Impact of an online reference system on the diagnosis of rare or atypical abdominal tumors and lesions

Abstract

The purpose of the present study is to evaluate whether an online reference system (ORS, STATdx Elsevier, Amsterdam, Netherlands) impacts finding the histologically confirmed diagnosis of rare or atypical abdominal tumors and lesions in radiologic imaging. In total, 101 patients with rare tumor entities or lesions and atypical manifestations of common tumors were enrolled retrospectively. Blinded readings were performed by four radiologists with varying levels of experience, who reported on: (a) correct diagnosis (CD), (b) time needed to find the diagnosis, and (c) diagnostic confidence, initially without followed by the assistance of the ORS. The experienced reader (3 years of experience post-residency, CD 49.5%), as well as the advanced reader with 1 year of experience post-residency (CD 43.6%), and a resident with 5 years of experience (CD 46.5%) made the correct diagnosis more frequently compared to the less experienced reader (CD 25.7%). A significant improvement in making the correct diagnosis was only achieved by the advanced reader, the resident with 5 years of experience (CD with ORS 58.4%; p < 0.001). The advanced reader with 1 year of experience post-residency improved slightly (CD ORS 47.5%). The experienced reader (CD ORS 50.5%) and the less experienced reader (CD ORS 27.7%) did not improve significantly. The overall subjective confidence increased significantly when ORS was used (3.2 ± 0.9 vs. 3.8 ± 0.9; p < 0.001). While the ORS had a positive impact on making the correct diagnosis throughout all readers, it favored radiologists with more clinical experience rather than inexperienced residents. Moreover, the ORS increased the diagnostic confidence of all radiologists significantly. In conclusion, the ORS had no significant impact on the diagnosis of rare or atypical abdominal tumors and lesions except for one reader. The greatest benefit is the increase in diagnostic confidence.

Keywords: Abdominal tumors; CT; Computed tomography; Diagnostic performance; ORS; Online reference system; STATdx.

Figure 1

A 62 years old, female patient was admitted to the department of gynaecology with lumbago and paresthesia of the legs. The abdominal portal venous CT scan showed a presacral mass with partial calcifications (1). The tumor exhibited contrast enhancement of the well-defined margin with a more fluid-like necrotic core. Enlarged vessels (2) near the tumor, often seen in solitary fibrous tumors (SFT), were also noted. SFTs typically compress rather than infiltrate surrounding tissues, as seen here by the shifted rectum. Only 1/3 of SFTs are located in the abdomen, and approximately 25% recur locally^,. The diagnosis of an SFT was confirmed histologically after resection.

Figure 2

A 74-year-old male patient was referred to visceral surgery for an unclear adrenal mass by his GP. The abdominal portal venous CT scan showed a bimorphic mass. Dedifferentiated liposarcomas typically consist of solid dedifferentiated tumor parts (1) often containing necrosis, and an adjacent lipomatous well-differentiated tumor mass (2). The solid part was adherent to the liver (3), while the lipomatous parts surrounded the kidney (4) and displaced the adjacent intestine. Dedifferentiated liposarcomas typically occur in the retroperitoneal space and mostly arise de novo, while around 10% dedifferentiate from a previous well-differentiated liposarcoma. The initially suspected liposarcoma was later confirmed by the histopathologic report, stating a dedifferentiated liposarcoma with parts of a well-differentiated liposarcoma.

Figure 3

Bar chart showing the diagnostic confidence of the readers (1–4) using a 5-point Likert scale with 1—not confident at all, 2—slightly confident, 3—somewhat confident, 4—fairly confident, and 5—completely confident. The subjective confidence of each reader increased significantly with the use of the online reference system (ORS) STATdx.

Figure 4

Bar chart showing the expenditure of time of each single reader (1–4) without and with the online reference system (ORS) STATdx in minutes.