A height-to-length ratio of <0.605 was found to be a useful cutoff value for differentiating NMIBC from MIBC. Three-dimensional US rendering is a new diagnostic tool that shows potential in discriminating NMIBC from MIBC [68]. It allows for retrieval and manipulation of volume data in multiple planes, increasing objectivity and improving the primary bladder tumor diagnosis rate (100% with 3-D US versus 88.9% with 2-D US) when identifying T3b disease [69]. However, the technique has limitations, including difficulty in visualizing the entire tumor, particularly in flat or plaque-like tumors, the presence of coexistent calcification, a rigid abdominal wall, or central obesity [70]. Contrast-enhanced US has also been shown to better differentiate MIBC from NMIBC [71]. In a study of 34 patients who underwent both grayscale and contrast-enhanced US before TURBT [71], contrast-enhanced US performance was similar to the reference standard of TURBT in differentiating MIBC from NMIBC. Ge et al [72] also found that preoperative contrast-enhanced US is highly efficient in discriminating Ta to T1 or low-grade bladder cancer from stage T2 or high-grade bladder cancer. Contrast-enhanced US shows a high sensitivity, specificity, and diagnostic accuracy, making it a promising method for distinguishing T staging and grading of bladder cancer. Li et al [73] demonstrated that the combined use of contrast-enhanced US and DWI-MRI is more accurate in diagnosing bladder cancer than either method alone, making it a feasible and effective diagnostic approach for bladder cancer. For patients with MIBC, the probability of positive bone scans increases, as does its importance in guiding proper management and avoiding unnecessary radical surgery [77]. One study found that 14.5% of patients with bladder cancer had bone metastasis at presentation, with deep muscle invasion being the most common factor associated with metastatic disease [78].
Pretreatment Staging of Urothelial Cancer. A height-to-length ratio of <0.605 was found to be a useful cutoff value for differentiating NMIBC from MIBC. Three-dimensional US rendering is a new diagnostic tool that shows potential in discriminating NMIBC from MIBC [68]. It allows for retrieval and manipulation of volume data in multiple planes, increasing objectivity and improving the primary bladder tumor diagnosis rate (100% with 3-D US versus 88.9% with 2-D US) when identifying T3b disease [69]. However, the technique has limitations, including difficulty in visualizing the entire tumor, particularly in flat or plaque-like tumors, the presence of coexistent calcification, a rigid abdominal wall, or central obesity [70]. Contrast-enhanced US has also been shown to better differentiate MIBC from NMIBC [71]. In a study of 34 patients who underwent both grayscale and contrast-enhanced US before TURBT [71], contrast-enhanced US performance was similar to the reference standard of TURBT in differentiating MIBC from NMIBC. Ge et al [72] also found that preoperative contrast-enhanced US is highly efficient in discriminating Ta to T1 or low-grade bladder cancer from stage T2 or high-grade bladder cancer. Contrast-enhanced US shows a high sensitivity, specificity, and diagnostic accuracy, making it a promising method for distinguishing T staging and grading of bladder cancer. Li et al [73] demonstrated that the combined use of contrast-enhanced US and DWI-MRI is more accurate in diagnosing bladder cancer than either method alone, making it a feasible and effective diagnostic approach for bladder cancer. For patients with MIBC, the probability of positive bone scans increases, as does its importance in guiding proper management and avoiding unnecessary radical surgery [77]. One study found that 14.5% of patients with bladder cancer had bone metastasis at presentation, with deep muscle invasion being the most common factor associated with metastatic disease [78].