CT CHEST - TRACHEOMALACIA

INDICATIONS: Tracheomalacia

PATIENT PREP: None

IV CONTRAST: None

ORAL CONTRAST: None

POSITIONING: Feet First Supine, Arms above head

TOPOGRAMS: AP. Range: Above C4 (Above trachea) through lung bases/costophrenic angles or adrenals if history of lung cancer. 25 mA, 110 kV.

Lateral. Range: Above C4 (Above trachea) through lung bases/costophrenic angles or adrenals if history of lung cancer. 25 mA, 110 kV

SCAN TYPE: Spiral/Helical

NOTES: The key to performing the“TRACHEA–DYNAMIC EXPIRATION” scan is GOOD COACHING with the breathing instructions. Instruct the

patientto take in a BIG breath and hold it, WAIT until the end of the instructions and when we say NOW, then SLOWLY BLOW their breath out with

their MOUTHOPEN. The patient MUST NOT PURSE THEIRLIPS, THEY MUST BLOW OUT WITH THEIR MOUTH OPEN.Adjust

parameters to makescan as fastas possible using Low Dose technique in order to capture the scan during FORCED DYNAMIC EXPIRATION.

ALARA – Keep radiation dose As Low As Reasonably Achievable.

CHEST - INSPIRATION

Scan
Range / ScanDirection
Scan Type / Respiration / Scan
Delay
(Seconds) / CARE
DOSE
4D / Quality
Reference
mAs / kV / Detector Configuration
Slices Per Tube Rotation / Pitch
Table Increment/Speed: (mm/rotation) / Rotation
Time
(Seconds) / SFOV
(cm)
C4 (Above Trachea)
Through Lung Bases/CPA
If H/O Lung CA
Scan thru Adrenals / Craniocaudal
Spiral/Helical / Suspended
Inspiration / 6
Seconds / ON / 100 / 110 / Detectors: 16 x 0.6 mm
Slices Per Tube Rotation: 16 / Pitch: 1.5
Table Increment/Speed: 14.4 mm/rotation / 0.6
Seconds / 50
cm
Plane / Slice
Thickness / Interval / Kernal / Window
Width/Level / DFOV
(cm)
RECON – AXIAL SOFT TISSUE / Axial / 3.0 mm / 3.0 mm / B35s
HeartView Medium / Mediastinum
400/40 / FOV just beyond
patient’s body
RECON – AXIAL LUNG / Axial / 1.0 mm / 1.0 mm / B60s
Medium Sharp / Lung
1200/-600 / FOV just beyond
patient’s body
RECON – AXIAL MIPS
Axial MIPS / Axial MIPS
Recon Card 3D Axial MIP Thin / 10.0 mm / 2.0 mm / B60s
Medium Sharp / Lung
1200/-600 / FOV just beyond
patient’s body
RECON – CORONAL LUNG MPR
Coronals Angled in Plane to Body Part / Coronals Angled in Plane to Body part
Recon Card 3D Coronal MPR / 1.0 mm / 1.0 mm / B60s
Medium Sharp / Lung
1200/-600 / FOV just beyond
patient’s body
RECON – SAGITTAL LUNG MPR
Sagittals Angled in Plane to Body Part / Sagittals Angled in Plane to Body Part
Recon Card 3D Sagittal MPR / 1.0 mm / 1.0 mm / B60s
Medium Sharp / Lung
1200/-600 / FOV just beyond
patient’s body

TRACHEA – DYNAMIC EXPIRATION

Scan
Range / ScanDirection
Scan Type / Respiration / Scan
Delay
(Seconds) / CARE
DOSE
4D / Effective
mAs / kV / Detector Configuration
Slices Per Tube Rotation / Pitch
Table Increment/Speed: (mm/rotation) / Rotation
Time
(Seconds) / SFOV
(cm)
C4 (Above Trachea)
To Well Below Carina
(Entire Trachea) / Craniocaudal
Spiral/Helical / Dynamic
Expiration / 6 Seconds / OFF / 40 / 110 / Detectors: 16 x 1.2 mm
Slices Per Tube Rotation: 16 / Pitch: 1.5
Table Increment/Speed: 28.8 mm/rotation / 0.6
Seconds / 50
cm
Plane / Slice
Thickness / Interval / Kernal / Window
Width/Level / DFOV
(cm)
RECON – AXIAL SOFT TISSUE / Axial / 2.0 mm / 1.0 mm / B35s
HeartView Medium / Mediastinum
400/40 / FOV just beyond
patient’s body
RECON – SAGITTAL SOFT TISSUE MPR
Sagittals Angled in Plane to Body Part / Sagittals Angled in Plane to Body Part
Recon Card 3D Sagittal MPR / 2.0 mm / 1.0 mm / B35s
HeartView Medium / Mediastinum
400/40 / FOV just beyond
patient’s body

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*The operator must check the CTDIvol before and after the scan to ensure it is within the allowed dose range. Scans performed outside of the allowed range must be

documented and reviewed by the designated radiologist and/or physicist.

Allowed CTDIvol Dose Ranges:1 mGy – 50 mGy

XR29 Dose Notification Value (CTDIvol):50 mGy

Approximate Values for CTDIvol
Patient Size / Weight (kg) / Weight (lbs) / CTDIvol (mGy)
Small / 50-70 / 110-155 / 4-10
Average / 70-90 / 155-200 / 8-16
Large / 90-120 / 200-265 / 14-22
Reference: AAPM

*The AAPM recommended NEMA XR29 Dose Notification Value for an adult torso is 50 mGy. Dose notification levels less than the AAPM recommended can be set. The maximum CTDIvol should match the dose notification value. Exams with CTDIvol values less than the minimum allowed range should not be performed unless approved by a radiologist.

NETWORK:Exam to PACS

5/2018Page 2 of 2