Imaging of Abdominal Pain During Pregnancy

87 Pages·2016·4.07 MB·English

Imaging of Abdominal Pain During
Pregnancy

Genevieve L. Bennett, MD
Assistant Professor of Radiology/Obstetrics and Gynecology
NYU Langone Medical Center
U Penn Cape Cod July 2016
Learning Objectives
 Safety considerations
related to use of CT, MR
and contrast during
pregnancy

 Current guidelines/practice
standards

 Role of US, CT and MR in
evaluation of abdominal
pain during pregnancy-
examination
appropriateness and areas
of controversy
Ultrasound
 Imaging test of choice
 Widely available
 Low cost
 “Real time” imaging
 Safe for mother and fetus

 However…….sometimes there are
unanswered questions
CT
 Well established role in
the nonpregnant patient
for evaluation of
abdominal/pelvic pain
 Risks in pregnancy
 Radiation: GA and dose
Acute appendicitis 25 wks GA
 Teratogenesis
 Carcinogenesis
 Iodinated contrast
 Teratogenesis
 ? Fetal thyroid
Ionizing Radiation During Pregnancy

 Deterministic effects: malformations, neurologic
abnormalities, mental retardation, growth restriction
 Risk related to fetal dose and fetal age at
exposure, require a threshold dose
 Greatest risk during the 2nd to 15th weeks - time of
organogenesis
 Risk of abnormality at fetal does </= 5 rads is
negligible- NCRP, ACOG, ACR

ACR/SPR Practice parameter for imaging pregnant or potential pregnant
adolescents and women with ionizing radiation 2014.
From Wieseler,K.M., et al RadioGraphics 2010; 30:1215
Adapted from ACR Practice guideline for Imaging the Pregnant
or Potentially Pregnant Patient with Ionizing Radiation, 2008
Radiation Induced Carcinogenesis
 Stochastic effect: Does not require an absolute
threshold dose. Likelihood incr. as dose incr.

 Data less consistent –variable risk estimates-
controversial

 Small but finite increased risk of developing
childhood cancers (leukemia) after in utero
exposure of 10 mGy (inc. from 0.2 - 0.3% to 0.3-
0.7%)

ACR/SPR Practice Parameter for Imaging Pregnant or Potentially

Pregnant Adolescents and Women with Ionizing Radiation, 2014
Current Practice Guidelines

 ACR: No deterministic radiation effects for fetal
doses <50mGy (5 rad), stochastic risks are
suspected but data are not consistent, consider
risk vs benefit, keep dose as low as possible,
obtain consent.

 ACOG: Exposure to less than 50mGy (5 rad)
has not been associated with an increase in fetal

anomalies or pregnancy loss.
Take Home Points
 Pregnant women exposed to <5 rads have
similar pregnancy outcomes as those
receiving background radiation
 The maximal limit of ionizing radiation to
which the fetus should be exposed during
pregnancy is a cumulative dose of 5 rads
 Small but increased risk of childhood
cancers
 Always consider risk/benefit
 Obtain informed consent
Estimated Fetal Exposure for
Diagnostic Imaging Tests
Exam Fetal Dose(rads) # exams = 5rads

CXR 0.00007 71,429
AXR 0.245 20
IVP 1.398 3
Chest CT <.100 > 50
Abdominal CT 2.600 1

From Toppenberg, K.S., et al. Safety of Radiographic Imaging During
Pregnancy. American Family Physician 1999; 59