Ultrasound

From Anvita Health Wiki

Contents 1 More Specific Terms 2 Introduction 3 More General Terms 4 References

More Specific Terms

• bladder scan
• carotid ultrasound
• doppler effect/shift/principle/phenomenon
• duplex doppler scan
• echocardiography
• elastography
• endoscopic ultrasound
• fetal ultrasound
• hepatobiliary ultrasonography
• laparoscopic ultrasound
• ophthalmic biometry; A-scan ultrasound biometry
• renal ultrasound
• transcranial sonography (TCS)
• transvaginal ultrasonography (TVS)
• ultrasonic (supersonic, hypersonic)

Introduction

• The use of high frequency sound waves (1.6-10 MHz) in medical imaging. Deep structures may be delineated by measuring the reflection or transmission of ultrasonic waves. The ultrasound image displays in a single plane at a time; however, computer calculations allow for 2 dimensional real-time imaging. Real-time imaging displays motion, doppler displays flow.

• 1971 pulsed doppler (M-mode - movement)
• 1974 B mode (brightness) 'Duplex scanner' M & B modes

• Advantages of ultrasound:
• biologically harmless
• can display motion
• requires no contrast
• provides images in many planes
• available at the bedside
• able to differentiate solid tissue from fluid
• low cost
• Disadvantages of ultrasound:
• bone cannot be penetrated
• gas-containing structures (e.g. bowel) are obstacles
• operator-dependent

• angle of incination should be 60 degrees

• Clinical uses of ultrasound:
• echocardiography
• location of foreign bodies in the eye
• pregnancy

• suspected ectopic pregnancy
• suspected fetal demise
• estimate of gestational age
• confirm presence of multiple fetuses
• localization & evaluation of placenta
• estimate of amount of amniotic fluid

• normal, oligohydramnios, polyhydramnios

• detectection of fetal anomalies
• repeated ultrasound does not pose risk to fetus [2]

• postpartum retained products of conception
• newborn

• head - intracranial hemorrhage, hydrocephalus
• kidneys - renal dysplasia, lower urinary tract obstruction
• liver - biliary atresia, hepatitis

• spleen

• splenomegaly
• subcapsular hematoma
• the spleen is the most commonly injured organ in blunt abdominal trauma

• pancreas - tumor versus cyst or pseudocyst
• liver - solid or cystic lesions, abscesses
• kidneys

• hydronephrosis; b) renal cysts; c) renal tumors;
• polycystic kidney disease

• abdominal abscesses
• gallstones - 90% of gallstones are radiolucent
• dilation of the biliary tree as in obstructive jaundice
• abdominal aortic aneurysms
• thyroid - cystic versus solid nodules
• parathyroid adenoma
• testes - tumor versus hydrocele or hematocele

More General Terms

• radiography (diagnostic imaging, roentgenography)

References

1. Introduction to Clinical Imaging, Radiology Syllabus, UCSF, 1993
2. Journal Watch 25(2):16-17, 2005 Newnham JP, Doherty DA, Kendall GE, Zubrick SR, Landau LL, Stanley FJ. Effects of repeated prenatal ultrasound examinations on childhood outcome up to 8 years of age: follow-up of a randomised controlled trial. Lancet. 2004 Dec 4;364(9450):2038-44. PMID: [1]
3. National Guideline Clearinghouse Ultrasound scanning during pregnancy. (Finnish Medical Society Duodecim) ngc-guideline: [2]
   - Gynaecological ultrasound examination. Finnish Medical Society Duodecim ngc-guideline: [3]
   - Ultrasonography in pregnancy American College of Obstetricians and Gynecologists ngc-guideline: [4]
   - Ultrasonographic examinations: indications and preparation of the patient. (Finnish Medical Society Duodecim) ngc-guideline: [5]
   - Clinical practice guidelines for therapeutic ultrasound. Ottawa Panel ngc-guideline: [6]
   - ACR-AIUM-SRU practice guideline for the performance of diagnostic and screening ultrasound of the abdominal aorta in adults. American College of Radiology ngc-guideline: [7]
   - ACR-AIUM-SRU practice guideline for the performance of peripheral arterial ultrasound using color and spectral Doppler. American College of Radiology ngc-guideline: [8]
   - ACR-AIUM-SRU practice guideline for the performance of peripheral venous ultrasound examination. American College of Radiology ngc-guideline: [9]
   - ACR-AIUM-SRU practice guideline for the performance of scrotal ultrasound examinations. American College of Radiology ngc-guideline: [10]
   - ACR-AIUM-SRU practice guideline for the performance of ultrasound evaluation of the prostate (and surrounding structures). American College of Radiology ngc-guideline: [11]

ultrasound (US, UTZ)