CT CYSTOGRAM – LOW DOSE
INDICATIONS: Vesico-vaginal fistula, bladder leak, bladder trauma
PATIENT PREP: None
IV CONTRAST: NONE
ORAL CONTRAST: None. Patient does not need to drink water.
POSITIONING: Feet First Supine
TOPOGRAMS: AP. Range: Iliac crest through ischial tuberosities. 35 mA, 120 kV.
SCAN TYPE: Spiral/Helical
NOTES: PERFORM WITHOUT CONTRAST AND THEN WITH CONTRAST INSTILLED INTO BLADDER
Patient must sign Diagnostic Cystogram Consent form.
This exam requires Radiologist involvement. See Procedure below.
Document in the comments section of the online form the amount of contrast mixture administered.
Use Low Dose technique.
ALARA – Keep radiation dose As Low As Reasonably Achievable.
CYSTOGRAM CONTRAST
- Need 3-5% Contrast/Saline Mixture
- Remove 20mL Saline out of 500mL Saline Bag
- Add 20mL Isovue 370 to Saline Bag and mix
PROCEDURE: *PERFORM WITHOUT CONTRAST AND THEN WITH CONTRAST INSTILLED INTO BLADDER*
Patient to arrive with Foley catheter already placed into the urinary bladder. Have patient empty bag before procedure.
After NonContrast scan performed, instill contrast into bladder.
Instill 125mL Cystogram Contrast mixture into the bladder by flowing contrast mixture through the Foley catheter under gravity into the bladder.
Maintain sterility of internal components. Roll patient left and right to mix contrast and residual urine.
Scan Supine. Have Radiologist review the images to determine the next course of action. Possibly finished. Possibly instill more contrast until
bladder fully distended and then scan possibly Supine, Prone, Oblique, or after emptying bladder, Post Void.
NONCONTRAST – LOW DOSE
ScanRange / Scan
Direction / Respiration / Scan
Delay
(Seconds) / CARE
DOSE
4D / Quality
Reference
mAs / CARE
kV / Quality
Reference
kV / Detector Configuration
Slices Per Tube Rotation / Pitch
Table Increment/Speed:
(mm/rotation) / Rotation
Time
(Seconds) / SFOV
(cm)
Iliac Crest
Through
Ischial Tuberosities
(Through Bladder) / Craniocaudal / Suspended
Inspiration / 5
Seconds / ON / 60 / ON / 120 / Detectors: 64 x 0.6 mm
Slices Per Tube Rotation: 32 / Pitch: 0.8
Table Increment/Speed:
15.36 mm/rotation / 0.5
Seconds / 50
cm
Plane / SAFIRE
Strength / Slice
Thickness / Interval / Kernal / Window
Width/Level / DFOV
(cm)
RECON / Axial / ON
3 / 3.0 mm / 3.0 mm / I40f
Medium / Abdomen
300/40 / FOV just beyond
patient’s body
RECON
Coronals Angled in Plane to Body Part / Coronals Angled in Plane to Body Part
Recon Card 3D Coronal MPR / ON
3 / 3.0 mm / 3.0 mm / I40f
Medium / Abdomen
300/40 / FOV just beyond
patient’s body
RECON
Sagittals Angled in Plane to Body Part / Sagittals Angled in Plane to Body Part
Recon Card 3D Sagittal MPR / ON
3 / 3.0 mm / 3.0 mm / I40f
Medium / Abdomen
300/40 / FOV just beyond
patient’s body
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CYSTOGRAM – LOW DOSE
ScanRange / Scan
Direction / Respiration / Scan
Delay
(Seconds) / CARE
DOSE
4D / Quality
Reference
mAs / CARE
kV / Quality
Reference
kV / Detector Configuration
Slices Per Tube Rotation / Pitch
Table Increment/Speed:
(mm/rotation) / Rotation
Time
(Seconds) / SFOV
(cm)
Iliac Crest
Through
Ischial Tuberosities
(Through Bladder) / Craniocaudal / Suspended
Inspiration / 5
Seconds / ON / 60 / ON / 120 / Detectors: 64 x 0.6 mm
Slices Per Tube Rotation: 32 / Pitch: 0.8
Table Increment/Speed:
15.36 mm/rotation / 0.5
Seconds / 50
cm
Plane / SAFIRE
Strength / Slice
Thickness / Interval / Kernal / Window
Width/Level / DFOV
(cm)
RECON / Axial / ON
3 / 3.0 mm / 3.0 mm / I40f
Medium / Abdomen
300/40 / FOV just beyond
patient’s body
RECON
Coronals Angled in Plane to Body Part / Coronals Angled in Plane to Body Part
Recon Card 3D Coronal MPR / ON
3 / 3.0 mm / 3.0 mm / I40f
Medium / Abdomen
300/40 / FOV just beyond
patient’s body
RECON
Sagittals Angled in Plane to Body Part / Sagittals Angled in Plane to Body Part
Recon Card 3D Sagittal MPR / ON
3 / 3.0 mm / 3.0 mm / I40f
Medium / Abdomen
300/40 / FOV just beyond
patient’s body
Approximate Values for CTDIvol
Patient Size / Weight (kg) / Weight (lbs) / CTDIvol (mGy)
Small / 50-70 / 110-155 / 10-17
Average / 70-90 / 155-200 / 15-25
Large / 90-120 / 200-265 / 22-35
Reference: AAPM
Allowed CTDIvol Dose Ranges: 7 mGy – 50 mGy
XR29 Dose Notification Value (CTDIvol): 50 mGy
*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.
CHARGES: CPELVW (Bill for CT Pelvis With)
NETWORK: Exam to PACS
3/2017 Page 2 of 2