Partial Rhombencephalosynapsis and Chiari Type II Malformation in a Child: a True Association Supported by DTI Tractography

Partial rhombencephalosynapsis (PRECS) has been recently reported in association with Chiari II (CII). However, its existence as a true malformation is challenged due to the anatomical changes potentially induced by CII. The aim of this report was to investigate the contribution of midbrain/hindbrain tractography in this setting. A 13-year-old boy with a known CII malformation and operated myelomeningocele was referred for brain imaging after a first complex partial seizure. In addition to the classical features of CII, MRI showed partially fused cerebellar hemispheres and multiple supratentorial abnormalities. Diffusion tensor imaging (DTI) color map and tractography showed absent transverse fibers on the midsection of the cerebellum, scarce fibers of the middle cerebellar peduncle (MCP), absence of the middle pontine crossing tract, and fibers running vertically in the medial part of the cerebellum. Vertical mediocerebellar fibers are a feature of classical RECS and the paucity or absence of MCP fibers is mainly described in CII. In our patient, DTI and FT therefore demonstrated structural characteristics of both RECS and CII confirming their potential coexistence and suggesting possible shared embryological pathwa

Pseudoprogression after proton beam irradiation for a choroid plexus carcinoma in pediatric patient: MRI and PET imaging patterns

Purpose: Pseudoprogression is a rare complication of radiation therapy, and discrimination between true progression and pseudoprogression is of paramount importance for further medical care. We present a case of intra-axial pseudoprogression following complementary proton radiation therapy for a choroid plexus carcinoma in a child. We aim to highlight radiological patterns of pseudoprogression after proton beam therapy. Case report: A 6-year-old girl presented with choroid plexus carcinoma, manifesting as change in behavior, tremor, and balance disorder. Partial resection and chemotherapy were performed. Complementary localized proton beam therapy (54Gy) was administered on the residual tumor. Eight month follow-up MRI showed an abnormal, irregular, rim-like enhancement in the pons and both temporal lobes within the field of irradiation. These lesions had a low cerebral blood volume (CBV) on perfusion MR imaging and no restricted diffusion. However, the lesions were hypermetabolic on O-(2-[18F]fluoroethyl)-l-tyrosine (FET)-PET MRI. Follow-up MRI showed disappearance of these lesions confirming the perfusion MR diagnosis of pseudoprogression. Conclusion: Based on this case, radiological patterns of pseudoprogression after proton beam therapy may be a low CBV and no restricted diffusion. Lesions can be hypermetabolic on FET-PET imagin

Can early MRI distinguish between Kingella kingae and Gram-positive cocci in osteoarticular infections in young children?

Background: K. kingae is a common causative organism in acute osteoarticular infections (OAIs) in children under 4years of age. Differentiation between K. kingae and Gram-positive cocci (GPC) is of great interest therapeutically. Objective: Our aim was to identify early distinguishing MRI features of OAIs. Materials and methods: Thirty-one children younger than 4years of age with OAI underwent MRI at presentation. Of these, 21 were caused by K. kingae and ten by GPC. Bone and soft tissue reaction, epiphyseal cartilage involvement, bone and subperiosteal abscess formation were compared between the two groups. Interobserver agreement was measured. Results: Bone reaction was less frequent (P = 0.0066) and soft tissue reaction less severe (P = 0.0087) in the K. kingae group. Epiphysis cartilage abscesses were present only in the K. kingae group (P = 0.0118). No difference was found for bone abscess (P = 0.1411), subperiosteal abscess (P = 1) or joint effusion (P = 0.4414). Interobserver agreement was good for all criteria. Conclusion: MRI is useful in differentiating K. kingae from GPC in OAI. Cartilaginous involvement and modest soft tissue and bone reaction suggest K. kinga

Antenatal and postnatal ultrasound in the evaluation of the risk of vesicoureteral reflux

Antenatal hydronephrosis (ANH) is a frequent anomaly detected on fetal ultrasound scans. There is no consensus recommendation for the postnatal follow-up and/or the necessity to perform a voiding cystourethrography (VCUG) to diagnose vesicoureteral reflux (VUR). We conducted a cohort/non-randomized trial of 121 patients with ANH, defined as an anterior posterior diameter (APD) ≥5mm after the 20th week of gestation, to evaluate the ability of the antenatal and postnatal ultrasonography results to predict VUR. All infants had two successive ultrasounds at 5days and 1month, respectively, after birth. A VCUG was performed at 6weeks in children with a persistent APD ≥5mm and/or an ureteral dilatation observed on at least one of two postnatal ultrasounds. In total, 88 patients had VCUG and nine had VUR, with five having high-grade reflux (>grade II). The risk of VUR increased significantly with the degree of APD detected on the postnatal ultrasound scan (p = 0.03). The odds ratios were 5.0 [95% confidence interval (CI) 0.5-51.2] for APD = 7-9mm and 9.1 (95% CI 1.0-80.9) for APD ≥10mm. The results of this study show that among our patient cohort antenatal ultrasound was not predictive of reflux. There was, however, a relation between the importance of the postnatal renal pelvis diameter and the risk of VUR. A cut-off of 7mm showed a fair ability of ultrasonography to predict VUR and a cut-off of 10mm enabled all severe refluxes in the 88 patients who had a VCUG to be diagnose

MRI neurography and diffusion tensor imaging of a sciatic perineuroma in a child

Perineuroma, rare in children, presents as a painless mononeuropathy of a major nerve trunk. Resection of the lesion with end-to-end sural nerve grafting appears to be the treatment of choice. This technique is not recommended if the unhealthy segment of nerve is too long or if spinal roots are involved. However, in children, reports of direct MR evaluation of nerve trunks and of the exiting nerve roots are limited. We report a 7-year-old girl with an intramural sciatic nerve perineuroma in whom the diagnosis was made by MRI and confirmed by biopsy. The MR protocol combining 3-D T2-W STIR SPACE, fat-saturated gadolinium-enhanced T1-W images, and diffusion tensor imaging with tractography was a valuable tool for depicting peripheral nerve and roots in order to plan surgical treatmen

Diffusion-weighted imaging findings in Perthes disease with dynamic gadolinium-enhanced subtracted (DGS) MR correlation: a preliminary study

Background: Legg-Calvé-Perthes disease (LCP) is necrosis of the proximal femoral epiphysis of vascular origin. Clinical course and outcome in LCP disease varies considerably between different patients. Earlier prognostic criteria than those offered by conventional radiography are necessary to identify children who require prompt surgical treatment. Objective: To assess the significance of signal alteration on diffusion-weighted MR imaging (DWI MR) in LCP. Materials and methods: Twelve boys with unilateral LCP disease (Catterall grade 2 and 3), at the initial sclerotic stage and early fragmentation phase, underwent dynamic gadolinium-enhanced subtracted (DGS) and DWI MR. For DGS MR, the lateral pillar enhancement was recorded. For DWI imaging, we measured ADC values in the diseased and the unaffected epiphyses and metaphyses. Receiver operating characteristic curves were performed to analyze the performance of DWI in establishing agreement with the results of DGS MR, which is the gold standard for prognosis. Results: Femoral epiphysis increased diffusivity was observed in the affected hip in all cases. Increased metaphysis diffusivity in the affected side was observed in all cases with absent lateral pillar enhancement at DGS MR. Conclusion: DWI seems to be a noninvasive means of distinguishing between Perthes disease with favourable and unfavourable prognosi

MRI with fibre tracking in Cogan congenital oculomotor apraxia

Background: Congenital ocular motor apraxia (COMA) occasionally shares with Joubert syndrome (JS) and related disorders (JSRDs) a peculiar malformation, the ‘molar tooth sign' (MTS). In JSRDs, the absence of superior cerebellar peduncles (SCP) decussation is reported. Objective: To investigate whether COMA demonstrates similar abnormal axonal pathways. Materials and methods: Eight healthy age-matched controls, three children with clinical COMA and one child with clinical JSRD underwent examination with a 1.5-T MRI scanner. Diffusion-weighted imaging (DWI), colour-coded fractional anisotropy maps and three-dimensional diffusion tensor imaging (DTI) tractography of the cerebellorubral network were analyzed. Results: On DTI cartography, the ‘red dot' originally supposed to represent the SCP decussation in the midbrain was present in controls as well in those with COMA but absent in the single case with JS. In none of the subjects including controls was 3-D FT able to depict the SCP decussation. When seeded, the red dot resulted in the ventral tegmental decussation (VTD). It was normal in controls and in patients with COMA but was absent in our single patient with JSRD. MTS was identified in alla patients with COMA and in the patient with JSRD. Conclusion: MTS can be present in both COMA and JSRD but the underlying anatomy depicted by fibre tracking is distinct. The main difference is the integrity of the VTD in COM

Noninflammatory fallopian tube pathology in children

Noninflammatory tubal abnormalities are rare in children and usually not well covered by traditional educational material. The presenting symptoms are nonspecific and are common to many other conditions, so its preoperative diagnosis is rarely made. The purpose of this study was to review the hospital charts and imaging findings in children and sexually inactive adolescents who showed fallopian tube pathology. Understanding of the pertinent findings of previous imaging examinations might assist radiologists in making the correct preoperative diagnosis and increase the likelihood of preserving the fallopian tubes. The clinical entities described in this article include isolated tubal torsion, paratubal cysts, hydrosalpinx, undescended/ectopic fallopian tube, and tubal inguinal herni

Correlation of lung abnormalities on high-resolution CT with clinical graft-versus-host disease after allogeneic versus autologous bone marrow transplantation in children

Background: Late-onset noninfectious pulmonary complications (LONIPCs) are life-threatening complications of bone marrow transplantation (BMT). Several pathological patterns are described in the literature with different prognoses, and with different relationships to graft-versus-host disease (GVHD). The role of high-resolution CT (HRCT) is not yet well established. Objective: To illustrate different patterns of LONIPCs on HRCT in allogeneic versus autologous BMT in order to investigate the correlation with chronic GVHD (cGVHD). Materials and methods: A total of 67 HRCT scans were performed in 24 patients with noninfectious pulmonary disease at least 3months after BMT (16 allogeneic, 8 autologous). Abnormality patterns and extension on HRCT images were correlated with the clinical outcome and with the severity of cGVHD. Results: Of 24 patients, 9 showed LONIPCs (1 autologous, 8 allogeneic). There was a significant association between abnormalities on HRCT and severe cGVHD (P = 0.038), with no specific pattern. Prognosis seemed to be related to the severity of cGVHD and not to the extent of abnormalities on HRCT. Conclusion: The significant association between abnormalities on HRCT and severe GVHD suggests that LONIPCs can be a pulmonary manifestation of the disease. HRCT is a useful tool when combined with clinical dat