Bladder cancer: staging with CT and MR imaging

Magnetic resonance (MR) imaging and computed tomography (CT) were compared in 30 patients with histologically proved bladder cancer. MR imaging was accurate in depicting the presence or absence of extravesical spread in 22 patients (accuracy, 73%; sensitivity, 82%; specificity, 62%), and CT was accurate in 24 patients (accuracy, 80%; sensitivity, 94%; specificity, 62%). The MR examinations of two patients were of undiagnostic quality and therefore considered to be technical failures. Each technique resulted in five false-positive and one false-negative examination for the diagnosis of extravesical tumor spread. In 28 patients the integrity of the bladder wall was assessed with MR imaging. In 22 patients the bladder wall was disrupted, and 18 of these patients had deep muscle invasion. In six patients the bladder wall was intact, and none of these patients had evidence of deep muscle invasion at pathologic examination. In this study MR imaging was slightly inferior to CT in the delineation of invasive tumors beyond the bladder wall. However, if one excludes from analysis the two patients with undiagnostic studies, there is no significant difference in accuracy between the two techniques.     

膀胱癌与生存素

膀胱癌是在泌尿生殖道发生占第二位的癌。最普通型膀胱癌是尿乳突细胞癌（Urothelial cell carcinoma,UCC）,大约占所有膀胱肿瘤的95％。检查膀胱肿瘤的金标准是细胞学检查。大多数UCC为浅表肿瘤,侵袭深度限于膀胱壁黏膜下（Ta、T1期）,大约有70％的患者在初次切除后复发,其中有的最终将向侵袭性和更具浸润性病变进展（T2-T4期）。这就迫使所有浅表膀胱癌患者在追踪期间需频繁地做细胞学检查。该检查虽较准确,但为有创检查,且检查费用较高,患者经济负担较重,加之小的乳头损害,以及原位平面生长的癌常常易被漏诊。自20世纪末发现生存素（Survivin）,用于膀胱癌的诊断及预测复发以来,已成为热点研究领域。     

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.     

Colorectal cancer imaging

Official estimates rank colorectal cancer third in both incidence and cause of death for all U.S. cancers. This article discusses the role of diagnostic imaging in screening, diagnosis and treatment of cancers of the colon and rectum. After completing this article, readers should be able to: Explain basic anatomy of the colon and rectum. Discuss the histology and staging of colorectal cancer. Identify various colorectal screening tests, including colonoscopy, computed tomography (CT) colonography and magnetic resonance (MR) colonography. Understand the role of diagnostic imaging in the diagnosis and staging of colorectal cancer. Describe diagnostic imaging of colorectal cancer recurrence.     

Prostate cancer imaging

As prostate cancer is a biologically heterogeneous disease for which a variety of treatment options are available, the major objective of prostate cancer imaging is to achieve more precise disease characterization. Magnetic resonance imaging (MRI) may enhance the staging of prostate cancer compared with clinical evaluation, transrectal ultrasound, or computed tomography (CT), and allows concurrent evaluation of prostatic, periprostatic, and pelvic anatomy. In clinical practice, the fusion of MRI or dynamic contrast-enhanced MRI (DCE-MRI) with MR spectroscopic imaging (MRSI) is improving the evaluation of cancer location, size, and extent, while providing an indication of tumor aggressiveness. Pretreatment knowledge of these prognostic variables is essential for achieving minimally invasive, patient-specific therapy.     

Bladder cancer following low or high dose pelvic irradiation

Eleven women presenting to this department since 1971 with bladder cancer have had previous pelvic irradiation. The tumours were generally of high grade and advanced T-category. Prognosis was poor and only 32% survived for one year. The interval observed between low dose pelvic irradiation and subsequent bladder cancer was longer than after high dose pelvic irradiation (mean interval of 30 years compared with 16.5 years).     

膀胱憩室并发膀胱癌1例

患者男,67岁。发热1月,查体发现膀胱占位。外科查体无明显阳性体征。盆腔超声显示膀胱右侧壁不规则团块,约4cm×3cm×4cm。尿常规：红细胞（＋＋＋）,白细胞（＋＋＋）,蛋白（＋＋）。盆腔CT平扫＋强化扫描显示：膀胱右后壁见一囊袋状影,壁明显不均匀增厚,膀胱右后壁不均匀增厚（图1）,有明显强化（图2）,与盆壁分界欠清楚。膀胱左后壁见一小憩室影。     

Bladder cancer: the value of routine bone scintigraphy

Two hundred and twenty-one patients with invasive bladder cancer had routine bone scintigraphy performed as part of tumour staging. The incidence of detectable metastases was 12%. Skeletal scintigraphy at diagnosis has a sensitivity of only 38%. The predictive value of a negative examination was 92%. These results suggest that skeletal scintigraphy is not indicated as a routine staging procedure in carcinoma of the bladder.     

Breast cancer imaging devices

Conventional mammography is a screening procedure constrained by low specificity in the detection of breast cancer. Approximately 40% of women undergoing mammography screening have dense breast tissue, and conventional mammographic imaging has a sensitivity range of only 50%-85% for malignant lesions. Magnetic resonance imaging (MRI) is now recommended for breast cancer screening in high-risk patients. However, approximately 15% of patients cannot tolerate MRI. These are the clinical situations in which positron emission mammography (PEM) and breast-specific gamma (BSG) camera systems fulfill a need for primary breast cancer imaging. Because breast cancer is the most common malignancy and the second most common cause of cancer death among women, many nuclear medicine imaging techniques are essential in the evaluation and therapy of patients with this disease. Nuclear medicine surgical techniques consist of sentinel lymph node localization and the use of radiolabeled seeds for intraoperative localization of nonpalpable breast cancers. The Food and Drug Administration (FDA) has approved the PEM Flex Solo II scanner, which has the capability for stereotactic biopsy, with an array of pixelated lutetium yttrium orthosilicate (LYSO) crystals, position-sensitive photomultiplier tubes (PS-PMT), and a spatial resolution of 2.4 mm. Clear PEM is a scanner in development with cerium-doped LYSO (LYSO:Ce) crystals, multipixel avalanche photodiodes, depth of interaction measurement with a resolution of 1.3 mm. The Dilon 6800 Gamma Camera is a BSG device approved by the FDA with stereotactic biopsy guidance capability, a pixelated array of sodium iodide crystals, PS-PMTs, and an extrinsic spatial resolution of 6 mm at 3 cm from the camera. GE has just received clearance from the FDA for a molecular breast imaging camera, the Discovery NM 750 b, with pixelated cadmium zinc telluride crystals, semiconductor photoelements and an extrinsic resolution of 3.5 mm at 3 cm. The Society of Nuclear Medicine has issued guidelines for BSG camera image interpretation recommendations and clinical indications. Different crystals and camera architectures are under investigation to further improve resolution for both PEM and BSG imaging.     

Bladder tumour staging: comparison of diffusion- and T2-weighted MR imaging

The aim of this work was to evaluate the clinical feasibility of diffusion-weighted (DW) MRI in detection and staging of urinary bladder tumour and to compare DW MRI with the T₂-weighted technique. One hundred and six patients with bladder tumour were prospectively included in our study. All patients were evaluated with MR imaging. We started with axial T₂-weighted high resolution MR of the urinary bladder, then DW MRI. Two radiologists independently interpreted the MR images, and discrepancies were resolved by consensus. The accuracy of DW MRI in staging of bladder tumour was evaluated using the final histopathological findings. In DW imaging (DWI) staging accuracy was 63.6% and 69.6% in differentiating superficial from invasive tumours and organ-confined from non-organ-confined tumours, respectively. On a stage by a stage basis, DWI accuracy was 63.6% (21/33), 75.7% (25/33), 93.7% (30/32) and 87.5% (7/8) for stages T1, T2, T3 and T4, respectively. In the T₂-weighted technique, the overall staging accuracy was only 39.6% and accuracy for differentiating superficial from invasive tumours and organ-confined from non-organ-confined tumours was 6.1% and 15.1%, respectively. DW is superior to T₂-weighted MRI in staging of organ-confined tumours (≤T2) and both techniques are comparable in the evaluation of higher-stage tumours.