| Theme |
Present Status and Future Aspects of EUS |
| Title |
Diagnosis of Pancreatic Tumors with Contrast-Enhanced EUS |
| Author |
Masayuki Kitano |
Department of Gastroenterology and Hepatology, Kinki University School of Medicine |
| Author |
Hiroki Sakamoto |
Department of Gastroenterology and Hepatology, Kinki University School of Medicine |
| Author |
Kiyoshi Maekawa |
Division of Abdominal Ultrasound, Department of Gastroenterology and Hepatology, Kinki University School of Medicine |
| Author |
Masatoshi Kudo |
Department of Gastroenterology and Hepatology, Kinki University School of Medicine |
| [ Summary ] |
The first report on contrast-enhanced EUS in diagnosing pancreatic tumors concerned the use of carbon dioxide gas, which was infused through the celiac or supramesenteric artery during angiography. Recent developments in intravenous ultrasound contrast agents have enabled us to perform contrast-enhanced EUS with minor invasiveness, playing an important role in diagnosing pancreatic tumors. Echoendoscopically equipment with color and power Doppler modes is employed for contrast-enhanced EUS. The tumor images were classified into 3 patterns according to the vascularity seen in the surrounding tissue after intravenous injection of Levovist (300 mg / dl). Since EUS is superior to any other modality, such as contrast-enhanced CTs in respect to spatial and time resolution, contrast-enhanced EUS is useful in diagnosing small lesions that other imaging modalities fail to detect. However, sensitivity and specificity in diagnosing panctreatic carcinomas by contrast-enhanced EUS is inferior to contrast-enhanced CT due to artifacts such as blooming. The second generation of contrast agents, such as Definity, produce stronger pseudo-Doppler signals than Levovist, resulting in clear visualization of vasculature tissue in the pancreas. The invention of echoendoscopes equipped with conrast harmonic modes would lead to further developments in the detection and differential diagnosis of small pancreatic nodules. |