Table 1.
Advantages and disadvantages of evaluation of rectal tumor comparing MRI and TRUS
| Variable | MRI | TRUS |
|---|---|---|
| Availability | Radiology department | Office |
| Patient contraindications | Metal implants, claustrophobia | None |
| Anatomic location | Good | Excellent |
| Tissue resolution | Excellent | Good |
| Anatomic coverage | Wide | Narrow |
| Operator dependency | High | Very high |
| Early cancer | ||
| T1 vs. T2 | Poor | Good |
| T1/T2 vs. T3 | Good | Good |
| T4 | Excellent | Only anterior tumors |
| Mesorectal nodes | Moderate | Moderate |
| Internal Iliac/superior rectal nodes | Good | Poor |
| Relationship to mesorectal fascia | Excellent | Poor |
| Infiltration of levator muscle | Good | Moderate |
| Infiltration of anal sphincter | Moderate | Good |
MRI, magnetic resonance imaging; TRUS, transrectal ultrasonography.