Clinical applications of computerized tomography 3-D reconstruction imaging for diagnosis and surgery in children with large liver tumors or tumors at the hepatic hilum

The present study assessed the benefits of 3-D reconstruction of spiral computerized tomography (CT) scans for the diagnosis of and surgical guidance to large liver tumors or tumors at the hepatic hilum. We retrospectively analyzed the cases of 18 children with large liver tumors or with tumors at the hepatic hilum treated in past 5 years. The ages ranged from 45 days to 14 years. Ten cases were examined using the three-dimensional reconstruction using 64 slice spiral CT and eight patients underwent conventional CT or conventional enhanced CT scanning. In 16 cases, the volume of tissue removed exceeded one-third the entire volume of the liver (considered “large” tumors). The largest tumor removed weighed 4.8 kg. In two cases, the excised tissue represented less than one-third of the total liver volume, but in these cases the location of the tumor was considered “complex” due to the proximity to major hepatic vessels. Seven tumors were located in the right lobe, three in the left lateral segment, three in medial segment, three extended beyond the right lobe and two extended beyond the left lateral segment. Pathological diagnoses included hepatoblastoma (n = 9), hepatocellular carcinoma (n = 2), mesenchymal hamartoma (n = 4), teratoma (n = 1) and adenoma (n = 2). The 3-D reconstructed images could be rotated to view the image from several sides, were semitransparent and allowed for the measurement of tumor size and determination of spatial relation to blood vessels. All 18 children had curative resections as indicated by “tumor-free” microscopic margins. No major intra- or postoperative complications were encountered. Three-dimensional CT imaging can provide high quality images of the tumors and location of the tumor relative to vital hepatic blood vessels. This technique offers a kind of comparatively accurate method compared with traditional imaging techniques, it could help the surgeon identify the tumor borders accurately and devise a comparative safe surgical strategy. With its help the surgeon could identify vital hepatic blood vessels before operation, so they can avoid massive hemorrhaging and avoid massive hemorrhaging during operation. This technique should be more widely applied in the resection of large or complex liver tumors.     

CT三维重建及肝脏体积测定在小儿肝脏肿瘤手术中的应用

目的探讨螺旋CT三维成像及肝脏体积测定在小儿巨大肝脏肿瘤和位于肝门部位肝脏肿瘤手术治疗中的价值。方法2002年1月至2009年1月本院诊治巨大和位于肝门部位的小儿肝脏肿瘤25例,均使用螺旋CT增强扫描,并在CT工作站行肝动脉、门静脉及肝静脉的三维影像重建,测量全肝体积,预测切除肝脏体积,并计算残余肝脏体积及残余肝脏体积与标准化肝脏体积之比。结果25例经CT三维重建后均获得清晰的肿瘤瘤体及与血管毗邻关系的图像。其中手术患儿21例,未手术患儿4例。21例手术患儿中,行右半肝切除6例,左半肝切除5例,右三叶切除5例,左二三叶切除1例,肝中叶切除4例,手术患儿术后平均残余肝脏体积为182．55cm^3,最小残余肝脏体积为62．26m^3,平均残余肝脏体积与标准化肝脏体积之比（平均残余肝脏体积比）为44．69％,最小残余肝脏体积比为20．16％,所有患儿同手术期均未发生严重肝功能衰竭。结论通过CT三维重建的画面,可以旋转地动态观察肝脏血管的走行、位置及与肿瘤的关系,并可计算出术后残余肝脏体积及残余肝脏体积与标准化肝脏体积之比,为判断手术的可行性、手术方案的选择与制定及评估术后残余肝脏功能提供了很大的帮助。     

Focal nodular hyperplasia involving portal cavernoma]

Focal nodular hyperplasia is a rare hepatic tumor in children representing only 2% of all pediatric hepatic tumors. We report a case in teen-ager who had a symptomatic portal cavernoma at 9 years of age, and had been treated by porto-mesenteric surgical shunt. At 16 years, liver ultrasounds revealed multiple hepatic nodules. Focal nodular hyperplasia was suggested by CT scan and magnetic resonance imaging. Given the symptoms and the unusual and multiple lesions, diagnosis was confirmed by surgical biopsy. FNH pathogeny is discussed in this context.     

Atypical radical liver resection in hepatoblastoma

Five consecutive patients (age at presentation 2 1/2–30 months) with hepatoblastoma during a 4-year period are reported. The youngest died due to uncontrolled spontaneous hepatic bleeding prior to any treatment. After considerable tumor shrinkage was achieved by preoperative combined chemotherapy (doxorubicin and cisplatinum), an atypical liver resection with ultrasound knife equipment (USK) was successfully carried out in four patients, all of whom were discharged from the pediatric surgical department free of symptoms on 4th to 10th postoperative day. No recurrences and no tumor metastases occurred following the completion of postoperative chemotherapy. Atypical liver resection with USK is a safe surgical modality that allows the liver parenchyma to be crushed while leaving the bile ducts and vessels intact. These structures can be identified and divided separately. Complete tumor removal from the parenchyma can be performed radically regardless of the surgical resectability as defined by the anatomic borders of the liver segments.     

Imaging of liver tumours in childhood

Primary liver tumours account for 6% of all paediatric neoplasms. In a child with a clinical abdominal mass, imaging (in consultation with a paediatric surgeon) aims to confirm the intrahepatic site, determine its likely resectability, exclude metastatic abdominal disease, and characterise the mass. The imaging in 44 patients with primary liver tumour over a 33-year period was reviewed and correlated with surgical/pathological findings. Characterising hepatic masses with ultrasound, computed tomography, nuclear medicine, and angiography is less important than determining its resectability and alerting the surgeon to vascular anomalies and the presence of metastatic disease. We conclude that a chest X-ray and ultrasound study are the primary methods for evaluation of a child with suspected hepatic mass. With careful attention to technique, the mass can be evaluated and an assessment made of tumour resectability preoperatively. Based on this review, we propose a schema for the initial evaluation of suspected hepatic masses in children. Offprint requests to: J. F. de Ocampo     

Clinical application of a three-dimensional imaging technique in infants and young children with complex liver tumors

Introduction

Three-dimensional (3D) imaging instead of two-dimensional (2D) computed tomography (CT) for diagnosis and preoperative planning in infants and young children with complex liver tumors is a promising technique for precision hepatectomy.

Methods

This study was a retrospective analysis of 26 infants and young children with giant liver tumors involving the hepatic hilum who underwent precise hepatectomy at the Affiliated Hospital of Qingdao University between February 2012 and January 2015. All patients received upper abdominal contrast-enhanced CT scanning before surgery. 16 patients used Hisense CAS system for 3D reconstruction as the reconstruction group. While ten patients underwent 3D CT reconstruction by the CT Workstation as the control group. The clinical outcomes were analyzed and compared between the two groups. The 3D reconstruction of abdominal organs and blood vessels was generated using the Hisense CAS system. Diagnosis and preoperative planning assisted by the system was used for preoperative and intraoperative decision-making for precise hepatectomy.

Results

All patients underwent successful surgery. The 3D models clearly demonstrated the association of liver tumors with the intrahepatic vascular system and provided a preoperative assessment of resectability, assisting surgeons in preoperative procedural planning. Anatomic hepatectomy was successfully completed in the reconstruction group. The mean operation time was shorter in the reconstruction group (137.81 ± 17.51 min) than in the control group (192 ± 34.66 min) (P < 0.01). The mean intraoperative blood loss was lesser in the reconstruction group (21.81 ± 14.05 ml) than in the control group (53.50 ± 21.35 ml) (P < 0.01). The difference was statistically significant.

Discussion

2D CT scan images cannot accurately display the spatial relationship between the tumor and surrounding vasculature. The 3D reconstruction model used in this study gave detailed and accurate anatomical information and allowed for the assessment of tumor resectability and provided a detailed road map for preoperative decision-making and predicted the postoperative liver function.

Conclusions

3D visualization technology provides preoperative assessment and allows individualized surgical planning. Surgical controllability, accuracy, and safety can be improved in infants and young children undergoing precise hepatectomy for complex liver tumors.

     

MR imaging of hepatic hemangiomas of infancy and changes seen with interferon alpha-2a treatment

The purpose of this study was to describe the appearance on magnetic resonance (MR) imaging of hepatic hemangioma, and how the appearance changes in infants who have received interferon alpha-2a (IFN) treatment. We retrospectively studied 16 MR examinations in seven infants (mean age 3.2 months; range 5 days to 13 months) who were symptomatic with hepatic hemangiomas. Five of these seven patients had MR examinations both before and after treatment with IFN. In six of the seven patients, the hepatic hemangiomas were multicentric; they were usually discrete, well-defined nodules, best seen on T2-weighted images as high intensity lesions. One patient had a large solitary heterogeneous lesion. They all exhibited fast flow (seen as flow voids on spin-echo images and high signal intensity structures on gradient-recalled echo images) and enlarged hepatic arteries and veins. There was enlargement of the proximal abdominal aorta with distal tapering. Treatment was followed by accelerated regression of the hemangiomas in size and number and variable shrinkage of the enlarged vessels. As the tumor nodules regressed, they were replaced by normal-appearing hepatic parenchyma; neither fat nor fibrosis was detected by MR imaging.Presented in part at the 36th Annual Meeting of the Society for Pediatric Radiology, May 1993, in Seattle, WA.     

Cystic mesenchymal hamartoma of the liver

Two cases of multicystic mesenchymal hamartoma of the liver in children are described. In both cases noninvasive imaging techniques (ultrasound, CT or MR, radionuclide scan) showed a bulky cystic mass suggesting a correct preoperative diagnosis, while selective arteriography defined the operability of the tumor.     

Surgical treatment of hepatoblastoma

Surgical resection remains the cornerstone of cure in hepatoblastoma (HB). Meticulous review of contrast enhanced CT/MR imaging facilitates PRETEXT and POST‐TEXT grouping to determine optimal timing and desired extent of liver resection. Excellent knowledge of liver anatomy is essential and the dissection must ensure protection of the vascular inflow and outflow to the remaining liver at all times. Referral to a liver specialty center in advanced cases may facilitate resectability. Potential surgical complications include bleeding, vascular injury, cardiac arrest, liver failure, and bile leak. The risk of complications can be minimized with preoperative planning, appropriate referral, and precise surgical technique. Pediatr Blood Cancer 2012; 59: 800–808. © 2012 Wiley Periodicals, Inc.     

MR imaging of glioblastoma in children: usefulness of diffusion/perfusion-weighted MRI and MR spectroscopy

Background Glioblastoma is relatively uncommon in childhood and maybe difficult to differentiate from other brain tumors such as primitive neuroectodermal tumor, ependymoma, or benign astrocytoma. Objective To describe the characteristic MR features in children with glioblastoma and to evaluate the usefulness of diffusion and perfusion MR imaging and MR spectroscopy in pediatric glioblastoma. Materials and methods MR imaging in 11 children (12 tumors) with biopsy-proven glioblastoma was reviewed retrospectively. In one patient, there was a recurrent glioblastoma. We reviewed CT and MRI imaging for tumor location, density/signal intensity, and enhancement pattern. Routine MR imaging was performed with a 1.5-T scanner. In six patients, diffusion-weighted MR images (DWIs) were obtained with a single-shot spin echo EPI technique with two gradient steps, and apparent diffusion coefficients (ADCs) were calculated. Using the gradient EPI technique, perfusion-weighted MR images (PWIs) were obtained in four patients from the data of dynamic MR images. The maximum relative cerebral blood volume (rCBV) ratio was calculated between the tumor and contralateral white matter in two cases. In three patients, proton MR spectroscopy was performed using a single voxel technique with either STEAM or PRESS sequences. The locations of the tumor were the thalamus and basal ganglia (n=8), deep white matter (n=3), and brain stem (n=1).Results Intratumoral hemorrhage was seen in four tumors. The tumors showed high-signal intensity or DWIs, having a wide range of ADC values of 0.53–1.30 (mean ±SD=1.011±0.29). The maximum rCBV ratios of glioblastoma were 10.2 and 8.5 in two cases. MR spectroscopy showed decreased N-acetylaspartate (NAA) and increased choline in three cases. The MR findings of glioblastoma in children were: a diffusely infiltrative mass with hemorrhage involving the deep cerebral white matter, thalami, and basal ganglia. Conclusion Diffusion/perfusion MR imaging and MR spectroscopy are very helpful in diagnosing glioblastoma, determining the biopsy site, and evaluating tumor recurrence.This paper was presented as a scientific contribution at the 39th Annual Congress of the European Society of Paediatric Radiology, Bergen, Norway, June 2002     

Gadobenate-dimeglumine-enhanced magnetic resonance imaging for hepatic lesions in children

Background

Magnetic resonance imaging enhanced by hepatocyte-specific contrast media has been found useful to characterize liver lesions in adults and children.

Objective

To present our experience with gadobenate dimeglumine (Gd-BOPTA)-enhanced MRI for evaluation of focal liver lesions in children.

Materials and methods

We retrospectively reviewed gadobenate-dimeglumine-enhanced MR images obtained for evaluation of suspected hepatic lesions in 30 children. Signal characteristics on various sequences including 45- to 60-min hepatobiliary phase images were noted by two radiologists. Chart review identified relevant clinical details including history of cancer treatment, available pathology and stability of lesion size on follow-up imaging.

Results

Of the 30 children who had gadobenate-enhanced MRI, 26 showed focal lesions. Diagnoses in 26 children were focal nodular hyperplasia (FNH) in 15, hemangiomas in 3, regenerating nodules in 3, focal fatty infiltration in 2, indeterminate lesions in 3, and one patient each with adenomas, hepatoblastoma and metastasis. Two patients had multiple diagnoses. All FNH lesions (39), all regenerative nodules (19) and an indeterminate lesion were iso- or hyperintense on hepatobiliary-phase images while all other lesions (28) were hypointense to hepatic parenchyma. The average follow-up period was 21.7 months.

Conclusion

Our experience with gadobenate-enhanced MRI indicates potential utility of gadobenate in the evaluation of pediatric hepatic lesions in differentiating FNH and regenerating nodules from other lesions.     

Imaging findings in pediatric adrenocortical carcinoma

Background. Adrenocortical carcinoma (ACC), a tumor that is rare among children, causes clinically evident hormonal disturbances. Imaging methods are used to stage disease and to plan surgical resection.¶Objective. To describe the findings of the various imaging methods used to evaluate ACC.¶Materials and methods. We reviewed the records of ten consecutive patients (mean age, 8.1 years) who presented from 1987 to 1998 with ACC. All patients underwent computed tomography (CT) scanning; five underwent magnetic resonance (MR) imaging; four underwent ultrasonography (US); and eight underwent radionuclide bone scans.¶Results. Seven patients presented with signs of hormonally functional tumors. Typical imaging findings consisted of a large, well-defined suprarenal tumor, containing calcifications (seven patients) with a thin capsule and central necrosis or hemorrhage (six patients). The inferior vena cava (IVC) was compressed by tumor in three patients, and ultrasonography demonstrated invasion of the IVC wall in one of these. Three patients' bone scans showed that the primary tumor took up radioactive tracer. Spread to lungs or liver or both was demonstrated in six patients.¶Conclusions. CT, US and MR imaging are effective methods of imaging the primary tumor. Chest CT and bone scintigraphy should be performed to detect metastases. The presence of a thin tumor capsule, a stellate central zone of necrosis, and evidence of hormonal function help distinguish ACC from neuroblastoma.     

Liver tumors

Liver tumors in children are rare, potentially complex, and encompass a broad spectrum of disease processes. Any age group may be affected, including the fetus. Most present with abdominal distension and/or a mass. Accurate preoperative diagnosis is usually possible using a combination of ultrasound scanning and cross-sectional imaging techniques (CT and/or MR), supplemented by liver biopsy and measurement of tumor markers. The most common benign tumors are hemangiomas, but mesenchymal hamartoma, focal nodular hyperplasia, and adenoma also are found. In Western countries, hepatoblastoma is the most common primary malignant liver tumor; disease-free survival is now possible in more than 80% of affected patients because of advances in combination chemotherapy, improved techniques of surgical resection, and the selective use of liver transplantation. In contrast, there has been less progress in the management of hepatocellular cancer, which still poses many therapeutic challenges.     

Hypergalactosemia in early infancy: Diagnostic strategy with an emphasis on imaging

Background:  Portosystemic shunt is one of the main causes of persistent hypergalactosemia without enzyme deficiency, but the diagnostic imaging strategy has not yet been established. The purpose of the present study was to establish a diagnostic imaging strategy.
Methods:  A retrospective investigation of the clinical and imaging findings of 10 children with persistent hypergalactosemia without enzyme deficiency detected by screening was undertaken.
Results:  Abnormal ultrasonography (US) findings were detected in all eight patients with liver disorders. In three patients with citrin deficiency, the combination of fatty liver on US and laboratory evidence of cholestasis led to the diagnosis. In three patients with portosystemic shunt, US on sedation clearly depicted the shunt vessels. The extent was more easily understood on contrast computed tomography (CT). Per-rectal portal scintigraphy with N -isopropyl-p-I-123 iodoamphetamine and lung perfusion scintigraphy with ^99mTc macroaggregated albumin were useful for evaluation of portal shunt index and assessment of pulmonary arteriovenous shunt. One patient underwent transarterial coil embolization. In two patients with hepatic tumor, the lesions and its vascularity were clearly demonstrated on US and dynamic CT. In one patient, small shunt index on per-rectal portal scintigraphy suggested no need for treatment. The other patient was treated with a combination of steroid, radiation, and interventional radiology. The etiology remained unknown in two children.
Conclusions:  In the assessment of hypergalactosemia, US is the modality of choice. CT is a useful tool for more detailed evaluation of the abnormalities found on US. Per-rectal portal scintigraphy and pulmonary perfusion scintigraphy play an important role in the evaluation of portosystemic shunt. Interventional radiology is sometimes effective.     

Methylmalonic acidemia: brain imaging findings in 52 children and a review of the literature

BACKGROUND: Methylmalonic acidemia (MMA) is an autosomal-recessive inborn error of metabolism. OBJECTIVE: To recognize the CT and MR brain sectional imaging findings in children with MMA. MATERIALS AND METHODS: Brain imaging studies (47 MR and 5 CT studies) from 52 children were reviewed and reported by a neuroradiologist. The clinical data were collected for each patient. RESULTS: The most common findings were ventricular dilation (17 studies), cortical atrophy (15), periventricular white matter abnormality (12), thinning of the corpus callosum (8), subcortical white matter abnormality (6), cerebellar atrophy (4), basal ganglionic calcification (3), and myelination delay (3). The brain images in 14 patients were normal. CONCLUSION: Radiological findings of MMA are nonspecific. A constellation of common clinical and radiological findings should raise the suspicion of MMA.     

并发消化道出血的先天性门体分流畸形8例影像学特征病例系列报告

摘要目的：探讨合并消化道出血的先天性门体分流畸形的影像学特征,以提高对该畸形的认识。方法：纳入复旦大学附属儿科医院病历系统中先天性门体分流且病史中有消化道出血症状的病例,采集性别、年龄、临床表现、CTA和MRA影像学资料、外科手术结局。CTA为GE Light speed 64排螺旋CT扫描仪,MRA为Siemens Avanto 1.5 T 扫描仪,提取纳入病例的CTA原始图像,以1.25 mm层厚/0.625 mm层间隔重建,传入后处理工作站进行多平面重建;提取纳入病例的MRA原始图像,传入MR工作站进行后期多平面重建;由2名从事儿科影像诊断10年以上医生独立读片,观察门静脉及其属支的形态及走行,异常门体分流位置、途径,髂静脉、下腔静脉及肠管、肠壁血管分布。结果：2008年3月至2017年1月符合本文病例纳入标准的连续病例8例,男6例,年龄3月至10岁,7例贫血,7例便血,1例呕血。8例均行CTA检查,其中2例同时行MRA检查。截止出院时,6例行手术治疗,2例随访观察。8例先天性门体分流畸形患儿均为肝外型门体分流,2例肝外型Ⅰ型,6例为Ⅱ型。以便血为表现的7例中,髂内静脉、直肠上静脉及结肠静脉扩张扭曲;以呕血为表现的1例,脾静脉和肠系膜上静脉汇合后通过胃冠状静脉汇入左肾静脉,胃冠状静脉显著扩张、扭曲。结论：合并便血的先天性门体分流大部分通过肠系膜下静脉与髂静脉异常沟通,发生便血的比例高。     

Pilomatricomas in children: imaging characteristics with pathologic correlation

Background Although pilomatricoma commonly occurs in children, there is still a poor understanding of the imaging characteristics of pilomatricoma and lack of agreement regarding its imaging findings and histopathologic features. Objectives To characterize the radiologic appearance of pilomatricomas on US, CT, and MR and to correlate the imaging findings with histopathologic features. Materials and methods The imaging findings of 47 pilomatricomas on US (n = 17), CT (n = 31), and MR (n = 5) were retrospectively evaluated. Pathologic specimens of all cases were reviewed and compared with imaging findings. Results All lesions were well-circumscribed, subcutaneous nodules with partial attachment to the overlying skin. On US, the lesions were mostly hyperechoic with posterior acoustic shadowing and hypoechoic rim. On CT, they appeared as enhancing soft-tissue masses with varying amounts of calcification. MR findings were internal reticulations and patchy areas on T2-weighted images and contrast-enhanced T1-weighted images, corresponding to edematous stroma on pathology. Peritumoral inflammatory changes and connective capsule on pathology were well correlated with imaging findings. Conclusion Pilomatricoma should be considered when US or CT shows a well-defined hyperechoic or calcific nodule in subcutaneous fat attached to the skin in children. MR images may be helpful in diagnosis. Pathologic findings are well correlated with imaging findings.     

Malignant liver tumors of children.

Malignant liver tumors in children are uncommon but have a high mortality. Survival rates have improved with advances in chemotherapy, imaging, tumor biology, and supportive care. However, complete surgical resection is the cornerstone of successful management. Important determinants of outcome are stage, histology, and resectability. A multidisciplinary team approach to the care of pediatric patients with liver tumors using the latest guidelines from clinical trials provides the best opportunity for care.     

Management of liver tumors in childhood

Primary neoplasms of the liver occur rarely during childhood and constitute only 0.3-2% of all pediatric tumors. However, they comprise a variety of entities including benign and malignant epithelial, as well as mesenchymal tumors, the most common of these being hepatoblastoma and hepatocellular carcinoma. Clinical presentation, especially in young children is relatively uniform with abdominal enlargement and a painless tumor, and often specific symptoms develop late. Prerequisites for clinical diagnosis are a comprehensive laboratory workup and good quality imaging mainly with ultrasound, as well as CT and/or MRI scans. Histological diagnosis is essential for differential diagnosis and may only be omitted in some hepatoblastoma patients of the typical age (6 months to 3 years) with an excessively elevated serum-alpha-fetoprotein. Surgery is the mainstay of treatment for all benign and malignant liver tumors. Hepatoblastomas mostly respond well to chemotherapy. Therefore, this modality should always be combined with surgical resection in these patients and in many cases can reduce the size of a large tumor to resectability. Prognosis nowadays usually is good in all benign tumors and hepatoblastoma, as well as in some other rare malignancies, but dismal in hepatocellular carcinoma and other chemotherapy non-sensitive malignant tumors.