The Complex Spine in Children with Spinal Muscular Atrophy: The Transforaminal Approach-A Transformative Technique.

BACKGROUND AND PURPOSE: Spinal muscular atrophy, a genetic disease resulting in loss of motor function, presents from in utero to adulthood. Depending on progression and secondary scoliosis, spinal stabilization may be necessary. When planning intrathecal access in these patients, spinal anatomy is the most important factor. Therefore, when planning intrathecal nusinersen injections, we subdivided patients with spinal muscular atrophy into simple-versus-complex spine subgroups. Our purpose was to present our experience with our first 42 transforaminal intrathecal nusinersen injections. MATERIALS AND METHODS: We reviewed 31 consecutive patients with spinal muscular atrophy types 1-3 who presented for intrathecal nusinersen injections from March 2017 to September 2018. Nine children had complex spines (ie, spinal instrumentation and/or fusion) and required preprocedural imaging for route planning for subarachnoid space access via transforaminal or cervical approaches. RESULTS: A total of 164 intrathecal nusinersen injections were performed in 31 children 4-226 months of age, with 100% technical success in accessing the subarachnoid space. Nine patients with complex spinal anatomy underwent 45 intrathecal nusinersen injections; 42 of 45 procedures were performed via a transforaminal approach with the remaining 3 via cervical techniques. There were no complications. CONCLUSIONS: Our initial experience has resulted in a protocol-driven approach based on simple or complex spinal anatomy. Patients with simple spines do not need preprocedural imaging or imaging-guided intrathecal nusinersen injections. In contrast, the complex spine subgroup requires preprocedural imaging for route planning and imaging guidance for therapy, with the primary approach being the transforaminal approach for intrathecal nusinersen injections.

Bilateral complete labyrinthine aplasia with bilateral internal carotid artery aplasia, developmental delay, and gaze abnormalities: a presumptive case of a rare HOXA1 mutation syndrome.

The human HOXA1 mutation syndromes commonly present with abnormalities of the inner ear and ICAs. Previous cases describe varying degrees of hypoplasia or aplasia of the affected structures, often with asymmetric involvement. We present imaging findings documenting complete absence of the ICAs bilaterally with bilateral CLA, which, to our knowledge, has not been previously reported.

Improved delineation of ventricular shunt catheters using fast steady-state gradient recalled-echo sequences in a rapid brain MR imaging protocol in nonsedated pediatric patients.

BACKGROUND AND PURPOSE: Rapid brain MR imaging is often substituted for head CT in multiply imaged patients with shunted hydrocephalus. Fast TSE-T2 sequences are commonly used in these protocols. One limitation of TSE-T2 sequences is the decreased catheter delineation compared with CT. The aim of this study was to compare fast TSE-T2 with rapid SS-GRE sequences in the evaluation of intracranial shunt catheter delineation as part of a rapid nonsedated pediatric brain MR imaging protocol. MATERIALS AND METHODS: We evaluated the findings from 179 consecutive patients who underwent routine clinical imaging according to the rapid nonsedated pediatric brain MR imaging protocol. Comparison of the quality of intracranial shunt catheter localization on SS-GRE versus TSE-T2 was performed. RESULTS: Of the total of 179 rapid nonsedated pediatric brain MR images that were reviewed, 62 (35%) had an intracranial shunt catheter. The shunt catheter tip was better localized on the SS-GRE than on the TSE-T2 images in 49/62 (79%) of these patients. Of the remaining 13/62 (21%), the TSE-T2 was either better or equivalent in localizing the shunt catheter tip. CONCLUSIONS: Our study shows that rapid SS-GRE sequences can provide better delineation of standard intracranial shunt catheters than standard rapid MR imaging protocols containing only fast TSE-T2 sequences.

Imaging and intervention in the gastrointestinal tract in children.

Vascular and interventional techniques have become an integral component of modern pediatric healthcare. Minimally invasive procedures of the gastrointestinal tract now comprise a large part of any active pediatric interventional practice. Magnetic resonance cholangiopancreatography offers a reliable, non-invasive means to evaluate patients with possible pancreatic or biliary pathology. This article reviews treatment of esophageal strictures and placement of gastronomy and gastrojejunostomy tubes and discusses new developments. Placement of percutaneous cecostomy tubes is a relatively new procedure that creatively uses the techniques developed for placement of percutaneous gastronomy tubes. This procedure offers significant benefits and lasting positive lifestyle changes for patients suffering from fecal incontinence. Liver biopsy in high-risk patients can be performed safely using measures designed to significantly decrease the risk of post-biopsy hemorrhage, such as track embolization or the transjugular approach.

Non-endoscopic removal of radiologically placed percutaneous primary gastrostomy tubes: a new technique.

PURPOSE: To present a new technique for non-endoscopic removal of radiologically inserted primary percutaneous gastrostomy tubes (PGT) and to assess the utility and safety of this technique in the pediatric population. MATERIALS AND METHODS: Over a 9-year period 172 children (80 F, 92 M) mean age 10 years (range 0.29-24 years) underwent removal of radiologically placed PGTs in the Radiology Department. All procedures were performed with conscious sedation. The procedure time ranged from 20 to 45 min (mean 30 min). The procedures were performed electively at > or = 3 14 months for either gastrostomy button placement (70), balloon gastrostomy and jejunostomy placement (55), or G tube removal at termination of enteral feeding (15). RESULTS: PGT disc retrievals were successful performed in 169 of 173 (98%). No technical failures occurred, but five procedures failed due to PGT disc lodgement in gastric wall (four), and gastrocolic fistula (one). One child had a repeat procedure due to premature removal of the primary PGT necessitating replacement. No deaths occurred. PGT discs retrieval was performed at a mean time interval of 14 months from initial PGT insertion (range 3-40 months). CONCLUSION: Non-endoscopic GT disc removal is a quick and safe procedure. It facilitates easy conversion to a gastrostomy button in the radiology setting and avoids the risk of a retained percutaneous gastrostomy tube remnant and intra/transmural migration of discs.

"Push-pull" gastrostomy: a new technique for percutaneous gastrostomy tube insertion in the neonate and young infant.

OBJECTIVE: To evaluate a newly developed method combining antegrade and retrograde techniques for percutaneous gastrostomy tube (PGT) insertion in the neonate and young infant. MATERIALS AND METHODS: From January 1994 to December 2000, 85 children (47 male, 38 female), mean age 4.5 months (range 0.44-9.13 months) underwent PGT insertion using the "push-pull" technique. With the addition, 57 children had a jejunostomy tube placed as well at or within 24 h of the PGT procedure. The mean weight was 3.74 kg, range 1.5-7.0 kg. The indications for the procedure included failure to thrive in 40 patients (25%), static encephalopathy in 21 (25%), neurological/congenital abnormalities in 12 (14%), aspiration in 7 (8%), and cardiac problems in 5 (6%). RESULTS: Eighty-five PGTs were successfully inserted in 85 children. One procedure was initially unsuccessful due to failed conscious sedation and was completed under general anesthesia. Four of 85 patients initially had attempted antegrade placement that failed, and the procedure was successfully completed using the "push-pull" method. One major complication occurred: a gastrocolic fistula at day 5 post-procedure, which was surgically repaired without sequelae. Tube-related problems included; tube dislodgement (n = 1) and procedure-related stomal infection (n = 3). CONCLUSION: The "push-pull" gastrostomy technique is a safe, effective method of percutaneous gastrostomy tube placement in neonates. It facilitates successful placement of the PGT in patients in whom the classic antegrade method is not possible. It has become the procedure of choice in this group.

Pediatric tracheotomy: is postoperative chest X-ray necessary?

A retrospective study of 101 children who underwent tracheotomy at the Children's Hospital of Pittsburgh from 1993 to 1996 was performed. The following criteria were reviewed in each patient: age, gender, race, prematurity, weight during tracheotomy, presence of preoperative airway support, duration of tracheotomy, nature (emergent versus elective), tracheotomy tube size, reason for tracheotomy, accompanying medical diagnoses, chest x-ray (CXR) findings, surgical service, postoperative symptoms (up to 3 days), and operative mortality rate. Of these criteria, our results show that CXR-screenable complications occurred in patients who underwent emergent recannulation, as well as those who exhibited ventilatory distress (oxygen saturation level of <90%) and specific changes in postoperative symptoms. Pneumothorax developed after tracheotomy in 3 of the 101 patients; each had one of these risk factors. We conclude that CXR of all pediatric patients after tracheotomy may be unnecessary with the use of flexible endoscopy and screening restrictions that are both health-conscious and cost-effective.

MRCP in the evaluation of pancreaticobiliary disease in children.

BACKGROUND: Radiologic assessment of pancreaticobiliary ductal disease (PBDD) in children currently consists of physiologic tests (radionuclide examinations) or invasive anatomic studies (ERCP and PTC). An accurate noninvasive and reproducible examination that can direct the subsequent need for more invasive studies would be helpful in this patient group. OBJECTIVE: To determine the effectiveness of MRCP as a screening tool for PBBD in the pediatric population. MATERIALS AND METHODS: Over the last year, 33 patients ranging from 7 months to 20 years of age were prospectively evaluated with MRCP on a 1.5 T magnet. One patient was examined twice, several months apart. Thirteen patients had liver transplants. Coronal SPGR and heavily T-2W FSE cross-sectional images were obtained. Standard and oblique 2- to 6-cm-thick slab SSFSE (single-shot fast spin echo) acquisition and 3D MIP reconstruction of 2D FSE images were obtained in the planes of the CBD and pancreatic duct. Nine studies were performed with the patient under sedation with chloral hydrate or nembutal and fentanyl with quiet respiration, and the non-sedated patients were assessed with single breath hold or quiet respiration. Three patients received secretin. MRCP results were correlated with ERCP (9), PTC (7), liver biopsy (13), clinical information (6), surgery (3), and autopsy (2). RESULTS: All 34 studies performed were considered diagnostic. Periportal fluid, proximal bowel fluid, and gallbladder distention did not significantly diminish the diagnostic information in any cases. Motion artifact did not cause serious degradation in image quality. MRCP depicted abnormalities including stones, stricture, intraductal tumor, and extrinsic compression, all of which were confirmed at ERCP, PTC ( two unsuccessful in patients with non-dilated ducts by MRCP), surgery, liver biopsy, and autopsy. There were no false-negative examinations. Normal pancreatic studies performed to exclude pancreas divisum were followed without additional clinical or laboratory evidence of pancreatitis. Secretin administration increased the conspicuity of the pancreatic duct in two of three patients. CONCLUSION: MRCP is a fast non-invasive method of evaluating the pancreatic duct and biliary tree in children. A normal MRCP may obviate the need for PTC or ERCP. Abnormalities detected on MRCP can direct the type of intervention.

Intrahepatic chemoembolization in unresectable pediatric liver malignancies.

OBJECTIVE: To determine the effectiveness of a new multidisciplinary approach using neoadjuvant intrahepatic chemoembolization (IHCE) and liver transplant (OLTx) in patients with unresectable hepatic tumors who have failed systemic chemotherapy. MATERIALS AND METHODS: From November 1989 to April 1998, 14 children (2-15 years old) were treated with 50 courses of intra-arterial chemotherapy. Baseline and post-treatment contrast-enhanced CT and alpha-fetoprotein levels were performed. Seven had hepatoblastoma, and 7 had hepatocellular carcinoma (1 fibrolamellar variant). All patients had subselective hepatic angiography and infusion of cisplatin and/or adriamycin (36 courses were followed by gelfoam embolization). The procedure was repeated every 3-4 weeks based on hepatic function and patency of the hepatic artery. RESULTS: Six of 14 children received orthotopic liver transplants (31 courses of IHC). Pretransplant, 3 of 6 showed a significant decrease in alpha-fetoprotein, while only 1 demonstrated a significant further reduction in tumor size). Three of 6 patients are disease free at this time. Three of 6 patients died of metastatic tumor 6, 38, and 58 months, respectively post-transplant. One of 14 is currently undergoing treatment, has demonstrated a positive response, and is awaiting OLTx. Three of 14 withdrew from the program and died. Four of 14 patients developed an increase in tumor size, developed metastatic disease, and were not transplant candidates. Two hepatic arteries thrombosed, and one child had a small sealed-off gastric ulcer as complications of intrahepatic chemoembolization. CONCLUSION: The results of intrahepatic chemoembolization are promising and suggest that some children who do not respond to systemic therapy can be eventually cured by a combination of intrahepatic chemoembolization orthotopic liver transplant. Alpha-fetoprotein and cross-sectional imaging appear to be complementary in evaluating tumor response. IHCE does not appear to convert an anatomically unresectable lesion to a candidate for partial hepatectomy.

Management of hepatic venous obstruction after split-liver transplantation.

Stenosis of the hepatic vein anastomosis is an unusual but critical complication after liver transplantation. In pediatric liver transplantation, the scarcity of size-matched donors has required the use of segmental liver allografts, either as reduced-size or split-liver grafts. This report illustrates the primary use of a hepatic vein stent to manage hepatic venous outflow obstruction in a pediatric split-liver recipient, and reviews experience in the management of hepatic venous outflow obstruction after liver transplant using stent methods.

Use of indium-111-labeled hepatocytes to determine the biodistribution of transplanted hepatocytes through portal vein infusion.

PURPOSE: Hepatocyte transplantation is useful for ex vivo gene therapy and liver repopulation. Methods for hepatic reconstitution were recently developed, but hepatocyte transplantation systems must be optimized. The authors report their experience with In-111 oxyquinolone labeling of a test dose of hepatocytes (108 cells) for noninvasive assessment of the biodistribution of transplanted hepatocytes in a 5-year-old child with omithine transcarbamoylase deficiency. MATERIALS AND METHODS: Donor hepatocytes (approximately 108) were radiolabeled using a commercially available In-111 oxyquinolone solution (specific activity of 1 mCi/ml). RESULTS: The overall labeling efficiency was 36.4%. A final dose of approximately 290 ,uCi of the In-111-labeled hepatocytes in 10 ml serum-free phosphate-buffered saline was infused percutaneously into the portal vein approximately 2.5 hours after their preparation. The study was performed 3 hours before cell transplantation (109 cells). Quantitative analysis of the biodistribution of In-111-labeled hepatocytes indicated that cells were predominantly localized in the liver immediately after portal vein-infused transplantation. The predominant hepatic distribution was persistent for as long as 7 days after the procedure, with an average liver-to-spleen ratio of 9.5 to 1. No significant pulmonary radiotracer uptake was present. CONCLUSION: These results indicate that In-111 labeling of hepatocytes is useful for the short-term noninvasive analysis of the biodistribution of transplanted hepatocytes.

A multihospital survey of radiation exposure and image quality in pediatric fluoroscopy.

BACKGROUND: Traditionally, pediatric radiologists have been advocates of fluoroscopy systems that provide diagnostic images at the lowest possible radiation dose to the pediatric patient. Manufacturers of fluoroscopic equipment vary as to their claims of "low radiation" exposures. OBJECTIVES: To obtain comparative data on radiation exposure and image quality from four pediatric hospitals, across variants of fluoroscopic equipment (such as pulsed versus continuous fluoroscopy). MATERIALS AND METHODS: Images were acquired from phantoms that simulated the size of a 3-year-old child. Phantom results, both stationary and rotating dynamic, were evaluated for radiation exposure and for image resolution of high- and low-contrast objects. RESULTS: Radiation exposure from the four fluoro units varied widely; the lowest-dose selectable fluoro mode produced exposures varying between 34 and 590 mrads/min among the four fluoro units, and the highest-dose selectable fluoro mode produced 540-2,230 mrads/min. The lowest radiation exposures were produced by pulsed fluoro units, and the very lowest radiation exposure was produced by a fluoroscope that had been especially optimized for pediatric imaging. There was only a small variation in image quality among the hospitals for visualization of stationary objects. A wide variability was noted for detection of objects on the moving phantom. CONCLUSIONS: The variability in the number of detected objects was considerably smaller than the variability in radiation exposure. Pulsed fluoroscopy provides improved resolution for moving objects. Optimization of one hospital's fluoroscope especially for pediatric imaging produced the best ratio of image quality to radiation exposure.

Use of intrahepatic chemotherapy to treat advanced pediatric hepatic malignancies.

BACKGROUND: To evaluate the effect of intrahepatic arterial chemotherapy (IAC) on children with primary hepatic malignancies. METHOD: A nonrandomized inception cohort of 11 pediatric patients was referred for treatment of advanced primary hepatic malignancies at Children's Hospital of Pittsburgh. None of the patients was a candidate for resection before the initiation of IAC. Tumor response to treatment was observed by determining serum alpha-fetoprotein (AFP) levels and by abdominal computed tomographic scan. The patients received hepatic artery infusions of cisplatin and/or doxorubicin. The last five also received gelfoam embolization. RESULTS: Eight of 11 patients had multiple IAC treatments. Eight patients had AFP-producing tumors, and five of the eight had dramatic reductions in serum levels after IAC treatment. Five of the 11 patients underwent successful orthotopic liver transplantation after receiving IAC therapy, and the five explanted specimens showed varying degrees of tumor necrosis. One-year survival in patients in the authors' center is 67% for those with hepatoblastoma and 40% for those with hepatocellular carcinoma. Three-year survival is 60% and 30% for patients with hepatoblastoma and hepatocellular carcinoma, respectively. CONCLUSION: Intrahepatic arterial chemotherapy therapy can halt the progression and possibly down-stage advanced pediatric hepatic malignancies. This therapy can also be used as a successful adjunct in altering a patient's chance for successful liver transplantation.

Imaging of postnatal maturation of the skull base.

The skull begins to form when mesenchyme thickens and condenses around the developing brain. At the skull base, most of this mesenchyme derives from neural crest, and some arises from general head mesenchyme. This article reviews the patterns for maturation of the ossification, sutures, and synchondroses in the occipital, the sphenoid, and the orbitoseptal regions, and reports additional data derived from specific study of CT scans of the skull base in children and young adults.