From the Research
To visualize the latissimus dorsi region, a standard MRI of the thoracic spine or chest wall with axial T1-weighted and T2-weighted sequences would be most appropriate, as it provides excellent soft tissue contrast without the need for contrast enhancement unless suspicion of inflammation, tumor, or infection exists. The MRI should include the posterior chest wall from approximately T7 to L3 vertebral levels, covering the full anatomical distribution of the latissimus dorsi muscle. This approach is supported by the most recent and highest quality study available, which emphasizes the judicious use of intravenous contrast in musculoskeletal MRI, restricting it to cases where there is demonstrable added value 1.
The use of T1-weighted and T2-weighted sequences is crucial for evaluating the latissimus dorsi muscle, as it allows for the assessment of muscle architecture, potential tears, edema, atrophy, or other pathological changes. The patient would likely be positioned supine in the scanner with arms at their sides or above their head to minimize motion artifacts.
Some studies suggest that contrast enhancement may not always be necessary, even in the evaluation of soft-tissue tumors or bone tumors, where fast STIR sequences can provide equivalent or superior information compared to T1-weighted fat-suppressed contrast-enhanced sequences 2, 3. However, the decision to use contrast should be made on a case-by-case basis, considering the specific clinical context and the potential risks and benefits of contrast administration.
In certain cases, additional sequences such as diffusion-weighted imaging (DWI) or T2-STIR may be useful, particularly when evaluating perianal fistula or other complex pathologies, as they can provide valuable information without the need for contrast enhancement 4. The choice of MRI sequence and the use of contrast should be guided by the clinical question and the potential benefits and risks of each approach, with the goal of providing the most accurate diagnosis while minimizing harm to the patient.
Key points to consider when visualizing the latissimus dorsi region include:
- The use of axial T1-weighted and T2-weighted sequences for excellent soft tissue contrast
- The inclusion of the posterior chest wall from approximately T7 to L3 vertebral levels
- The potential for contrast enhancement with gadolinium in cases of suspected inflammation, tumor, or infection
- The consideration of additional sequences such as DWI or T2-STIR in complex cases
- The importance of positioning the patient to minimize motion artifacts.