Efficacy of gadolinium-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging for differentiation between superficial and muscle-invasive tumor of the bladder: a comparative study with computerized tomography and transurethral ultrasonography

Imaging of Bladder Cancer

Bladder cancer is a heterogeneous and frequently multifocal disease with a variable clinical course. The management of bladder cancer is therefore challenging and complicated. CT and MR imaging have replaced the traditional excretory urography and are emerging as the imaging modalities of choice for work-up of patients who have bladder cancer. Imaging provides essential diagnostic information for detection, staging, and post-treatment follow-up of bladder cancer.

Staging bladder carcinoma by three-dimensional ultrasound rendering

Organ-confined staging for bladder cancer has major impact on further treatment. Most imaging techniques for this purpose are insufficient. We, therefore, assessed the value and the limitations of a new diagnostic tool, the 3-D ultrasound (US) rendering, to distinguish invasive from noninvasive bladder cancers. A total of 63 patients underwent 3-D US of the bladder before transurethral resection or radical cystectomy. The US findings were compared with the pathologic stages of the transurethral resection material or the cystectomy specimens. Superficial (pTa) carcinomas were correctly staged in 66% by 3-D US. Lamina propria infiltrating (pT1) were correctly staged in 83% and the quota of correct staging of infiltrating carcinomas (>pT1) by 3-D rendering was 100%. The overall accuracy was 79%. Three-dimensional US rendering is most valuable to discriminate between superficial stages <pT1 and muscle invasive carcinoma >pT1. This new technique might improve staging of bladder cancer.

Dynamic MRI of bladder cancer: evaluation of staging accuracy

OBJECTIVE

The purpose of this study was to evaluate the accuracy of gadoliniumenhanced MRI in staging bladder cancer in a series of patients with surgically proven bladder cancer.

MATERIALS AND METHODS

Seventy-one patients with biopsy-proven bladder cancer underwent MRI on a 1.5-T scanner with a phased-array pelvic coil. Conventional T1-weighted spin-echo, T2-weighted spin-echo, and unenhanced and enhanced (0.1 mmol/kg gadolinium) fast spoiled gradient-echo images with fat suppression were obtained. Two blinded reviewers evaluated the MR images and assigned a stage that was compared with the pathologic stage (n = 67) or with clinical follow-up for at least 2 years after MRI (n = 4).

RESULTS

Agreement among the reviewers was good in assigning a radiologic stage for bladder cancer (kappa = 0.80). On a stage-by-stage basis, MRI accuracy was 62%, and overstaging was the most common error (32%). Staging accuracy improved to 85% and 82% in differentiating superficial from invasive tumors and organ-confined from non-organ-confined tumors, respectively. The time interval between MRI and transurethral resection (</= 60 days and >/=61 days) was not a statistically significant factor in differentiating superficial from invasive and organ-confined from non-organ-confined tumors (p > 0.05). MRI accuracy in staging transitional cell carcinoma was not significantly different from that obtained in staging non-transitional cell carcinoma (p > 0.05).

CONCLUSION

MRI shows good reproducibility between reviewers for staging bladder cancer. Although overall staging accuracy was only moderate, the accuracy for differentiating superficial versus invasive disease and organ-confined versus non-organ-confined disease was high.

Bladder imaging using multidetector row computed tomography, volume rendering, and magnetic resonance imaging

Both multidetector row computed tomography (MDCT) and magnetic resonance imaging (MRI) are used to evaluate the bladder noninvasively. MDCT offers fast imaging with near-isotropic data sets optimized for three-dimensional imaging, including the latest software for volume rendering. MRI provides distinctive soft tissue contrast resolution and can perform dynamic imaging without radiation exposure. This article discusses the techniques and protocols of each modality with case illustrations of their application in a range of bladder pathologies to show their respective distinct advantages and limitations.

MR imaging of the bladder

MR imaging of the bladder can now be routinely and easily performed with consistent quality. The latest techniques provide high-resolution images of the soft tissue contrast and the ability to perform dynamic contrast imaging and functional pelvic floor studies. MR imaging fits in as a complimentary tool to cystoscopy and to conventional pelvic floor dynamic studies and can provide a unique imaging perspective of the bladder. It is important, however, to remain cognizant of the limitations of its use in tumor detection and discrimination.

Current concepts in assessment and treatment of bladder cancer

Transitional cell carcinoma of the bladder is comprised of a variety of cancer diatheses that manifest a spectrum of distinct biologic potentials. The challenge is to control superficial disease recurrence and progression and to identify invasive carcinoma at an earlier stage, when it may be more amenable to cure.

MRI of the female and male pelvis: current and future applications of contrast enhancement

Magnetic resonance imaging (MRI) of the pelvis has proven to be a most valuable diagnostic tool to examine pathologies of various organ systems in the pelvis. For most conditions MRI was found to be superior to other imaging modalities, like ultrasound and computed tomography. Controversy still exists on the value of intraluminal and intravenous contrast enhancement. This article gives an overview on currently available intraluminal and intravenous contrast agents. The techniques and results for contrast-enhanced MRI in the female and male pelvis are discussed based on a review of the literature. New developments and upcoming techniques, such as lymph node specific contrast agents and breathhold volumetric MRI, are described and initial results are presented.

Histopathological analysis of a bladder cancer stalk observed on MRI

Papillary transitional cell carcinoma of the bladder has a loose connective tissue stalk. For staging of bladder cancer on magnetic resonance imaging (MRI), it is important to clearly separate the cancer from the bladder wall. It is possible to distinguish a stalk from the cancer by the difference of intensity on the using MRI. Sixteen stalks of 20 polypoid bladder tumors on any of the T(2)W(I), dynamic images and delayed enhanced images were demonstrated. Most of the stalks show lower signal intensity than the tumors on T(2)W(I), less enhancement on dynamic images and stronger enhancement on delayed enhanced images. The stalk consisted of fibrous connective tissue, capillary blood vessels, inflammatory cell infiltration and edema. This stalk extended from the bladder wall to the center of the tumor. Some of the superficial muscular bundles were pulled into the stalk. These histopathological findings were compatible with the patterns of signal intensities on MRI. The identification of the stalk of a polypoid tumor may be an important observation to exclude bladder wall invasion by tumor.

Relationship of MRI and clinical staging to outcome in invasive bladder cancer treated by radiotherapy

AIM

To compare MRI and clinical staging of invasive bladder cancer prospectively and identify additional prognostic features on MRI before radiotherapy.

METHODS AND MATERIALS

143 patients with a pathological diagnosis of transitional cell carcinoma underwent MRI (1.0 T) of the abdomen and pelvis before radical radiotherapy. Tumour size, site, degree of infiltration, presence of adenopathy and hydronephrosis were assessed and an appropriate radiological stage assigned. Following radiotherapy all patients received regular cystoscopic follow-up. Date of first relapse and date of death were recorded.

RESULTS

The median follow-up was 2.8 years for survivors. Those patients upstaged from T2a clinically to T3b on MRI had a significantly worse outcome (P = 0.0078). In univariate analysis a number of MRI features were significantly associated with adverse outcome: tumour size, circumferential tumour extent, and presence of hydronephrosis (all P < 0.05). After adjustment for clinical T stage and histological grade, all these MRI features and the MRI T stage were found to confer additional prognostic information in predicting early disease relapse and death (P < 0.05).

CONCLUSION

This study demonstrates that MRI before radiotherapy provides valuable additional prognostic information compared to clinical staging.

A new staging criterion for bladder carcinoma using gadolinium-enhanced magnetic resonance imaging with an endorectal surface coil: a comparison with ultrasonography

OBJECTIVE

To evaluate the accuracy of a new staging criterion, submucosal linear enhancement (SLE) on gadolinium-diethylenetriamine-pentaacetic acid-enhanced T1-weighted magnetic resonance imaging (MRI) using an endorectal surface coil (endorectal enhanced MRI), and to compare the accuracy of this method with that of transurethral ultrasonography (TUUS).

PATIENTS AND METHODS

The study included 71 patients with bladder tumours (63 men and eight women, mean age 65.5 years, range 31-85). The SLE coincided with abundant submucosal vascular beds, as reported in a previous study. When the SLE beneath the tumour maintained continuity, the tumour was diagnosed as superficial (</= T1), but if the SLE was interrupted by the tumour, the disease was considered invasive (>/= T2a). Superficial muscle invasion (less than half the muscle layer) and deep muscle invasion (more than half the muscle layer) were classified as T2a and T2b, respectively. When the tumour formed an extravesical mass, the tumour was classified as T3b.

RESULTS

The staging accuracy for bladder tumours using SLE on endorectal-enhanced MRI or TUUS was 83% and 60%, respectively (P < 0.01). Using the SLE, muscle invasion of bladder tumour was diagnosed with an accuracy of 87%, a sensitivity of 91% and a specificity of 87%; this was significantly better than with TUUS (P < 0.01).

CONCLUSION

The criterion of SLE on Gd-DTPA enhanced T1-weighted MRI using an endorectal surface coil is useful for staging bladder tumour, and the staging accuracy is significantly better than with TUUS.

Fast dynamic gadolinium-enhanced MR imaging of urinary bladder and prostate cancer

Among the noninvasive imaging modalities, contrast enhanced magnetic resonance (MR) imaging is the most powerful tool with which to visualize vascularity. Common pathology only shows microvessel density, whereas dynamic MR imaging is sensitive to the total endothelial surface area of perfused vessels. Therefore, dynamic MR imaging may be of additional value in tumor staging and in evaluating therapies that affect the perfused microvessel density or surface area, such as chemo-, radiation, or anti-angiogenic therapy. In urinary bladder cancer, this technique results in improved local and nodal staging, in improved separation of transurethral granulation tissue and edema from malignant tumor, and in improved evaluation of the effect of chemotherapy. In prostate cancer, dynamic MR imaging may be of help in problematic cases. This technique can assist in determining seminal vesicle infiltration, in depicting of minimal capsular penetration, and in recognizing tumors within the transitional zone. Also, based on very rapid enhancement, very poorly differentiated tumors can be recognized. Evaluation of the effects of therapy is another promising area, however a lot of research remain to be done. This article reviews some basics of fast enhancement techniques, provides practical information, and shows recent developments, in using these fast techniques for staging and grading of bladder and prostate cancer, and for evaluating the effect of therapy.

Magnetic resonance imaging of urinary bladder cancer

The treatment and prognosis of urinary bladder cancer are largely determined by the tumour stage and the presence or not of metastases. Magnetic resonance imaging and clinical staging complement each other. Magnetic resonance imaging is the most accurate technique for differentiating the various stages of deep tumour infiltration and for detecting metastases, whereas clinical staging is the best technique for differentiating between post-biopsy effects and the various stages of superficial tumours. The role played by magnetic resonance imaging in the staging of this disease and the monitoring of therapy is reviewed and illustrated. Finally, the authors present an overview of the current and future applications of this technique.

MR imaging of the prostate and bladder

Magnetic resonance imaging has become an important imaging modality for the male pelvis. Its unparalleled ability to depict soft tissue structures and highlight pathology have made it the best method for determining the extent of many disease processes. This article reviews the use of MR to evaluate diseases of the prostate gland and bladder. In both, the major indication for imaging is the local staging of cancer, and MR is currently the best imaging modality. This article will discuss the critical clinical issues concerning prostate cancer and neoplasms of the bladder, and the contribution of MR imaging.

Normal bladder wall morphology in Gd-DTPA-enhanced clinical MR imaging using an endorectal surface coil and histological assessment of submucosal linear enhancement using [14C]Gd-DOTA autoradiography in an animal model

OBJECTIVE

The purpose of this study was to investigate normal bladder wall morphology in gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced magnetic resonance (MR) imaging using an endorectal surface coil and to perform histological assessment of submucosal linear enhancement with experimental [14C]-gadolinium-tetraazacyclododecane-tetraacetic acid (Gd-DOTA) autoradiography.

METHODS AND MATERIAL

MR imaging of the bladder was performed using an endorectal coil in 13 consecutive patients with bladder carcinoma and T1-, T2-, and Gd-DTPA-enhanced spin-echo images of the bladder wall were compared. After injection of [14C]Gd-DOTA into a hamster, autoradiograms of the bladder wall were obtained and compared with serial histological sections.

RESULTS

The normal bladder wall appeared as a homogeneous layer of intermediate intensity on T1-weighted images. After administration of Gd-DTPA, the bladder wall was visualized as three layers: an inner thin layer of low intensity, a middle layer of marked enhancement, and a thick outer layer of intermediate intensity. The autoradiograms demonstrated dense accumulation of [14C]Gd-DOTA in the submucosal layer. Thus, the inner, middle, and outer layers corresponded to the mucosa, submucosa, and muscularis propria, respectively. The thickness of the bladder wall demonstrated on T2-weighted images was almost equal to that of the outer layer on enhanced T1-weighted images. Thus, T2-weighted images revealed only the muscle layer as an intermediate-intensity band. In the preliminary clinical study, MR imaging invariably showed accurate stages of the bladder carcinoma in 13 patients.

CONCLUSION

In MR imaging of the normal bladder wall, the submucosa was strikingly enhanced after Gd-DTPA administration, separating the bladder wall into three layers. This may have a potential role in the staging of bladder tumors.

What is new in bladder cancer imaging

Treatment and prognosis of urinary bladder cancer largely are determined by the tumor stage and presence of metastases. MR imaging and clinical staging complement each other. MR imaging is the most accurate technique for differentiating the various stages of deep tumor infiltration and detection of metastases, whereas clinical staging is the best technique for differentiating between postbiopsy effects and the various stages of superficial tumors. The role of MR imaging in staging of this disease and monitoring of therapy is reviewed and illustrated. Finally, the authors present an overview of current and future applications of this technique.

Detection of muscle layer invasion with submillimeter pixel MR images: staging of bladder carcinoma

Conventional magnetic resonance (MR) images used for the pelvic organs generally have a pixel size of 1.3 mm x 1.3 mm. We obtained images with a higher resolution than conventional images, and evaluated the usefulness of this type of image in staging urinary bladder carcinoma. Twenty-six patients having either transurethral resection of bladder tumor (TUR-BT) or cystectomy were retrospectively studied. T2-weighted images of the bladder were acquired with a 20 cm field-of-view, a matrix size of 224 x 224 (pixel size: 0.9 mm x 0.9 mm), and a slice thickness of 7 mm using a 0.5 T system. MR appearances of the carcinoma were divided into the following five categories: no abnormality found on the inner surface of the bladder wall (0), high signal layer or protrusion without breakage of the wall (I), partial disruption of the wall (II), transmural disruption of the wall (III), and complete disruption with mass formations in the perivesicular region (IV). These findings were correlated with the TNM pathologic staging determined from each tissue specimen. A prediction for muscle layer invasion was calculated by selecting pathologic stage pT2 and MR category III as a boundary measure. The accuracy was 96.2%, the sensitivity 100.0%, and the specificity 91.7%. The results obtained indicate that submillimeter pixel MR imaging shows promise as a noninvasive method for the preoperative staging of bladder cancers.