In some cases, MRI without IV contrast may be appropriate, particularly if the initial US has a high index of suspicion for the diagnosis of a cyst. Image-Guided Biopsy Liver An indeterminate liver lesion detected on US is often further evaluated with a diagnostic CT or MRI prior to biopsy, in order to avoid biopsy of solid benign liver lesions such as hemangiomas or areas of FNH [4]. Percutaneous image-guided biopsy may be necessary to establish the diagnosis, particularly when the imaging features on a CT or MRI examination indicate possibility of malignancy. In some liver lesions, such as lymphoma, histopathologic analysis is the only technique that can make a definitive diagnosis [20]. Various techniques exist for guidance of the biopsy, and US and CT are the most commonly utilized modalities for biopsy guidance. When a biopsy is performed to diagnose or rule out malignancy in indeterminate lesions, the overall technical success rate under grayscale US guidance is 74%, which can be increased to 100% under CEUS guidance [21,22]. The percentage of tumor cells in the biopsy sample is greater with a higher number of collected biopsy samples [23]. Furthermore, for lesions not seen on grayscale US, the success rate for CEUS-guided biopsy can be as high as 88% to 96% [24,25]. US fusion with CT or MRI, can be used for percutaneous biopsy of lesions with poor sonographic conspicuity, with a 96% technical success rate [25]. Lesions that are isointense on CT can also present a challenge for CT-guided biopsy; however, use of anatomic landmarks or IV contrast can achieve accuracy of 96% to 98% [26]. Image-guided biopsies carry a risk of postbiopsy bleeding, which may be as high as 9% to 12%, particularly with hypervascular lesions [27,28]. In addition, a very small risk of needle-track seeding exists. RBC Scan Abdomen and Pelvis There is no relevant literature to support the use of a Tc-99m red blood cell (RBC) scan in this clinical scenario.
Liver Lesion Initial Characterization. In some cases, MRI without IV contrast may be appropriate, particularly if the initial US has a high index of suspicion for the diagnosis of a cyst. Image-Guided Biopsy Liver An indeterminate liver lesion detected on US is often further evaluated with a diagnostic CT or MRI prior to biopsy, in order to avoid biopsy of solid benign liver lesions such as hemangiomas or areas of FNH [4]. Percutaneous image-guided biopsy may be necessary to establish the diagnosis, particularly when the imaging features on a CT or MRI examination indicate possibility of malignancy. In some liver lesions, such as lymphoma, histopathologic analysis is the only technique that can make a definitive diagnosis [20]. Various techniques exist for guidance of the biopsy, and US and CT are the most commonly utilized modalities for biopsy guidance. When a biopsy is performed to diagnose or rule out malignancy in indeterminate lesions, the overall technical success rate under grayscale US guidance is 74%, which can be increased to 100% under CEUS guidance [21,22]. The percentage of tumor cells in the biopsy sample is greater with a higher number of collected biopsy samples [23]. Furthermore, for lesions not seen on grayscale US, the success rate for CEUS-guided biopsy can be as high as 88% to 96% [24,25]. US fusion with CT or MRI, can be used for percutaneous biopsy of lesions with poor sonographic conspicuity, with a 96% technical success rate [25]. Lesions that are isointense on CT can also present a challenge for CT-guided biopsy; however, use of anatomic landmarks or IV contrast can achieve accuracy of 96% to 98% [26]. Image-guided biopsies carry a risk of postbiopsy bleeding, which may be as high as 9% to 12%, particularly with hypervascular lesions [27,28]. In addition, a very small risk of needle-track seeding exists. RBC Scan Abdomen and Pelvis There is no relevant literature to support the use of a Tc-99m red blood cell (RBC) scan in this clinical scenario.