Detective flow imaging endoscopic ultrasound for locating optimal puncture site for a poorly vascularized pancreatic mass

Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) is an established procedure with high diagnostic accuracy for tissue acquisition and pathological diagnosis of pancreatic ductal adenocarcinoma (PDAC) [1]. However, EUS-FNB sometimes demonstrates inconclusive results in PDAC rich in necrotic or fibrotic components [2] [3]. In such cases, identifying hot spot areas with viable cancerous cells is important to obtain adequate samples. Detective flow imaging (DFI) is a novel Doppler imaging technology that visualizes low-velocity blood flow in the absence of motion artifacts [4] [5], which was challenging to visualize on conventional color Doppler imaging. Herein, we present a case in which DFI imaging helped determine the hot spot area during EUS-FNB for a poorly vascularized pancreatic mass.

An 85-year-old male patient was referred to our hospital for pancreatic mass evaluation. Contrast-enhanced computed tomography revealed a large hypodense mass in the pancreatic body and tail with poor contrast enhancement ([Fig. 1]). EUS detected a well-defined heterogeneous mass in the pancreatic body. EUS-FNB was performed using a 22-gauge Franseen needle (Acquire; Boston Scientific, Natick, Massachusetts, United States) with three needle passes. However, the acquired materials contained only fibrotic and necrotic components without epithelial cells. Repeated EUS-FNB was required to confirm the diagnosis. Previous EUS-FNB findings indicated that the tumor contained abundant fibrotic tissues; thus, intratumoral vessel evaluation using the DFI was planned. Conventional color Doppler imaging revealed no intratumoral vessels ([Fig. 2] a), whereas DFI imaging demonstrated fine, irregular intratumoral vessels, indicating a hot spot area ([Fig. 2] b). EUS-FNB with DFI guidance was performed using the same needle type against the area where vessels were displayed on DFI ([Fig. 3] a, [Video 1]). The acquired specimen contained cancerous tissue, resulting in a final diagnosis of PDAC ([Fig. 3] b). This case indicates that DFI helps determine the optimal puncture site for diagnosis of poorly vascularized PDAC.

Fig. 1 Contrast-enhanced computed tomography showing a large hypodense mass in the pancreatic body and tail with very poor contrast enhancement. a Early phase. b Delayed phase.

Fig. 2 a Conventional color Doppler endoscopic ultrasound (EUS) showing no intratumoral vessels. b Detective flow imaging EUS illustrating fine irregular vessels inside the pancreatic mass.

Fig. 3 a EUS-guided tissue acquisition was performed using a Franseen needle on DFI guidance against the area where intratumoral vessels were displayed. b Histopathological evaluation of the acquired specimen demonstrating atypical cell clusters with irregularly sized nuclei, resulting in pancreatic ductal adenocarcinoma diagnosis.

Detective flow imaging helps determine the optimal puncture site for poorly vascularized pancreatic mass.Video 1

Publication History

Received: 20 May 2024

Accepted after revision: 13 June 2024

Article published online:
12 September 2024

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