Outcomes of five cases of retinoblastoma with optic nerve invasion on imaging.

PURPOSE: To investigate the timing of enucleation, treatment course, and outcome for retinoblastoma (RB) with optic nerve (ON) invasion on imaging. STUDY DESIGN: Retrospective clinical study. METHODS: Of the 160 patients with RB who presented to the National Center for Child Health and Development in Japan between 2005 and 2022, ON invasion on imaging at the initial presentation was seen in five patients. The clinical, computed tomography (CT), and magnetic resonance imaging (MRI) findings, and treatment courses were reviewed retrospectively. RESULTS: MRI showed ON invasion in all five patients (three with unilateral RB, 2 with bilateral RB); in two patients CT detected no invasion. Enucleation was performed in four patients, three of whom underwent neoadjuvant therapy and one had a positive ON resection margin following the enucleation as initial treatment. One patient did not undergo enucleation due to cerebrospinal fluid dissemination. All enucleated patients underwent adjuvant chemotherapy. Four patients underwent radiotherapy. During follow-up (mean, 89.4 months), four patients survived and one died. CONCLUSION: MRI is recommended to evaluate ON invasion and determine the timing of enucleation for RB. The appropriate choice of neoadjuvant or adjuvant therapy would be helpful to avoid radiotherapy for RB with ON invasion on imaging.

Quantitative Analysis of the Clinical Reasons Influencing the Frequency of Pediatric Head CT Examinations: A Single-Center Observation Study.

Epidemiological studies on radiation exposure from pediatric CT scans have attracted attention in terms of radiological protection. These studies have not taken into account the reasons why CT examinations were performed. It is presumed that there are clinical reasons that justify more frequent CT examinations in children. The purpose of this study was to characterize the clinical reasons why relatively high numbers of head CT examinations (NHCT) are frequently performed and to conduct a statistical analysis to determine the factors governing the NHCT. Patient information, the date of examination, and medical conditions for examination data stored on the radiology information system were used to investigate the reasons for undergoing CT examinations. The target facility was National Children's Hospital; data were obtained from March 2002 to April 2017, and the age of the study population was less than 16 years old. Quantitative analysis of the factors associated with frequent examinations was conducted by Poisson regression analysis. Among all patients who had a CT scan, 76.6% had head CT examinations, and 43.4% of children were under 1 year old at the time of the initial examination. There were marked differences in the number of examinations depending on the disease. The average NHCT was higher for children younger than 5 days of age. Among children less than 1 year of age with surgery, there was a marked difference between hydrocephalus, with a mean = 15.5 (95% CI 14.3,16.8), and trauma, with a mean = 8.3 (95% CI 7.2,9.4). In conclusion, this study revealed that NHCT was significantly higher in children who had undergone surgery than in those who had not been to the hospital. The clinical reasons behind patients with higher NHCT should be considered in investigating a causal relationship between CT exposure and brain tumors.

Evaluation of radiation dose reduction in head CT using the half-dose method.

PURPOSE: The present study introduced the half-dose method (HDM), which halves the radiation dose for conventional head computed tomography (CT), for postoperative hydrocephalus and follow-up for craniosynostosis at a children's hospital. This study aimed to evaluate the contribution of selective head CT scanning optimization towards the overall reduction of radiation exposure. MATERIALS AND METHODS: We retrospectively assessed 1227 and 1352 head CT examinations acquired before and after the introduction of the HDM, respectively, in children aged 0-15 years. The radiation exposure was evaluated using the CT dose index volume (CTDI-vol), dose-length product (DLP), rate of HDM introduction, and effect of reducing in-hospital radiation dose before and after the introduction of the HDM. For an objective evaluation of the image quality, head CT scans acquired with HDM and full-dose method (FDM) were randomly selected, and the image noise standard deviation (SD) was measured for each scan. In addition, some HDM images were randomly selected and independently reviewed by two radiologists. RESULTS: The HDM was introduced in 27.9% of all head CTs. The mean CTDI-vol of all head CTs was 21.5 ± 6.9 mGy after the introduction, a 14.9% reduction. The mean DLP was 418.4 ± 152.9 mGy.cm after the introduction, a 17.2% reduction. Compared to the FDM images, the noise SD of the HDM ones worsened by almost 0.9; however, none of the images were difficult or impossible to evaluate. CONCLUSION: The HDM yielded diagnostically acceptable images. In addition, a change in protocol for only two diseases successfully reduced the patients' overall radiation exposure by approximately 15%. Introducing and optimizing the HDM for frequently performed target diseases will be useful in reducing the exposure dose for the hospital's patient population.

Usefulness of central radiologic review in clinical trials of children with hepatoblastoma.

BACKGROUND: No previous research papers have reported a comparative survey of local radiologic diagnoses and central review in children with hepatoblastoma. OBJECTIVE: To evaluate the utility of central review of children with hepatoblastoma enrolled in a clinical trial. MATERIALS AND METHODS: The study included 91 children enrolled in a clinical trial conducted by the Japanese Study Group for Pediatric Liver Tumor. We compared the results of the initial pre-treatment extent of tumor (PRETEXT) disease staging performed at local sites with the results obtained on central review to determine the concurrence rates for tumor staging and additional criteria. RESULTS: The concurrence rate for PRETEXT staging was 70%. As the stage increased, the concurrence rate decreased. Using additional criteria, central review identified 143 lesions (157.1%), about 1.8 times higher than the number identified for the local site diagnoses. The additional criterion found most often on central review was "multifocal lesion" (n=19). The concurrence rate for lung metastases was high. However, our central review found many false-positive assertions of hepatic vein lesions, portal vein invasion and extrahepatic lesions among the local site diagnoses. CONCLUSION: In a clinical trial of hepatoblastoma, central review provided a more precise diagnosis than local site diagnoses with respect to severe PRETEXT stages III and IV cases and other cases including hepatic and portal vein invasion. The central review process appears to be effective and essential for improving the quality of clinical trials.

Predisposing conditions for bacterial meningitis in children: what radiologists need to know.

A variety of underlying diseases can predispose infants and children to bacterial meningitis (BM). For the diagnosis, treatment, and prevention of its recurrence, radiologists should be familiar with its predisposing conditions so that they can suggest the appropriate imaging approach. Predisposing conditions of BM can be broadly classified into two categories: infection spread from the adjacent tissue to the cerebrospinal fluid (CSF) space and immunodeficiency. Diseases in the former category are further divided according to regardless of whether there is a structural defect between the CSF space and the adjacent tissue. When a structural defect is suspected in a patient with BM, computed tomography (CT) of the head and magnetic resonance (MR) imaging are first-line imaging examinations. Radionuclide cisternography should be implemented as a second-line step to identify the CSF leak site. In patients with suspected parameningeal infection without any structural defect, such as sinusitis or otitis media/mastoiditis, CT or MR images can identify not only the disease itself but also the associated intracranial complications. The purpose of this article is to discuss the diagnostic approach and imaging findings associated with the variety of conditions predisposing patients to recurrent BM, focusing on the role of radiology in their management.

Successful endoscopic surgical treatment of pleuroperitoneal communication in two infant cases.

BACKGROUND: Pleuroperitoneal communication (PPC) is an uncommon, but potentially life-threatening complication of peritoneal dialysis (PD). If a fistula does not close with conservative treatment, surgical repair is required. However, approximately half of these patients are forced to shift from PD to hemodialysis. Although it is important to confirm the site of the fistula to achieve a successful surgical treatment, this identification is more difficult in pediatric patients than in adults. CASE PRESENTATION: We report two infantile cases of severe PPC associated with PD. In both cases, the age at onset was less than 2 years, and right-sided pleural effusion with dyspnea was observed. PPC was diagnosed by the change in color of the pleural fluid after the injection of a dye into the peritoneal cavity. Peritoneal scintigraphy and single-photon emission computed tomography and computed tomography (SPECT/CT) were performed, and these were effective in locating the fistula site. Endoscopic surgery (video-assisted thoracic surgery (VATS) and laparoscopic surgery) was performed. Indocyanine green (ICG), which was injected into the abdominal cavity, showed the exact site of the fistula. The fistula was successfully closed by attaching an absorbable sheet to it from the thoracic side and an autograft (the falciform ligament) to it from the abdominal side in one patient. In the other patient, the fistula site was resected and sutured, and reinforced with an absorbable sheet. In both cases, PD was resumed without any complication. CONCLUSION: We successfully treated two infants of PPC by endoscopic surgery. To identify the fistula site, the ICG navigation method was useful. Even in small infants, PPC can be treated successfully by endoscopic surgical repair if the site of the fistula is identified.

Challenge for management without tracheostomy tube after laryngo-tracheal separation in children with neurological disorders.

OBJECTIVES: The present study analyzed surgical outcomes of laryngotracheal separation (LTS) in children with neurological disorders. The purpose of this study was to investigate respiratory impairment and severe complications after LTS in children, and identify the possibility of permanent tracheostomy without a tracheostomy tube as the safest respiratory management method. METHODS: Twenty-eight patients (male:female = 16:12) with neurological disorders (6 months to 32 years) who underwent LTS between January 2012 and April 2018 were reviewed. Tracheal diameter, Cobb angle, and sternocervical spine distance (SCD) were measured to assess the potential risk and possibility of removing tracheostomy tube management. RESULTS: Tracheostomy tube could be removed shortly after LTS in 57% (16/28). However, nine of these patients developed respiratory problems that required tracheostomy tube placement 2 years after LTS. New requirements for a tracheostomy tube as a stent were strongly correlated with SCD (P < .05, odds ratio > 1) as well as tracheal deformity. CONCLUSIONS: Respiratory management in neurologically impaired children after LTS without a tracheostomy tube is challenging because thoracic deformity during physical growth affects tracheal disfiguration. Thoracic deformities and progression of scoliosis should be considered in respiratory management approaches in children with neurological disorders, and long-term follow-up by computed tomography is necessary. LEVEL OF EVIDENCE: IV.

A Case of High Altitude Cerebral Edema With a Prolonged Motivational Deficit.

We report a case of prolonged motivational deficit as a sequela of high altitude cerebral edema (HACE), the most severe form of neuropsychiatric dysfunction arising from traveling to high altitude. Magnetic resonance imaging of the brain showed hyperintense lesions in the globi pallidi bilaterally on T2-weighted images. Single-photon emission computed tomography showed hypoperfusion in dorsolateral and orbital prefrontal cortices bilaterally and in the anterior cingulate cortex. This case suggests that a prolonged motivational deficit can occur in patients with HACE. The case may also suggest that HACE can cause network disturbances between the prefrontal cortex and the globi pallidi.

[Combined Modality Therapy for Giant Hepatocellular Carcinoma and Multiple Lung Metastases-A Case Study].

Here, we present the case of a 47-year-old woman with liver masses having distinct borders, which were located approximately 13 cm from the left hepatic lobe S4, as visualized on a CT scan. Hepatocellular carcinoma(HCC)was suspected from these contrast findings. Additionally, we found nodules in the right upper lobe of the lung and in the left apex. Although test results for hepatitis B and C viruses were negative, the α-fetoprotein(AFP)level was elevated. The tumor was diagnosed as a HCC with suspected multiple lung metastases. Thereafter, a resection was performed for the HCC. However, multiple recurrences were observed. Arterial embolization using transcatheterization was performed thrice 5 months after resection. Further, 6 months after resection, lenvatinib therapy was initiated as the pulmonary nodule increased in size. One year after the operation, a recurrent neoplastic lesion in the liver was detected on the contrast-enhanced MRI. Since the earlier treatment with transcatheter arterial embolization proved to be minimally effective, we opted for arterial injection chemotherapy with cisplatin plus 5-FU for approximately 3 months. The contrast-enhanced CT revealed that the lesion became a low absorption lesion in the liver outside the central area, and the AFP also decreased rapidly. Therefore, the therapy was considered effective. As a side effect of arterial injection chemotherapy, the patient developed a duodenal ulcer. However, after treating the ulcer, a pulmonary metastasectomy was performed and no obvious recurrence was noted. Typically, for treatment of extrahepatic metastases of HCC, drugs such as sorafenib or lenvatinib that have molecular targets are selected according to a treatment algorithm based on liver cancer practice guidelines. However, these drugs were not effective in this case, whereas arterial injection chemotherapy showed satisfactory therapeutic effect on the recurrences in the liver. Although there was a complication of duodenal ulcer, this case report highlights that combined modality therapy including arterial injection chemotherapy is successful in treating HCC.

Outcomes of 50 Cases of Pediatric Liver Transplantation for Intrapulmonary Shunt While Considering the Deteriorated Prognosis of Severe Intrapulmonary Shunt Patients.

BACKGROUND: Intrapulmonary shunt (IPS) is recognized in 10% of chronic liver disease patients. Liver transplantation (LT) is associated with a high risk of morbidity and mortality in patients with IPS. PATIENTS AND METHODS: Of 519 pediatric LT cases between November 2005 and October 2018, 50 patients with IPS were enrolled in this study. The patients were divided into 3 groups, according to the shunt ratio, calculated by scintigraphy: mild (15%-20%, n = 26), moderate (20%-40%, n = 19), and severe (> 40%, n = 5). We compared the patients' characteristics before LT and the outcomes of LT between these groups. RESULTS: The major original disease resulting in LT in the mild and moderate groups was biliary atresia (73.1% and 52.6%, respectively), while that in the severe group was congenital portosystemic shunt (60%). The median ages at LT were 7.5, 6.1, and 8.3 years in the mild, moderate, and severe groups, respectively. All of the mild and moderate IPS patients lived; however, 3 patients with severe IPS (60.0%) died within 3 months. The shunt ratios of the mild and moderate IPS patients normalized within 2 years after LT, while the 2 surviving severe IPS patients showed a slight improvement. The autopsy findings of the lung in 1 deceased severe IPS patient showed medial hypertrophy and proliferation of intimal cells of the pulmonary arteries, suggesting a diagnosis of portopulmonary hypertension. CONCLUSIONS: LT can be safely performed for mild and moderate IPS patients; however, LT for severe IPS patients should be carefully indicated because concomitant portopulmonary hypertension may be masked by IPS.

[Study of the Treatment for Colorectal Cancer(CRC)in Elderly People Aged 80 Years or Older].

Aging in local cities is increasing in Japan, and Kitakyushu city is one of them. In particular, in the area in which our hospital is located, the old-age dependency ratio(ie, individuals who are 65 years old or older per hundred individuals who are 15-64 years old)is 35.2%, which is much higher than the old-age ratio of 26% in Japan, and the average age is 50.6 years. In Yahatahigashi-ku, elderly people who are older than 80 years of age account for 35.4%of the population. In consideration of this, we examined how far to do the treatment administered for CRC in elderly patients. We studied 17 patients who were older than 80 years of age and diagnosed with CRC in 2017. The performance status(PS)scores were PS 0, 1, 2, 3, and 4 in 4, 5, 1, 6, and 1 cases(s), respectively. The patients who were immobile, but still able to retain regular dietary intake, also underwent surgery. The degree of progression of the cancer was Stage Ⅰ, Ⅱ, ⅢA, ⅢB, and Ⅳ in 1, 11, 3, 0, and 2 cases, respectively, and chemotherapy was administered for the 2 patients with Stage Ⅳcancer. One patient died unexpectedly due to thoracic aortic rupture after the surgery. In our hospital, we positively perform surgeries for CRC to avoid decreases in ADL. On the other hand, we often encounter unexpected complications due to many comorbidities. We report the CRC treatment strategy for elderly people in our hospital with specific examples.

[A Case Report of Gastrointestinal Bleeding with Difficulty in Diagnosis].

The authors report a case involving a 55-year-old female patient who presented with melena and anemia 8 years ago. Esophagogastroduodenoscopy, colonoscopy, and CT did not reveal any sign of lesions except multiple uterine myoma. On reevaluation after the onset of melena, we did not find any lesions. However, the patient had a recurrent episode of melena with progressive anemia(Hb level 12.8 g/dL→9.8 g/dL). CT revealed a 29mm mass in the right side of the pelvis, which was retrospectively observed in the past CT scan, although its position had changed. We suspected gastrointestinal stromal tumor (GIST). Small intestine fluoroscopy revealed the tumor with effusion of barium inside the translucent areas of the ileum. For diagnostic treatment, laparoscopic partial jejunum resection was performed. Pathological diagnostic examination revealed that the tumor consisted of spindle cell disarray with moderate density, fewer heterocysts, and rare mitosis. The tumor cells were c-kit positive and CD34 negative in immunohistochemistry. All the results were consistent with GIST. Eight years had passed before diagnosis and surgical treatment were performed. This case report emphasizes the difficulty of diagnose of GIST because of its low malignancy and slow progression.

[Appendix Cancer with Long-Term Survival after Multimodality Therapy-A Case Report].

We report a case of long-term survival in a 65-year-old woman with recurrent appendix cancer. In March 2002, she was diagnosed with appendix cancer and underwent ileocecal resection. The pathological diagnosis was mucinous cystadenocarcinoma, pT2N0M0, Stage Ⅰ. In April 2006, ovariohysterectomy was performed for right ovarian metastases. In February 2011, tumor resection was performed for disseminated recurrence after 4 courses of systemic chemotherapy(bevacizumab plus mFOLFOX6). Although no recurrent lesions had been detected on imaging, stepwise elevation of serum CEA level was observed from June 2016. In November 2017, computed tomography scan revealed a slow-growing tumor on the liver. We performed partial resection of the right hemidiaphragm for the disseminated tumor, and the pathological diagnosis was mucinous adenocarcinoma. The patient has been on continuous postoperative follow-up without recurrence until June 2019. Appendix cancer is relatively rare and has a worse prognosis compared to colorectal cancer because of higher frequency of disseminated metastases. With the multimodality therapy, our patient showed long-term survival over 17 years despite a disseminated recurrence. In cases of mucinous cystadenocarcinoma of the appendix, persistent follow-up and aggressive treatment are recommended.

[Giant Retroperitoneal Liposarcoma Treated by Surgical Resection and Chemotherapy - A Case Report].

As the treatment for the liposarcoma, there is no effective chemotherapy and a surgical remedy is required. We present the case of a 64-year-old man who complained about difficulty in swallowing and discomfort of throat. Computed tomography revealed a large enhancing left sided retroperitoneal mass invading the retroperitoneal space and it was displaced to the right. Preoperative diagnosis was retroperitonealmal ignant tumor. Tumor excision were performed and around 4.0 kg tumor was removed though its size was too big and resected it separately. Tumors increased 5 months later and became the second enucleation. After the second operation, we used eribulin as postoperative adjuvant chemotherapy. However, we needed extraction 3 times by the surgery because it recurred as peritonealdissemination. We continue surgicaltreatment and chemotherapy together as there are a part increasing relatively slowly and a high grade part increasing rapidly.

[A Case Involving the Re-Application of TAE for the Rupture of Recurrent Dissemination Lesion after Initial TAE and Hepatectomy Was Performed for A Previous Rupture of HCC].

The patient was a 65-year-old man who had been previously diagnosed with chronic hepatitis B, but the patient had discontinued treatment while in his thirties. The patient was admitted to the emergency department after losing consciousness due to abdominal pain. Emergency contrast CT was performed in the shock state, and the diagnosis was hemorrhagic shock due to rupture of hepatocellular carcinoma(HCC). Emergency TAE was performed, and hemostasis was successful due to left hepatic arterial embolism. The tumor was confined to the liver lateral area and it was judged to be resectable curatively, upon state restoration. Ten days after TAE, lateral segmentectomy of the liver was performed. Pathological findings indicated moderately differentiated HCC, mostly necrotic and partially viable. He was discharged on 11POD. On 69POD, the patient reexperienced sudden abdominal pain after lunch. The abdominal pain continued while emergency contrast CT was performed at the time of visit in the shock state. Recurrence of multiple dissemination via high-absorption ascites was found around the largest tumor nest with lower left diaphragm diameter of 15cm, and it was judged that the HCC disseminated recurrence had ruptured. Emergency TAE was performed again, and hemostasis was successful by embolization of the left gastric artery and lower left diaphragm artery. Subsequently, tumor growth slowed after initiating oral administration of sorafenib, and the patient is alive 8 months after re-TAE.

[An Examination of Colon Cancer Treatment Policies for the Elderly].

Currently, the rate of aging is increasing rapidly and the number of elderly patients in hospitals is rising in Japan. Under such circumstances, we established an emergency care unit for the elderly at our hospital in July 2014 to provide acute healthcare of the community. Our unit has been active in providing treatment for acute diseases in elderly individuals in the community. We are also pursuing continuous medical care for elderly individuals in collaboration with the community comprehensive care unit at our hospital and other facilities in the community, such as care facilities for the elderly and specialist elderly nursing homes. From January to December 2015, we examined treatment policies for colon cancer at our hospital. The presence or absence of dementia and patient's age are factors considered before treatment at our hospital; however, in many cases colon cancer was treated using surgery if the patient's generalcondition permitted it. In colon cancer patients, this takes into consideration the decreased quality of life resulting from losing the ability to eat due to bleeding and intestinal obstruction. We hereby report specific cases of colon cancer treatment policies for elderly patients at our hospital, together with a discussion of the literature.

[Advanced Digestive Cancer in Super Elderly Patients More Than 85 Years Old - Two Cases That Required Major Invasive Surgery].

Case 1 involved an 87-year-old woman. She had increased serum amylase levels, and intraductal papillary mucinous adenocarcinoma( IPMC)in the accessory pancreatic duct was diagnosed following various medical examinations. Radical surgery is possible for such a lesion when there are no issues detected following evaluation. The patient and her family decided that she should undergo surgery; therefore, pancreatoduodenectomy was performed for Stage III IPMC. Various morbidities required medical treatment, but she was finally discharged from hospital 89 days after surgery. She has had no recurrence 2 years and 11 months after surgery. Case 2 involved a 90-year-old man. He had liver dysfunction, and progressive hepatocellular carcinoma( HCC)was diagnosed based on computed tomography(CT)findings. The tumor size reduced to around 10 cm with enforced 2 degrees TACE. The patient and his family chose for him to undergo radical surgery; therefore, right trisegmentectomy of the liver was performed for Stage III HCC. He was discharged from the hospital 22 days after surgery, and has had no recurrence for the past 1.6 years. More careful examination and a general assessment are necessary to make decisions on surgical indications in super elderly patients.

[Relapse-Free Survival Following Multidisciplinary Therapy for Hepatocellular Carcinoma with Multiple Lung Metastases--A Case Report].

Chemotherapy is not effective for metastatic hepatocellular carcinoma(HCC); however, prolonged survival can be expected for patients with multiple metastases who are treated with surgical resection in addition to chemotherapy. We present a case of a 36-year-old woman with hepatitis B who developed HCC with multiple intrahepatic and lung metastases after undergoing resection of HCC in 2010 in Canada. The patient returned to Japan for additional treatment. She was treated with TACE therapy and systemic chemotherapy, but her lung metastases did not improve. The patient's PIVKA-Ⅱ levels remained moderately elevated after initiation of chemotherapy. Therefore, we performed surgical resection of the lung metastases in March 2014. Five months later, the patient received additional TACE therapy when an isolated metastasis was found in the residual liver. Since then, no recurrence of HCC has been found, and the patient's PIVKA-Ⅱ levels have remained in the normal range. This case demonstrates that surgical resection for multiple lung metastases is possible in select patients.

[A Case That in Most Part of the Metastatic Liver Tumor Fell into Spontaneous Necrosis after Surgery of Rectal Cancer].

We present a case of a 74-year-old woman treated with maintenance dialysis for chronic renal failure. She had undergone intravascular treatment of lower limb arteriosclerosis obliterans 3 times. Low anterior resection was performed for rectal cancer StageⅡ, but adjuvant chemotherapy was not administered after the operation. S5/S6 partial hepatectomy was performed after confirming a liver metastatic recurrence 7 months after the first operation. Tumor pathology examination of the resected specimen revealed necrosis in most parts of the specimen. Residual primary lesion similar to adenocarcinoma tissue was found only in a small part of the specimen. Artery wall embolism and recanalization image with cholesterol crystals indicated a Grison's lesion, which was considered to have likely developed into tumor necrosis from the embolization. Spontaneous regression of a malignant tumor is a rare condition found 1 case in 6-10 ten thousand cases. In hepatocellular carcinoma, secondary tumor infarction from tumor invasion and tumor thrombus may occur. The present case was a metastatic liver cancer, in which the cholesterol crystal embolism possibly reached the tumor necrosis. The suggested cause of the cholesterol crystal embolism in this case was intravascular treatment related.

CT and endoscopic evaluation of larynx and trachea in mucopolysaccharidoses.

BACKGROUND: Mucopolysaccharidoses (MPSs) are lysosomal storage disorders caused by lysosomal enzyme deficiencies that result in systemic accumulation of glycosaminoglycans (GAGs). Accumulation of GAGs in the upper airway can lead to respiratory failure. The aim of this study was to investigate changes of the airway by flexible endoscopy and CT. METHODS: Thirty-five patients aging from 2 to 16 years (mean: 9.2±4.4 years) participated in this study. The majority had MPS I (n=5) or MPS II (n=25). The shape of the trachea and the cross-sectional trachea surface area (TSA) was determined at the Th1 and Th2 levels. Airway obstruction was evaluated from endoscopic findings and classified into 3 grades (Grades 0, 1, and 2). Forty-five patients in the control group who underwent tracheal CT for other conditions were retrospectively selected from the database. RESULTS: Tracheal morphology was abnormal in 50-60%, which showed a transversely collapsing narrow trachea. Tracheal deformity was severe in MPS II and MPS IV. The mean TSA of the MPS patients was 55.5±29.0 mm(2) at Th1 and 61.4±29.0 mm(2) at Th2, while that of the control group was 90.1±41.9 mm(2) and 87.9±39.3 mm(2), respectively. Respiratory distress was noted in 15 of the 35 patients, among whom 7 patients showed tracheal deformity and 7 patients had laryngeal redundancy. Three patients had no abnormalities of the larynx or trachea, so other factors such as pharyngeal stenosis or lower airway stenosis might have contributed to their respiratory distress. CONCLUSION: CT and flexible endoscopy allow quantitative and morphological evaluation of airway narrowing, which is beneficial for airway management in MPS children.