Simultaneous Detection of Biliary Injury and Vascular Infarct using 99mTc-HIDA Scintigraphy in a Patient with Trauma

Case

A 45-year-old m ale sustained a fall from height, after which he became unconscious. After regaining consciousness, he complained of severe abdominal pain, which was nonradiating and not relieved by medication. After focused assessment with sonography in trauma assessment, diagnosis of blunt trauma to the abdomen with hemoperitoneum and Grade III liver injury was made. The patient underwent exploratory laparotomy with peritoneal lavage, and a left pelvic drain was placed. Over the course of next few days, leak (with bile) of >500 mL was noted from the drain. Ultrasound was only able to identify some free fluid in the peritoneal cavity. Contrast-enhanced computed tomography (CECT) identified nonenhancing lacerations in the segments V/VIII and doubtful involvement of segment IV of the liver with likely areas of infarct in the right lobe. The patient was referred to the department of nuclear medicine with primary objective of identification of the site of biliary leak. During the dynamic images, reduced extraction with persistent photopenia was noted in the region of the right lobe of the liver [Figure 1a and b]. On the other hand, preserved radiotracer extraction was noted in the left lobe of the liver [Figure 1]. Biliary leak was seen in the subhepatic region within 15 min, which rapidly transited into the peritoneal cavity. Single-photon emission computed tomography (SPECT)/computed tomography (CT) was acquired to evaluate the tracer in the intestines. It showed a significant radiotracer collection in the hilum [Figure 2a and b] and the right subhepatic region [Figure 2c and d]. Radiotracer activity was also seen transiting from the hilar region into the duodenum and distal intestines [Figure 2e and f]. In addition, a relatively hypodense area with no significant radiotracer activity was noted in the segments V/VIII of the right lobe of the liver (corresponding to the site of vascular infarct as identified in CECT) [Figure 2g and h]. Furthermore, the preserved radiotracer extraction as seen in the segment IV in SPECT/CT ruled out any significant vascular compromise (CECT had shown doubtful involvement). Furthermore, a laceration was seen extending from the hepatic surface till hilum in the region of segment V [Figure 2a (arrow) and b]. Pooling of the radiotracer was noted in the perihilar extent of this laceration [Figure 2b (arrow)], and an injury to right hepatic duct was identified as likely origin of the biliary leak. Due to patent bilio-enteric pathway and reduction in the amount of bile in the drain, clinicians decided on conservative management. The patient was also sent for magnetic resonance cholangiopancreatography (MRCP), which confirmed injury to the right anterior sectoral duct (from segment V/VIII). The patient improved during consecutive days.

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Figure 1 Dynamic frames (a) and delayed static (b) 99mTc-HIDA scintigraphy images in a 45-year-old male with history of blunt trauma to the abdomen, showing a relatively photopenic defect in the region of the right lobe (a) and biliary leak in the sub-hepatic region (b)

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Figure 2 Single-photon emission computed tomography (SPECT)/computed tomography (CT) in the same patient showing radiotracer collection in the hilum [a and b] and the right subhepatic region [c and d]. A laceration can also be seen extending from the hepatic surface till hilum in the region of segment V [a and b (arrows)]. Also seen is some drainage from the hilar region into the duodenum and distal intestines [e and f]. The hypodense area in planar images in Figure 1 corresponded to the segments V/VIII (confirmed as site of vascular infarct in CECT) [g and h]

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While 99mTc-HIDA scintigraphy has been routinely used in imaging postoperative biliary leaks[12] and patency of bilio-enteric pathway, it has been underutilized in cases with blunt hepatic trauma. While some studies have pointed to a role in the identification of infarcts in patients with liver failure and venous occlusion,[34] literature on its utility for simultaneous assessment of vascular injury in hepatic trauma patients is scarce. In this case, we were able to identify the site of biliary leak, demonstrate the patency of biliary enteric pathway, confirm vascular infarcts in the segments V/VIII, and rule out similar vascular injury to segment IV. In this way, this single, cheap, and relatively common investigation was able to impact patient management. Demonstration of the capability of this tracer in the assessment of hepatic vascular injury is important in cases with trauma, as additional solid organ injuries (like vascular or renal) may preclude contrast administration or patient may not be stable enough to undergo MRCP. In addition, this case shows the importance of SPECT/CT in the identification of patent bilio-enteric pathway, when a relatively small amount of activity was transiting through the physiological pathway (which could not be confirmed in planar imaging, as it was being obscured by the biliary leak into the peritoneum).