Autoimmune pancreatitis: possibilities of CT characterization.
BACKGROUND
Pancreatitis is defined as an inflammatory disease of the pancreas, leading to morphological and pathological changes. Recently, an autoimmune pathogenesis of this disease has been proposed. This type of pancreatitis should be differentiated from other pancreatic diseases, since appropriate therapy is effective and morphological changes and pancreatic function can recover to normal levels.


OBJECTIVE
To assess the possibility of distinguishing autoimmune pancreatitis from other pancreatic diseases with an analogous clinical presentation on the basis of CT findings alone.


METHODS
The CT images of 7 patients with proven autoimmune pancreatitis, along with those of 20 patients with other pancreatic diseases, but with an analogous clinical presentation, were retrospectively evaluated in a blinded fashion by 2 radiologists. In particular, the radiologists had to search for the typical signs of autoimmune pancreatitis. Discordant cases were further analyzed in the presence of a 3rd radiologist. The final diagnosis was acquired by means of a majority or overall consensus. The sensitivity, specificity, positive and negative predictive values of CT were calculated against each of the diseases (autoimmune pancreatitis; other pancreatic diseases), in order to evaluate the diagnostic value of the scan.


RESULTS
After the consensus evaluation, the correct diagnosis was reached in 25/27 (92.5%) cases, with only 2/27 wrong diagnoses (autoimmune pancreatitis diagnosed as another pancreatic disease and vice versa). The sensitivity and specificity of CT against autoimmune pancreatitis were 86 and 95%, respectively. The positive and negative predictive values were 89 and 93%, respectively.


CONCLUSIONS
Patients with autoimmune pancreatitis demonstrate imaging findings that enable the correct diagnosis by dynamic CT, even in the presence of nonspecific clinical symptoms. The precise classification of the disease is extremely important, since simple steroid therapy then represents the correct treatment, and leads to complete recovery.
Procacci
C
C
Department of Radiology, University of Verona Medical School, Policlinico G.B. Rossi, Verona, Italy. procacci@borgoroma.univr.it
Carbognin
G
G
Biasiutti
C
C
Frulloni
L
L
Bicego
E
E
Spoto
E
E
el-Khaldi
M
M
Bassi
C
C
Pagnotta
N
N
Talamini
G
G
Cavallini
G
G
D000328:Adult; D001327:Autoimmune Diseases / Q000000981:diagnostic imaging*; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008232:Lymphoproliferative Disorders / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010195:Pancreatitis / Q000000981:diagnostic imaging / Q000276:immunology*; D011237:Predictive Value of Tests; D014057:Tomography, X-Ray Computed