A three-dimensional measurement method on MR arthrography of the hip to classify femoro-acetabular impingement.

PURPOSE: (1) To investigate correlations between different types of FAI and the ratio of acetabular volume (AV) to femoral head volume (FV) on MR arthrography. (2) To assess 2D/3D measurements in identifying different types of FAI by means of cut-off values of AV/FV ratio (AFR). MATERIALS AND METHODS: Alpha angle, cranial acetabular version, acetabular depth, lateral center edge angle, AV, and FV of 52 hip MR arthrography were measured. ANOVA test correlated different types of FAI with AFR. ROC curves classified FAI by cut-off values of AFR. Accuracy of 2D/3D measurements was calculated. RESULTS: ANOVA test showed a significant difference of AFR (p value < 0.001) among the three types of FAI. The mean values of AFR were 0.64, 0.74, and 0.89 in cam, mixed, and pincer types, respectively. Cut-off values of AFR were 0.70 to distinguish cam types from mixed and pincer types, and 0.79 to distinguish pincer types from cam and mixed types. Cut-off values identified 100%, 73.9%, and 55.6% of pincer, cam, and mixed types. 2D and 3D classifications of FAI showed accuracy of 40.4% and 73.0%. CONCLUSIONS: 3D measurements were clearly more accurate than 2D measurements. Distinct cut-off values of AFR discriminated cam types from pincer types and identified pincer types in all cases. Cam and mixed types were not accurately recognized.

Role of cone-beam computed tomography with a large field of view in Goldenhar syndrome.

INTRODUCTION: Goldenhar syndrome is a rare disease with hemifacial microsomia and craniofacial disorders originating from the first and second branchial arches, such as ocular, auricular, and vertebral anomalies. The complexity and variety of the ways in which the disease presents itself usually need several examinations. In this study, we aimed to evaluate both craniofacial and vertebral skeletal anomalies and asymmetries between the nonaffected and affected sides in patients with Goldenhar syndrome by using cone-beam computed tomography. METHODS: Ten patients (7-14 years old; 6 boys, 4 girls) were evaluated via NewTom 5G cone-beam computed tomography (QR srl, Verona, Italy) with a large field of view (18 × 16 cm). Ten anatomic facial landmarks were identified to measure the following distances bilaterally: sella turcica (ST)-mandibular angle, ST-condyle, ST-mastoid, ST-mental foramen, ST-fronto zygomatic suture, ST-zygomatic temporal suture, ST-zygomatic facial foramen, ST-sphenopalatine fossa, mandibular angle-mandibular symphysis, and mandibular angle-condyle. The following 6 volumes were calculated bilaterally: orbit, maxillary sinus, condyle, external ear canal, middle ear, and internal auditory canal. These measurements were performed to assess skeletal asymmetries to compare the nonaffected side with the affected side by the Wilcoxon test. Cervical spine anomalies were classified into fusion anomalies and posterior arch deficiencies. RESULTS: All patients showed a deficit of skeletal development on the affected side. Statistically significant differences (0.001 ≤ P value ≤ 0.043) between the nonaffected and affected sides were recorded for all measurements, except for ST-frontozygomatic suture, mandibular angle-mandibular symphysis, and maxillary sinus volume. Vertebral fusion anomalies and posterior arch deficiencies were found in 7 and 4 patients, respectively. CONCLUSIONS: Cone-beam computed tomography with a large field of view was able to accurately identify craniofacial and vertebral skeletal anomalies, and to quantify asymmetries between the nonaffected and affected sides for an efficient maxillofacial treatment planning.

Repetition of Examination Due to Motion Artifacts in Horizontal Cone Beam CT: Comparison among Three Different Kinds of Head Support.

AIMS AND OBJECTIVES: The aim of this study was to evaluate the repetition rate of examination due to motion artifacts in horizontal cone beam computed tomography, using three different kinds of head support, with reference to the patient's age. Further purpose was to evaluate how comfortable head supports were. MATERIALS AND METHODS: Seven hundred and fifty patients underwent a maxillofacial/dental arches volumetric imaging scan. They were divided into three groups depending on the head support used: foam headrest, foam headrest with head strap, and head restraint helmet. Each group was subdivided into three age groups: ≤18-year-old, 19-65-year-old, and ≥66-year-old patients. A severity index of motion artifacts, divided into four tiers from absence to remarkable artifacts, was adopted. Finally, each patient gave their judgment about the head support comfort by a questionnaire including ten yes/no questions. A three-score scale (insufficient, sufficient, and good) was used to judge the comfort. Collected data were analyzed using the SPSS® version 23.0 statistical analysis software. RESULTS: Forty-one patients (5.4%) repeated the examination. In 16 (2.1%), 15 (2.0%), and 10 (1.3%) of them, foam headrest, foam headrest with head strap, and head restraint helmet were used, respectively. Examination was repeated in 5.3%, 3.8%, and 10.6% in ≤18-year-old, 19-65-year-old, and ≥66-year-old patients, respectively. Patients almost always judged good the comfort for each kind of support. The lowest percentage of satisfaction was observed for the headrest with head strap and was judged good in 78% of the cases. CONCLUSIONS: The repetition rate of examination showed similar values among the foam headrest, foam headrest with head strap, and head restraint helmet in under 66-year-old patients. In over 65-year-old patients, the head restraint helmet obviously decreased the repetition rate of examination. All three head supports were good comfort, especially the foam headrest.

Parvovirus b19 DNA CpG dinucleotide methylation and epigenetic regulation of viral expression.

CpG DNA methylation is one of the main epigenetic modifications playing a role in the control of gene expression. For DNA viruses whose genome has the ability to integrate in the host genome or to maintain as a latent episome, a correlation has been found between the extent of DNA methylation and viral quiescence. No information is available for Parvovirus B19, a human pathogenic virus, which is capable of both lytic and persistent infections. Within Parvovirus B19 genome, the inverted terminal regions display all the characteristic signatures of a genomic CpG island; therefore we hypothesised a role of CpG dinucleotide methylation in the regulation of viral genome expression.The analysis of CpG dinucleotide methylation of Parvovirus B19 DNA was carried out by an aptly designed quantitative real-time PCR assay on bisulfite-modified DNA. The effects of CpG methylation on the regulation of viral genome expression were first investigated by transfection of either unmethylated or in vitro methylated viral DNA in a model cell line, showing that methylation of viral DNA was correlated to lower expression levels of the viral genome. Then, in the course of in vitro infections in different cellular environments, it was observed that absence of viral expression and genome replication were both correlated to increasing levels of CpG methylation of viral DNA. Finally, the presence of CpG methylation was documented in viral DNA present in bioptic samples, indicating the occurrence and a possible role of this epigenetic modification in the course of natural infections.The presence of an epigenetic level of regulation of viral genome expression, possibly correlated to the silencing of the viral genome and contributing to the maintenance of the virus in tissues, can be relevant to the balance and outcome of the different types of infection associated to Parvovirus B19.