What initial diagnostic procedure is recommended for a woman with progressive left lower quadrant abdominal pain suspected to be acute diverticulitis?

The initial diagnostic procedure recommended for a woman with progressive left lower quadrant abdominal pain suspected to be acute diverticulitis is a CT of the abdomen and pelvis. This imaging modality is preferred because it provides detailed cross-sectional images of the gastrointestinal tract, allowing for the visualization of diverticula, inflammation, and potential complications such as abscess formation or perforation.

CT scans are highly sensitive and specific for diagnosing diverticulitis and can also help rule out other causes of abdominal pain. This makes CT not only a diagnostic tool but also a way to assess the severity of the condition. Additionally, CT pelvis scans are non-invasive and can be performed quickly, which is crucial in situations where timely diagnosis and management are necessary.

In comparison to other imaging techniques, such as ultrasound, X-ray, or MRI, CT is superior for accurately diagnosing diverticulitis. Ultrasound may be less effective due to operator dependency and difficulty in visualizing the entire abdomen, particularly in overweight patients. X-rays lack the detail needed to diagnose diverticulitis and are not routinely used for this condition. Lastly, MRI, while useful in certain contexts (especially in pregnant patients to avoid radiation), is not the first-line imaging choice for diverticulitis due to cost and availability considerations.