Introduction:
The early pancreatic ultrasound can greatly aid in the diagnosis and treatment of pancreatic diseases. Pancreatic ultrasound uses sound waves to create images and help determine if there are any abnormalities, such as inflammation of the pancreas, cyst masses or changes in characteristics of pancreas tissue.
Here is a complete guide to pancreatic ultrasound, patient preparations, anatomy and interpretation.
What is pancreatic ultrasound?
A pancreas ultrasound is a specialised diagnostic examination that use to visualise the pancreas and assess its anatomical characteristics. The procedure helps sonographers to evaluate the size, shape and overall parenchyma. Although factors such as intestinal gas may occasionally reduce image quality, a pancreas ultrasound remains a highly valuable, cost-effective and widely first-line imaging modality for the initial evaluation of pancreatic pathology.
When is pancreatic ultrasound recommended?
A pancreatic ultrasound is recommended when a healthcare provider needs to evaluate the pancreas for abnormalities, investigate symptoms or monitor known pancreatic disease. For example, a pancreatic ultrasound may be recommended in the following conditions:
- Persistent abdominal pain (radiate toward back)
- Suspected acute or chronic pancreatitis
- Yellowing of the eyes and skin (jaundice)
- Abnormal blood test (amylase, lipase)
- Unexplained weight loss
- Gallstones suspected to have involvement of the pancreas
How to prepare patients for pancreatic ultrasound?
Patient preparation is essential for accurate scanning; however, following guidelines can enhance the quality of the image and diagnostic accuracy:
| Preparation Recommendation |
| Food No food or drinks for 6–8 hours prior to the scan |
| Water Small sips only, as needed for medications |
| Foods that produce gas Avoid for 24 hours prior to the exam. |
| Smoking Avoid for several hours before the scan |
| Medications Keep essential medicines unless advised otherwise |
| Clothing wear loose comfortable clothing |
| Medical history: Describe relevant medical conditions to the health |
provider
Special considerations:
- Diabetic patients: Fasting guidelines should be tailored, and they should check with their health care provider for meal times and changes in medication.
- Children: Fasting times are usually shorter and depend on age. Parents should follow the imaging centre’s instructions.
Scanning techniques for pancreatic ultrasound
A systematic scanning technique is required to achieve the best visualisation of the pancreas. Patient positioning and probe manipulation are important, as bowel gas may obscure the gland.
1. Patient Position
- Start in the supine position.
- When visualisation is restricted, then roll the patient into the additional left lateral decubitus or right lateral decubitus.
- Taking a deep breath in might help to move the pancreas down below the ribs to get a better image.
2. Transducer Selection
- Most adults will require a 2–5 MHz curvilinear transducer.
- However, a linear transducer with a frequency of 5-9 MHz could be helpful in thin patients or when examining superficial lesions.
3. Scanning Planes
To ensure the complete examination and evaluation of the pancreas in both planes
- Transverse (axial) plane
- Longitudinal (sagittal/oblique) plane
Examine the head, neck, body and tail systematically, evaluating the surrounding vascular landmarks.
Sonographic anatomy of pancreas:
The pancreas is a retroperitoneal gland in the upper abdomen extending from the duodenum to the splenic hilum. The normal pancreas is homogeneous, has smooth margins and is equal to or slightly more echogenic than the liver on ultrasound in adults.
Pancreatic Head
The head of the pancreas is within the C-loop of the duodenum. It is the largest part of the pancreas and is located anterior to the inferior vena cava (IVC). The common bile duct runs through or behind the head and can be seen on ultrasound.
Pancreatic Neck
The neck is a short part that joins the head and body. It is immediately anterior to the portal vein confluence, the point at which the superior mesenteric vein (SMV) merges with the splenic vein to form the portal vein. Nevertheless, this is a vascular landmark that is important for determining the pancreatic neck.
Pancreatic Body
The body is elongated and is directed towards the left side of the abdomen. It is located in front of the aorta, superior mesenteric artery (SMA), and splenic vein. These vessels are good landmarks on ultrasound for locating the pancreatic body.
Pancreatic Tail
The tail is the narrowest part of the pancreas and points towards the splenic hilum. It is located close to the spleen and upper pole of the left kidney. Overlying bowel gas is the most problematic aspect to visualise and is typically the tail.
Main Pancreatic Duct
The main pancreatic duct is located in the middle of the pancreas. It is seen in healthy adults as a thin anechoic tubular structure and is usually 2-3 mm or less in diameter.
Normal sonographic features of pancreas:
On ultrasound, a normal pancreas will have the following characteristics:
- Homogeneous, fine echotexture
- Smooth, well-defined margins
- Isoechoic to slightly hyperechoic compared to the liver
- Normal size and anatomical form.
Normal Pancreatic Measurements
| Structure | Normal Measurement |
| Pancreatic Head | 2.5–3.5 cm |
| Pancreatic Neck | 1.5–2.5 cm |
| Pancreatic Body | 1.5–2.5 cm |
| Pancreatic Tail | 2.0–3.0 cm |
| Main Pancreatic Duct | < 2 – 3 mm |
Frequently Asked Questions (FAQs)
1. Is there any fasting required prior to a pancreatic ultrasound?
Yes, 6–8 hours of fasting do help to minimise the bowel gas and enhance image quality.
2- Does a pancreatic ultrasound take about 10 minutes?
The exam typically lasts for 15-30 minutes.
3. Does an ultrasound of the pancreas hurt?
No, it is a safe and painless procedure, and there is no radiation exposure.
4. Is pancreatic cancer detectable using ultrasound?
Ultrasound may help detect suspicious masses in the pancreas, but further tests such as CT or MRI scans or biopsy may be necessary.
5. Is a pancreatic ultrasound safe during pregnancy?
Yes, it’s non-invasive and safe during pregnancy
