Efficiency of unenhanced MRI in the diagnosis of acute appendicitis: comparison with Alvarado scoring system and histopathological results.
OBJECTIVE
The purpose of this study was to assess the diagnostic value of unenhanced magnetic resonance imaging (MRI) in the diagnosis of acute appendicitis and compare with Alvarado scores and histopathological results.


METHODS
The study included 85 consecutive patients (mean age, 26.5±11.3 years) who were clinically suspected of having acute appendicitis. Each patients Alvarado scores were recorded and unenhanced MRI was performed, consisting of T1-weighted, T2-weighted and fat-suppressed T2-weighted fast spin-echo sequences. The MR images were prospectively reviewed in consensus for the presence of acute appendicitis by two radiologists who were blinded to the results of the Alvarado scores. The study population were divided into three subgroups based on the MRI findings: Group I: definitely not appendicitis, Group II: probably appendicitis, Group III: definitely appendicitis. All patients were divided into two subgroups according to Alvarado scores as Group A (low: 1-6), and Group B (high: 7-10). MR findings were compared with Alvarado scores and histopathological findings.


RESULTS
Sixty-six (77.6%) of the 85 patients with clinically suspected acute appendicitis, had undergone surgery. The diagnosis of appendicitis could be correctly achieved with MRI in 55 (83.3%) of 57 (86.4%) patients with histopathologically proven acute appendicitis. The sensitivity, specificity, positive predictive value and negative predictive value of MRI examination and Alvarado scoring system in the diagnosis of acute appendicitis were 96.49%, 66.67%, 94.83%, 75.0% and 84.21%, 66.67%, 94.12%, 40.0%, respectively.


CONCLUSIONS
MRI is a valuable technique for detecting acute appendicitis even in the cases with low Alvarado scores. To increase the diagnostic accuracy and preventing unnecessary laparotomies for suspected appendicitis, shorter and cheaper unenhanced basic MRI may be performed.
Inci
Ercan
E
Department of Radiology, İstanbul Bakirkoy Dr. Sadi Konuk Training and Research Hospital, İncirli-Bakirkoy, İstanbul, Turkey. ercan_inci@mynet.com
Hocaoglu
Elif
E
Aydin
Sibel
S
Palabiyik
Figen
F
Cimilli
Tan
T
Turhan
Ahmet Nuray
AN
Aygün
Erşan
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D001064:Appendicitis / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity