Osteoid osteoma appearing after bony fracture in a girl with osteogenesis imperfecta.

Osteoid osteoma (OO) is a common, benign bone tumor. However, there are no case reports of OO associated with osteogenesis imperfecta (OI), or pathological fractures in OO. A 3-year-old girl with OI sustained a complete right tibial diaphyseal fracture. Bony fusion was completed after 4 months of conservative therapy; nevertheless, 18 months later spontaneous pain appeared at the fracture site, without any cause. Plain radiographs showed a newly apparent, rounded area of translucency 1 cm in diameter, just overlapping the previous fracture. Images obtained using three-dimensional time-resolved contrast-enhanced magnetic resonance angiography showed strong central enhancement in the early phase, with an apparent nidus, suggesting the diagnosis of OO. Nineteen months after the first fracture, while skipping, the patient refractured her tibial diaphysis at the site of the previous fracture. This is a very rare case of OO, apparently co-existing with OI and leading to a bony fracture. In our case, the combination of bone fragility in OI and a recent fracture at the site of the OO may have caused the re-fracture.

Retinal hemorrhages and damages from tractional forces associated with infantile abusive head trauma evaluated by wide-field fundus photography.

We evaluated the distribution and types of retinal hemorrhages (RHs) and other damages in eyes with abusive head trauma (AHT). This retrospective, consecutive case series of AHT and non-AHT conditions involved 54 children with AHT, 43 children with head bruises, and 49 children with blunt eye trauma, each of non-AHT supported by reliable witness accounts. RHs and other damage were evaluated using ophthalmoscopy and wide-field fundus photography. A variety of RH types and other damage were identified in the AHT group but not in the non-AHT group. RHs in AHT extended from the posterior pole to the far periphery in 77% of eyes and on/near the veins in 86% and arteries in 85%, most of which were in the far periphery. Retinoschisis, white-dot lesions, and retinal folds were seen even in the far periphery. RHs on/near the veins and arteries, retinoschisis, and retinal folds suggest a traumatic mechanism of the tractional force of the vitreous that is attached to the entire retinal surface. Identifying the distribution and arterio and venous origins of RHs is a key factor in determining the association with trauma. Thus, wide-field fundus photography is useful to record and evaluate the origin of the RHs and other retinal damage.

Sirolimus treatment for intractable lymphatic anomalies: an open-label, single-arm, multicenter, prospective trial.

Introduction: Intractable lymphatic anomalies (LAs) include cystic lymphatic malformation (LM; macrocystic, microcystic, or mixed), generalized lymphatic anomaly, and Gorham-Stout disease. LAs can present with severe symptoms and poor prognosis. Thus, prospective studies for treatments are warranted. We conducted a prospective clinical trial of sirolimus for intractable LAs. Methods: This was an open-label, single-arm, multicenter, prospective trial involving five institutions in Japan. All patients with LAs received oral sirolimus once daily, and the dose was adjusted to ensure that the trough concentration remained within 5-15 ng/mL. We prospectively assessed the drug response (response rate for radiological volumetric change in target lesion), performance state, change in respiratory function, visceral impairment (pleural effusion, ascites, bleeding, pain), laboratory examination data, quality of life (QOL), and safety at 12, 24, and 52 weeks of administration. Results: Eleven patients with LAs (9 generalized lymphatic anomaly, 1 cystic LM, 1 Gorham-Stout disease) were treated with sirolimus, of whom 6 (54.5%; 95% confidence interval: 23.4-83.3%) demonstrated a partial response on radiological examination at 52 weeks of administration. No patients achieved a complete response. At 12 and 24 weeks of administration, 8 patients (72.7%) already showed a partial response. However, patients with stable disease showed minor or no reduction after 12 weeks. Adverse events, such as stomatitis, acneiform dermatitis, diarrhea, and fever, were common with sirolimus. Sirolimus was safe and tolerable. Conclusion: Sirolimus can reduce the lymphatic tissue volume in LAs and may lead to improvements in clinical symptoms and QOL.

Assessment of mediastinal shift angles in congenital pulmonary airway malformation: a new fetal magnetic resonance imaging indicator of congenital lung disease.

BACKGROUND: The mediastinal shift angle is a new fetal magnetic resonance imaging (MRI) index that is reportedly correlated with postnatal survival in fetuses with congenital diaphragmatic hernia. However, its correlation in patients with congenital pulmonary airway malformation (CPAM) has not been assessed. OBJECTIVE: This study aimed to establish a normal range for the right/left mediastinal shift angles, to evaluate the mediastinal shift angle in fetuses with CPAM, to compare the mediastinal shift angle with the CPAM volume ratio, and to evaluate the predictive value of the mediastinal shift angle measurements. MATERIALS AND METHODS: To establish the normal range, we measured the mediastinal shift angle bilaterally in 124 fetuses without any lung abnormality (the control group). Subsequently, the mediastinal shift angle was measured in 32 fetuses pathologically diagnosed with CPAM. Moreover, the mediastinal shift angle and CPAM volume ratio were compared using fetal MRI. RESULTS: The mean values for the right/left mediastinal shift angles were 18.6°/26.3° and 39.2°/35.9° for control fetuses and fetuses with CPAM, respectively. The mediastinal shift angle and the CPAM volume ratio showed a positive statistical correlation. The area under the curve demonstrated high discriminatory accuracy for the mediastinal shift angle (0.76). CONCLUSION: The mediastinal shift angle has potential to replace the CPAM volume ratio for evaluating the severity of CPAM in fetal MRI.

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.

"Another inchworm sign" on dynamic contrast-enhanced magnetic resonance imaging in pediatric patients with cystitis cystica and glandularis: Radiologic-pathologic correlation.

Cystitis cystica and glandularis is a hyperproliferative disease of the urothelium, and may form a papillary or polypoid mass. Clinically, these mass lesions are often difficult to distinguish from malignant tumors. We present a pediatric patient of cystitis cystica and glandularis with a bladder mass and discuss dynamic contrast-enhanced magnetic resonance imaging (MRI) findings and histopathological profiles, which have not been previously explored in the literature. Dynamic contrast-enhanced MRI showed unique, superficial, strong enhancement that resembles an inchworm in appearance. The term "inchworm sign" is a characteristic finding on diffusion-weighted MRI, proposed as a criterion for T-staging in non-muscle-invasive bladder cancer. We would like to propose another "inchworm sign" on dynamic contrast-enhanced MRI as a new hallmark of cystitis cystica and glandularis, which may differentiate it from a malignant tumor.

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.

Incidence of hospitalization for abusive head trauma in Chiba City, Japan.

BACKGROUNDS: This study aimed to examine the incidence of abusive head trauma (AHT) admissions by calculating admission rates of AHT cases among infants <12 months old in a population-based sample in Chiba city, Chiba prefecture, Japan. METHODS: We retrospectively examined medical records of infants admitted to all pediatric secondary and tertiary hospitals in Chiba city between 2011 and 2015. We collected 13 AHT cases, as assessed by hospital-based multidisciplinary child protection teams. One experienced pediatric radiologist and two pediatricians evaluated the case histories and computed tomography images of cases to evaluate them clinically as "strongly" or "moderately" suspected AHT. RESULTS: The overall incidence per 100 000 person-years was 34.5 cases (95% confidence interval (CI): 18.4-59.1), of which 13.3 (95% CI: 4.3-31.0), were strongly suspected to be AHT and 21.3 (95% CI: 9.2-41.9) were moderately suspected. There were no statistical differences in computed tomography findings between severe and moderately suspected AHT. CONCLUSIONS: The incidence of hospitalization of infants with AHT was similar to that reported in population-based studies in other countries.

Ultrasonography as a Diagnostic Support Tool for Childhood Takayasu Arteritis Referred to as Fever of Unknown Origin: Case Series and Literature Review.

INTRODUCTION: Childhood Takayasu arteritis (c-TA) often shows nonspecific symptoms, such as fever of unknown origin (FUO). Delay of diagnosis may result in organ dysfunction by arterial occlusion; therefore, early diagnosis is very important. Although ultrasonography is the first-line screening tool for children with FUO, its diagnostic efficacy of evaluation of systemic arteries in c-TA that presents as FUO remains unclear. We evaluated the suitability of ultrasonography evaluation that included systemic vessels for the early diagnosis of c-TA initially presenting as FUO. METHODS: We review five patients who received a diagnosis of c-TA in our institution and also performed a literature review regarding TA cases with FUO and diagnosed on the basis of initial ultrasonography. RESULTS: As in our cases, the median period from onset to diagnosis was 25 days (interquartile range [IQR], 21-35). Comparing the initial ultrasonography findings with later contrast-enhanced computed tomography (CECT) findings in the abdominal aorta, celiac artery, superior mesenteric artery, bilateral renal arteries, and bilateral common carotid arteries, the concordance rate between ultrasonography and CECT was moderate (Kappa coefficient was 0.50). All the patients were successfully treated without severe vascular damage. The literature review revealed 12 articles; although 9 of the 13 patients did not show the characteristic features (such as blood pressure discrepancy, bruit, or pulse deficiency), the median time to diagnosis was still 5 months (IQR, 3-12). CONCLUSIONS: During initial screening for patients with FUO, ultrasonography including evaluation of systemic vessels could contribute to earlier diagnosis of c-TA.

Value of parametric indexes to identify tracheal atresia with or without fistula on fetal magnetic resonance imaging.

BACKGROUND: Tracheal atresia causes some secondary changes (dilated trachea, flattened/inverted diaphragm, hyperintense and hyperinflated lungs). They can be reduced if a high airway fistula is present. OBJECTIVE: This study evaluated fetal MR images of tracheal atresia and the secondary changes, focusing on the presence of a fistula. MATERIALS AND METHODS: We assessed fetal MR images of tracheal atresia without fistula (n=4, median 26 weeks), tracheal atresia with fistula (n=4, median 33 weeks) and controls (n=30, median 32 weeks). We evaluated airway obstruction using true-positive rate in tracheal atresia and false-positive rate in controls indicating they are likely normal variants. Tracheal diameter, craniocaudal-anteroposterior ratio of the right hemidiaphragm, lung-to-liver signal intensity ratio, and cardiothoracic ratio were compared among the three groups using the Kruskal-Wallis test followed by pairwise comparison using the Mann-Whitney U test. RESULTS: True-positive rate was 100% in tracheal atresia, while false-positive rate was 20% in controls. The Kruskal-Wallis test showed differences among groups in craniocaudal-anteroposterior ratio and cardiothoracic ratio (P<0.001) but not in tracheal diameter (P=0.256) or lung-to-liver signal intensity ratio (P=0.082). The pairwise comparison in craniocaudal-anteroposterior ratio and cardiothoracic ratio showed differences between controls and tracheal atresia without fistula (P<0.01) and with fistula (P<0.05). CONCLUSION: Fetal MRI is useful for the diagnosis of tracheal atresia, and detection of airway obstruction is essential. Lower craniocaudal-anteroposterior ratio and cardiothoracic ratio might be reliable measures even if a fistula is present.

Acute hematogenous pelvic osteomyelitis: appropriate timing for magnetic resonance imaging.

BACKGROUND: The precise time of appearance of bone marrow edema in acute hematogenous pelvic osteomyelitis (AHPO) is unknown. The purpose of the present research is to clarify the time of appearance of bone marrow edema on magnetic resonance imaging (MRI) in AHPO. Our hypothesis was that onset is slower than in long-bone osteomyelitis. METHODS: We selected 12 patients (mean, 11.8 years) with MRI findings and clinical diagnosis of AHPO. The signal ratios of bone marrow (BM) and gluteus maximus muscle (M, BM/M ratio) in fat-suppressed T2- and T1-weighted images (T2WI, T1WI) were calculated to evaluate changes in bone-marrow signals. The correlation between BM/M ratios and days from onset was evaluated statistically and compared with lower extremity osteomyelitis. RESULTS: Bone marrow/M ratio of T2WI increased over time after the onset of the primary symptom in all patients and showed a statistically positive correlation (r = 0.36). In seven patients in whom an MRI scan was conducted twice, all showed higher values for the second MRI, and changes were more pronounced over time. The mean BM/M ratio of T2WI was 4.1 when 7 days or less had elapsed from the primary symptom, and 6.4 when more than 7 days had elapsed. The BM/M ratios in the sacroiliac joint group were lower than in the non-sacroiliac joint group. CONCLUSIONS: Unlike long-bone osteomyelitis, it took 1 week before findings for AHPO became fully evident. A definitive diagnosis can be made in patients with suspected sacroiliitis by performing a further MRI scan at 7 days or later.

Mediastinal and hilar soft tissue mass-like lesions in congenital unilateral pulmonary vein atresia: A retrospective review of seven pediatric patients.

BACKGROUND: Congenital unilateral pulmonary vein atresia (CUPVA) is known to lead to the formation of an abnormal confluent mediastinal and hilar soft tissue mass, thoracic hypoplasia, and interlobular septal thickening on the affected side. The purpose of the present study is to investigate the frequency and severity of mediastinal soft tissue mass-like lesions and examine other abnormal findings associated with CUPVA. METHODS: We retrospectively reviewed seven children with CUPVA who underwent contrast-enhanced CT scans and measured the soft tissue mass volume in the bilateral mediastinum (affected and normal side). The location of abnormal soft tissue was divided into three anatomical sections (paratracheal, peribronchial, and the dorsal aspect of the left atrium). The relationships among soft tissue volume and anatomical section were statistically evaluated. Also, the presence of thoracic hypoplasia, small ipsilateral pulmonary arteries, interlobular septal thickening, and ground-glass opacities were investigated. RESULTS: In all cases, CT scans confirmed the presence of confluent soft tissue mass-like lesions in the affected mediastinum. The soft tissue volume on the affected side was 5.5-fold greater than the volume on the normal side (average: 18.0 cm3 and 4.25 cm3 respectively, P < 0.01). Thoracic hypoplasia and interlobular septal thickening were found in all patients. Small pulmonary arteries and ground-glass opacities were present in six of the seven patients. CONCLUSION: Abnormal mediastinal and hilar soft tissue is commonly found in patients with CUPVA. So, if we encounter the mediastinal soft tissue mass in patients with CUPVA, no further test will be indicated.

Indication for voiding cystourethrography during first urinary tract infection.

BACKGROUND: There is confusion surrounding the precise indications for voiding cystourethrography (VCUG) during the assessment of vesicoureteral reflex (VUR) after a first febrile urinary tract infection (UTI). The aim of this study was to determine the combination of clinical, laboratory and ultrasonography factors correlating with grades IV-V VUR in young children with a first febrile UTI. METHODS: Children 0-24 months of age who were brought to the emergency department at National Center for Child Health and Development with the diagnosis of first time febrile UTI between March 2004 and May 2011, were enrolled. We compared clinical, laboratory and ultrasonography findings between children with grades IV-V VUR (high-grade VUR) and those with no or grades I-III VUR (normal or low-grade VUR). RESULTS: A total of 231 patients were eligible and 19 had high-grade VUR. Poor clinical appearance, presence of a uropathogen other than Escherichia coli, positive blood culture, hydroureter and thickened renal pelvic wall were all independently associated with high-grade VUR. When one or more of these factors were present, sensitivity, specificity, positive or negative predictive value, and positive or negative likelihood ratio were 94.7%, 69.4%, 23.1%, 99.3%, 3.1 and 0.1, respectively. When none of the factors was present, the proportion of high-grade VUR was 0.7%; if one factor, 11.3%; two factors, 55.6%; three factors, 85.7%. CONCLUSIONS: In the absence of five specific factors during the first febrile UTI episode in young children, VCUG is not necessary to detect high-grade VUR. When more than one factor is present, however, VCUG is indicated.

Efficacy and safety of sirolimus treatment for intractable lymphatic anomalies: A study protocol for an open-label, single-arm, multicenter, prospective study (SILA).

INTRODUCTION: Lymphatic anomalies (LAs) refer to a group of diseases involving systemic dysplasia of lymphatic vessels. These lesions are classified as cystic lymphatic malformation (macrocystic, microcystic or mixed), generalized lymphatic anomaly, and Gorham-Stout disease. LAs occur mainly in childhood, and present with various symptoms including chronic airway problems, recurrent infection, and organ disorders. Individuals with LAs often experience progressively worsening symptoms with a deteriorating quality of life. Although limited treatment options are available, their efficacy has not been validated in prospective clinical trials, and are usually based on case reports. Thus, there are no validated standards of care for these patients because of the lack of prospective clinical trials. METHODS: This open-label, single-arm, multicenter, prospective study will assess the efficacy and safety of a mammalian target of the rapamycin inhibitor sirolimus in the treatment of intractable LAs. Participants will receive oral sirolimus once a day for 52 weeks. The dose is adjusted so that the nadir concentration remains within 5-15 ng/ml. The primary endpoint is the response rate of radiological volumetric change of the target lesion confirmed by central review at 52 weeks after treatment. The secondary endpoints are the response rates at 12 and 24 weeks, respiratory function, pleural effusion, ascites, blood coagulation parameters, bleeding, pain, quality of life, activities of daily living, adverse events, side effects, laboratory examinations, vital signs, and pharmacokinetic data. RESULTS: This is among the first multicenter studies to evaluate sirolimus treatment for intractable LAs, and few studies to date have focused on the standard assessment of the efficacy for LAs treatment. Our protocol uses novel, uncomplicated methods for radiological assessment, with reference to the results of our previous retrospective survey and historical control data from the literature. CONCLUSIONS: We propose a multicenter study to investigate the efficacy and safety of sirolimus for intractable LAs (SILA study; trial registration UMIN000028905). Our results will provide pivotal data to support the approval of sirolimus for the treatment of intractable LAs.

Osteomyelitis of a sacral neurocentral synchondrosis: a case report of another metaphyseal equivalent.

Pelvic osteomyelitis may occur in a metaphyseal equivalent, defined as a portion of flat or irregular bone that is adjacent to cartilage. The pelvic bone is known to have several metaphyseal equivalents and of these, the sacroiliac joint is the most frequent site of involvement. However, a sacral neurocentral synchondrosis has not been recognized as a metaphyseal equivalent, and there have been no previous reports describing this as the site of origin of sacral osteomyelitis. We here report two cases of sacral osteomyelitis originating in a neurocentral synchondrosis, another metaphyseal equivalent. We, as pediatric radiologists, should recognize a sacral neurocentral synchondrosis as another metaphyseal equivalent, especially in infants and younger patients.

Pathological characterization of pachydermia in pachydermoperiostosis.

Pachydermoperiostosis is a rare hereditary disease, which presents with the cutaneous manifestations of pachydermia and cutis verticis gyrata. Histological findings in pachydermia frequently include dermal edema, mucin deposition, elastic fiber degeneration, dermal fibrosis and adnexal hyperplasia. However, the severity of these findings varies between clinical reports, and a systematic multiple-case clinicopathological correlative analysis has not been performed to date. In the present study, we reviewed the skin biopsy specimens obtained from the pachydermia of six pachydermoperiostosis patients. The severity of the characteristic histological features was semiquantitatively evaluated and correlated with the grade of pachydermia. Dermal edema, mucin deposition and elastic fiber degeneration were observed in all cases. Patients with severe pachydermia had sebaceous gland hyperplasia and fibrosis. These results suggest that the triad of mucin deposition, dermal edema and elastic fiber degeneration are found from very early stage pachydermia, and could be considered diagnostic findings. To ensure an earlier diagnosis of pachydermoperiostosis, a biopsy should be taken when a patient has grade 1 pachydermia to determine the presence of this histological triad.

The degree of spleen stiffness measured on acoustic radiation force impulse elastography predicts the severity of portal hypertension in patients with biliary atresia after portoenterostomy.

BACKGROUND/PURPOSE: Acoustic radiation focus impulse (ARFI) elastography is a new method for assessing the degree of tissue stiffness. We herein evaluated the degree of spleen stiffness (SS) using ARFI elastography in patients with biliary atresia (BA) after Kasai portoenterostomy (KPE). METHODS: We retrospectively collected the liver stiffness (LS) and SS values on ARFI elastography from 43 patients undergoing KPE between September 2010 and November 2013. We analyzed the correlations between these values and variables related to the severity of liver dysfunction and portal hypertension (PHT). The data were expressed as the standard deviation score (z-score) relative to the previously reported normal values for the patient's age. RESULTS: The SS value was significantly associated with the spleen diameter and development of collateral vessels, in comparison to the LS value. Interestingly, there was a significant correlation between SS value and the portal vein (PV) diameter. Thirty patients (69.8%) consequently underwent LT; these patients showed higher SS values and smaller PV diameters than the patients monitored without LT. CONCLUSIONS: The degree of SS measured on ARFI elastography can be used to predict the severity of PHT in BA patients after KPE.

Comparison of patients with Kawasaki disease with retropharyngeal edema and patients with retropharyngeal abscess.

UNLABELLED: Kawasaki disease with retropharyngeal edema (KD with RPE) is a rare complication, and it is diagnosed by neck CT. Most reported cases had a delayed diagnosis because those patients' conditions were misdiagnosed as retropharyngeal abscess (RPA). The purpose of this study was to differentiate KD with RPE from RPA. We performed a retrospective case-control study comparing children with KD with RPE to those with RPA hospitalized at the tertiary pediatric hospital in Tokyo between 2005 and 2011. The 39 patients revealing RPE on neck CT were divided into two groups: group A was classified as KD (n = 21) and group B was classified as non-KD (n = 18). Patients in group B were finally evaluated as having RPA clinically and were treated with antibiotic therapy. A significantly higher proportion of patients in group B complained of dysphagia (11 patients vs. 5 patients; p = 0.0170) and neck pain (17 patients vs. 12 patients; p = 0.0106). Neck CT revealed a ring enhancement (16 patients vs. no patients; p < 0.0001) and mass effect in a greater proportion of patients in group B (11 patients vs. 1 patient; p < 0.0003). CONCLUSION: Careful attention to manifestations and close analyses of CT imaging may allow clinicians to differentiate KD with RPE from RPA.