Glossary of case review gen US
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- what are common risk factors for ectopic pregnancy
- PRIOR ECTOPIC
- Pelvic ultrasound
- IS THERE A POSITIVE PREGNANCY TEST??????
OR . . .
WHAT IS THE AGE OF THE PATIENT, BECAUSE ANY WOMAN OF CHILDBEARING AGE IS AT RISK
- What are the less common risks
Hx of tubal surgery or tubal ligation
- Woman with a positive pregnancy test or is just of childbearing age
- Must rule out an ectopic
LOOK FOR AN IUP, and you have excluded it, as this explains the elevated beta HCG. The prevalence of heterotopic pregnancy is exceedingly small, unless the patient is undergoing assisted fertilization. In those cases, the risk is still very small, but greater.
- See something in the uterine cavity
- THERE ARE ONLY 4 RELIABLE CRITERIA FOR IUP
1) Double decidual sac sign
2) Yolk sac
- Fluid collection in uterine cavity with echogenic rim
- INSUFFICIENT TO DIAGNOSE IUP
MUST HAVE 2 DISTINCT ECHOGENIC RIMS SURROUNDING THE FLUID COLLECTION
This could be a pseudogestational sac of ectopic pregnancy, formed by secretions of the endometrium which is being stimulated by pregnancy hormones
- What percent of early pregnancies are ectopic
THAT IS AN INCREDIBLY HIGH PROPORTION
- What raises the pre-test probablility
- Clinical suspicion based on symptomatology raise the chance TEN FOLD!!!
THUS among the group of patients presenting for ectopic pregnancy, 15%
- If the patient has positive beta HCG and clinical suspicion of an ectopic pregnancy, and no IUP is visualized?
- Make sure the patient had an ENDOVAGINAL SCAN.
ASSUMING they DID, then there is now a 55% CHANCE OF ECTOPIC PREGNANCY!
So, if there is no IUP, there is a more than 50% chance that there is an ectopic!
- What is the differential diagnosis for positive HCG and no IUP visualized?
- 1) Ectopic pregnancy
2) Too early to be visualized
3) Abnormal IUP (so doesn't meet one or more of the 4 strict reliable criteria)
4) Spontaneous abortion (either completed or in progress)
- Now that you have greater than 50% chance of an ectopic. What now?
- Make the diagnosis of an ectopic
If you find pelvic free fluid, that raises the probability of an ectopic to 75 PERCENT!
Or, if you find an adnexal mass, ANY adnexal mass, that raises the probability to 75 PERCENT as well!
If you see NO PELVIC FLUID and NO ADNEXAL MASS, the patient is STILL AT RISK FOR ECTOPIC, but the risk drops to 25%, which is still way too high to be acceptable. Thus, even if you don't find an adnexal mass, you have BY NO MEANS RULED OUT AN ECTOPIC
- What should you always be aware of on boards?
- LARGE ECTOPIC PREGNANCY
You see a baby in which you can measure a biparietal diameter in a woman presenting with pain. BUT ON CLOSE INSPECTION, THE BABY IS OUTSIDE OF THE UTERUS!!
- What is the most important characteristic in evaluating an ovarian mass
- Is there bloodflow -- r/o torsion -- if patient is presenting with pain or nausea
After that, it is SIZE (which also applies to torsion as well)
- Ovarian mass
- Don't try and decide whether it is benign or malignant as the first step
The first thought you should have is "could this be a mass that will go away on its own" because the majority of ovarian masses that occur in women of childbearing age are non-neoplastic cysts. So, you must always ask the age of the patient. But, just because the patient is postmenopausal still does not mean that the lesion will not regress on its own, its just less likely as with premenopausal women.
- Ovarian cyst in premenopausal woman
- Serous inclusion cyst
Corpus luteum cyst
Others . . . corpus albicans cyst and theca lutein cyst
- If you think lesion could be one of these, what is protocol?
- Repeat imaging in 6 weeks
- Ovarian mass or cyst . . . How do you decide if reimaging at a later time is appropriate?
- 2 CRITERIA
Under 6 cm
- Unilocular cystic mass under 6 cm. You re-image in 6 weeks. Patient comes back, and the lesion is still there, unchanged.
- It is still most likely a benign lesion, but if it has not gotten smaller, it may not go away on its own. It still might, but now there is less of a chance of that.
Main DDx for unilocular cyst are these 6:
CORPUS LUTEUM CYST
SEROUS INCLUSION CYST
Less likely to be unilocular cyst are these 3:
Cystadenoma of low malignant potential
- Characteristics of ovarian masses that are almost definitely benign
- Unilocular thin walled cyst under 10 CM in premenopausal patient, and under 5 CM in a postmenopausal patient
Hemorrhage in a unilocular cyst -- occurs in follicular cysts, corpus luteum cysts, endometriomas. When it does occur in a neoplasm, it is almost always a benign neoplasm. Endometriomas can have 1 or 2 thin complete or incomplete septations.
Any thin walled anechoic cyst with 1 or 2 thin septations
ANY mass containing high amplitude echoes that cast an acoustic shadow -- DERMOID. So even if it is a very strange looking mass, if you see bright echoes with acoustic shadowing, you are dealing with a dermoid.
- Ovarian mass with thin septae that have nodules on them
- HIGHLY PREDICTIVE OF MALIGNANCY
- What characteristics are suggestive of malignant ovarian neoplasm?
- LARGE size, especially if multiseptated
Septal nodules are highly suggestive
Irregular wall or mural nodules
ANY SOLID MASS -- not all are malignant (fibrothecomas, brenner tumors) but ALL SHOULD BE SURGICALLY EXCISED
- What is another way to evaluate whether a lesion is benign or malignant
- VERY CONTROVERSIAL -- resistivity to flow in the mass
Not a very helpful way to make a decision, but some people still do.
- What is the resistive index cutoff
- Lower than 0.4 considered low resistance, considered more likely to be malignant
Over 0.4, considered high resistance flow.
You should use morphologic assessment as primary tool to decide whether benign or malignant. If resistive index further supports your assessment, then that is good. Statistically, there is a significant difference if you compare a large group of malignant ovarian lesions with a large group of benign ones, BUT in any given patient, that means not a whole lot.
- Endometrial thickness
- MUST BE EVALUATED WITH ENDOVAGINAL SCAN, unless obviously thickened on TA
- Evaluation of endometrial thickness
- The junctional zone is the lucent band of myometrium just outside the endometrium. LOOK FOR IT, and measure the endometrium from the edge of the bright reflector to the other edge of the bright reflector.
- Normal endometrial thickness
- MUST KNOW:
1) Is patient premenopausal
2) Is patient on tamoxifen
- Normal endometrial thickness values
Up to 16 mm (thinnest during menses, intermediate during proliferative phase before ovulation, thickest after ovulation in the secretory phase)
Up to 8 mm if patient is NOT bleeding
If the woman is bleeding, 4 mm is the upper limit. Doesn't matter if she is on hormones or not. 4mm is still the cutoff. The reason the limit is lower for a bleeding woman is that the most common reason for postmenopausal bleeding in a patient not on hormones is endometrial atrophy. (for one on hormones, it is withdrawal bleeding) Basically, all patients with postmenopausal bleeding should have a biopsy, BUT before doing the biopsy, you give the patient an opportunity to prove that atrophy is the cause for the bleeding. If under 4mm, you can assume she has atrophy. If greater than 4mm, you cannot assume she has atrophy, and thus will still need the biopsy. The other reason is that atrophic endometrium, if biopsied, often comes back from pathology with "insufficient tissue for evaluation".
- Appearance of endometrial carcinoma
- Often very big ugly mass
- DDx endometrial thickening
- IS IT DIFFUSE OR FOCAL?
- Telling the difference between endometrial polyp and submucosal fibroid
- Endometrial polyps do not shadow, submucosal fibroids DO SHADOW
Endometrial polyps have SINGLE FEEDING VESSELS, submucosal fibroids have multiple feeding vessels
BUT, THE WAY THESE ARE USUALLY WORKED UP IS WITH SONOHYSTEROGRAPY
- Abnormal uterus (unicornuate, bicornuate, etc)
- LOOK AT THE KIDNEYS -- 25% chance of associated renal anomaly
NORMAL OVARIES -- they form separately, so having a uterine abnormality means nothing towards having an ovarien abnormality
- Abnormal uterus
- Decide whether it is bicornuate or septate by external imaging -- MRI -- to look for external contour dent. If the dent is greater than 1 cm, that is BICORNUATE, not septate, and cannot be repaired hysteroscopically like septate can
- T-shaped uterus
- DES exposure
- Treatment of submucosal fibroids
- Hysteroscopic shelling-out
- MRI of uterus with low signal mass with high signal lace-like latticework within
- hyaline/myxoid degenerating fibroid
- MRI with uterus with mass with swirls of high and low signal
- HAS TO COME OUT
Most probably a cystic/hemorrhagic degenerating fibroid, but cannot tell these from leiomyosarcomas by imaging
- When is US not enough for uterine imaging
- 1) Cant tell what is going on
2) Pre-myomectomy or pre-embolization
3) Fast growing
- Endometrial outpouchings form, and irritate the myometrium. The myometrium responds by trying to wall these all off. That is why junctional zone gets so thick.
- Appearance of adenomyosis
- Junctional zone thickened to OVER 1 CM
on US -- Thick walled, very heterogeneous, very UGLY, can't see anything.
BUT, can also be FOCAL. How do you tell fibroid from adenomyoma? It has IRREGULAR interdigitating margins. IT IS VERY IMPORTANT TO DIFFERENTIATE THESE, because they cannot be shelled out and they cannot be embolized. Both fibroids and focal adenomyosis are low on T1 and T2 and have similar echogenicity, so you really have to go on the MARGINS. Smooth, its fibroid. Irregular and interdigitating, its adenomyosis.
- What is DDx of abnormal uterine bleeding
- ANATOMIC (non functional) causes are the ones we care about
- Endometrium seen, but has cysts in it
- ONLY 2 THINGS
POLYP or CYSTIC CHANGE OF TAMOXIFEN
- Premenopausal patient with dysfunctional bleeding and on endovaginal exam, endometrium not thickened.
- DO THE SONOHYSTEROGRAM
The numerical cutoffs are for diagnosing CANCER or hyperplasia. That doesn't mean that you have excluded a legitimate anatomic cause of abnormal bleeding just because the EVUS shows non-thickened endometrium. If the patient has a good history, you MUST DO THE SONOHYSTEROGRAM TO LOOK FOR AN ANATOMIC CAUSE, because these are often not visible on the endovaginal.
- Will will either be
To tell them apart:
1) Could be difficult, because fibroid could look like its on a stalk too. BUT, FIBROID IS COVERED BY ECHOGENIC ENDOMETRIUM, so it is hypoechoic but has an echogenic CAP. Whereas polyp IS endometrium, so the whole thing will be echogenic with or without cysts in it.
2) Use color doppler. Fibroid has minimal flow. Polyp has distinct feeding vessel.
Can also have multiple endometrial polyps or submucosal fibroids or BOTH
OR you could have diffuse thickening of endometrium which is either hyperplasia or carcinoma
- Endometrial hyperplasia
- Due to increased circulating estrogens
Hormone replacement, tamoxifen, obesity, estrogen producing tumors
HYPERPLASIA IS A RISK FACTOR FOR ENDOMETRIAL CARCINOMA, so you can't just forget about it. The cause must be treated.
- Estrogen producing tumors
- Granulosa cell
- Postmenopausal patient with bleeding. EVUS shows endometrial thickenss of 5 mm
- Do sonohysterography
If thickening is diffuse, do RANDOM BX OR D and C
IF THICKENING IS FOCAL, however, doing a random bx could give you the wrong answer. So, by doing the sonohysterogram you determine what needs to be biopsied, and it will be done HYSTEROSCOPICALLY.
- Staging of endometrial carcinoma
- JUST REMEMBER ONE THING:
If less than 1/2 of myometrium is invaded, these patients do well
If greater than 1/2 invaded, these patients do POORLY with higher chance of recurrence and metastases
Other thing is whether it invades cervix or not
- Staging of cervical carcinoma
- HAS THE LESION INVADED EITHER THE PARAMETRIUM OR BEYOND THE UPPER 1/3 OF VAGINA
If not, can just do hysterectomy
- Lesion confined to cervix
- Lesion invades beyond cervix, but not into parametrium
- Lesion invades parametrium, but no hydronephrosis and no pelvic sidewall involvement
- Hydronephrosis, lower 1/3 of vagina or pelvic sidewall involvement
- When is surgery performed
- IIb or not IIb -- IIb is parametrial invasion, and these patients are NOT treated surgically. They are given radiation.
IIa and better is surgical
- Donut view on MRI -- Is lesion confined to cervix. Should be DARK all around.
See stranding of tissues adjacent to cervix/uterus -- IIb. If it is not obvious, you can hedge, and they will probably treat it surgically. Because their staging is based on what they can feel on physical exam. If they couldn't have felt it, then it will still go to surger.
- US technique for abdomen
- NPO so stomach doesnt obscure pancreas, and so gallbladder not contracted
- Why does Budd-Chiari spare the caudate
- Caudate drains directly into the IVC
- Structure of portal triad
- Portal vein is the one with echogenic walls
Hepatic artery is the one in the middle
Bile duct is the other one.
In 20% of patients, the bile duct is between the hepatic artery and the portal vein, instead of the hepatic artery being the monkey in the middle like normal.
In those cases, look to see which is straigher. Normally you can get the bile duct in a view in which you can see it longitudinally over several centimeters, whereas you cant do that with the hepatic artery cause it is so tortuous. The hepatic artery is regular in diameter throughout its course, unlike the bile duct which is variable in size throughout its course
- Thyroid US rules
- Nodules greater than 1.5 cm undergo biopsy regardless of US appearance, unless demonstrably HOT on I-123 uptake scan
Nodules with malignant features under go biopsy regardless of size
- Malignant features for thyroid nodule
- Just like mammo except for 1 thing:
Irregular exterior margins
Thick surrounding HALO
- Hypoechoic pancreatic mass
Focal pancreatitis -- history
- Multiple pancreatic lesions
- Complications of epididymitis
- Variant of epididymitis
- Focal epidymitis
Tail epididymitis -- think TB
- carotid US, which is internal which is external
- Internal is external -- internal is the more lateral branch. It is lateral and posterior.
External is internal! -- External is medial and anterior
EXTERNAL has branches in the neck
INTERNAL does not
- Differential for hypoechoic testicular mass
- Seminoma, focal orchitis , focal infarct, hematoma, abscess, sarcoidosis
- one common appearance for seminoma
- seminoma's do not have cystic components or calcifications. They are purely hypoechoic.
- Testicular mass with calcification
- think non-seminomatous germ cell tumor.
- Autosomal dominant polycystic kidney disease
- suggest MRI to look for berry aneurysm.
- Cystic liver disease in autosomal dominant polycystic kidney disease
- in autosomal dominant, liver cysts can be very prevalent and very severe, however, there will not be any associated hepatic insufficiency.
- Positive screening in family member
- two cysts in one kidney or one cyst in each kidney under 30 years. Two cysts in each kidney between 30 and 59. At least four cysts in each kidney above age 60.
- For criteria for acute cholecystitis
- gallbladder enlargement -- 4 cm transverse, gallstones, sonographic murphy's, wall thickening.
- Normal common bile duct size
- 6 cm. Add 1 cm for each decade over 60. If not dilated where it crosses hepatic artery and in pancreatic head, but there is mild dilatation of the mid portion, this is usually normal.
- Simple cyst on renal sonography
- other lesions that can mimic a cyst: aneurysm (put on flow), lymphoma, calyceal diverticulum.
- Cystic lesion, upper pole
- differential also includes renal duplication with obstructed upper pole moiety.
- Cystic lesion appears to have internal echoes
- turn on harmonics.
- Transverse image of the abdomen showing splenic vein. What is superficial to the pain
- the pancreas
- hyperechoic hepatic mass
- hemangioma, metastasis, HCC, focal fat
- same lesion with increased through transmission
- hemangioma often has increased through transmission. Other mentioned lesions can, so differential is not significantly altered.
- Atypical hemangioma
- hyperechoic periphery, hypoechoic center.
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