From the Guidelines
For a 66-year-old female with worsening right lower quadrant abdominal pain over one month, I recommend starting with an abdominal and pelvic CT scan with contrast as the initial imaging study. This recommendation is based on the high diagnostic yield of CT scans for detecting appendicitis and other causes of right lower quadrant pain, as reported by Rud et al 1 with a summary sensitivity of 95% and summary specificity of 94% for CT in the diagnosis of appendicitis. The use of CT scans is also supported by the American College of Radiology Appropriateness Criteria, which suggests that CT of the abdomen and pelvis is an excellent diagnostic imaging modality for the evaluation of patients with nonspecific right lower quadrant pain 1.
Some key points to consider in this patient's evaluation include:
- The patient's history of total hysterectomy, which may affect the interpretation of imaging findings
- The patient's age, which may increase the risk of certain conditions such as diverticulitis or inflammatory bowel disease
- The patient's symptoms, which are improving with dietary modifications but still warrant thorough investigation
- The patient's prior normal colonoscopy, which is outdated and may need to be repeated regardless of imaging findings
Alternative imaging options, such as ultrasound, may be considered if there are concerns about radiation exposure or contrast allergies. However, CT scans are generally preferred due to their high diagnostic accuracy and ability to evaluate a wide range of potential causes of right lower quadrant pain. If the CT scan is inconclusive, additional imaging studies such as MRI enterography may be beneficial to evaluate for small bowel pathology that could be missed on standard imaging 1.
It is also important to note that the patient's prior normal colonoscopy from 10 years ago is outdated, and current guidelines recommend screening every 5-10 years 1. Therefore, a repeat colonoscopy should be considered regardless of imaging findings. Overall, a comprehensive evaluation including imaging and potential colonoscopy is necessary to determine the cause of this patient's symptoms and develop an appropriate treatment plan.
From the Research
Imaging Recommendations
The patient's symptoms of worsening mild to moderate right lower quadrant abdominal pain, which improves with avoidance of spicy and acidic foods, and history of total hysterectomy and normal colonoscopy 10 years ago, suggest that the pain may not be related to the colon or reproductive system.
- The study by 2 discusses the approach to evaluation of patients presenting with acute onset right lower quadrant abdominal pain and the choice of various imaging modalities, suggesting that although CT remains the workhorse in evaluation, US and MRI play an important ancillary role.
- According to 3, the American College of Radiology has appropriateness criteria for patients presenting with right lower quadrant pain, which can guide clinicians in ordering the most appropriate imaging study.
- However, the patient's symptoms do not clearly point to a specific diagnosis, and the studies provided do not directly address the patient's specific condition.
- The studies 4 and 5 focus on right upper quadrant pain and gallbladder pathology, which may not be directly relevant to the patient's right lower quadrant pain.
- The study by 6 discusses the role of ultrasound and CT in evaluating emergent gallbladder pathology, but does not specifically address right lower quadrant pain.
Possible Imaging Modalities
Based on the available evidence, possible imaging modalities for the patient's right lower quadrant abdominal pain include: