Chest CT protocols

Mannudeep K. Kalra, MD, DNB

Massachusetts General Hospital

Harvard Medical School

Dianna D. Cody, PhD

M.D. Anderson Cancer Center

Specific principles

• Routine chest CT

• Lung nodule follow up CT

• Review audience sample protocols• Review speaker protocols • Review AAPM protocols

https://aapm.org/pubs/CTProtocolsRoutine chest CT

Institution 1: Routine chest CT protocolLung nodule Follow up

Scan type Helical Helical

Scan range Apex to Adrenals Apex to Adrenals

Rotation time 0.5 sec 0.5 sec

Beam coll. (Det. Config.) 24 x 1.2 mm 24 x 1.2 mm

Pitch 0.9 0.9

KV 120 100- 120

Quality Ref. mAs 124 100

Image thickness 5mm 3mm and 1.5 mm

FBP or IRT (kernel) B35 (no Safire or IRIS) B31 (no Safire or IRIS)

Institution 1: Siemens 64 Routine Chest

Scan type Helical Helical

Scan range Apex to Adrenals Apex to Adrenals

Rotation time 0.5 sec 0.5 sec

Beam coll. (Det. Config.) 24 x 1.2 mm 64 or 32 x 0.6 mm

Pitch 0.9 1.4

KV 120 120

Quality Ref. mAs 124 100

Image thickness 5mm 5 mm

FBP or IRT (kernel) B35 (no Safire or IRIS) B31 (no Safire or IRIS)

Institution 1: Siemens 64

Routine Chest

Scan type Helical Helical Helical

Scan range Apex to Adrenals Apex to Adrenals Apex to Adrenals

Rotation time 0.5 sec 0.5 sec 0.5 sec

Beam Coll. (Det. Con) 24 x 1.2 mm 24 x 1.2 mm 64 or 32 x 0.6 mm

Pitch 0.9 0.9 1.4

KV 120 100- 120 120

Quality Ref. mAs 124 100 100

Image thickness 5mm 1.5 & 3 mm 5 mm

FBP or IRT (kernel) B35 (no Safire) B31 (no Safire) B31 (no Safire)

Institution 1: Siemens 64

Routine Chest

Scan type Helical Helical

Scan range Apex to Adrenals Apex to Adrenals

Rotation time 0.5 sec 0.5 sec

Beam coll. (Det. Config.) 24 x 1.2 mm 24 x 1.2 mm

Pitch 0.9 0.9

KV 120 120

Quality Ref. mAs 124 124

Image thickness 5mm 5mm

FBP or IRT (kernel) B35 (no Safire or IRIS) B35 (no Safire or IRIS)

Dose: Lung nodule FU = Routine chestInstitution 1: Routine

Siemens 64

Institution 1: Lung nodule

Scan type Helical Helical

Scan range Apex to Adrenals Apex to Lung bases only

Rotation time 0.5 sec 0.5 sec

Beam Coll. (Det. Config.) 24 x 1.2 mm 24 x 1.2 mm

Pitch 0.9 0.9

KV 120 100- 120

Quality Ref. mAs 124 40-60 mAs FIXED

Image thickness 5mm 3mm and 1.5 mm

FBP or IRT (kernel) B35 (no Safire or IRIS) B31 (no Safire or IRIS)

Lung nodule doses must be much lowerInstitution 1: Siemens 64

Institution 2: Routine chest CT protocol

Scan type Helical Helical Helical

Scan range Apex to Adrenals Apex to Adrenals Apex to Adrenals

Rotation time 0.28 sec 0.5 sec 0.5 sec

Beam Coll. (Det. Con) 128 x 0.6 mm 24 x 1.2 mm 64 or 32 x 0.6 mm

Pitch 0.45 0.9 1.4

KV 120 100 - 120 120

Quality Ref. mAs 124 80 65 mAs

Image thickness 5mm 1.5 & 3 mm 5 mm

FBP or IRT (kernel) I 45 & I 50 Safire I 31 (Safire) I31 (Safire)

Siemens Definition 128 Routine Chest CT Institution 2

Institution 3: Doses Routine chest CT = Lung nodule follow up CT

Scan type Helical Helical

Scan range Apex to Adrenals Apex to Adrenals

Rotation time 0.5 sec 0.5 sec

Beam Coll. (Det. Config.) 128 * 0.6 128 * 0.6

Pitch 1 1

KV Care KV Care KV

Quality Ref. mAs 170 170

Image thickness 5mm 5mm

FBP or IRT (kernel) B 43 & 80 (no Safire) B 43 & 80 (no Safire)

Routine Chest CT = Lung nodule FU

Institution 3: Routine Institution 3: Lung nodule

(Siemens 128 )

Institution 4: Doses1. Routine chest CT dose: Too high 2. Routine chest CT = Lung nodule FU CT

Routine Chest CT = Lung nodule FU

Scan type Helical (Routine chest) Helical (Lung nodule)

Scan range Apex to Adrenals Apex to Adrenals

Rotation time 0.5 sec 0.5 sec

Beam Coll. (Det. Config.) 24 x 1.2 mm 24 x 1.2 mm

Pitch 0.75 0.75

KV4 120 120

Quality Ref. mAs 225 225

Image thickness 3mm 3 mm

FBP or IRT (kernel) - -

Institution 4: Siemens 64

Institution 4: Siemens 64Routine Chest CT >> Lung nodule FU

Scan type Helical (Routine chest) Helical (Lung nodule)

Scan range Apex to Adrenals Apex to Adrenals

Rotation time 0.5 sec 0.5 sec

Beam Coll. (Det. Config.) 24 x 1.2 mm 24 x 1.2 mm

Pitch 0.75...higher better motion 0.75…higher better

KV 120………100/120 120……..100/120

Quality Ref. mAs 225 ….…..100 225………40-60

Image thickness 3mm 3 mm

FBP or IRT (kernel) - -

Institution 5: Routine chest CT protocolPhilips

Institution 5: Philips Ingenuity 128Scan type Helical Comments

Scan range Apex to Adrenals

Rotation time 0.5 sec

Beam Coll. (Det. Config.) 64 x 0.625 mm

Pitch Auto 1.1

KV 120

mAs/Image <150 lbs 90; 150-250 lbs 120 lbs >250 150 (no AEC)

No AEC

Image thickness 3 mm and 1.5 mm 3 mm

FBP or IRT (kernel) Filter B Filter B/C

Routine Chest CT

Scan type Helical Helical Helical

Scan range Apex to Adrenals Apex to Adrenals Apex to Adrenals

Rotation time 0.5 sec 0.4 sec 0.4 sec

Beam Coll. (Det. Config.) 64 x 0.625 mm 64 x 0.625 mm 64 x 0.625 mm

Pitch Auto Auto (~ 0.9) 1.1

KV 120 100-120 120

mAs/Image <150 lbs 90; 150-250 lbs 120 lbs >250 150 (no AEC)

100 (Z-DOM)

140(??? Z-DOM)

Image thickness 3 mm and 1.5 mm 3 mm and 1.5 mm 3 mm

FBP or IRT (kernel) Filter B Filter B (iDose 2) Filter B/C

Philips Ingenuity 128Routine Chest CT Institution 5

Institution 6: Philips

Lung nodule FU << Routine chest CT dose

Institution 6: Philips 64 Brilliance

Scan type Helical (Routine chest CT) Helical (Lung nodule FU)

Scan range Apex to Adrenals Apex to Adrenals

Rotation time 0.4 sec 0.4 sec

Beam Coll. (Det. Config.) 32 X 1.25 mm 32 X 1.25 mm

Pitch 1.1 1.1

KV 120 120

mAs/Image 100 (Z-Dom) 40 (Z-Dom)Image thickness 3 mm and 1.5 mm 3 mm

FBP or IRT (kernel) Filter B Filter B

PHILIPS: ROUTINE CHEST CT: AAPM

GE: Routine chest CT (non ASIR): AAPM

Do not use noise

index for 5mm for thinner

slices and vice versa.

GE:Routine chest

CT (ASIR)

AAPM

GE 64 Routine Chest CT

Scan type Helical Helical

Scan range Apex to Adrenals Apex to Adrenals

Rotation time 0.4 sec 0.4 sec

Beam Coll. (Det. Config.) 64 * 0.625 64 * 0.625

Pitch 1.375 0.984

KV 120 100-120

NI (min – max mA) 13 (100 – 650)16.8 ASIR 50%

20-25 (100-400)30-37 ASIR 40%

Image thickness 5 mm 2.5 and 1.25 mm

FBP or IRT (kernel) Standard Detail

AAPM MGH

Toshiba: Routine chest CT : AAPM (Disclosure)

Special caveats

• Be aggressive with lower kV (<80 kg) or < 30 BMI

• Prefer use of AEC for routine chest CT

• Adapt AEC to clinical indication: Dose for lung nodule FU CT must be lower than routine chest CT doses

• When possible position arms above shoulder

• When not, position arms on the chest rather than by side

Salient points in Chest CT protocols

Lung nodule FU CT: • 100-120 KV

• Fixed low mA or modify AEC

• Apex to lung bases only

• CTDI vol 1.5 - 3 mGy

IRT: 1-2 mGy or lower

Routine chest CT • 100-120 KV (80 kV < 50 kg)

• Always with AEC

• Apex to Adrenal coverage

• Target CTDI vol 3-7 mGyIRT: 2-5 mGy or lower