CT — Embolie pulmonară (MCB)

Updated 05/02/24 CTA PE (Pulmonary Embolus) Reviewed 05/14/25 Indications - shortness of breath, dyspnea, chest pain, tachycardia, pulmonary embolus, DVT, elevated D-dimer, pulmonary hypertension. Hemoptysis indication uses CTA thoracic aorta protocol. If indication is PE and hemoptysis, tech should contact ordering clinician to pick either PE or hemoptysis which will determine which protocol to use. GENERAL SCAN NOTES Move the patient's arms over his/her head if possible. Remove any metal from the imaging field of view. Topogram - lung apices through diaphragm (obtained during end inspiration). Craniocaudal scan coverage: Regular patients - lung apices through adrenal glands (just have patient stop breathing). Pregnant patient - lung apices through lung bases (just have patient stop breathing). Having the patient just stop breathing rather than taking in a deep breath reduces the influx of unopacified contrast from the abdomen into the pulmonary arteries. Scan caudal to cranial to reduce motion artifact in lung bases where PEs are more common. Adjust FOV (field of view) on topogram to smallest without cropping anatomy. IV Contrast: Administer weight-based Omnipaque-350 - 1 mL/kg up to 150 mL (100 mL minimum). Inject at 4 mL/sec followed by 40 mL saline flush, 20-gauge or larger in forearm or more proximal. Bolus track off right atrium triggered at 95 HU. Test Bolus Method – Give 20 mL contrast bolus followed by saline flush. Track enhancement curve off pulmonary artery with target 100 HU to get timing delay. Give another 80 mL contrast and begin scanning caudal-cranial after timing delay. Use 25 mL contrast for test bolus and 100 mL contrast for actual scan in patients weighing over 250 lbs. 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.

CTA PE (Pulmonary Embolus) SIEMENS PARAMETERS & RECONS Scan
Care
Rot Scan
Mode kV mAs Care
Dose Pitch Acq Coll kV & Lvl Time Time Sensation 16 spiral 120 150 on 1.15 16 0.75 0.5 NA 10.9 Go Up 32 spiral 110 56 on on 70 1.50 32 0.7 0.8 7.1 Sensation 64 spiral 120 150 on 1.20 64 0.6 NA 0.5 6.5 Definition 64 spiral 120 127 on 1.40 64 0.6 on 0.3 3.3 Go Top 64 spiral 100 62 on 1.50 64 0.6 0.33 on 70 1.7 Drive 128 spiral 100 105 on 1.20 128 0.6 0.28 on 1.8 Force 192 spiral 100 105 on 1.20 192 0.5 on 0.25 1.3 Recon
Name of Series Thick Interval Kernel Window IR
Lvl Direction AX LUNG 3.0 3.0 Br57 / B70f lung 3 head/feet AX ANGIO 3.0 3.0 Br40 / B41f mediastinum 3 head/feet AX ANGIO THINS 1.5 1.5 Br40 / B41f mediastinum 3 head/feet COR SOFT 3.0 3.0 Br40 / B41f mediastinum 3 front/back SAG SOFT 3.0 3.0 Br40 / B41f mediastinum 3 left/right AX MIPS 5.0 3.0 Br40 / B41f mediastinum 3 head/feet 3D VRT (spin) 0.75 0.5 Bv36 / B31f CT angio GE PARAMETERS & RECONS Scan
Smart
Slice
Beam
Rot
Dose
ASIR Scan
Type SFOV kV mA
Range Noise
Index mA Thick Coll Pitch Speed Time Red Time NA LS 16 helical large 120 100-440 16.36 on 2.5 20 1.375 27.50 0.5 NA 5.5 Opt 540 helical 120 2.5 20 large 100-440 16.36 on 1.375 27.50 0.5 NA NA 5.5 LS VCT 64 helical large body 120 100-600 14.14 on 2.5 40 0.984 39.375 0.5 40 40 3.8 Disc VCT 64 helical large body 120 100-600 14.14 on 2.5 40 0.984 39.375 0.5 40 40 3.8 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 ANGIO 2.5 2.5 std full head/feet 400/40 AX ANGIO THINS 1.25 1.25 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 MIPS 5.0 3.0 std full 1600/-600 head/feet 3D VRT (spin) 0.625 0.625 std full 400/40

CTA PE (Pulmonary Embolus) PHILLIPS PARAMETERS & RECONS Scan
Dose
3D
Rot Scan
Colli Mode kV Avg
mAs Index Dose Detect Pitch Time Time Incisive 128 helical 120 103 3.1 20 on 64 1.20 0.50 0.625 Name of Series Thick Interval Filter Window iDose Recon
Direction AX LUNG 3.0 3.0 YA lung 3 head/feet AX ANGIO 3.0 3.0 B mediastinum 3 head/feet AX ANGIO THINS 1.5 1.5 B mediastinum 3 head/feet COR SOFT 3.0 3.0 B mediastinum 3 front/back SAG SOFT 3.0 3.0 B mediastinum 3 left/right AX MIPS 5.0 3.0 B mediastinum 3 head/feet 3D VRT (spin) 0.75 0.5 B