Chest CT Protocols Revisions Effective January 2012 Chest 1: Pulmonary Nodule Follow-up: Low-Dose Helical CT (Unenhanced) (Non-metastatic) Technologist Instructions Technique Siemens Sensation 64 64 x 0.6 (beam collimation 32 x 0.6) Patient “must cough” several times prior to scan to clear secretions kV 100 (≤180 LBS) 120 (180-250 LBS) 140 (>250 LBS) Patient imaged supine with arms elevated over head to minimize beam- hardening artifact Gantry Rotation Time 0.33 sec Breathing: hyperventilate x3; Take a breathe in and stop breathing mAs (Reg-Lg) 40-80 Scan extends from thoracic inlet through adrenal glands Scanner effective mAs (Reg-Lg) 25-50 Primary Scout performed in PA projection (tube at gantry bottom, patient supine) to minimize breast dose Detector Collimation (mm) (T) 0.6 mm Repeat any scans with motion Number of active channels (N) 32 Detector configuration (N x T) 32 x 0.6 mm Collimation (on operator console) 64 x 0.6 mm
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Same Same Send to TerraRecon as 3x2 for Radiologist to reconstruct
Patient “must cough” several times prior to scan to clear secretions
Collimation 2 x 1.0 mm 24 x 1.2mm
Breathing: hyperventilate x3; Take a small breathe in and stop breathing
Slice Width 3.0mm 3.0mm 3.0mm 5.0 mm
Repeat any scans with motion
Pitch 3-5mm/sec or Pitch 1-1.6
0.75
Kernel B70s Very Sharp
B40F Medium
B60F Sharp
Increments 1-2mm 3.0mm 3.0mm 5.0 mm
Image Sequence
Cr-Ca Cr-Ca Cr-Ca
FOV Tailored to Airway
Tailored to patient
Same
Oral Contrast - 3.0ml/sec 80 ml Omni 350 30 ml saline flush
Injection Rate N/A 40 sec Prep Time
(delay) N/A “On”
Appropriate patients after scout acquired
Care Dose Breast Shield
“On” Appropriate patients after scout acquired
Yes After scout acquired
Yes
PACS Yes Yes Yes Volume
Rendering with Lung Isolation Algorithm
Yes
Axial MIP: Lung Window (5 x 3) True Coronal: Soft-Tissue & Lung Window True Sagittal: Soft-tissue Window VRT: Tracheal-bronchial Tree
Chest CT Protocols Revisions January 2012 Chest 11: Large Airways Disease-Malacia Chest 11 Tracheomalacia Clinical Indications
Tracheomalacia Tracheobronchomalacia Mounier-Kuhn Syndrome SERIES 1: SCOUT AP and LATERAL Send all Data to PACS SERIES 2: TRACHEA END INSPIRATION MID C4 THRU ADRENAL GLAND HELICAL 3mm 3mm Interval DELAY 39.37 100kVp 0.5SEC .984 :1 320 mA Standard
RECON 1 3mm X 3mm Interval Standard RECON 2 2.5mm X 2.5mm Interval Lung RECON 3 1.25mm X 1.25mm Interval Standard SERIES 3 DYNAMIC BREATHING MID C4 TO DIAPHRAGM
Patient should inhale to full lung capacity and begin to forcefully exhale like “blowing out a candle” during scan. Use designated “mouthpiece” COORDINATE ONSET OF SCAN ACQUISITION WITH BEGINNING OF FORCEFUL EXHALATION
HELICAL 3mm 3 5mm Interval 39.37 120kVp 0.5SEC .984 :1 80 mA Standard
NOTE: TRACHEA SHOULD CHANGE IN SHAPE (ANT BOWING POST WALL OR COLLAPSE)
RECON 1 2.5mm X 2.5mm Interval Standard RECON 2 2.5mm X 1.25mm Interval Standard
Chest CT Protocols Revisions Effective January 2012 Designated Lung Cancer Screening Program (LCSP) Patients Only!: Chest 12: LCSP: Chest Low-Dose Helical CT (Unenhanced) Technologist Instructions
Technique Siemens Sensation 64 64 x 0.6
(beam collimation 32 x 0.6) Patient “must cough” several times prior to scan to clear secretions
kV 120
Patient imaged supine with arms elevated over head to minimize beam-hardening artifact
Gantry Rotation Time 0.5 sec
Breathing: hyperventilate x3; Take a breathe in and stop breathing
mAs (Reg-Lg) 40-80
Scan extends from thoracic inlet through adrenal glands
Scanner effective mAs (Reg-Lg)
25-50
Primary Scout performed in PA projection (tube at gantry bottom, patient supine) to minimize breast dose
Detector Collimation (mm) (T)
0.6 mm
Repeat any scans with motion
Number of active channels (N)
32
Detector configuration (N x T)
32 x 0.6 mm
Collimation 64 x 0.6 mm
(on operator console) Image Sequence Cr-Ca Table incrementation
(mm/rotation) (I) 19.2 mm
Pitch ([mm/rotation]/beam collimation) (I/NT)
1.0 mm
Table Speed (mm/second) 38.4 mm/sec Scan Time (40 cm thorax) 11 sec Nominal Reconstructed Slice
Width 2 mm
Reconstruction Interval 1.8 mm Reconstruction Algorithm B30 CTDI vol (Dose in mGy) 1.9-3.8 mGy DFOV = smallest diameter of
the chest wall that will completely contain the lung parenchyma as measured from the widest point of outer rib to outer rib
In addition to the axial soft tissue (B40f) and lung (B60f) window reconstructions, perform the following recons: Axial MIP: Lung Window (5 x 3) True Coronal: Soft-Tissue & Lung Window True Sagittal: Soft-tissue Window