Pediatric liver transplantation for fibropolycystic liver disease

Fibropolycystic liver disease includes CHF, Caroli's syndrome, and Caroli's disease. Patients with Caroli's disease and Caroli's syndrome have an increased risk of recurrent cholangitis, intrahepatic calculi, biliary cirrhosis, and cholangiocarcinoma. The aim of this study was to examine the post-transplantation outcomes of children with fibropolycystic liver disease. Of the 158 children transplanted at Seoul National University Hospital, there were four patients with Caroli's syndrome, two patients with CHF, and one patient with Caroli's disease. One patient underwent combined liver/kidney transplantation. Associated renal manifestations included ARPKD in three children and nephronophthisis in one child. The indications for LT were recurrent cholangitis, decompensated cirrhosis, and refractory complications of portal hypertension. Both graft and patient survival rates were 100% at a median follow-up period of two yr after LT. Three children with growth failure achieved catch-up growth after LT. In three patients with ARPKD, mean serum creatinine levels increased from 0.53 mg/dL at the time of LT to 0.91 mg/dL at the last follow-up (p = 0.01). LT is an excellent option for children with complications from fibropolycystic liver disease. Renal function should be monitored cautiously after LT in the patients with ARPKD.     

Magnetic resonance cholangiography – feasibility and application in the paediatric population

Objective. To assess the feasibility of magnetic resonance cholangiography (MRC) in paediatrics. Materials and methods. MRC was attempted in 41 children from 1 week to 14-years. There were three groups: (1) children studied with MRI for non-biliary problems as controls; (2) infants with jaundice; and (3) older children suspected of biliary disease. The examination was successfully performed in 35 children, which included 12 children studied for non-biliary problems, 12 infants with jaundice, and 11 older children with suspected biliary disease. Results. In group 1, the entire common duct was visualised in all 12 children. In group 2, successful demonstration of the common duct was achieved in two of the ten infants with subsequent confirmation of normal bile duct patency. In the last group of patients with suspected biliary disease, MRC gave good anatomical display of six choledochal cysts but failed to demonstrate the anomalous choledochopancreatic channel. It helped to confirm the diagnosis of two cases of pancreatic head cysts, and one case of Caroli's disease. Conclusion. MRC can be applied to the paediatric population, but its value depends on the type of problem to be evaluated. With current spatial resolution, its value in the diagnosis of biliary atresia is probably limited because it cannot reliably demonstrate the bile ducts in young infants with non-obstructive jaundice. In older children, it could provide a non-invasive anatomical display of the biliary tree and its disease. It has a potential role in addressing problematic cases encountered during ultrasonography. Received: 30 April 1997 Accepted: 22 October 1997     

Autosomal recessive polycystic kidney disease and congenital hepatic fibrosis (ARPKD/CHF)

ARPKD/CHF is an inherited disease characterized by non-obstructive fusiform dilatation of the renal collecting ducts leading to enlarged spongiform kidneys and ductal plate malformation of the liver resulting in congenital hepatic fibrosis. ARPKD/CHF has a broad spectrum of clinical presentations involving the kidney and liver. Imaging plays an important role in the diagnosis and follow-up of ARPKD/CHF. Combined use of conventional and high-resolution US with MR cholangiography in ARPKD/CHF patients allows detailed definition of the extent of kidney and hepatobiliary manifestations without requiring ionizing radiation and contrast agents.     

Appearance of autosomal recessive polycystic kidney disease in magnetic resonance imaging and RARE-MR-urography

Purpose. To describe the appearance of autosomal recessive polycystic kidney disease (ARPKD) on MRI and RARE-MR urography. Materials and methods. Seven boys and one girl (aged 3 months to 14 years, median 2.5 years) were evaluated. Images were obtained with 0.23-T and 1.5-T MR systems using T1-weighted (T1-W) spin-echo, T2-weighted (T2-W) turbo-spin-echo and RARE-MR-urography sequences. Signal intensities, morphological appearance of the affected kidneys and, specifically, the picture of the urinary tract on RARE-MR-urography were evaluated. Results. All children showed kidney enlargement, reniform but humpy kidney shape, homogeneously grainy renal parenchyma, normal renal pelvis and normal calyces. Signal intensity was hyperintense in T2-W images in all cases. In six cases (n = 7), T1-W images were hypointense. On RARE-MR urography a hyperintense, linear radial pattern was seen in the cortex and medulla which represents the characteristic microcystic dilatation of collecting ducts in ARPKD. Three boys and the girl presented with a few circumscribed small subcapsular cysts. Conclusions. In order to confirm the diagnosis of ARPKD, RARE-MR urography seems to be a non-invasive imaging tool that shows directly the microcystic dilated water-filled collecting ducts. Received: 14 September 1999/Accepted: 24 September 1999     

Liver disease in autosomal recessive polycystic kidney disease

Hepatic complications occur in a significant proportion of children with autosomal recessive polycystic kidney disease (ARPKD). PKHD1/fibrocystin, the defective gene in ARPKD, is expressed in the cilia of bile duct epithelium and leads to abnormalities in the rubric of the ductal plate malformation. Portal hypertension and biliary disease are the major liver problems seen in ARPKD. Complete blood counting, physical examination, ultrasonography and magnetic resonance (MR) cholangiography are indicated as screening procedures for hepatic disease in ARPKD. Medical and surgical interventions are potentially indicated for children with portal hypertension and/or biliary disease. A high index of suspicion for the diagnosis of cholangitis needs to be maintained in children with biliary disease. The implications of hepatic disease need to be considered in the decision-making regarding renal transplantation in ARPKD.     

Comparison of turbo inversion recovery magnitude (TIRM) with T2-weighted turbo spin-echo and T1-weighted spin-echo MR imaging in the early diagnosis of acute osteomyelitis in children

Objective. To compare turbo inversion recovery magnitude (TIRM) with standard T1-weighted (T1-W) and T2-weighted (T2-W) MR sequences in the very early detection of acute osteomyelitis in children. Materials and methods. In 15 children with osteomyelitis, 15 sets of T1-W spin-echo (SE) (TR/TE, 400–640/12–17), T2-W turbo spin-echo (TSE) (TR/TE/ETL, 3290–4465/112–120/11), and TIRM (TR/TE/TI, 4000–6120/60/160) images were acquired with a 1.0-T magnet. Contrast-to-noise (C/N) ratios and percentage of signal between lesion and normal bone marrow were analysed with a computer-assisted image analysing system in a region of interest (ROI). Results. In 13 of 15 patients, the absolute signal enhancement in a ROI on the TIRM images was better than on the T1-W SE and T2-W TSE images and in 14 of 15 cases, C/N ratios were also better on the TIRM images than on the other sequences. In the other cases, the TIRM signal was diagnostically equivalent. On the TIRM images, the signal difference between normal and pathological tissue was increased to 43–281 % (mean 124 %). On the T2-W TSE images, this signal difference was 4–79 % (mean 36 %) and on the T1-W SE images 6–77 % (mean 37 %). Conclusion. The TIRM sequence is highly sensitive for detecting bone marrow oedema in the very early stage of acute osteomyelitis in children. MRI utilising the TIRM sequence allowed for an early diagnosis. With scan time of less than 4 minutes, this sequence is superior to T1-W SE and T2-W TSE images for detecting early osteomyelitis-associated bone marrow oedema. Received: 18 August 1997 Accepted: 17 June 1998     

New approaches to the autosomal recessive polycystic kidney disease patient with dual kidney–liver complications

Improved neonatal medical care and renal replacement technology have improved the long‐term survival of patients with ARPKD. Ten‐yr survival of those surviving the first year of life is reported to be 82% and is continuing to improve further. However, despite increases in overall survival and improved treatment of systemic hypertension and other complications of their renal disease, nearly 50% of survivors will develop ESRD within the first decade of life. In addition to renal pathology, patients with ARPKD develop ductal plate malformations with cystic dilation of intra‐ and extrahepatic bile ducts resulting in CHF and Caroli syndrome. Many patients with CHF will develop portal hypertension with resulting esophageal varices, splenomegaly, hypersplenism, protein losing enteropathy, and gastrointestinal bleeding. Management of portal hypertension may require EBL of esophageal varices or porto‐systemic shunting. Complications of hepatic involvement can include ascending cholangitis, cholestasis with malabsorption of fat‐soluble vitamins, and rarely benign or malignant liver tumors. Patients with ARPKD who eventually reach ESRD, and ultimately require kidney transplantation, present a unique set of complications related to their underlying hepato‐biliary disease. In this review, we focus on new approaches to these challenging patients, including the indications for liver transplantation in ARPKD patients with severe chronic kidney disease awaiting kidney transplant. While survival in patients with ARPKD and isolated kidney transplant is comparable to that of age‐matched pediatric patients who have received kidney transplants due to other primary renal diseases, 64–80% of the mortality occurring in ARPKD kidney transplant patients is attributed to cholangitis/sepsis, which is related to their hepato‐biliary disease. Recent data demonstrate that surgical mortality among pediatric liver transplant recipients is decreased to <10% at one yr. The immunosuppressive regimen used for kidney transplant recipients is adequate for most liver transplant recipients. We therefore suggest that in a select group of ARPKD patients with recurrent cholangitis or complications of portal hypertension, combined liver–kidney transplant is a viable option. Although further study is necessary to confirm our approach, we believe that combined liver–kidney transplantation can potentially decrease overall mortality and morbidity in carefully selected ARPKD patients with ESRD and clinically significant CHF.     

The current status and further prospects for lung magnetic resonance imaging in pediatric radiology

Lung MRI makes it possible to replace up to 90% of CT examinations with radiation-free magnetic resonance diagnostics of the lungs without suffering any diagnostic loss. The individual radiation exposure can thus be relevantly reduced. This applies in particular to children who repeatedly require sectional imaging of the lung, e.g., in tumor surveillance or in chronic lung diseases such as cystic fibrosis. In this paper we discuss various factors that favor the establishment of lung MRI in the clinical setting. Among the many sequences proposed for lung imaging, respiration-triggered T2-W turbo spin-echo (TSE) sequences have been established as a good standard for children. Additional sequences are mostly dispensable. The most important pulmonary findings are demonstrated here in the form of a detailed pictorial essay. T1-weighted gradient echo sequences with ultrashort echo time are a new option. These sequences anticipate signal loss in the lung and deliver CT-like images with high spatial resolution. When using self-gated T1-W ultrashort echo time 3-D sequences that acquire iso-voxel geometry in the sub-millimeter range, secondary reconstructions are possible.

     

Fast fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging of the brain: a comparison of multi-shot echo-planar and fast spin-echo techniques

Purpose. To evaluate fast spin-echo and multi-shot echo-planar fluid-attenuated inversion recovery (FLAIR) sequences in paediatric brain imaging. Materials and methods. Matched images from 32 patients with suspected tumour or white matter disease were independently evaluated by two paediatric neuroradiologists. The observer preferences for image quality and lesion detection were analysed for differences between fast spin-echo FLAIR and multi-shot echo-planar FLAIR. Diagnostic quality was compared with that of fast spin-echo T2-weighted images. Results. Images of a diagnostic quality equivalent to that of fast spin-echo T2-weighted images were achieved with both FLAIR techniques. Grey and white matter differentiation and cerebrospinal fluid (CSF) nulling were significantly better on fast spin-echo FLAIR sequences. CSF flow artefact was reduced on multi-shot echo-planar FLAIR. There was no difference in lesion detection. Fast spin-echo FLAIR images were visually preferred at the expense of longer imaging time. Conclusion. Fast FLAIR techniques are complementary to fast spin-echo T2-weighted sequences in imaging of the paediatric brain. We find that the fast spin-echo FLAIR sequence is preferable to the multi-shot echo-planar technique. Received: 20 August 1996 Accepted: 6 November 1996     

Diagnosis of liver cirrhosis in children based on colour Doppler ultrasonography with histopathological correlation

Background. Changes in hepatic architecture in cirrhosis and chronic active hepatitis affect liver vascular haemodynamics. Objective. To determine the criteria for the diagnosis of liver cirrhosis using Doppler US. Materials and methods. Twenty-two children with liver disease of unknown histology were prospectively examined and compared with eight normal children. Doppler US of portal vein velocity, arterio-portal velocity ratio, loss of reverse flow component in the hepatic vein and hepatic artery visualisation were examined prior to liver biopsy. Doppler results were compared with histological activity indices. Twelve patients had cirrhosis and ten had chronic active hepatitis. Results. The most sensitive method (83 %) for the assessment of cirrhosis was portal vein velocity less than 20 cm/sec. Arterio-portal velocity ratio (greater than 3) and hepatic artery visualisation were less sensitive (75 % and 33 % respectively) but specificity was 100 % for all three methods. When these three methods were evaluated together, sensitivity increased to 91 % and accuracy to 96 %. Loss of reverse flow component was less specific (77 %) but was sensitive (75 %). Conclusions. Portal vein velocity, arterio-portal vein ratio and hepatic artery visualisation together were reliable in diagnosis of cirrhosis in the paediatric age group. Received: 11 August 1997 Accepted: 17 June 1998     

Radiological features of focal nodular hyperplasia of the liver in children

Background. Focal nodular hyperplasia (FNH) is an unusual hepatic tumour in children and should be distinguished from other hepatic lesions. Objective. To describe the imaging characteristics of FNH in children. Materials and methods. We examined five patients (three boys and two girls, mean age 9.4 years) with pathologically confirmed FNH. The diagnosis was obtained by tumour resection (n = 4) and percutaneous needle biopsy (n = 1). One patient with multiple FNHs showed recurrent lesions after tumour resection. All patients were studied with US (including colour and power Doppler US [n = 3]) and CT. Dynamic enhanced CT scans were available in three patients. MRI (n = 2) or coeliac angiography (n = 1) was performed in three patients. Results. Seven of eight FNH lesions in five patients were demonstrated by imaging. The average size of the lesions was 6.5 cm. Six lesions detected on US showed variable echogenicity with a central hyperechoic scar (n = 2). On Doppler examination, central or peripheral hypervascular areas were seen (n = 3). Six lesions detected on contrast-enhanced CT showed high attenuation (n = 4) or iso-attenuation (n = 2). On early phase scans, all the lesions (n = 3) showed high attenuation. Irregular linear or ovoid central scars were detected in two patients on CT. MR demonstrated three lesions in two patients, one of which had not been detected by US or CT. A central low signal intensity scar (n = 1) was seen on T2-weighted MRI. Coeliac angiography performed in one patient showed a hypervascular mass with homogeneous staining. Conclusion. FNH in children shows a wide spectrum of imaging findings on various radiological examinations and the typical central scar was not always seen on imaging studies. Dynamic enhanced CT obtained in the early phase and colour Doppler studies may be helpful in the diagnosis of FNH by allowing characterisation of tumour vascularity. FNH should be included in the differential diagnosis of liver mass in children. Received: 10 September 1997 Accepted: 17 April 1998     

High-resolution heavily T2-weighted magnetic resonance imaging for evaluation of the pituitary stalk in children with ectopic neurohypophysis

Background

In anterior pituitary deficiency, patients with non visible pituitary stalk have more often multiple deficiencies and persistent deficiency than patients with visible pituitary stalk.

Objective

To compare the diagnostic value of a high-resolution heavily T2-weighted sequence to 1.5-mm-thick unenhanced and contrast-enhanced sagittal T1-weighted sequences to assess the presence of the pituitary stalk in children with ectopic posterior pituitary gland.

Materials and methods

We retrospectively evaluated the MRI data of 14 children diagnosed with ectopic posterior pituitary gland between 2010 and 2014. We evaluated the presence of a pituitary stalk using a sagittal high-resolution heavily T2-weighted sequence and a 1.5-mm sagittal T1-weighted turbo spin-echo sequence before and after contrast medium administration.

Results

A pituitary stalk was present on at least one of the sequences in 10 of the 14 children (71%). T2-weighted sequence depicted the pituitary stalk in all 10 children, whereas the 1.5-mm-thick T1-weighted sequence depicted 2/10 (20%) before contrast injection and 8/10 (80%) after contrast injection (P=0.007).

Conclusion

Compared with 1.5-mm-thick contrast-enhanced T1-weighted sequences, high-resolution heavily T2-weighted sequence demonstrates better sensitivity in detecting the pituitary stalk in children with ectopic posterior pituitary gland, suggesting that contrast injection is unnecessary to assess the presence of a pituitary stalk in this setting.

     

Ultrasound findings in children with toxocariasis: report on 18 cases

Purpose. To evaluate abdominal ultrasound (US) findings in children infected with Toxocara canis. Materials and methods. Eighteen children, 18 months to 7 years of age, with serological diagnosis of T. canis infection underwent abdominal US. Eosinophil counts, hemoglobin levels and immunoglobulin E titers were measured for all patients. Results. Abdominal ultrasound revealed multiple hypoechoic areas in the livers of 15 patients (83.3 %). Hepatohilar lymph-node enlargement was present in 14 patients (77.7 %), 2 of whom also showed peripancreatic lymph-node enlargement. Hepatomegaly was present in 13 patients (72.7 %) and splenomegaly in 9 (50 %). Conclusion. The most prevalent findings of abdominal ultrasound examination of children with T. canis infection are hepatic granulomas and abdominal lymph-node enlargement. This infection should be considered in the differential diagnosis of any children who exhibit these findings on abdominal US examination, especially for those with eosinophilia. Received: 10 November 1998 Accepted: 21 December 1998     

Association of congenital hepatic fibrosis with autosomal dominant polycystic kidney disease

The association of autosomal recessive polycystic kidney disease (ARPKD) with congential hepatic fibrosis (CHF) is well known; a rare occurrence is that of congenital hepatic fibrosis with autosomal dominant polycystic kidney disease (ADPKD). We report a family with ADPKD in which congenital hepatic fibrosis with severe portal hypertension (PHT) presented in a 4-year-old girl; the kidneys were initially normal. Typical changes of autosomal dominant polycystic kidney disease developed in the next decade and were also found in the mother and sister (neither of whom had any evidence of portal hypertension). Severe variceal bleeding was treated by sclerotherapy and beta receptor blocade.     

The value of new MRI techniques in adrenoleukodystrophy

Purpose. To evaluate the significance of new techniques in MRI examinations of the brain in children with X-linked adrenoleukodystrophy (ALD). Materials and methods. Five patients aged between 2 and 15 years with childhood ALD were examined with MRI. Following conventional spin-echo (CSE) sequences, a fast spin-echo (FSE) sequence with T2 contrast was performed in four patients, an FSE turbo-inversion- recovery (TIR) sequence in two, magnetization transfer contrast (MTC) imaging in two, and localized proton spectroscopy (MRS) in four patients. Results. FSE compared favorably with CSE with a time saving of 70 %. On TIR images the contrast between normal and demyelinated white matter was greater than on CSE and FSE images. Calculated MTC values revealed a severe MTC loss within the demyelinated regions and a moderate reduction in the border zones. In this way, calculation of MTC might be useful to differentiate between edematous changes and areas of irreversible demyelination. MRS revealed a reduction in N -acetylaspartate and an elevation in choline (Cho). The degree of MRS changes paralleled the severity of demyelination. A Cho elevation may precede visible demyelination on T2-weighted images. Conclusion. T2-weighted FSE sequences can replace CSE without any disadvantages and with effective time saving. The indication for MTC imaging and MRS in children with ALD is not yet finally defined. These new techniques may reveal the earliest signs of cerebral involvement or of disease progression, a matter of great importance in selecting the optimal therapeutic approach. Received: 2 August 1996 Accepted: 25 September 1996     

Caroli's syndrome. Report of a case beginning in childhood with favorable course

Caroli's disease is a rare entity that is included in the fibropolycystic abnormalities of the bile ducts. Ultrasonographic patterns consist of evident dilatation of the bile ducts. Although it is thought to be a congenital disease, it usually presents in young adults and few cases have been reported in children. We present the case of a 10-year-old boy with Caroli's syndrome (Caroli's disease, congenital hepatic fibrosis and polycystic renal disease). Evolution was favorable.     

Contrast-enhanced magnetic resonance angiography for the detection of crossing renal vessels in children with symptomatic ureteropelvic junction obstruction: comparison with operative findings

Background Crossing renal vessels (CRV) are associated with ureteropelvic junction (UPJ) obstruction, particularly when presentation is beyond the neonatal period. Their presence may influence surgical management. Objective To evaluate the accuracy of contrast-enhanced magnetic resonance angiography (CE-MRA) in the identification of CRV in children requiring surgical treatment of symptomatic UPJ obstruction, against a gold standard of laparoscopic or open surgical findings. Materials and methods We reviewed CE-MRA studies (3-D T2-weighted turbo spin-echo and multiphase 3-D spoiled gradient echo following intravenous gadolinium administration) of 14 children, age range 6–15 years, performed prior to surgery for suspected CRV-related UPJ obstruction. Consensus reviews of the CE-MRA studies were compared with surgical findings. Results CE-MRA demonstrated CRV at the level of the obstruction in nine and no crossing vessels in five children. These were all verified intraoperatively (χ² = 14.0; P < 0.001). In eight of the nine patients with CRV there was no evidence of intrinsic obstruction at surgery. In the remaining patient there was fibrosis of the upper ureter. Conclusion CE-MRA is an accurate means of identifying CRV in children older than 6 years with symptomatic UPJ obstruction.     

Fast-recovery fast spin-echo T2-weighted MR imaging: a free-breathing alternative to fast spin-echo in the pediatric abdomen

In the mid 1990s, the fast spin-echo (FSE) and turbo spin-echo (TSE) T2-weighted (T2-W) sequences became available and are now widely accepted alternatives to conventional spin-echo sequences since they result in reduced acquisition times while maintaining tissue contrast. Since that time, there has been continued development of new sequences to further decrease acquisition times, minimize artifacts, and preserve lesion detection. The purpose of this pictorial essay is to qualitatively illustrate the newly available fast recovery (FR) FSE T2-W MR images of the abdomen compared with the images acquired using the routine FSE T2-W sequence in non-breath-hold studies in children.     

MR findings of complicated multifetal gestations

This paper presents a review of various complications of multifetal gestations identified on MR imaging and highlights findings of those complications unique to monochorionic twinning. The goal is to illustrate the potential of MR as a useful application in these clinical circumstances. A total of 32 women with multifetal gestations and suspected complication detected initially by US underwent T2-weighted MR imaging. Additional T1-weighted images were obtained when intracranial hemorrhage was suspected. MR and US findings were compared in all cases. Of 32 cases, six demonstrated fetal complications specific to monochorionic twinning; the findings consisted of conjoined twins (n=2), twin-twin transfusion syndrome (n=1), co-twin demise with embolic disease (n=2), and twin-reversed arterial perfusion. (TRAP) syndrome (n=1). MR imaging confirmed US findings in all cases and was particularly helpful in delineating the extent of intracranial complications of monochorionic twins. The technique also showed improved anatomical detail in cases of conjoined twins. MR imaging provided additional information in cases of complicated monochorionic twinning, making it a useful complementary technique when combined with initial sonographic assessment.     

Diagnostic imaging of primitive neuroectodermal tumour of the chest wall (Askin tumour)

Objectives. To describe the radiological features of primitive neuroectodermal tumour (PNET) of the chest wall (Askin tumour) at diagnosis and to analyse the radiological changes occurring as a consequence of treatment and during follow-up. Materials and methods. Nine children with histologically proven PNET were studied. At diagnosis, all patients underwent chest X-ray (CXR), chest CT and bone scintigraphy; three patients also had MR and three had US. During treatment and follow-up, CT was performed in all patients. Results. CT demonstrated a solid heterogeneous chest wall mass in all children at diagnosis and six had a rib lesion. Small nodular densities in the extra-pleural fat were identified in three patients at diagnosis. US, performed in three patients, excluded tumour infiltration of the lung or diaphragm, which had been suspected on CT. On MR, the lesions showed high signal intensity in T1-weighted/proton-density images and intermediate/high signal intensity in T2-weighted images compared with muscle. Minimal chest wall involvement was demonstrated in one case by MRI. Extensive necrosis of tumour mass with pseudo-cystic appearance was documented in the five patients who underwent chemotherapy. Macroscopically complete resection was performed in five patients but there was early local recurrence after surgery in two, identified by CT in one and by MR in the other. Conclusions. PNET of the chest wall should be considered in a child with a chest wall mass. CT is valuable for evaluating tumour extension at diagnosis, the effects of chemotherapy and assessing tumour recurrence after surgery. However, CT can overestimate pleural, lung or diaphragmatic infiltration, which are better evaluated by US. MR was superior to CT in the evaluation of tumour extension in one of three patients and may be considered complementary to CT, particularly in very large chest wall tumours. Received: 23 May 1997 Accepted: 23 February 1998