AC joint: AC joint width <6 mm. Right and left differ no more than 3 mm. Coracoclavicular space < 11-13 mm. Right and left differ no more than 5 mm.

Tracheomalacia: <7 mm AP diameter or more than 50% reduction in AP diameter from inspiration to expiration. In children, use more than 70%.

Mega Trachea: normal men 13-27 mm, normal women 10-23 mm in diameter.

Left ventricular aneurysm: usually located in the apical, anterior, or anterior lateral wall, neck to largest internal diameter >0.9. Left ventricular pseudoaneurysm: usually located in the posterior lateral wall, neck to largest internal diameter <0.5.

Right heart strain during acute PE: RV/LV ratio >0.9 indicates right heart strain. (measurement of short axis diameter at4 chamber level)

Pulmonary artery hypertension:  Diameter of main pulmonary artery >29 mm or more than adjacent ascending aorta.

SMA syndrome: <8 mm between SMA and aorta at the level of duodenum, or <15 degree between proximal SMA and aorta and proximal dilatation of the duodenum.

Gallbladder polyp: <= 5 mm usually benign, >1 cm suspicious. in between indeterminate.

Gallbladder size: Enlarged: transverse diameter >4 cm or longitudinal diameter >11 cm. Hydrops: transverse diameter >5 cm.

Gallbladder ejection fraction normal range: 35%-75%.

Portal hypertension size criteria: >13 mm on US and >17 mm on CT at the level anterior to IVC.

Gastric banding:  Normal phi angle with vertical line 4-58 degree. Band should be at least 2 cm from GE junction and at least 5 cm below diaphragm. Pouch diameter about 4 cm. Stoma opening diameter about 3-4 mm.

Gastric emptying scintigraphy normal value: 37-90% retained activity after 1 hour, 30-60% after 2 hours, 0-10% after 4 hours.

Fetal ultrasoud hydronephrosis: AP diameter 4-7 mm mild, 7-10 mm moderate, >10 mm severe.

Varicocele vein size criteria: >3 mm either before or after valsalva.

Popliteal artery aneurysm: >7 mm or more than 50% change in diameter.