techniques for evaluating musculoskeletal neoplasms. Conventional imaging modalities, ultrasound, CT, MRI, positron emission tomography, and image-guided interventions are discussed.     

Contemporary imaging modalities for the surveillance of patients with renal cell carcinoma

In recent years, there have been multiple advances in imaging technologies that have improved the surveillance for recurrence of neoplasms. Multidetector row CT and dynamic contrast enhanced MRI now provide excellent anatomic detail and are beginning to show functional detail as the rapid capture of images following contrast administration improves. Positron emission tomography is emerging as a useful tool in evaluating patients with suspected metastatic disease to the abdomen and bone, particularly when combined with CT. The role of ultrasound in the surveillance of renal cell carcinoma is yet unclear, but its role may be expanding with use of newly developed contrast drugs. Herein we review the relevance of these modalities to the follow-up of patients with renal cell carcinoma.     

囊性肾癌27例诊治分析

目的:探讨囊性肾癌(CRCC)的临床特点,提高其诊治水平。方法:回顾性分析27例CRCC患者的症状与体征、影像学表现、手术方式、病理检查及随访结果。结果:综合B超、CT、MRI、超声造影等检查诊断CRCC 24例,疑似肾癌2例,误诊为肾囊肿1例。行保留肾单位手术15例,根治性肾切除11例,肾囊肿去顶减压后再行根治性肾切除1例。病理检查报告为透明细胞癌26例,乳头状肾细胞癌1例;临床分期T1aN0M08例,T1bN0M012例,T2aN0M05例,T2bN0M02例;组织分级G16例,G221例。27例随访6~78个月,平均21个月,除1例术后3个月局部复发外,其余26例均无复发和转移。结论:综合多种影像学检查能提高CRCC的诊断率,部分患者保留肾单位手术能达到与根治性肾切除术同样的治疗效果。除肾癌囊性坏死型外,其余类型预后较好。     

Relative merits of mri, transrectal endosonography and ct in diagnosis and staging of carcinoma of prostate

Magnetic resonance imaging (MRI) and transrectal sonography of 27 patients with biopsy-proved carcinoma of the prostate were performed to compare the sensitivity of these modalities to each other for diagnosis and to computed tomography (CT) for staging. Sonography was superior to MRI for the detection of intraglandular carcinoma and capsular disruption. MRI was superior to both sonography and CT for evaluating seminal vesicle invasion, and slightly better than CT for detecting lymphadenopathy.     

A case of renal cell carcinoma diagnosed by MAG3 scintigraphy because of moderate renal dysfunction

An 84-year-old man presented at our hospital with complaints of severe gross hematuria and lower right abdominal pain. A right renal mass was detected by ultrasound sonography and plain computerized tomography (CT) scan, but an exact diagnosis was not obtained. Because the patient presented with moderate renal dysfunction and severe gross hematuria, we were unable to perform imaging studies using contrast material or ureteroscopic instruments. Finally, mercaptoacetylglycyl-glycylglycine (MAG3) scintigraphy and magnetic resonance imaging (MRI) demonstrated renal cell carcinoma, and we performed transarterial embolization (TAE) therapy using ethanol and gel foam. Based on their efficacy and noninvasiveness, we conclude that MAG3 scintigraphy and MRI are the optimal modalities for imaging in patients with renal dysfunction.     

Bildgebung des Nierenzellkarzinoms

Renal cell cancer is the most frequently encountered malignant tumor of the kidney. The modern imaging techniques computed tomography (CT) and magnetic resonance imaging (MRI) play a vital role in the diagnostic work-up of renal masses. Contrast-enhanced ultrasound (CEUS) is able to visualize subtle enhancement in hypovascular tumors with high sensitivity. Recent advances in multidetector CT (MDCT) enable high resolution imaging of local findings. CT is able to provide large volume coverage of the chest and abdomen within seconds for the assessment of lymph node and distant metastasis staging. Local renal cell cancer staging can be achieved with similar diagnostic accuracy using CT or MRI. Both modalities allow visualization of a tumor’s relationship to the renal collecting system and pelvis, the renal artery and veins including the IVC. It is the radiologist’s task to accurately detect and stage renal malignances in order that each individual patient receives the therapy best suited to them.     

Renal imaging in patients requiring renal replacement therapy

Recent advances in imaging technology and interventional radiologic procedures have resulted in an increased variety of radiological techniques that can be used to assess patients who present with renal failure and require renal replacement therapy. This chapter provides an overview of the relative strengths and weaknesses of the available imaging methods. In particular, it covers the expanding role of the cross-sectional, noninvasive, multiplanar imaging techniques such as gray-scale and Doppler ultrasound, magnetic resonance imaging (MRI) and angiography (MRA), and nonenhanced helical or multislice computed tomography (CT). These imaging methods are increasingly replacing those used in the past, such as the conventional radiographic urogram, which requires a high dose of intravenous contrast media, and digital subtraction arteriography. The chapter also covers the radiologic investigation of complications of acquired renal cystic disease, including renal cell carcinoma, hemorrhage, cyst infection and rupture, and nephrolithiasis.     

Staging of bladder carcinoma by magnetic resonance imaging. A preliminary report

Magnetic resonance imaging (MRI) of bladder carcinoma was performed in 10 patients who subsequently underwent operations for tumor staging. MRI was performed with a 0.1 T resistive magnetic resonance unit. Images were obtained in the transverse, coronal and sagittal directions with different repetition and echo times. Simultaneously, computed tomography (CT) was performed in 9 of the 10 patients. The accuracy of MRI and CT staging was then evaluated by comparison with the staging from pathologic diagnosis. All of the tumors, which were 2.3-6.3 cm in diameter, were readily depicted by both imaging techniques. The overall accuracy of MRI staging for the 10 patients in whom staging had been pathologically confirmed was 90%, while the accuracy of CT staging for the 9 patients was 55%. Although no statistically significant differences in accuracy between CT and MRI staging can be established on the basis of the above results because of the small number of patients included in this study, MRI appears to be a very useful modality for staging bladder carcinoma.     

小肾癌的影像学诊断比较分析（附35例报告）

目的：探讨影像学检查在小肾癌诊断中的应用价值。方法：回顾性分析我科35例术后经病理确诊为小肾癌患者的B超、IVU、CT、MRI等影像学资料,比较分析各影像学检查的优缺点。结果：35例小肾癌病例,常规行B超、IVU检查,并结合CT或MRI检查。其中,B超诊断肾癌23例,准确率65．7％。IVU提示有肾盂肾盏受压等间接征象5例（14．3％）。21例行CT检查,诊断肾癌20例,准确率95．2％。14例行MRI检查,诊断肾癌13例,准确率92．9％。结论：综合应用B超、IVU、CT和MRI检查对于小肾癌的早期诊断具有重要意义,尤以CT检查更具价值。     

Magnetic resonance imaging in oncology: an overview

This review discusses a growing area of imaging in oncology. Traditionally, the primary role of magnetic resonance imaging (MRI) has been in the investigation of neurological diseases and in the diagnosis of musculoskeletal abnormalities. With the increasing availability of MRI systems and with the advances in technology, the role of this modality out with these areas is rapidly expanding. This review outlines the areas where MRI has a specific role in the imaging of patients with cancer. In particular, emphasis is placed on areas outside of the central nervous and musculoskeletal systems. This review describes the areas where MRI may be advantageous over other imaging modalities such as computerised tomography (CT). Specific emphasis is placed on the staging of abdominal and pelvic malignancies, the detection of recurrence and the impact of MRI in hepatic imaging. In addition this article reviews the value of dynamic contrast enhanced MRI sequences, as well as the importance of newer organ specific MR contrast agents in hepatic and lymph node imaging.     

Contemporary imaging of the renal mass

Contemporary imaging techniques for renal mass evaluation are essential to clinical management and surgical planning. Ultrasonography can be used to distinguish cystic from solid lesions but is less sensitive and accurate in renal mass characterization than computed tomography (CT) and magnetic resonance imaging (MRI). Multiphase CT imaging before and after administration of contrast is the primary imaging modality for characterization and staging of renal lesions. MRI is increasingly used as a problem solving tool. Advanced MRI techniques such as diffusion-weighted imaging and perfusion-weighted imaging are being explored in assessment of renal lesions. These techniques are discussed in this article.     

影像学无创评估肝纤维化研究进展

肝纤维化是慢性肝病进展后病理改变,为肝硬化及肝细胞癌发展的重要环节。早期诊断肝纤维化和准确分期对尽早干预意义重大。肝穿刺活检是临床诊断肝纤维化的金标准,但患者接受度差,且无法评估肝脏整体。近年来,影像学技术如超声弹性成像、MRI、CT、PET/CT及人工智能逐渐用于评估肝纤维化。本文就影像学无创评估肝纤维化研究进展进行综述。     

双侧原发性肾癌5例报告

目的:探讨双侧原发性肾癌的诊断、治疗和预后。方法:回顾性分析2001年3月~2005年6月诊治的5例双侧同期原发性肾癌患者的临床资料。5例均经B超、CT等检查确诊,施行保留肾单位手术联合对侧肾癌根治术。结果:术后恢复顺利,无外科并发症,4例为双侧肾透明细胞癌,1例为双侧肾乳头状腺癌。随访5~51个月(平均20.4个月),无局部复发、转移及肾功能不良。结论:双侧原发性肾癌早期无特殊临床表现,主要依靠影像学检查诊断。外科手术为主要治疗方法,保留肾单位手术联合对侧肾癌根治术既能有效治疗恶性肿瘤,又能确实保存肾功能,预后良好。