CT appearance of transitional cell carcinoma of the renal pelvis: Part 1. Early-stage disease

Upper and Lower Tract Urothelial Imaging Using Computed Tomography Urography

Computed tomography (CT) urography is the best noninvasive method of evaluating the upper urinary tract for urothelial malignancies. However, the utility of CT urography is heavily contingent on the use of proper image acquisition protocols. This article focuses on the appropriate protocols for optimizing CT urography acquisitions, including contrast administration and the timing of imaging acquisitions, as well as the use of ancillary techniques to increase collecting system distention. In addition, imaging findings are discussed that should raise concern for urothelial carcinoma at each of the 3 segments of the urinary tract: the intrarenal collecting systems, ureters, and bladder.

Common and uncommon adult unilateral renal masses other than renal cell carcinoma

Many different masses can involve the kidney other than the commonly encountered renal cell carcinoma (RCC). The purpose of this article is to review the characteristic clinical and imaging findings of common and uncommon masses that predominantly present unilaterally in the adult patient, other than RCC. Awareness of such lesions and knowing the clinical scenario is important for appropriate diagnosis and management, especially in a multidisciplinary care setting.

Detection of upper tract urothelial neoplasms: sensitivity of axial, coronal reformatted, and curved-planar reformatted image-types utilizing 16-row multi-detector CT urography

BACKGROUND

The purpose of our study was to determine the sensitivity of 16-row multi-detector computed tomography urography (CTU) axial, coronal reformatted, and curved-planar reformatted image-types for upper tract urothelial neoplasm detection.

METHODS

Twenty-one CTU examinations were identified that contained one or more pathology-proven upper tract urothelial neoplasms during our study period. Two readers independently reviewed 1.25 and 2.5 mm axial, coronal reformatted, and curved-planar reformatted excretory phase CTU images. Each reader then documented the location and appearance of lesions suspicious for upper tract urothelial neoplasm. These results were correlated with relevant endoscopic/surgical procedure notes as well as pathology results.

RESULTS

Reader #1 detected 72%, 63%, 75%, and 72% of the known 32 upper tract urothelial neoplasms using 1.25 mm axial, 2.5 mm axial, coronal reformatted, and curved-planar reformatted image-types, respectively. Reader #2 detected 72% of the known neoplasms using each of the four image-types. No significant difference in sensitivity between image-types was identified. After combining the results for all four image-types, readers #1 and #2 had overall sensitivities of 94% and 91%.

CONCLUSIONS

Axial, coronal reformatted, and curved-planar reformatted image-types have similar sensitivities for the detection of upper tract urothelial neoplasm in 16-row multi-detector CTU. Reviewing multiple image-types increases the sensitivity of urothelial lesion detection.

Computed tomography and magnetic resonance imaging features of lesions of the renal medulla and sinus

The kidneys can harbor a wide variety of lesions, many of which can be visualized by computed tomography and magnetic resonance imaging. In this article, the pertinent renal anatomic relationships as well as the histologic composition and function of the renal medulla and sinus are reviewed. Additionally, computed tomography and magnetic resonance imaging features of renal sinus and medullary lesions in adult patients are presented. This article reviews the salient imaging features of various malignant, benign neoplastic, and nonneoplastic lesions of the sinus and medulla.

Imaging of kidney cancer

Advances in molecular genetics have expanded the understanding of renal cell tumors. Now it is understood that renal cortical tumors are a family of neoplasms with distinct cytogenetics and molecular defects, unique histopathologic features, and different malignant potentials. Imaging contributes to clinical management of patients with renal tumors in providing diagnostic information for tumor detection, characterization, staging, treatment planning, and follow-up.

Multiphasic multidetector-row CT (MDCT) in detection and staging of transitional cell carcinomas of the upper urinary tract

The aim of this study was to evaluate the potential of multiphasic multidetector-row CT (MDCT) in the detection and staging of transitional cell carcinomas (TCC) of the upper urinary tract. We performed a retrospective chart review of 39 consecutive patients with 41 histologically verified TCC of the renal pelvis and/or the ureter. The urinary tract was examined using MDCT performing unenhanced and contrast-enhanced scans during the corticomedullary (CMP), nephrographic (NP) and pyelographic phase (PP). Tumors were staged according to the TNM classification. MDCT and histopathological findings were correlated. The attenuation of the lesions was documented in Hounsfield units (HU). In MDCT, all 41 TCC--including two multicentric TCC--were detected. TCC confined to the organ (stage 0a-II) was correctly staged in 28/29 tumors (96.6%). Stage III-IV tumors were correctly staged in 8/12 patients (66.6%). Overall, MDCT was accurate in predicting pathologic TNM stage in 36/41 upper urinary tract TCC (87.8%). There was no significant difference of mean attenuation of TCC between CMP, NP and PP (P > 0.05). MDCT with its high spatial and temporal resolution is an accurate tool for detection TCC of the upper urinary tract, with 87.8% accuracy in predicting its stage.

The renal sinus: pathologic spectrum and multimodality imaging approach

Various pathologic conditions can occur in the renal sinus, primarily originating in the constituents of the renal sinus, and the renal sinus can be secondarily involved by surrounding renal parenchymal and adjacent retroperitoneal lesions. Lipomatosis and cysts are common renal sinus lesions with little clinical significance, but differentiation from other pathologic conditions is important. Renal vascular lesions such as renal artery aneurysm or arteriovenous fistula can mimic other parapelvic or peripelvic lesions at excretory urography, but their vascular nature is evident at color Doppler ultrasonography, contrast material-enhanced computed tomography (CT), and magnetic resonance (MR) imaging. Although most tumors originating in the renal pelvis are transitional cell carcinoma or squamous cell carcinoma, renal parenchymal tumors such as renal cell carcinoma or benign multilocular cystic nephroma have a tendency to grow into the renal sinus. Rare tumors of mesenchymal origin can develop in the renal sinus, but their imaging findings are nonspecific. The observation of renal sinus fat is important for detecting a small tumor located in that area and determining the exact tumor stage. Multiplanar CT or MR images can allow exact evaluation of the extent of complex renal sinus disease.

Transitional Cell Carcinoma of the Upper Urinary Tract: Spectrum of Imaging Findings

Transitional cell carcinoma (TCC) accounts for up to 10% of neoplasms of the upper urinary tract and usually manifests as hematuria. Imaging plays an important role in assessment of upper tract disease, unlike in bladder TCC, diagnosis of which is usually made at cystoscopy. Traditional imaging modalities, such as excretory urography, retrograde pyelography, and ultrasonography, still play pivotal roles in diagnosis of upper tract TCC, in combination with endourologic techniques. The multicentric nature of TCC makes assessment of the entire urothelium essential before treatment. The advent of minimally invasive surgery, which allows renal preservation in selected patients, makes accurate tumor staging mandatory to determine the appropriate therapy; staging is usually performed with computed tomography (CT) or magnetic resonance (MR) imaging. Vigilant urologic and radiologic follow-up is warranted to assess for metachronous lesions and recurrence. The emerging technique of CT urography allows detection of urinary tract tumors and calculi, assessment of perirenal tissues, and staging of lesions; it may offer the opportunity for one-stop evaluation in the initial assessment of hematuria and in follow-up of TCC. Similar MR imaging protocols can be used in patients who are not candidates for CT urography, although detection of urinary tract calcifications may be suboptimal.

Multidetektorcomputertomographie (MDCT) der Nieren

Multidetector computed tomography (MDCT) possesses distinct advantages for examination of the kidneys. It carries the potential of becoming the gold standard of diagnostic work-up and surgical planning for most renal diseases and replacing conventional methods such as i.v. urography and angiography. The most outstanding improvements, in comparison to single slice spiral CT, are the speedier image acquisition and enhanced z-axis resolution, which aids particularly in visualization of the urinary tract as it aligns along the axis of the body. Respiratory artifacts are few or nonexistent even in patients who cannot hold their breath. This overview presents a strategy for prudent management of MDCT examinations and describes examination of the most important and frequent renal diseases using MDCT.

CT Urography

With the recent introduction of multi-detector row helical computed tomography (CT), the radiologic evaluation of patients with urologic disease has changed rapidly. Two major approaches to CT urography have been developed. The first approach combines axial CT with timed excretory urography (EU) performed by using conventional radiography, digital radiography, or CT scanned projection radiography (SPR). This approach produces traditional projection urograms, and the timed imaging technique is familiar to radiologists and clinicians. Additional excretory phase CT can be performed when the EU findings are positive or indeterminate. Improved CT SPR processing technology produces radiographlike images, thus eliminating patient transportation between the CT and urography suites or the necessity for a CT suite with a ceiling-mounted x-ray tube and a modified CT tabletop for performance of EU. The second approach to CT urography combines axial CT with thin-section excretory phase CT. The near-isotropic volume data set enables creation of high-resolution two- and three-dimensional reformatted images. However, the increased amount of radiation and the time required for data manipulation are concerns. Further studies evaluating large numbers of patients with various urothelial abnormalities will be necessary to determine the optimal CT urography technique for clinical practice.

Carcinoma de células transicionais do trato urinário: aspectos da tomografia computadorizada

Embora relativamente incomum, o carcinoma de células transicionais do trato urinário é o segundo tumor mais freqüente do rim. Neste trabalho foram analisadas, de forma retrospectiva, as tomografias computadorizadas de dez pacientes com carcinoma de células transicionais confirmado por exame histopatológico. A bexiga foi acometida em 60% dos casos, o sistema pielocalicinal em 60% e o ureter em 10% deles. Lesões sincrônicas estiveram presentes em 40% das vezes. Os aspectos encontrados foram lesões vegetantes, espessamento da parede do ureter e lesões infiltrativas do rim. Foram descritos dois casos de tumores calcificados e um carcinoma de células transicionais surgindo no interior de um divertículo de bexiga. A tomografia computadorizada detectou extensão local do tumor em 80% dos pacientes e lesão a distância em 20%. A tomografia computadorizada permitiu caracterizar a extensão da doença, localmente e a distância, possibilitando que um grupo selecionado de pacientes pudesse ser tratado de forma conservadora.

Helical CT of the Abdomen and Pelvis: Potential Diagnostic Pitfalls of Arterial-Phase Imaging in the Genitourinary Tract

Spiral computed tomography (CT) is the state of the art today in imaging many features of the genitourinary tract. The use of dual-phase CT imaging improves our ability to detect and stage a wide range of pathologies. However, imaging in the arterial phase has several potential pitfalls that can result in either overcalling or undercalling genitourinary pathology. This paper reviews some of the common pitfalls and presents strategies on how to avoid them.

Role of computer technology in medical illustration

OBJECTIVE

Recent improvements of computer technology have resulted in a new approach to medical illustration and the scientific research process. The purpose of this manuscript is to define the current state of the art and to review paths of progress.

CONCLUSION

Using examples, we compared the process of time-intensive hand-rendered art with current art created using new computer technology. Specific emphasis was made on the newest technologies and how high-quality lower cost medical art can now be created. These newly available tools and illustration methods have resulted in a new approach to research, creation, and reproduction of medical art.

13-year survival comparison of percutaneous and open nephroureterectomy approaches for management of transitional cell carcinoma of renal collecting system: equivalent outcomes

BACKGROUND AND OBJECTIVE

Transitional cell carcinoma (TCC) of the renal collecting system traditionally has been managed by open nephroureterectomy with en bloc resection of a bladder cuff. However, for a select patient population with a solitary kidney or bilateral disease, the morbidity and mortality associated with chronic renal insufficiency and dialysis is deterring. In these situations, a more conservative approach such as antegrade percutaneous resection should be considered. The long-term disease-free outcome of percutaneous management in comparison with open nephroureterectomy has not been previously reported. We evaluated our experience with two surgical approaches to treat upper tract TCC: percutaneous resection and nephroureterectomy/nephrectomy to assess the clinical efficacy of these surgical modalities.

PATIENTS AND METHODS

We retrospectively identified 162 patients who had clinically localized TCC of the upper urinary tract. Records were reviewed to identify those with 13-year follow-up (N = 110) in respect to tumor grade, stage, disease-free status, length of cancer-specific survival, and overall survival. Statistical analysis of the results of open nephroureterectomy/nephrectomy (N = 60) and percutaneous resection (N = 50) was performed using Kaplan-Meier survival curves and Student's t-test.

RESULTS

All patients had disease in clinical stage Ta through T3. During a mean follow-up of 46.6 (range 6-150) months, grade 1 disease demonstrated little invasive potential. Of the disease-specific deaths, 60% (17/26) were of patients with grade 3 lesions, with a mean cancer survival period of 15.2 months after the initial procedure. Disease-specific survival rates after open and percutaneous approaches for grade 2 disease were 53.8 and 53.3 months, respectively (P > 0.05).

CONCLUSIONS

Tumor grade appeared to be the most important prognostic indicator in patients with renal TCC regardless of the surgical approach. Grade 3 tumors were more aggressive, presenting in an advanced stage with invasion, and recurrences were usually associated with metastasis. In this population, nephroureterectomy is warranted if the patient is a surgical candidate. The percutaneous option for grade 1 or 2 disease may be extended beyond the population with solitary kidneys and a risk of chronic renal failure to be offered to healthy individuals with normal contralateral kidneys who are willing to abide by a strict and lengthy follow-up.