A  CT scan of the sinuses in DT (Detail) and Sub-MM (Sub-Millimeter) modes provides high-resolution imaging of the sinus cavities and surrounding structures. Here are the key points:

1. Purpose:
Evaluates the detailed anatomy and pathology of the sinuses, nasal cavity, and adjacent structures.
Diagnoses conditions such as sinusitis, nasal polyps, tumors, and anatomical variations.
Aids in planning for sinus surgery and assessing the impact of disease on surrounding structures.

2. Contrast Agent:
Typically, no contrast is used for standard sinus evaluations.
Contrast-enhanced scans may be employed if there is a need to assess soft tissue abnormalities or differentiate complex lesions.

3. Imaging Technique:
DT Mode (Detail Mode): Provides high-resolution images with fine detail to better visualize small anatomical structures and subtle pathology.
Sub-MM Mode: Utilizes ultra-thin slice thickness (sub-millimeter) for precise imaging of fine structures and detailed assessment of pathology.

4. Indications:
Evaluation of chronic sinusitis, nasal congestion, and sinus infections.
Detection of nasal polyps, tumors, and other lesions in the sinuses.
Assessment of anatomical variations and their impact on sinus function.

5. Protocol:
The patient is positioned supine with the head aligned to optimize imaging of the sinuses.
High-resolution, thin-slice images are captured in the axial plane, with DT and Sub-MM modes used to enhance detail and clarity.

6. Key Findings:
Identifies sinus obstruction, fluid levels, mucosal thickening, and bony erosion.
Detects polyps, tumors, and anatomical anomalies affecting sinus function and drainage.

7. Advantages:
High-resolution imaging with DT and Sub-MM modes provides superior detail compared to standard CT, enhancing the ability to visualize small and complex structures.
Improved diagnostic accuracy for subtle pathologies and precise surgical planning.

8. Safety Considerations:
Limited radiation exposure due to the focused imaging of specific areas; contrast use is minimized and considered based on the clinical need.

9. Clinical Scenarios:
Commonly used in diagnosing and managing chronic sinus conditions, preoperative planning for sinus surgeries, and evaluating complex sinus pathologies.

This format ensures a thorough understanding of the CT scan’s role and capabilities in evaluating sinus conditions with high precision.