CT CHEST LOW DOSE – PULMONARY NODULES - CANYON PARK

INDICATIONS: We must have a prior CT on PACS documenting known pulmonary nodules in order to use the Low Dose

Protocol. EXCEPTION: “If there is anything else: i.e. nodules + adenopathy: may need routine dose.”

PATIENT PREP: No Prep

IV CONTRAST: None

ORAL CONTRAST: None

POSITIONING: Feet First Supine, Arms above head

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

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

SCAN TYPE: Spiral/Helical

SCAN RANGE: Above Lung Apices through Lung Bases/Costophrenic Angles (CPA)

*If history of Lung Cancer scan through Adrenals

NOTES: ALARA – Keep radiation dose As Low As Reasonably Achievable.

Packs Per Day X Number of Years Smoking = Pack-Years

BMI<30: Care Dose ON

Reference mAs: 50

kV: 110

BMI>30: Care Dose OFF

mAs: 70

kV: 110

BMI Calculator Website:

CHEST LOW DOSE – PULMONARY NODULES

Scan
Range / Scan
Direction/
Scan Type / Respiration / Scan
Delay
(Seconds) / CARE
DOSE
4D / mAs / kV / Detector Configuration
Slices Per Tube Rotation / Pitch
Table Increment/Speed: (mm/rotation) / Rotation
Time
(Seconds) / SFOV
(cm)
-Above Lung Apices Thru Bases/CPA
-If H/O Lung CA
Scan thru Adrenals / Craniocaudal
Spiral/Helical / Suspended
Inspiration / 6
Seconds / BMI<30: ON
BMI>30: OFF / BMI<30: 50
BMI>30: 70 / 110 / Detectors: 16 x 1.2 mm
Slices Per Tube Rotation: 16 / Pitch: 0.8
Table Increment/Speed: 15.36 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 / 1.5 mm / 1.0 mm / B70s
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 / B70s
Sharp / Lung
1200/-600 / FOV just beyond
patient’s body
RECON – CORONAL SOFT TISSUE MPR
Coronals Angled in Plane to Body Part / Coronals Angled in Plane to Body Part
Recon Card 3D Coronal MPR / 3.0 mm / 3.0 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 / 3.0 mm / 3.0 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:0.5 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