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case review gen US

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what are common risk factors for ectopic pregnancy
PRIOR ECTOPIC


PID


IUD
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
IVF



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


3) Embryo


4) Heartbeat
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
1.5%

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


Follicular 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
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:


FOLLICULAR CYST


CORPUS LUTEUM CYST


ENDOMETRIOMA


PARAOVARIAN CYST


SEROUS INCLUSION CYST


SEROUS CYSTADENOMA


Less likely to be unilocular cyst are these 3:

Cystic teratoma


Mucinous cystadenoma


Cystadenofibroma


RARELY:


Cystadenoma of low malignant potential


Serous cystadenocarcinoma
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
PREMENOPAUSAL

Up to 16 mm (thinnest during menses, intermediate during proliferative phase before ovulation, thickest after ovulation in the secretory phase)



POSTMENOPAUSAL


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?


Diffuse:

Endometrial hypertrophy


Endometrial cancer


Focal:


Endometrial polyps


Submucosal fibroid
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
Adenomyosis
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


Submucosal fibroids


Polyps


Hyperplasia


Carcinoma


Atrophy
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.
Sonohysterogram
Will will either be


Submucosal fibroid

or


Submucosal fibroid


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


Thecoma
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
I
Lesion confined to cervix
IIa
Lesion invades beyond cervix, but not into parametrium
IIb
Lesion invades parametrium, but no hydronephrosis and no pelvic sidewall involvement
III
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
Imaging
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:


Microcalcifications


Irregular exterior margins


Thick surrounding HALO
Hypoechoic pancreatic mass
ADENOCARCINOMA


Focal pancreatitis -- history


Mets


Lymphoma
Multiple pancreatic lesions
METS


LYMPHOMA
Complications of epididymitis
Orchitis


Abscess


Pyocele


Ischemia
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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