Updated 05/01/24 CT Trachea Reviewed 05/14/25 Indications - tracheal stenosis, tracheomalacia, inspiratory/expiratory stridor. Only use this protocol when ordered/protocoled as such. Use regular CT chest charges. Do not include a CT neck charge. GENERAL SCAN NOTES Move the patient's arms over his/her head if possible. Remove any metal from the imaging field of view. Have the patient cough a few times to clear secretions. This reduces incidence of small lung nodules. Topogram - hyoid bone through diaphragm (obtained during end inspiration).
Craniocaudal scan coverage: Supine end inspiration phase - 5 cm above clavicular heads through adrenal glands. Supine end expiration phase - 5 cm above clavicular heads through carina. Adjust FOV (field of view) on topogram to smallest without cropping anatomy. Scan parameters for the supine end inspiratory phase are the same as routine chest protocol. Scan parameters for the supine end expiratory phase are the same as low-dose chest protocol. IV Contrast: 100 mL Omnipaque-300, inject at 2 mL/sec, 30 secs scan delay. For GE scanners, it is essential for the 1st recon thickness on the scanner to match the 1st recon thickness in this protocol book for the prescribed Noise Index to be valid. The 1st recon should generally be the thickest recon in the protocol.

CT Trachea SIEMENS PARAMETERS & RECONS For the Supine End Inspiration phase: Scan
Care
Scan
Mode kV mAs Care
Dose kV & Lvl Pitch Acq Coll Rot Time Time Sensation 16 spiral 120 100 on NA 1.15 16 0.75 0.5 10.9 Go Up 32 spiral 130 51 on on 80 1.50 32 0.7 0.8 7.1 Sensation 64 spiral 120 100 on NA 1.40 64 0.6 0.5 5.6 Definition 64 spiral 120 110 on on 1.20 64 0.6 0.5 6.5 Go Top 64 spiral 120 62 on on 80 1.20 64 0.6 0.33 2.1 Drive 128 spiral 120 66 on on 1.20 128 0.6 0.5 3.3 Force 192 spiral 110 51 on on 1.20 192 0.5 0.5 2.6 Recon
Name of Series Thick Interval Kernel Window IR
Lvl Direction AX INSP LUNG 3.0 3.0 Br57 / B70f lung 3 head/feet AX INSP SOFT 3.0 3.0 Br40 / B41f mediastinum 3 head/feet COR INSP SOFT 3.0 3.0 Br40 / B41f mediastinum 3 front/back SAG INSP SOFT 3.0 3.0 Br40 / B41f mediastinum 3 left/right AX INSP THINS 1.0 0.8 Br40 / B41f mediastinum 3 head/feet AX INSP MIPS 8.0 3.0 Br40 / B41f lung 3 head/feet For the Supine End Expiration phase: Scan
Care
Scan
Mode kV mAs Care
Dose kV & Lvl Pitch Acq Coll Rot Time Time NA 1.15 16 0.75 0.5 10.9 Sensation 16 spiral 120 60 on on 80 1.50 32 0.7 0.8 7.1 Go Up 32 spiral 130 31 on NA 1.40 64 0.6 0.5 5.6 Sensation 64 spiral 120 60 on on 1.20 64 0.6 0.5 6.5 Definition 64 spiral 120 66 on on 80 1.20 64 0.6 0.33 2.1 Go Top 64 spiral 120 37 on on 1.20 128 0.6 0.5 3.3 Drive 128 spiral 120 40 on Force 192 spiral on 0.5 1.20 192 0.5 2.6 110 31 on IR
Recon
Name of Series Thick Interval Kernel Window Lvl Direction AX EXP LUNG 3.0 3.0 Br57 / B70f lung 3 head/feet AX EXP SOFT 3.0 3.0 Br40 / B41f mediastinum 3 head/feet

CT Trachea GE PARAMETERS & RECONS For the Supine End Inspiration phase: Scan
Smart
Slice
Beam
Dose
Scan
Pitch Speed Rot
Type SFOV kV mA
Range Noise
Index mA Thick Coll Time Red ASIR Time LS 16 helical large 120 100-440 16.36 on 2.5 20 1.375 27.50 0.5 NA NA 8.2 Opt 540 helical large 120 100-440 16.36 on 2.5 20 1.375 27.50 0.5 NA NA 8.2 LS VCT 64 helical large body 120 100-650 18.38 on 2.5 40 1.375 55.00 0.4 50 50 3.3 Disc VCT 64 helical large body 120 100-650 18.38 on 2.5 40 1.375 55.00 0.4 NA NA 3.3 Window
Recon
Name of Series Thickness Interval Recon
Algorithm Width/Level Direction AX LUNG 2.5 2.5 lung 1600/-600 head/feet Must be first recon. AX SOFT 2.5 2.5 std full 400/40 head/feet COR SOFT 2.5 2.5 std full 400/40 front/back SAG SOFT 2.5 2.5 std full 400/40 left/right AX THINS 1.25 1.0 std full 400/40 head/feet AX MIPS 8.0 3.0 std full 1600/-600 head/feet For the Supine End Expiration phase: Scan
Smart
Scan
Slice
Beam
Dose
Speed Rot
Thick Coll Pitch Time Red ASIR Type SFOV kV mA
Range Noise
Index mA Time LS 16 helical large 120 100-300 1.375 27.50 0.5 NA NA 8.2 25.46 on 2.5 20 Opt 540 helical large 120 100-300 0.5 NA NA 1.375 27.50 8.2 25.46 on 2.5 20 LS VCT 64 helical large body 120 50-300 0.984 39.375 0.5 30 70 5.7 25.46 on 2.5 40 5.7 0.984 39.375 0.5 NA NA Disc VCT 64 helical large body 120 50-300 25.46 on 2.5 40 Window
Recon
Name of Series Thickness Interval Recon
Algorithm Width/Level Direction AX LUNG 2.5 2.5 lung 1600/-600 head/feet Must be first recon. AX SOFT 2.5 2.5 std full 400/40 head/feet

CT Trachea PHILIPS PARAMETERS & RECONS For the Supine End Inspiration phase: Scan
Dose
3D
Scan
Mode kV Avg
mAs Index Dose Pitch Detect Colli Rot Time Time 0.75 Incisive 128 helical 120 92 19 on 1.00 64 0.625 8.4 Name of Series Thick Interval Filter Window iDose Recon
Direction AX LUNG 3.0 3.0 YA lung 3 head/feet AX SOFT 3.0 3.0 B mediastinum 3 head/feet COR SOFT 3.0 3.0 B mediastinum 3 front/back SAG SOFT 3.0 3.0 left/right B mediastinum 3 AX THINS 1.0 0.75 B mediastinum 3 head/feet AX MIPS 8.0 2.0 B lung 3 head/feet For the Supine End Expiration phase: Scan
Dose
3D
Colli-
Rot Scan
Mode kV Avg
mAs Index Dose Pitch

Detect mation Time Time 8.4 0.75 Incisive 128 helical 120 55 19 on 1.00 64 0.625 Name of Series Thick Interval Filter Window iDose Recon
Direction AX LUNG 3.0 3.0 YA lung 3 head/feet AX SOFT 3.0 3.0 B mediastinum 3 head/feet