Percutaneous Biopsy



Percutaneous Biopsy


Sudhen B. Desai, Robert J. Lewandowski and Albert A. Nemcek, Jr.


The clinical relevance of biopsy results must be considered before performing a procedure, but numerous patients undergo biopsy before definitive clinical evaluation. Therefore, biopsy results may dramatically alter the future workup of these patients.


Not all radiographic findings merit biopsy. The interventionalist must have awareness and understanding of the radiologic findings of normal variants, “pseudolesions,” and insignificant manifestations of pathology (e.g., focal fatty infiltration of the liver, simple renal cysts, hepatic hemangiomas). This avoids unnecessary interventions that are costly and potentially dangerous. It should also be established that less invasive means of establishing a confident diagnosis are unavailable or were previously unsuccessful in establishing a diagnosis, and no other potential biopsy sites that may be safer or easier to access are an option. Finally, there should be a discernible advantage to imaging guidance for accessing the target biopsy site.




Contraindications


Absolute contraindications to biopsy of a lesion include severe uncorrectable coagulopathy and a patient’s inability to cooperate.


Relative contraindications to biopsy of a lesion include:



Although gross ascites is frequently suggested as a contraindication, there is remarkably little evidence that ascites in the absence of coagulopathy increases the risk related to percutaneous biopsy of abdominal lesions.



Technique


Before image-guided biopsy is performed, certain clinical considerations must be entertained. Basic issues such as the initial complaint and site of greatest symptomatology (e.g., pain, palpable mass), allergies to medications, medical comorbidity, surgical history, and a thorough understanding of the procedure must be addressed with the patient. Appropriate laboratory parameters should also be noted, and test results obtained within an acceptable time frame. Many of these questions can easily be answered by referring clinicians and the medical record. However, review of these topics with the patient is mandatory to ensure accuracy of the data.


Review of dedicated imaging of the lesion in question should also have been performed. This enables preprocedural planning, selection of equipment, and targeting of the lesion. It may also change the modality by which the procedure is performed. If preprocedural imaging is not available, time should be set aside for a diagnostic evaluation to be performed with the imaging modality most likely to be used for biopsy.


The choice of which imaging modality to use varies according to a number of parameters. First and foremost is availability. Most institutions now have 24-hour access to ultrasound, fluoroscopy, and CT, but access to magnetic resonance imaging (MRI) remains limited.


Second is operator preference. Many interventionalists are comfortable using ultrasound and CT as guidance for biopsy. Fluoroscopic guidance for percutaneous biopsy is no longer as widespread as it once was, and most interventionalists currently have little experience with MRI guidance (in part because of lack of widespread availability of MRI-compatible devices).


Each imaging modality has relative advantages and disadvantages (Table 126-1), so certain situations may favor the use of specific modalities. Mobile lesions and lesions that require multiple imaging angles, for example, may be better suited to ultrasound-guided biopsy (Fig. 126-1). Deeper lesions that might be obscured by bowel gas or limited by body habitus may be easier to biopsy under CT guidance.



TABLE 126-1


Comparison of Imaging Modalities for Biopsy











































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Dec 23, 2015 | Posted by in INTERVENTIONAL RADIOLOGY | Comments Off on Percutaneous Biopsy
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  Advantages Disadvantages
CT
Can be time consuming
 
Certain imaging planes (e.g., craniocaudal) may be difficult to obtain.
 
Opportunity and cost (diagnostic evaluations vs. interventions on the scanner)
Radiation exposure
Ultrasound
Inadequate visualization of the target or needle (operator dependent or limited by habitus, bowel gas, fibrous scarring, bony structures, lesion depth)
Fluoroscopy
Radiation exposure
 
Single-dimension imaging
 
Not portable
CT fluoroscopy
? Impact on time, patient outcomes, radiation exposure
MRI