Evaluating the Head of the Pancreas in the Overall EUS Assessment of Chronic Pancreatitis (CP) Significantly Impacts the Overall Diagnosis

Abstract

EUS is a promising newer modality for the evaluation of chronic pancreatitis (CP). Many obstacles exist before becoming universally accepted as the “Gold Standard” imaging modality. These include lack of standardized nomenclature, variably agreed upon parenchymal and ductal features and overall criteria for diagnosis of CP (minimum features needed). In addition, frequent imaging artifacts result in less than optimal specificity of the various features. The Head of the Pancreas (HOP) because of its heterogeneous appearance (ventral anlage) is typically excluded from overall EUS analysis, historically. There is no information regarding frequency of missed diagnosis by exclusion of the HOP. AIM: To determine the importance of evaluation of the HOP in establishing a diagnosis of CP. Methods: The International Consensus Conference on EUS Diagnosis of CP convened in Rosemont, Illinois, 4/07. The result was the development of universal nomenclature and agreed upon endosonographic features of CP (Table A). A new criteria (“Rosemont Criteria”) for diagnosis of CP was ultimately established (Table B). Fifty consecutive patients with abdominal pain suggestive of CP underwent EUS by two expert endosonographers (Olympus). The body, tail and head of the pancreas were fully imaged for parenchymal and ductal pathology and recorded prospectively on data sheets. Presence or absence of each pathologic feature was deleted & agreed upon prior to termination of each exam. Using the Rosemont Criteria we determined presence of CP based on body/tail vs body/tail/head evaluation. CP was established by imaging the head/body only in 34 of 50 patients (68%) while CP was established by imaging the head/body/tail in 38 of 50 patients (76%). Conclusion: Imaging the HOP is important in the overall assessment of CP despite the potential for artifact. By excluding the HOP, nearly 10% patients will potentially have unrecognized CP. Knowledge of the fundamentals of ultrasonography is essential to prevent false positive studies. Tabled 1EUS Criteria- Parenchymal and Ductal Major A Minor 1. Hyperechoic foci (HF) (shadowing) 2. Main pancreatic duct MPD calculi 1. Cysts 2. Dilated Duct (≥ 3.5 mm) 3. Irregular MPD contour 4. Dilated side branch (≥1 mm) 5. Hyperechoic duct wall 6. Strands 7. HF (non-shadowing) 8. Lobularity (non contiguous) Major 1. Lobularity (honeycombing) Open table in a new tab