Right Lower Quadrant Pain: Evaluation of the Sensitivity, Specificity and Predictive Values of Ultrasonography and Colour Doppler in the Diagnosis

Background: Right lower quadrant (RLQ) pain is caused by a variety of pathological conditions. CT and ultrasonography play a major role in verifying the site of pathology. They also have a role in lesion characterization. Sonography still has many merits if a skillful operator is present. It has particular importance in searching for causes of RLQ pain. It is the preferred modality when acute appendicitis is suspected in women in the child-bearing age. Aim of Work: The aim of the study was to evaluate the role of the gray-scale ultrasound and colour Doppler in the diagnosis of various causes of right lower quadrant pain. Patients and Methods: Eighty patients were included in the study, 27 male and 53 female patients (age range 5-70 years). In 25 cases gastrointestinal pathology was detected including: appendicitis (22 cases), Crohn s disease (1 case) and intussusception (2 cases ). Gynecological abnormalities in 34 cases were: ectopic pregnancy in 10 cases, ovarian lesions in 24 Dermoid cyst (6), simple cysts (4), endometrioma (8), complicated cyst (6) including one case of tuboovarian abscess. Stone lower end right ureter was met with in 7 cases. One case showed lipoma of the right rectus muscle. The remaining 13 cases were normal. All cases were subjected to preliminary abdominal and pelvic ultrasound using 3.5-5 MHz curvilinear probe, followed by graded compression technique using 7-12 MHz linear array transducer. Transvaginal examination was performed in 30 cases. Colour Doppler study was performed in 50 cases to detect vascularity. CT was done in two cases (complicated appendicitis). MRI was done in 10 complex ovarian masses for better lesion characterization. Findings were correlated with surgical, histopathologic and clinical follow-up findings. Results: Among 22 cases opened surgically for appendicitis 19 patients were truly diagnosed by ultrasound examination as acute appendicitis, there were 3 false negative cases where the appendix appeared normal. Sensitivity, specificity, positive and negative predictive values of US colour Doppler were 86, 100, 100, 81 % respectively. In the rest of the gastrointestinal tract cases, Crohn s was suggested by US in one case and was confirmed by BMFT and two cases of intussusception were accurately diagnosed by US. In the gyneclogical cases: Ten 393 cases showed right ectopic pregnancy including one abdominal and 9 tubal locations with 8 being disrupted and one intact. TVS with addition of colour Doppler showed 100% Sensitivity, specificity, positive and negative predictive values in diagnosis of these cases. In ovarian complex cysts (24 cases), all of them could be detected by US, ten of which needed better characterization by MRI (endometrioma and dermoid). In ureteric stones [PUT showed stones in 5 cases, 2 detected by IVU (radiolucent)]. In one case there was lipoma of th e right rectus muscle. In 13 cases no abnormality detected. Conclusion: That the use of ultrasound examination in the evaluation of different causes of RLQ pain showed sensitivity, specificity, positive and negative predictive values of 96, 100, 100 and 81 % respectively. The combination of gray scale and colour Doppler study improved the diagnostic accuracy. Abdominal ultrasound using graded compression technique could help in detecting cases of acute appendicitis and differentiating them from other gastrointestinal or gynecological lesions. Transvaginal ultrasound study was a great help in verifying different gynecological lesions including, ectopic pregnancy and right ovarian lesions.