**3. Value of CT scan in guiding the surgical treatment**

The objective of surgery is to achieve complete resection of the tumor, both macro- and microscopically, which is paramount for cure of malignant liver cancers. The liver resection strategy is based on pre-operative understanding of liver segmentation, vascular occlusion techniques, and experience in performing different types of hepatectomy, including extensive resection (left and right trisegmentectomies). Although abdominal CT should only be considered if MR imaging is not available or contraindicated, there are some limitations of MRI in some hospitals at developing countries. In our experience, MRI is the best available technique for diagnosing liver tumors, but its value is less clear in preoperatively evaluating the resectability of liver tumors especially in pediatric patients. The development and rapid clinical acceptance of single-detector helical CT during the last decade and, more recently, the introduction of multidetector CT (MDCT) have resulted in significant improvements in the study of the liver. MDCT makes it possible to precisely image the vascular anatomy, including the anomalous branches, feeding arteries, or drainage veins. Moreover, each image phase could be independently and simultaneously extracted or combined. In addition to technical advances, such as shorter scanning times, multiplanar imaging, and improved ability to perform multiphasic contrast-enhanced studies, newer and better intravenous contrast media and advances in post-acquisition data processing techniques have renewed researchers' enthusiasm for using hepatic CT scanning [11].

Furthermore, the software program for volumetry provides a proposed remnant liver volume and an optimal cut line of the liver. Various preoperative simulations can thus be considered. This volumetric analysis positively contributes to the safety of the procedure by assisting in the selection of the optimal operations. Preoperative evaluation of the relationship between the tumor and surrounding vasculature was simulated to perform liver resection with 3D software (**Figure 4**).

**Figure 4.** Three-dimensional reconstructed liver indicating total liver volume, liver tumor volume, and intraoperative navigation system.

**Figure 3.** CT and three-dimensional reconstructed liver of undifferentiated embryonal sarcoma.

63% at 5 years and 58% at 10 years in a study of orthotopic liver transplantation in 41 HCC children <18 years. Recurrence was the primary cause of death in 86% [17]. The outcomes of

Pediatric hepatic sarcomas include undifferentiated embryonal sarcoma (UES), biliary rhabdomyosarcoma, and angiosarcoma [5]. UES is a rare malignant neoplasm, and its the incidence is higher than the other two types of sarcoma. UES was recently shown to share genetic features with mesenchymal harmatoma. Diagnosis of UES is usually between 6 and 10 years but some studies report presentation in young teenagers [18]. The tumor appears on ultrasound as a hetero-echoic mass, and a hypodense multicystic lesion on CT scan or MRI (**Figure 3**), usually

exceeding 10 cm in size, with a predominance for involving the right hepatic lobe [19].

liver transplantation in HCC are not as good as that for HB.

**Figure 2.** CT of hepatocellular carcinoma in pediatric patient.

**2.3. Pediatric hepatic sarcomas**

60 Liver Research and Clinical Management
