GI and GU Imaging Acquisition

Question 1

HIDA Imaging

Answer 1

• LEHR or LEGP collimator
  1. Flow (64x64 matrix)
  2. Dynamic for 60 min or static images
  3. Static imaging
  
  • Liver positioned in right upper FOV
  • Statics: 500-800k (Liver marker)
  • Dynamic: 1 min/frame, 60 frames
  • Rt. lat @ 60 min to differentiate GB
    from bowel.
    
    4. GBEF: Position in 20-30 LAO to SEPERATE GB from bowel.

Question 2

GI Bleed Imaging

Answer 2

• LEAP or LEHR collimator
• 128x128 matrix
• Anterior abdomen (bottom of heart @ upper FOV)
• Ant. flow: 1-5 sec/frame x 1 min.
• Dynamic imaging: 60-90 frames, 60 sec/frame: 20-30 min for Sulphur Colloid
• Possible delayed images may be done 2-6 hrs. post injection up to 24 hrs.

Question 3

Meckel’s Diverticulum Imaging

Answer 3

• Anterior dynamic imaging: most common. 60 frames/60 sec/frame

OR

• Statics: 3-5 min every 15 min for 60 min.
• Lateral and/or oblique views will determine MD vs. renal pelvis, ureter activity.
• Post void static image.

Question 4

Gastric Emptying Imaging

Answer 4

• Dynamic Imaging: 90-120 min.
• Image immediately post meal.
• Anterior (easiest) best for very ill patients.
• Static Imaging: Ant/Post: 1 min/image every 15 min. for 2 hrs.

OR

• Image @ 0,1,2, and 4 hrs.
• Pt. must be upright between images.
• No smoking.
• Provides information to generate a geometric mean. Best, but may be difficult to process.

Question 5

Esophageal Transit

Answer 5

• Image supine (flow, dynamic)
• Initial swallow followed by “dry” swallow every 15 sec. for 5-10 min.
• May repeat up to 5 times.
• Normal: 90% clear within 5-11 sec.

Question 6

GE Reflux

Answer 6

1. Drink solution.
2. 5-10 min. later begin imaging.
   
   • Pt. supine w/stomach @ bottom
     FOV.
   • If pt. has activity in esophagus
     give 30 mL of additional H2O.
3. Image dynamically for 30-60 min. 15-30 sec/frame.
4. LEAP/LEHR collimator.

Question 7

Liver/Spleen Imaging

Answer 7

1. No patient preparation.
2. Pt. is placed supine, FOV over upper abdomen.
   
   • Liver/spleen in CFOV
3. Anterior flow
4. Static Anterior blood pool image.
5. Wait 15 min. post injection.

Static Images:

• Ant/Post w/marker
• Ant/Post without marker
• Rt/Lt Lateral
• Obliques

FOLLOWED BY SPECT/CT

Question 8

Hemangioma Imaging

Answer 8

1. Flow study: 1 sec/frame, 60 frames
2. Static Imaging:
   - Early static: 1-2 hr. delay images/ statics.
   - Static images every 15 min. for 60-120 min.

EITHER OPTION NEED TO AQUIRE ALL POSITIONS

OR

• Dynamic image: 60 sec/frame for 60-90 min.

3. SPECT @ 1-2 hr. post injection.
   
   • No matter what.
   • Increases detection of smaller lesions.

Question 9

Renogram Imaging

Answer 9

• LEHR collimator
• Image posterior (unless transplant kidney)
• Dynamic acquisition:
  
  • Phase 1 (flow): 1-2 sec/frame for 1 min.
  • Phase 2 (function): 20-40 sec/frame for 20-30 min.
  • Post void static image: make sure no hang up.

Question 10

Renogram w/LASIX Imaging

Answer 10

Image for 20-30 min: 1 min/frame or (20-30 sec)

Question 11

Renogram w/ACE Inhibitor Imaging

Answer 11

1 Day Protocol:

• Baseline study w/o captopril (low dose).
• Captopril or stress study.

2 Day Protocol:

• Typically the stressed study is done first.
• 2 days later, non-captopril is performed.

*If Captopril or enalaprilat study is normal, there is no need to do baseline study.

Question 12

Thyroid Imaging

Answer 12

• Can be done at 4,6, or 24 hrs.
• Pinhole collimator or LEHR with zoom.

4 Images:

• Anterior w/thyroid cartilage & SSM marker and/or chin.
• Anterior w/out marker and closer to camera.
• 30-45 degree LAO
• 30-45 degree RAO
• Images are typically taken for 50k counts or 5-10 min.

Question 13

Parathyroid Imaging

Answer 13

• Ant neck 1.5 zoom (heart should be at bottom FOV).
• Ant neck 2.0 zoom
• LAO neck 2.0 zoom
• RAO neck 2.0 zoom
• SPECT/CT no matter protocol.

Question 14

In111 WBC Imaging

Answer 14

• MEGP collimator.
• Imaging @24 hr. (allows time to migrate) (could image sooner if necessary).
• Whole body (decrease scan speed).
• Spots of region of interest (10 min.).
• SPECT if necessary.

Question 15

Tc99m HMPAO WBC Imaging

Answer 15

• Image @ 1-4 hrs. post injection
• Whole body, spots, and/or SPECT
• Gut activity seen @ 4 hrs.
• Preferred in peds, less liver/spleen uptake/exposure.

Question 16

MIBG Imaging

Answer 16

• I131: 1 and 3 days post injection.
• I123: 6 & 24 hrs. post injection.
• Whole body or WB spots.
• SPECT.

Question 17

In111 Octreotide Imaging

Answer 17

• MEGP collimator
• 4 hr. spots of abdomen before bowel.
• 24 hr. WB and SPECT
• 48 hr. WB and SPECT