Routine Thorax | CT Protocols

CT- Beginners Tips

CT protocol for Routine Thorax

Indication

Screening Infection/Inflammation, Trauma, Masses of Lung pleura and mediastinum staging lymphoma lesions of the chest wall and esophagus Followups

Patient positioning 

Head First Supine with Arms elevated above the Head 

Topogram Position/Landmark

Anteroposterior; 1 inch below the level of the chin to Umbilicus.

Mode of Scanning

Helical with single breath-hold.

Scan Orientation

Caudocranial

• Starting Locations- The imaginary line joining the two costophrenic angles
• End Location- 1 cm above the Apex of the Lung 

Gantry Tilt

Nill

Field of view

Just fitting to the Thoracic Cavity including the soft tissues of the Chest wall.

Contrast Administration

Intravenous oral Air/Positive Contrast for Esophageal Evaluation 

The volume of Contrast

60-100 mL.

Rate of Injection of Contrast

2-2.5 ml/sec

Scan Delay

35-45 sec

Slice Thickness in Reconstruction

3-5 mm

Slice Interval

1.5-2.5 mm

Reconstruction Algorithm/Kernel

Medium smooth sharp for pulmonary parenchyma and  Bone

3D-Reconstructions

• MPR,
• MIP,
• VRT if needed 

Comments

Noncontrast Scans should be taken in the region of interest or lesion detected on Chest radiography or Topogram.

When scanning the chest and Abdomen in a single examination Abdomen protocol should be followed 

Scanned Volume should be extended to the level of Adrenals in suspected Bronchogenic  Cancers and to the level of the Celiac axis in the Carcinoma  Esophagus.

Additional Prone and Decubitus Scans should be taken through the region of interest in cases of Cavitary Lesions to demonstrate the mobility of its contents.

Criteria of Good Image Quality 

Absence of motion artefacts and Respiratory misregistration.