A 27-year-old woman presents to the emergency department (ED) complaining of gradually worsening, generalized abdominal pain and tactile fevers for the past 2 days. The pain started in the right lower quadrant but has spread throughout her entire lower abdomen. She states the pain worsens with walking or sneezing. She denies vomiting, diarrhea, dysuria, or abnormal vaginal discharge. She mentions a history of a kidney stone and states that the pain feels similar.

Vital signs are normal. Physical examination reveals bilateral mild lower abdominal tenderness that is slightly more severe on the right. No costovertebral angle tenderness is present.

Differential diagnoses include nephrolithiasis, appendicitis, ovarian cyst, and pelvic inflammatory disease. Complete blood cell count reveals a leukocyte count of 19,000/mL. Basic metabolic panel is normal except for a sodium level of 132 mEq/L. Urinalysis reveals a red blood cell count of 25 x 106/µL. Abdominal computed tomography and pelvic ultrasound are obtained.

What do the images show? What is the next best step in treatment?