Does a patient with a hernia and undergoing a liver biopsy require a computed tomography (CT) scan with contrast?

From the Guidelines

For hernias and liver biopsies, the use of CT scan contrast is not always necessary and should be determined on a case-by-case basis, considering the specific clinical situation and the nature of the suspected pathology. When it comes to diagnosing hernias, non-contrast CT scans are often sufficient as they can clearly show the anatomical defects characteristic of hernias [no direct evidence from 1, but general medical knowledge]. For liver biopsies, the decision to use contrast-enhanced CT scans depends on whether the biopsy aims to diagnose or rule out malignancy in a specific lesion previously identified on imaging. In cases where the lesion's boundaries and vascular structures need to be better visualized, contrast-enhanced CT may be beneficial 1. However, many liver biopsies are guided by ultrasound, which provides real-time imaging without radiation exposure, and the use of contrast is not applicable in these scenarios. The technical success rate of biopsy procedures can be influenced by the guidance modality used, with CEUS (contrast-enhanced ultrasound) guidance showing higher success rates for indeterminate lesions [as mentioned in 1, but not directly relevant to CT scans]. Ultimately, the decision to use contrast in CT scans for liver biopsies should be made by the radiologist, taking into account the specific clinical question, the nature of the suspected liver pathology, and whether previous contrast-enhanced imaging has already identified the target lesion. Key considerations include the potential risks associated with biopsy procedures, such as postbiopsy bleeding, which may be higher with hypervascular lesions 1. Given the information from the study by Chernyak et al 1, it's clear that the approach to liver biopsy and the use of contrast should be tailored to the individual case, prioritizing the safest and most effective method to obtain a diagnosis while minimizing risks. The use of anatomic landmarks or IV contrast can achieve high accuracy for CT-guided biopsies, especially for lesions that are isointense on CT 1. Therefore, the decision on whether to use CT scan contrast for hernias and liver biopsies should prioritize the individual's specific medical needs and the potential benefits and risks of contrast use, as determined by a healthcare professional.

From the FDA Drug Label

The decision to employ contrast enhancement, which may be associated with risk and increased radiation exposure, should be based upon a careful evaluation of clinical, other radiological, and unenhanced CT findings. Contrast enhancement appears to be greatest immediately after bolus administration (15 seconds to 120 seconds). Utilization of a continuous scanning technique (ie, dynamic CT scanning) may improve enhancement and diagnostic assessment of tumor and other lesions such as abscess, occasionally revealing unsuspected or more extensive disease

The use of CT scan contrast for hernia and liver biopsy is not directly addressed in the provided drug label. However, it is mentioned that the decision to use contrast enhancement should be based on a careful evaluation of clinical and radiological findings.

• The label does discuss the use of contrast for tumor and lesion assessment.
• It also mentions that unenhanced scanning may provide adequate diagnostic information in some cases. Based on this information, it appears that the use of CT scan contrast for hernia and liver biopsy would depend on the specific clinical situation and the judgment of the healthcare provider 2.

From the Research

CT Scan Contrast for Hernia and Liver Biopsy

• The use of CT scan contrast for hernia and liver biopsy is a topic of discussion in the medical field, with various studies examining the effects of different types of contrast media on patient outcomes 3, 4, 5, 6, 7.
• For liver biopsy, CT-guided liver biopsy has become an accepted part of the diagnostic evaluation of patients with benign and malignant hepatic disease, and the choice of needle and contrast media is crucial for diagnostic accuracy and safety 5.
• In terms of contrast media, iso-osmolar contrast media such as iodixanol have been shown to be safer and more effective than low-osmolar contrast media in reducing the risk of contrast-induced acute kidney injury (CI-AKI) 3, 6, 7.
• However, a study published in 2022 found that the selection between low-osmolar and iso-osmolar contrast media during coronary angiography (CAG) has no influence on the incidence of CI-AKI 7.
• For MRI of the liver, the choice of contrast agent depends on the clinical situation and question to be answered, with extracellular contrast agents (ECAs) and hepatobiliary agents (HBAs) being used for different purposes 4.

Key Findings

• Iso-osmolar contrast media such as iodixanol may be safer and more effective than low-osmolar contrast media in reducing the risk of CI-AKI 3, 6.
• The choice of contrast media and needle is crucial for diagnostic accuracy and safety in CT-guided liver biopsy 5.
• The selection between low-osmolar and iso-osmolar contrast media during CAG has no influence on the incidence of CI-AKI 7.
• ECAs and HBAs are used for different purposes in MRI of the liver, and the choice of contrast agent depends on the clinical situation and question to be answered 4.