Value of contrast-enhanced ultrasound combined with percutaneous ultrasound-guided fine-needle aspiration in the diagnosis of solid pancreatic lesions

Pancreatic cancer is one of the most aggressive cancers globally, with an overall 5-year survival rate of just 7%. For patients with solid pancreatic lesions—lumps that could be malignant (cancerous) or benign (like focal pancreatitis)—getting an accurate diagnosis is critical to guiding treatment. A 2022 study from Peking Union Medical College Hospital explores whether adding contrast-enhanced ultrasound (CEUS) to a common biopsy technique improves diagnostic accuracy for these lesions.

Authors and Affiliations

The study was conducted by researchers from Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College:
Yang Gui¹, Menghua Dai², Zhilan Meng³, Xiaoyan Chang³, Li Tan¹, Jing Zhang¹, Xueqi Chen¹, Tongtong Zhou¹, Qing Zhang¹, Mengsu Xiao¹, Ke Lyu¹, Yuxin Jiang¹

Department of Ultrasound
Department of Surgery
Department of Pathology
State Key Laboratory of Complex Severe and Rare Diseases, Dongcheng District, Beijing 100730, China

Why This Study Matters

Doctors often use percutaneous ultrasound-guided fine-needle aspiration (US-FNA) to biopsy solid pancreatic lesions. This method uses real-time ultrasound to guide a thin needle into the lesion, collecting cells for analysis. It’s safe, low-cost, and avoids radiation—but standard ultrasound has limits: it can miss necrosis (dead tissue), severe fibrosis (scarring), or lesions hidden in inflamed pancreatic tissue. These gaps can lead to inaccurate biopsies, false negatives, or the need for repeat procedures.

CEUS addresses these limitations. By injecting a contrast agent into the bloodstream, CEUS highlights the microvascular flow (tiny blood vessels) in and around lesions. This lets doctors see viable (living) tissue, avoid non-diagnostic areas (like necrosis), and detect lesions that standard ultrasound might miss. The study set out to test whether using CEUS before US-FNA improves biopsy results.

How the Study Was Done

This was a retrospective study (analyzing past data) of 181 patients who underwent US-FNA for solid pancreatic lesions at Peking Union Medical College Hospital between January 2014 and December 2018. Patients were split into two groups:

CEUS group: 123 patients who had CEUS before their biopsy.
US group: 58 patients who had standard ultrasound only.

All biopsies used ThinPrep cytology (TCT), a method that processes cells into clear, uniform samples—reducing errors from messy smears. The final diagnosis for each patient was confirmed either by surgery/pathology or at least 12 months of clinical and imaging follow-up (to track if lesions grew or stayed benign).

Key Results

The CEUS group outperformed the US group in nearly every measure of diagnostic accuracy:

Accuracy: 95.1% of CEUS-guided biopsies gave the correct diagnosis, compared to 86.2% in the US group. This difference was statistically significant (p = 0.036), meaning it’s unlikely to be due to chance.
Sensitivity: CEUS group detected 95.5% of malignant lesions vs. 88.0% in the US group.
Specificity: CEUS group correctly ruled out malignancy in 91.7% of benign cases vs. 75.0% in the US group.
Complications: No severe issues (like internal bleeding or death) occurred in either group. Only one case of mild pancreatitis was reported in each group, resolved with conservative treatment.

While sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were all higher in the CEUS group, these differences weren’t statistically significant—likely due to the study’s small sample size and unequal group sizes.

How CEUS Improves Biopsies

CEUS helped doctors in two critical ways:

Target Viable Tissue: Large pancreatic lesions often have necrotic or scarred areas that yield no useful cells. CEUS shows which parts of the lesion have blood flow (and thus living tissue), so the needle targets those spots. For example, one patient with a large solid pseudo-papillary neoplasm (SPN) had a previous biopsy fail because it hit necrotic tissue. CEUS guided the second biopsy to viable cells, leading to a correct diagnosis.
Detect Hidden Lesions: Inflammation (from pancreatitis) can mask malignant lesions on standard ultrasound. CEUS highlights the distinct microvascular pattern of tumors, even in inflamed tissue. For instance, a patient with pancreatic adenocarcinoma had a lesion hidden in an inflamed pancreas—CEUS showed the tumor’s hypo-enhancement (less blood flow than normal tissue), guiding the biopsy to the correct area.

Limitations to Consider

The study has important caveats:

Retrospective Design: Because researchers looked back at past data, they couldn’t control variables like how many biopsy passes were done or why some patients got CEUS vs. standard ultrasound.
Unequal Group Sizes: The CEUS group had more than twice as many patients as the US group, which could skew results.
Follow-Up Diagnoses: Most benign diagnoses were based on 12+ months of stable imaging, not surgery. While this is standard practice, surgical confirmation is more definitive.
Single Center: Results may not apply to patients at other hospitals with different equipment or expertise.

What This Means for Patients and Doctors

Despite its limitations, the study provides strong evidence that CEUS improves the accuracy of US-FNA for solid pancreatic lesions. For patients, this means fewer repeat biopsies, faster diagnosis, and more confidence in treatment plans. For doctors, CEUS is a tool to:

Avoid non-diagnostic samples (necrosis/fibrosis).
Find lesions hidden in inflammation.
Choose the safest, most effective biopsy path.

The researchers note that CEUS is more expensive and time-consuming than standard ultrasound—but its higher accuracy and lower repeat biopsy rate make it cost-effective in the long run. They also suggest that advanced pancreatic lesions should first be evaluated for percutaneous US-guided biopsy; if the lesion is invisible to percutaneous ultrasound, endoscopic ultrasound (EUS) (a more invasive method) can be used.

Conclusion

CEUS is a game-changer for pancreatic biopsy. By visualizing microvascular flow, it helps doctors target the right tissue, avoid diagnostic pitfalls, and get more reliable results. While larger, multicenter studies are needed to confirm these findings, the study shows that CEUS-guided US-FNA is a better option than standard ultrasound alone—especially for complicated cases. For patients with solid pancreatic lesions, this could mean faster, more accurate diagnoses and better outcomes.

doi.org/10.1097/CM9.0000000000001638

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