 Introduction/Background Premenopausal patients with acute pelvic pain often pose a diagnostic dilemma. They may exhibit additional nonspecific signs and symptoms, the most common being nausea, vomiting, and leukocytosis. The differential considerations encompass gynecological and obstetrical causes (eg, hemorrhagic ovarian cysts, pelvic inflammatory disease [PID], ovarian torsion, ectopic pregnancy, spontaneous abortion, or labor and placental abruption), as well as nongynecological etiologies (eg, appendicitis, inflammatory bowel disease, infectious enteritis, diverticulitis, urinary tract calculi, pyelonephritis, and pelvic thrombophlebitis). The choice of imaging modality is determined by the most likely clinically suspected differential diagnosis, because each modality differs in the ability to depict disease in the various pelvic organs. Thus, a thorough clinical evaluation of the patient is required to determine the index of suspicion among the various etiologies. Diagnostic considerations should be based upon the correlation of history, physical examination, and laboratory testing before a radiologic examination is chosen. Details on risk to the fetus, as well as guidelines on screening for pregnancy, minimizing radiation exposure, and risk assessment, can be found throughout this document. Special Imaging Considerations Details on risk to the fetus, guideline on screening for pregnancy, minimizing radiation exposure, and risk assessment can be found in the ACR-SPR Practice Parameter for Imaging Pregnant or Potentially Pregnant Adolescents and Women with Ionizing Radiation [1]. Use of contrast in MRI during pregnancy should be done with caution, because the gadolinium-chelate molecules are excreted in the amniotic fluid and may remain there for an indeterminate amount of time before finally being reabsorbed and eliminated [2].
Acute Pelvic Pain in the Reproductive Age Group.  Introduction/Background Premenopausal patients with acute pelvic pain often pose a diagnostic dilemma. They may exhibit additional nonspecific signs and symptoms, the most common being nausea, vomiting, and leukocytosis. The differential considerations encompass gynecological and obstetrical causes (eg, hemorrhagic ovarian cysts, pelvic inflammatory disease [PID], ovarian torsion, ectopic pregnancy, spontaneous abortion, or labor and placental abruption), as well as nongynecological etiologies (eg, appendicitis, inflammatory bowel disease, infectious enteritis, diverticulitis, urinary tract calculi, pyelonephritis, and pelvic thrombophlebitis). The choice of imaging modality is determined by the most likely clinically suspected differential diagnosis, because each modality differs in the ability to depict disease in the various pelvic organs. Thus, a thorough clinical evaluation of the patient is required to determine the index of suspicion among the various etiologies. Diagnostic considerations should be based upon the correlation of history, physical examination, and laboratory testing before a radiologic examination is chosen. Details on risk to the fetus, as well as guidelines on screening for pregnancy, minimizing radiation exposure, and risk assessment, can be found throughout this document. Special Imaging Considerations Details on risk to the fetus, guideline on screening for pregnancy, minimizing radiation exposure, and risk assessment can be found in the ACR-SPR Practice Parameter for Imaging Pregnant or Potentially Pregnant Adolescents and Women with Ionizing Radiation [1]. Use of contrast in MRI during pregnancy should be done with caution, because the gadolinium-chelate molecules are excreted in the amniotic fluid and may remain there for an indeterminate amount of time before finally being reabsorbed and eliminated [2].