Carcinoma of the urinary bladder, after prostate cancer, is the most common malignant tumor of the urinary tract in men and women and accounts for 2% of all malignancies. In 1993, in the United States 52,300 cases were registered. Although this number is still increasing because of aging of the population, smoking behavior (the most important single risk factor) is also an obvious influence. For example, bladder cancer mortality has decreased since 1990 because of changes in smoking behavior in the male Dutch population for successive birth cohorts after 1930 (Liemeney LALM, Witjes JA, unpublished data). The mortality in the United States in 1993 was 9900. Bladder cancer is seen predominantly in elderly men and the male to female ratio is 4:1.

About 90% to 95% of urinary bladder malignancies are transitional cell carcinomas, and the remaining 5% to 10% consist of squamous cell carcinomas and adenocarcinomas and a small number of sarcomas and metastases from other primary tumors. About two thirds of the tumors are superficial (< pT2) and are usually papillary.<sup>15Kiemeney L.A.L.M., Witjes J.A., Verbeek A.L.M., e al. The clinical epidemiology of superficial bladder cancer Br J Cancer 1993 ;  67 : 806-812

Cliccare qui per andare alla sezione Riferimenti</sup> One third of the tumors show infiltration into or beyond the muscular layer of the bladder wall.

The initial treatment and prognosis largely are determined by the depth of tumor infiltration (tumor stage); the presence of positive lymph nodes and distant metastases; and the histologic tumor type.<sup>14Jewett H.J. Proceedings: Cancer of the bladder. Diagnosis and staging Cancer 1973 ;  32 : 1072-1074 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> Therefore, exact staging is imperative. To describe local tumor extension (T), presence of lymph nodes (N), and distant metastases (M), the Union Internationale Contre le Cancer proposed a uniform clinical staging method (Fig. 1 and Table 1)<sup>14Jewett H.J. Proceedings: Cancer of the bladder. Diagnosis and staging Cancer 1973 ;  32 : 1072-1074 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> Table 1 also presents the American classification, known as Jewett-Strong.<sup>14Jewett H.J. Proceedings: Cancer of the bladder. Diagnosis and staging Cancer 1973 ;  32 : 1072-1074 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup>

In superficial tumors, those without muscle invasion (stage Ta, T1, or carcinoma in situ), patients are treated with local endoscopic resection with or without adjuvant intravesical instillations. Patients with a tumor invading the muscle layer of the bladder wall or with only minimal perivesical extension (stage T2, T3a, or minimal T3b) are selected for radical lymphadenectomy and cystectomy or radiotherapy after neoadjuvant chemotherapy. If the local tumor is in an advanced stage (stage T3b, T4a, or T4b), or if nodal or distant metastases are present, the initial treatment is palliative chemotherapy or radiation therapy. If in such a patient adjuvant surgical therapy is considered, monitoring the response to chemotherapy or radiotherapy and determining the final outcome are important.

Because clinical staging is not reliable for determining tumor extension beyond the bladder wall,<sup>12 TNM Classification of Malignant Tumors Geneva: Union Internationale Contre le Cancer (1978). 

Cliccare qui per andare alla sezione Riferimenti, 14Jewett H.J. Proceedings: Cancer of the bladder. Diagnosis and staging Cancer 1973 ;  32 : 1072-1074 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> other methods are needed. In the field of imaging, rapid changes occur. After the development of CT scanning and ultrasonography, MR imaging has matured. Since the introduction of this technique, several reports in the late 1980s and early 1990s showed the superiority of this technique for staging urinary bladder carcinoma.<sup>2Amendola M.A., Glazer G.M., Grossman H.B., e al. Staging of bladder carcinoma: MRI-CT-surgical correlation AJR Am J Roentgenol 1986 ;  146 : 1179-1183

Cliccare qui per andare alla sezione Riferimenti, 3Barentsz J.O., Debruyne F.M.J., Ruijs S.H.J.  Magnetic Resonance Imaging of Carcinoma of the Urinary Bladder Dordrecht: Kluwer (1990). 

Cliccare qui per andare alla sezione Riferimenti, 7Beyer H.K., Funke P.J., Brackins-Romero J., e al. Wertigkeit der Kernspintomographie bei der Diagnostik und Stadienbestimmung von Harnblasenneoplasmen Digitale Bilddiagnostik 1985 ;  5 : 167-172

Cliccare qui per andare alla sezione Riferimenti, 8Bryan P.J., Butler H.E., LiPuma J.P., e al. CT and MR imaging in staging bladder neoplasms J Comput Assist Tomogr 1987 ;  11 : 96-101 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 9Buy J.N., Moss A.A., Guinet C., e al. MR staging of bladder carcinoma: Correlation with pathologic findings Radiology 1988 ;  169 : 695-700

Cliccare qui per andare alla sezione Riferimenti, 11Fisher M.R., Hricak H., Tanagho E.A. Urinary bladder MR imaging. Part II. Neoplasm Radiology 1985 ;  157 : 471-477

Cliccare qui per andare alla sezione Riferimenti, 12 TNM Classification of Malignant Tumors Geneva: Union Internationale Contre le Cancer (1978). 

Cliccare qui per andare alla sezione Riferimenti, 13Husband J.E., Olliff J.F., Williams M.P., e al. Bladder cancer: Staging with CT and MR imaging Radiology 1989 ;  173 : 435-440

Cliccare qui per andare alla sezione Riferimenti, 15Kiemeney L.A.L.M., Witjes J.A., Verbeek A.L.M., e al. The clinical epidemiology of superficial bladder cancer Br J Cancer 1993 ;  67 : 806-812

Cliccare qui per andare alla sezione Riferimenti, 16Kim B., Semelka R.C., Ascher S.M., e al. Bladder tumor staging: Comparison of contrast-enhanced CT, T1- and T2-weighted MR imaging, dynamic gadolinium-enhanced imaging, and late gadolinium-enhanced imaging Radiology 1994 ;  193 : 239-245 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 17Koelbel G., Schmeidl U., Griebel J., e al. MR imaging of urinary bladder neoplasms J Comput Assist Tomogr 1988 ;  12 : 98-103 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 18Küper K., Koelbel G., Schmeidl U. Kernspintomographische Untersuchungen von Harnblasenkarzinomen bei 1.5 Tesla Fortschr Röntgenstr 1986 ;  144 : 674-680

Cliccare qui per andare alla sezione Riferimenti, 23Nicolas V., Harder T., Steudel A., e al. Die Wertigkeit bildgebender Verfahren bei der Diagnostik und dem Staging von Harnblasentumoren Fortschr Röntgenstr 1988 ;  148 : 234-239 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 25Rholl K.S., Lee J.K.T., Heiken J.P., e al. Primary bladder carcinoma: Evaluation with MR imaging Radiology 1987 ;  163 : 117-123

Cliccare qui per andare alla sezione Riferimenti, 31Tavares N.J., Demas B.E., Hricak H. MR imaging of bladder neoplasms: Correlation with pathologic staging Urol Radiol 1990 ;  12 : 27-33 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> Even now, the end of rapid technologic improvements in MR imaging is not in sight, and visualization of the bladder and of bladder carcinoma is expected to improve still further. This article describes the appearance of MR images of the normal and abnormal urinary bladder. The role of MR imaging in staging this disease and in monitoring therapy is reviewed and illustrated. Finally, the authors present an overview of current and future applications of this technique.