Ultrasound Measurement Cheat Sheet
Aorta
Item |
Normal |
Diameter |
<3 cm (outer-to-outer) |
Common iliac artery diameter |
≤6 mm |
Bladder
Item |
Normal |
Post-void residual |
≤100-150 mL |
Cardiac
Item |
Normal |
E-point septal separation (EPSS) impaired systolic funciton |
≤7 mm |
Aortic root diameter |
≤3.9 cm |
DVT
Areas for compression
- CFV above SFJ
- SFV at SJF
- CFV just below SJF
- Proximal SFV
- Mid SFV
- Distal SFV (if possible)
- Popliteal Fossa
CFV: Common femoral vein, SFJ: Saphenofemoral junction, SFV: Superficial femoral vein
Gallbladder
Item |
Normal |
Wall thickness |
≤3-4 mm |
CBD diameter |
≤4-7 mm (up to 8-9 mm if elderly or post-cholecystectomy) |
Gallbladder dimensions on short axis |
<4 x 10 cm |
Inferior Vena Cava
Central Venous Pressure |
Normal |
0-5 mmHg |
≤2.1 cm with >50% collapse with patient sniffing |
6-10 mmHg |
≤2.1 cm with <50% collapse or >2.1 cm with >50% collapse |
11-20 mmHg |
>2.1 cm with <50% collapse |
Intrauterine Pregnancy - endocavitary probe
Item |
Normal |
Gestational sac |
Present at 4-5 weeks estimated gestational age (EGA) |
Yolk sac |
Present at ~5.5 weeks EGA |
Fetal pole, cardiac activity |
Present at ~6 weeks EGA |
Criteria for nonviable intrauterine pregnancy
Item |
Ultrasound Finding |
Crown rump length |
≥7 mm and no heart beat |
Mean gestational sac diameter |
≥25 mm and no embryo |
Structures should be measured by assessing the luminal diameter of the structure, which is inner-to-inner wall except for:
- Aorta - which requires taking any thrombus or plaque into account
- Biparietal diameter of fetus - which is measured outer to inner wall of the skull
References