Search This Blog

Translate

Pages

728x90

بحث / search

mob

468x60

Friday, December 29, 2023

 


An intrauterine pregnancy on EUS effectively rules out

an ectopic pregnancy in the majority of patients.

Abdominal aortic aneurysm. EUS can quickly rule

out abdominal aortic aneurysm (AAA) in patients

presenting with nonspecific abdominal or low back

pain, avoiding the need for a computed tomography

27

• The 2008 American College of Emergency Physicians

u ltrasound guideli nes describe the history and training

process for the now 11 core appl ications of emergency

ultrasound.

(CT) scan. At the other end of the clinical spectrwn, in

a hypotensive patient with abdominal or back pain, EUS

may rapidly rule in the diagnosis of AAA, facilitating

life-saving transport to the operating room instead of

threatening decompensation during CT.

Acute cholecystitis. Physical examination and laboratory

findings are often nonspecific in acute cholecystitis. EUS

often helps rule in or out the diagnosis, prompting faster

intervention or disposition.

Renal colic. In the uncomplicated patient with flank

pain and hematuria, mild to moderate hydronephrosis

often further supports the diagnosis of nephrolithiasis

without the need for additional imaging.

Procedural applications. Use of ultrasound to aid in

performing procedures includes placement of peripheral

and central lines, abscess and foreign body localization,

interspace visualization for lumbar puncture, and

US guidance of pericardiocentesis, thoracentesis, and

paracentesis.

CONTRAINDI CATIONS

Relative contraindications to EUS include patient factors

such as obesity and excessive bowel gas, as well as physician

inexperience. If the specific clinical question is not

CHAPTER 8

answered or unexpected findings are encountered, then

always proceed to the next test. EUS is another advanced

diagnostic and procedural tool, but is not always a replacement for more definitive testing.

EQUIPMENT

US is analogous to a submarine's sonar system. Sound

waves are emitted by the US probe, travel through tissue,

are reflected off structures, and then return to the probe.

Travel time is translated by the computer into depth within

the body. Strength of returning echoes is translated into

brightness or intensity of the structure on the display.

Sound is a series of repeating pressure waves. Audible

sound is in 1 6-20,000 cycle/sec or Hz range, whereas diagnostic US uses sound waves in the 2-12 MHz range (mil ­

lion cycles/ sec).

No comments:

Post a Comment