Ultrasound Study Guide


1	Area of Interest	Normal Measurement

2	General Ultrasound
3	Speed of sound (soft tissue)	1540 m/s
4	Speed of sound (bone)	4080 m/s
5	Speed of sound (fat)	1450 m/s
6	Speed of sound (water)	1484 m/s
7
8	Aorta
9	Aorta	<3 cm or 1.5x proximal
10	Iliac	<1.5 cm
11	Aortic root	<3.8 cm
12
13	Cardiac
14	Small pericardial effusion	<1 cm
15	Pericardial volume	< 50 ml
16	Chronic wall thinning	<7 mm or >30% decrease
17	RV End-diastolic diameter	21 +/- 1 mm
18	TV Regurg	<2 m/s
19	LV End-diastolic diameter	<6 cm
20	LV wall thickness	0.6-1.2 cm
21	EPSS (see terms)	8-10 mm
22	Apical 4 view RV:LV ratio	<0.5
23
24	FAST
25	Pleural fluid	>20 ml detection limit
26	Peritoneal fluid	>200 ml detection limit
27
28	Hepatobiliary
29	GB wall	<3 mm (Anterior wall)
30	Common bile duct	<7 mm (inner to inner)
31	CBD (age criteria)	< 1/10th age
32	CBD (after cholecystectomy)	1 cm (all ages)
33	Mid-hepatic line	12.8 cm
34	Spleen length	12-14 cm
35
36	Musculoskeletal
37	Synovial bursa	~4 ml
38
39	Ocular
40	Globe	23.5 mm (vert), 24 mm (AP)
41	Optic Sheath Measurement	3 mm posterior to globe
42	Optic Sheath	4 (<1y), 4.5 (1-15y), 5 mm (adult)
43
44	Normal Pregnancy
45	Uterus	8 cm x 5 cm x 3 cm
46	Ovaries	4 cm x 3 cm x 2 cm
47	Fallopian tubes	10 cm long
48	Intradecidual sign	25 days (4 wks - not definitive)
49	Definitive pregnancy	By 5 weeks (transvag)
50	Fetal heartbeat	6 weeks
51	Fetal pole	6 weeks
52	Head and ext	7 weeks
53	Pathologic Pregnancy
54	Gestational sac	>10 mm without yolk sac
55	Gestational sac	>18 without fetal pole
56	Collapsed gestation sac
57	No FHR	with CRL > 5mm
58	Fetal pole with	FHR <90
59
60	Renal
61	Length	9-12 cm
62	Width	4-5 cm
63
64	Surgical Application
65	Appendix	<6 mm (compressible)
66	Pyloris	Muscle <3 mm, length <15 mm
67
68	Testicle
69	Testicle	2-3 cm wide, 3-5 cm long
70	Epididymus	6-7 cm long


1	IVC (cm)	Respiratory Change	CVP (cm)

2	<1.5	Total collapse	0-5
3	1.5-2.5	>50% change	5 to 10
4	1.5-2.5	<50% change	11 to 15
5	>2.5	<50% change	16 to 20
6	>2.5	No change	>20
7
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9
10	per paper
11
12	<2.1cm	>50%	5
13	>2.1cm	<50%	15


1	Terms	Meaning

2	Artifacts
3	Shadowing	Think gallstone, kidney stone, bone
4	Posterior enhancement	Increased sound speed through low density material (i.e cystic fluid)
5	Side lobe	Caused by lower intensity angulated beams generated by probe
6	Edge shadowing	Caused by refraction around the edges of an object
7	Mirror artifact	Caused by angular reflection of sound. Think diaphram
8	Ring down	Series of parallel bands radiating away from small crystals or air bubbles
9	Reverberation	Sounds bouncing back and forth between two layers before travelling back to probe.
10	Comet tails	Produced by front and back reflection of strong reflector. Narrow and organized into a small band
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12	Cardiac
13	E point	M-mode through MV in parasternal long axis view, first peak - passive LV filling
14	A point	M-mode through MV in parasternal long axis view, second peak - atrial contraction
15	Double peak	M-mode through MV, two peaks indicate normal sinus rhythm
16	EPSS	E-point septal separation - distance from E point to septal wall - large is abnormal = LV systolic dysfunction
17
18	Thoraxic
19	Seashore sign	M-mode thorax - positive lung sliding
20	Stratosphere sign	M-mode with reverberation artifact in setting of PTX with no lung sliding
21	B-lines	Comet tails - horizontal lines extends from pleura to botton of screen, moves with lung sliding. Excludes PTX. Think edema vs infiltrate
22	Air bronchograms	Hyperechoic foci that may represent consoludation (PNA, infarct, atelectasis)
23
24	Heptaobiliary
25	Mickey Mouse sign	Portal triad - Portal vein, common bile duct, hepatic artery. Largest = PV
26	Sonographic murphy	Maximum tenderness at point with identified GB
27	Wall echo shadow sign	GB is contracted around many stones - bright wall --> black bile line --> bright stone line --> posterior acoustic shadow
28	Parallel channel sign	Dilated CBD adjacent to PV
29	Antler sign	Dilated intrahepatic ducts from biliary obstruction
30	OIive Sandwich Sign	Hepatic artery between a dilated CBD and PV
31	Phrygian Cap	Folds of the GB fundus
32	Liver hemangioma	Hyperechoic liver mass
33	Spiral Valves of Heister	Valves located in GB neck
34
35	Ocular
36	30 degree test	Ocular ultrasound - check optic nerve sheath at primary gaze and shifted 30 degrees. Increased ICP will have no change in diameter. Normal = smaller
37
38	Pregnancy
39	Intradecidual sac sign	IDSS - consists of an region of echogenicity within the thickened decidua representing the implanted blastocyts
40	Pseudogestational sac	Endometrial breakdown in presence of ectopic - lacks thick chorionic ring
41	Ring of Fire Sign	Increased blood supply of gestation sac in ectopic
42	Interstitial pregnancy	Eccentric GS locations
43	Discriminatory Zone	Serum beta 1000-2000 should correlate to viable IUP on TV ultrasound
44	Sliding sign	Sliding of the gestational sac in the cervix
45
46	Musculoskeletal
47	Anisotropy	The property of being directionally dependent - i.e view nerves and tendon perpendicular to them or they will become less visible
48
49	Surgical Applications
50	Keyboard sign	Small bowel obstruction - prominent valvulae pattern in a dilated, fixed loop
51	Target sign	Intussusception, appendicitis, pyloric stenosis
52	Antral nipple sign	Refers to redundant pyloric mucosa protruding into the gastric antrum
53	Cervix sign	Pyloric stenosis


1	Sonogames Tips
2	Clicker	Make sure it works! Check the serial number.
3	Click Early	Put your first instinct in early. Lock in an answer. Can be changed but detrimental to time factor.
4	Seating	Get there early and sit closer. Lighting stinks, better visualization closer.
5	Scoring	30, 40, and 50 point questions. Progressively hard. Watch for trick questions in the 50s>40s questions.
6	Orientation	Know the orientation of images, especially coronal and cardiac views
7	Numbers	Know numbers noted on this page. Watch for numbers on images - frequency, depth, etc. Count heart beats, breaths, ribs, etc..
8
9	Hard Questions
10	McKenney Hemoperitonium Score: Right subphrenic space and subhepatic space; the left upper quadrant, including the left subphrenic space and perisplenic area; and pelvis (5 spaces). Largest vertical distance in any space + 1 point for each space with fluid. If >3, then will need laparotomy.
11
12	Bladder diameter	Gave 3 dimensions but in two views had repeated a same measurement. Answer = needed more information
13	Identify CFV	Vein medial (watch for dot orientation). For image, answer = left CFV
14	Identify pacer wire
15	Identify intraoccular lens
16	Identify and do finger ultrasound using water bath
17	Identify SBO	Answer = treat with NGT. Look up keyboard sign.
18	Pneumothorax	Partial lung sliding with lung point. Answer = chest tube.
19	SBO	Showed 4 images, all with SBO. The most OMINOUS sign was the image where there is peristalsis one direction and then regurgitation in other direction
20	Hertz of probes	Know what Hertz probes are (mega, milli, 2-5, million, thousand, etc.)
21
22	Hands-on	5 stations. Scored based on how well you do compared to others. 20 minutes each station.
23	Procedural skill	We had to do an LP with u/s assistance - find space in two views, mark, and go. As fast as possible. Once u/s marked - perform normal LP.
24	Find objects	8 objects in a silicone gel. Use linear probe to find it. Work as a team. Break off gel into 3 segments - be meticulous.
25		Metal - will have reverberation artifact
26		Wood - will have shadow (toothpick)
27		Cystic structure was actually a bullet - doesn't have to be a perfect cylinder because of artifact
28	Mission Impossible	Taboo, blind folded ultrasounds
29		Teacher tells the operator what study to do and how to adjust but can't use specific words
30		Operator is blind-folded, can talk (I think)
31		Machinist is not blind folded but can't talk. Adjusts knobs. Gives the probe to the operator.
32		Rotates every round
33	Cases	Tell the proctor which probe and where for different cases then answer clinical questions. Work as fast as possible
34	Recreate images	Will have sample image. Need to use an ultrasound to recreate given images exactly.
35		First question was to create a patient entry form
36		Know how to switch probes
37		Used water bath for finger ultrasound
38		Look at the hints! We missed one because they wanted a coronal IVC with right atrium but we did AP...
39	Central line insertion	One person could look at screen. One operated probe. One placed line then guidewire. Had to capture image of guidewire in vessel. There were 6 caveats (i.e., during one caveat, the person placing the central line had to wear handcuffs. during another, the probe operator had to wear earphones, etc.)
40	Stump the chump	You are given an image to obtain and you have to beat an ultrasound expert. You are given a 5 second head start.
41
42	Final Round
43	Question round	Take turns answering questions - can steal if other team misses. Was based solely on the 4 articles they give you ahead of time last year so read them.
44	Lightning round	Each team takes turns answering as many questions as possible. They did not have this the second year
45	Buzzer round	Look at image. Image goes away. Get asked an obscure questions: They did not have this the second year
46		- how many ribs were scanned through
47		- how many heart beats in the clip
48		- what was the charge of the battery
49	Imaging round	Completely subjective. You obtain an image on a dummy patient and then the opposite team does. Audience and 2 judges determine which image is better


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