First-Trimester Ultrasound, Early Pregnancy Complications, and Ectopic Gestation — WACS Viva & Clinical Scenarios (Obstetric and Gynaecological Imaging)

Exam-style first-trimester ultrasound, early pregnancy complications, and ectopic gestation viva scenarios with examiner probes and model answers for Radiology…

Scenarios covered

• SCENARIO 1: OSCE Station / Film Interpretation: A 28-year-old female presents at 7 weeks of amenorrhoea with mild lower abdominal cramping and spotting. Transvaginal ultrasonography demonstrates an intrauterine gestational sac with a mean sac diameter of 27 mm containing no embryonic pole or yolk sac. Formulate the definitive diagnostic interpretation, detail the discriminatory diagnostic criteria for non-viable intrauterine pregnancy, and outline the mandatory reporting documentation.
• SCENARIO 2: Clinical Case Vignette / Single Best Answer: A 24-year-old woman presents with acute right iliac fossa pain and positive serum beta-hCG. Transvaginal sonography reveals an empty uterine cavity with an eccentric adnexal ring mass exhibiting a peripheral ring of fire on color Doppler, separate from the right ovary, accompanied by echogenic fluid in the pouch of Douglas. Evaluate the imaging features distinguishing tubal ectopic pregnancy from a hemorrhagic corpus luteum cyst and describe the sonographic assessment of haemoperitoneum.
• SCENARIO 3: Viva Voce / Rapid-Fire Image Recognition: A 32-year-old female with a previous lower segment caesarean delivery presents at 6 weeks gestation with painless vaginal bleeding. Ultrasound demonstrates a gestational sac embedded within the anterior lower uterine segment myometrium with a residual myometrial thickness of 1.8 mm. Discuss the specific diagnostic sonographic criteria for caesarean scar ectopic pregnancy and contrast them with cervical ectopic pregnancy and low-lying intrauterine pregnancy.
• SCENARIO 4: Oral Examination / Practical Film Reading: A 22-year-old primigravida presents with severe hyperemesis, dark brown vaginal discharge, and a markedly elevated quantitative serum beta-hCG exceeding 150,000 mIU/mL. Pelvic ultrasound reveals a widened endometrial cavity filled with diffuse, heterogeneously echogenic vesicular tissue displaying a snowstorm appearance without identifiable fetal parts, alongside bilateral multilocular ovarian cysts. Analyze the diagnostic sonographic features of complete versus partial hydatidiform mole and explain the pathophysiology and imaging appearance of the as
• SCENARIO 5: Physics and Safety Viva: Explain the bioeffects and ultrasound safety parameters during first-trimester obstetric imaging, focusing on the Thermal Index, Mechanical Index, the ALARA principle, and the rationale for avoiding pulsed-wave spectral Doppler during early embryonic organogenesis.