Pregnancy Screening and Serum hCG Testing for CT Neck Imaging

Introduction to Pregnancy Screening

The American College of Radiology recommends that all premenopausal women undergo pregnancy screening before CT imaging to avoid fetal radiation exposure, which can be accomplished through clinical history or urine pregnancy testing rather than serum hCG 1
A negative pregnancy test essentially excludes intrauterine or ectopic pregnancy, according to the ACR Appropriateness Criteria 1
Urine hCG testing becomes positive approximately 9 days after conception and is sufficient for pregnancy screening purposes before imaging 1

Serum β-hCG should be checked before neck CT in specific clinical contexts, such as suspected germ cell tumors in men younger than 65 years with mediastinal or retroperitoneal masses, who require β-hCG and α-fetoprotein measurements 2
The National Comprehensive Cancer Network recommends serum β-hCG and AFP testing for occult primary workup in patients with mediastinal adenocarcinoma to evaluate for possible germ cell primary 2
Women with suspected gestational trophoblastic disease require serum hCG measurement, and imaging should be performed within 24 hours before treatment initiation 3, 4

Quantitative serum hCG is used as a diagnostic tumor marker for germ cell tumors or trophoblastic disease, as recommended by the Journal of Clinical Oncology 5, 2
The American College of Radiology states that for routine neck CT imaging without suspicion of these specific malignancies, urine pregnancy testing is sufficient and serum hCG is unnecessary 1

Heterophilic antibodies can cause false-positive hCG results in women, leading to unnecessary intervention, according to the Journal of Clinical Oncology 5, 6
The American College of Radiology advises against delaying urgent CT neck for serum hCG results when clinical suspicion for pregnancy is low and urine testing is negative 1