Automated liver volumetry and hepatic steatosis quantification with magnetic resonance imaging proton density fat fraction.

BACKGROUND: Preoperative imaging evaluation of liver volume and hepatic steatosis for the donor affects transplantation outcomes. However, computed tomography (CT) for liver volumetry and magnetic resonance spectroscopy (MRS) for hepatic steatosis are time consuming. Therefore, we investigated the correlation of automated 3D-multi-echo-Dixon sequence magnetic resonance imaging (ME-Dixon MRI) and its derived proton density fat fraction (MRI-PDFF) with CT liver volumetry and MRS hepatic steatosis measurements in living liver donors. METHODS: This retrospective cross-sectional study was conducted from December 2017 to November 2022. We enrolled donors who received a dynamic CT scan and an MRI exam within 2 days. First, the CT volumetry was processed semiautomatically using commercial software, and ME-Dixon MRI volumetry was automatically measured using an embedded sequence. Next, the signal intensity of MRI-PDFF volumetric data was correlated with MRS as the gold standard. RESULTS: We included the 165 living donors. The total liver volume of ME-Dixon MRI was significantly correlated with CT (r = 0.913, p < 0.001). The fat percentage measured using MRI-PDFF revealed a strong correlation between automatic segmental volume and MRS (r = 0.705, p < 0.001). Furthermore, the hepatic steatosis group (MRS ≥5%) had a strong correlation than the non-hepatic steatosis group (MRS <5%) in both volumetric (r = 0.906 vs. r = 0.887) and fat fraction analysis (r = 0.779 vs. r = 0.338). CONCLUSION: Automated ME-Dixon MRI liver volumetry and MRI-PDFF were strongly correlated with CT liver volumetry and MRS hepatic steatosis measurements, especially in donors with hepatic steatosis.

Traumatic Vertebral Artery Stenosis Inflicted by Stray Arrow.

A 17-year-old female presented to the emergency room with an arrow sticking out the right aspect of her neck. Her vital signs were stable with systolic blood pressure of 117 mmHg, without either tachycardia, dyspnea, or signs of active bleeding. She was fully conscious with intact sensory and motor function on all extremities. Computed Tomography (CT) showed that the tip of the arrowhead lodged at the transverse foramen of the third cervical vertebra. Digital subtraction angiography revealed that the arrowhead lies posterior to the right vertebral artery, narrowly missing it by about two millimeters. Emergency surgery was arranged in hybrid operating suite. An occlusion balloon catheter was introduced to right vertebral artery but not inflated prior to extracting the arrowhead. After extraction, oozing from the wound was noted. We then inflated the balloon while the neurosurgeon performed hemostasis with gauze compression and electrocoagulation probe. The right vertebral angiography after releasing of the balloon showed focal narrowing of the artery without contrast extravasation. The patient was discharged on the fifth hospital day, and no anticoagulant was prescribed due to lack of neurological deficit. Pre-surgical planning and partnership with the neurosurgeon lead to the optimal outcome for this case.

Regeneration and outcome of dual grafts in living donor liver transplantation.

In living donor liver transplantation (LDLT), the essential aims are to provide an adequate graft volume to the recipient and to keep a sufficient remnant liver volume in the donor. In some instances, these aims cannot be met by a single donor and LDLT using dual grafts from two donors is a good solution. From 2002 to 2009, five recipients in our hospital received dual graft LDLT. Two recipients received one right lobe and one left lobe grafts; the other three received two left lobe grafts. The mean final liver regeneration rate was 91.2%. Left lobe graft atrophy in the long term was observed in recipients who received a right and a left lobe grafts. The initial bigger volume graft in all recipients was noted to have better regeneration than the smaller volume grafts. Portal flow and bilateral grafts volume size discrepancy were considered as two major factors influencing graft regeneration in this study. We also noted that the initial graft volume correlated with portal flow in the separate grafts and finally contribute to individual graft regeneration. Because of compensatory hypertrophy of the other graft, recipients who experienced atrophy of one graft did not show signs of liver dysfunction.

Huge pelvi-abdominal malignant inflammatory myofibroblastic tumor with rapid recurrence in a 14-year-old boy.

Inflammatory myofibroblastic tumor (IMT) is an uncommon benign neoplasm with locally aggressive behavior but malignant change is rare. We report an unusual case of pelvic-abdominal inflammatory myofibroblastic tumor with malignant transformation in a 14-year-old boy presenting with abdominal pain and 9 kg body weight loss in one month. Computed tomography revealed a huge pelvi-abdominal mass (30 cm), possibly originating from the pelvic extraperitoneal space, protruding into the abdomen leading to upward displacement of the bowel loops, downward displacement of the urinary bladder, massive central necrosis, a well-enhanced peripheral solid component with prominent peritumoral vascularity. Subsequent examination confirmed the computed tomographic findings. Histopathologic examination revealed proliferative epitheloid and spindle cells, inflammatory cell infiltration and high mitotic counts. Immunohistochemistry was strongly positive for anaplastic lymphoma kinase and revealed a high proliferative index (ki-67 = 40%). DNA sequencing and electronic microscopy further confirmed the primitive fibroblastic cell phenotype of the tumor and a final diagnosis of inflammatory myofibroblastic tumor with malignant transformation was established. Rapid tumor recurrence was noted 20 d after radical tumor resection. To our knowledge, this is the largest documented case of IMT in a pediatric patient and the first report of IMT with malignant transformation originating from the pelvic extraperitoneal space.