Harry Holdorf PhD, MPA, RDMS, RVT, LRT(AS), CCP “Other” imaging techniques in Obstetrics Obstetrical Sonography 2 Lecture 23 Harry Holdorf PhD, MPA, RDMS, RVT, LRT(AS), CCP

CT scan and MRI

Under what circumstances can MRI be used safely in the pregnancy patient?

When the patient presents with possible Appendicitis or other potentially surgical conditions (i.e. Non-bone conditions).

How can MRI and CT be helpful in staging diseases for the obstetrical patient?

Gynecological malignancies, especially that of the ovaries Gynecological malignancies, especially that of the ovaries. Also, MRI and CT can be useful in staging cancers from other primary sites.

Give Several reasons why CT would be the exam of choice while treating the pregnant patient.

CT: Plus: Use of contrast agents can serve as a “light bulb”, illuminating certain tumors that ordinarily would not be detected with MRI. CT: Plus: readily available. CT: Plus: Less motion artifact. CT: Plus: Faster CT: Plus: Less likely for patient to be sedated. CT: Plus: Less chance of a magnetic problem. CT Plus: Cheaper.

Give Several reasons why MRI would be the exam of choice when treating the pregnant patient.

MRI Plus: No Radiation. MRI Plus: MRI can be repeated within a short time. MRI Plus: MRI is good for tumors of the brain.

Provide an argument as to why MRI should be the exam of choice for evaluating the first trimester pregnancy patient.

No harmful effects of MRI on the fetus have been demonstrated. No radiation. Can provide more diagnostic information than CT. Can facilitate open fetal surgery.

Provide an argument as to why MRI should not be the exam of choice for evaluating the first trimester pregnancy patient.

Concerns in pregnancy with heating and noise. Concern for the use of contrast agents that are known to cross the placenta and enter the fetal bloodstream.

Define Open Fetal Surgery

Open fetal surgery involves completely opening the uterus to operate on the fetus.

What are the three main priorities of open fetal surgery?

Maternal safety Avoiding preterm labor Achieving the aims of the surgery

Open fetal surgery should not be attempted prior to how many weeks of gestation?

Open fetal surgery should not be attempted prior to 18 weeks of gestation.

Open fetal surgery should not be attempted past how many weeks of gestation?

Open fetal surgery should not be attempted past 30 weeks of gestation.

What are the primary indications in which open fetal surgery may be indicated?

Congenital Diaphragmatic Hernia Congenital Cystic Adenomatoid Malformation (CCAM) Congenital Heart Disease Pulmonary Sequestration Sacrococcygeal Teratoma

Minimally Invasive Fetal Surgery Twin-to-Twin Transfusion Syndrome Laser ablation of vessels Amnio-infusion Amnio-infusion refers to the instillation of fluid into the amniotic cavity. This procedure is typically performed during labor through an intrauterine pressure catheter introduced trans-cervically after rupture of the fetal membranes

Endoscopic fetal surgery for Twin-to-Twin Transfusion Syndrome

The role of MRI and CT in the management of the obstetrical patient Summary: MRI and CT can be useful tools in the management of the obstetrical patient when maternal health is at risk. In addition, an MRI or CT scan may be indicated if the benefits of these examinations far out weigh the possible risks of radiation exposure or magnetic /heat exposure to the fetus, specifically if open fetal surgery may be a viable option.