What is the imaging of choice for a patient with right lower quadrant (RLQ) pain lasting 2 weeks?

From the Guidelines

For a patient with right lower quadrant (RLQ) pain lasting 2 weeks, contrast-enhanced CT scan of the abdomen and pelvis is the imaging modality of choice. This recommendation is based on the most recent and highest quality study by Kambadakone et al 1, which suggests that CT of the abdomen and pelvis is an excellent diagnostic imaging modality for the evaluation of patients with nonspecific RLQ pain. The study reports a summary sensitivity of 95% and summary specificity of 94% for CT in the diagnosis of appendicitis, and also highlights the ability of CT to identify alternative diagnoses.

The use of CT scan is particularly strong when the clinical presentation suggests subacute or chronic conditions rather than acute appendicitis. CT provides excellent visualization of abdominal structures and can identify various potential causes of persistent RLQ pain, including:

• Appendiceal abnormalities
• Inflammatory bowel disease
• Diverticulitis
• Neoplasms
• Gynecological conditions in females
• Urological issues

While ultrasound may be considered as an initial imaging study, especially in young patients, pregnant women, or those with contraindications to radiation exposure, it has limitations in visualizing deeper structures and is more operator-dependent 1. MRI could be an alternative in pregnant patients or those who cannot undergo CT scanning, but its use is not as widely recommended as CT scan for this specific clinical scenario.

The superiority of CT lies in its comprehensive evaluation capability, high sensitivity and specificity for various pathologies, and ability to guide further management decisions. For optimal results, both oral and intravenous contrast should be administered unless contraindicated, as this enhances visualization of bowel and vascular structures. This is supported by the study by Kambadakone et al 1, which highlights the importance of CT scan in the evaluation of patients with RLQ pain.

In pregnant women, the approach may be different, and a combination of US abdomen and MRI may be used as the initial imaging modality, as reported by Vasileiou et al 1. However, for non-pregnant patients, contrast-enhanced CT scan of the abdomen and pelvis remains the imaging modality of choice for evaluating RLQ pain lasting 2 weeks.

From the Research

Imaging Options for Right Lower Quadrant Pain

The imaging of choice for a patient with right lower quadrant (RLQ) pain lasting 2 weeks can vary depending on the patient's condition and other factors.

• Computed Tomography (CT) is often considered the primary imaging modality for evaluating RLQ pain in non-pregnant patients, as it can provide detailed images of the abdominal and pelvic organs 2.
• However, in pregnant patients or those who cannot undergo CT scans, other imaging modalities such as Ultrasound (US) and Magnetic Resonance Imaging (MRI) can be used 3, 4, 5.
• US is particularly useful in pediatric and pregnant patients due to its lack of radiation, while MRI is an excellent alternative for patients who cannot undergo CT scans or require further evaluation after inconclusive US results 3, 4, 5.
• The choice of imaging modality ultimately depends on the patient's specific condition, medical history, and the suspected cause of the RLQ pain.

Considerations for Imaging Modalities

When selecting an imaging modality for RLQ pain, several factors should be considered, including:

• The patient's age, sex, and medical history
• The severity and duration of the pain
• The presence of any underlying medical conditions
• The potential risks and benefits of each imaging modality
• The availability and accessibility of each imaging modality

Alternative Diagnoses to Appendicitis

It is essential to consider alternative diagnoses to appendicitis when evaluating RLQ pain, as various conditions can mimic its clinical presentation 6.

• Imaging studies can help establish specific diagnoses and guide proper medical or surgical treatment.
• A broad range of pathologic conditions can cause RLQ pain, originating from multiple organ systems, including the gastrointestinal and genitourinary systems 5.