It's not like all ruptured cysts are well appearing. It's not uncommon for them to have peritoneal signs if the cysts were hemorrhagic and saving young women's ovaries from radiation isn't the worst use of resources. I'll agree that there shouldn't be a CT or U/S done in this patient population prior to a pelvic though.
If you are ordering a (non-pregnancy) pelvic ultrasound to look for a "ruptured cyst" per se, you have to ask yourself, why am I?
If there's was a cyst, and it ruptured, you may not see it after it's popped. If you do see a cyst, that can be completely normal, incidental and may not be causing their pain.
In EM, always think "rule out." Beware of "rule in." A little incidental cyst "ruled in," doesn't means it's causing the RLQ pain.
Sure, if you see a torsion, ovarian abscess, or cyst with clinically significant hemorrhage (very, very, uncommon) your ultrasound has been worthwhile. However, 2 of those three can also be seen on CT. In the non-pregnant female patient, how often is a pelvic ultrasound really helpful on an
emergency basis?
Before you order your pelvic ultrasound, ask yourself what you are looking for and if you'll be satisfied it if it either shows it, or shows nothing. If they are not pregnant and you are not looking for torsion, should you just order a CT, or no imaging at all?
Or is this what's going through your head, "I really think this is nothing, but because I did some imaging study, any imaging study, I feel better now"?
Are you ordering a "patient satisfaction" ultrasound just because the patient wants one? In today's world, maybe it is valid to put in the chart, "patient insists upon ultrasound, study ordered." I don't know. We are so far away from being able to focus on what's medically right, and what's medically alone, it's a near impossible situation to be in often times.