Comparing the supine and erect pelvis radiographic examinations: an evaluation of anatomy, image quality and radiation dose

Objectives: Pelvis radiographs are usually acquired supine despite standing imaging reflecting functional anatomy. We compared the supine and erect radiographic examinations for anatomical features, radiation dose and image quality. Methods: Sixty patients underwent pelvis radiography in both supine and erect positions at the same examination appointment. Measures of body mass index and sagittal diameter were obtained. Images were evaluated using visual grading analysis and pelvic tilt was compared. Dose-area-product (DAP) values were recorded and inputted into the CalDose_X software to estimate effective dose (ED). The CalDose_X software allowed comparisons using data from the erect and supine sex-specific phantoms (MAX06 & FAX06). Results: Patient sagittal diameter was greater on standing with an average 20.6% increase at the iliac crest (median 30.0, interquartile range [26.0 to 34.0] cm), in comparison to the supine position [24.0 (22.3 to 28.0) cm; p < 0.001]. 57 (95%) patients had posterior pelvic tilt on weight-bearing. Erect image quality was significantly decreased with median image quality scores of 78% (69 to 85) compared to 87% for the supine position [81 to 91] (p < 0.001). In the erect position the ED was 47% higher [0.17 (0.13 to 0.33) mSv versus 0.12 (0.08 to 0.18) mSv (p < 0.001)], influenced by the increased sagittal diameter. 42 (70%) patients preferred the standing examination. Conclusion: Patient diameter and pelvic tilt were altered on weightbearing. Erect images demonstrated an overall decrease in image quality with a higher radiation dose. Optimal acquisition parameters are required for erect pelvis radiography as the supine technique is not directly transferable.

Relationship between maternal bone biomarkers and fetal adiposity through normal pregnancy

Purpose To examine the association of maternal bone markers (sclerostin, sRANKL, osteocalcin, 25OHD3) with fetal intra-abdominal and subcutaneous adipose tissue deposition and birthweight during normal pregnancy. Methods One hundred pregnant women (aged 30.4±5.6 years, mean±SD) with pre-pregnancy BMI=24.1±4.6 kg/m² were seen prospectively during each trimester. At each visit they were submitted to anthropometric measurements, a fasting blood sampling, a 75gr oral glucose tolerance test (OGTT) and a fetal ultrasonogram. At birth, neonates had birth weight measurement. Results In the 2 nd trimester maternal sclerostin concentrations correlated positively with fetal abdominal circumference and birth weight; maternal sRANKL concentrations correlated positively with fetal abdominal subcutaneous fat thickness, sagittal abdominal diameter and abdominal circumference. Fetuses born to mothers with greater (&gt;254 ng/mL) compared to fetuses born to mothers with lower (≤254 ng/mL) sRANKL concentrations had greater abdominal circumference, sagittal diameter and abdominal subcutaneous fat thickness. Maternal serum sclerostin concentrations were the best positive predictors of birth weight. In the 3 rd trimester maternal sclerostin concentrations correlated positively with fetal sagittal abdominal diameter; maternal sRANKL concentrations positively correlated with fetal abdominal circumference and fetal abdominal sagittal diameter. Conclusions Maternal bone markers sclerostin and sRANKL may relate with fetal intra-abdominal adipose tissue deposition through direct or indirect unknown as yet mechanisms contributing thus, to birthweight.

Morphometric analysis of foramen magnum using helical computed tomogrophy for gender determination

Background: The morphometric analysis of foramen magnum (FM) plays a crucial role in forensics and paleontology in identifying the gender of the unknown skeletal fragments. However, the reliability of these parameters vary among populations and races. The present study was conducted to investigate the reliability of the four foramen magnum parameters ie, foramen magnum transverse diameter, foramen magnum sagittal diameter, foramen magnum area and foramen magnum circumference in this native population. Methods: A total of 60 subjects belonging to both genders aged between 20 – 50 years who were undergoing computed tomography (CT) examination of head and neck region were selected for the study. The study sample comprised of 30 males in group A and 30 females in group B. The measurements were obtained from reformatted axial sections using helical CT scan. The FM sagittal diameter (FMSD) and the FM transverse diameter (FMTD) were measured by the greatest anteroposterior dimension and the greatest width of the foramen. The circumference (FMC) and the area (FMA) were obtained after tracing the bony margin of the FM on the CT image using CT workstation. Results: Mean values of all four parameters were found to be significantly higher in males compared to female subjects (P <0.001). Further, the accuracy of sex determination analyzed using the discriminant equation was 70% for males and 80% for females with overall accuracy of 75%. The predictability of gender was higher in female subjects than in male subjects. Conclusion: The dimensions of the foramen magnum can be used in gender determination of skeletal fragments with considerable accuracy. The Helical CT scan plays a pivotal role in providing accurate dimensions of the foramen magnum that could be useful in forensic testing.

Measurement of Anteroposterior diameters of normal brainstem by Magnetic Resonance Imaging

Aim: The aim of this study is to assess the anteroposterior diameter of brainstem (midbrain, pons and medulla) of normal Nepalese people to establish normal ranges and to correlate the measurement with pa­tient’s age and gender. Method: The study is a cross-sectional prospective study which is per­formed in Gandaki Medical College, Pokhara. The data is collected over the period of 5 months from May 2018 to September 2018. The data of total 103 patients are collected who underwent (Magnetic Resonance Imaging) MRI head. Measurements of sagittal diameter at predefined levels i.e. distance between upper border of pons to midway between superior and inferior colliculi (A) for midbrain, distance between an­terior surface of pons to the floor of fourth ventricle (B) for pons and anteroposterior diameter perpendicular to the long axis of medulla just above the posterior kink at cervicomedullary junction for medulla ob­longata were made and noted. Result: The mean anteroposterior diameter of midbrain, pons and me­dulla oblongata was found to be 1.7048 ± 0.12 cm, 2.27 ± 0.13cm and 1.3 ± 0.088 cm respectively. The average ratio of sagittal diameter of pons to sagittal diameter of midbrain was 1.34 ± 0.099 cm and average ratio of sagittal diameter of pons to medulla oblongata was 1.75 ± 0.123 cm. Conclusion: There was no statistically significant correlation of the sagittal diameter of midbrain, pons and medulla with patient’s gender. The sagittal diameter of brainstem reached maximum at the age 20 and stopped increasing. The sagittal diameter of midbrain and medulla ob­longata decreased slightly after the age of 50 and decreased significant­ly after the age of 70. There was no decrease in the sagittal diameter of pons after age.

Saber sheath trachea in chronic obstructive pulmonary disease patients

Saber sheath trachea is defined as an anteroposterior (sagittal) diameter of intrathoracic trachea exceeding to lateral (coronal) by a ratio of 2:1 as measured at the site 1 cm above the aortic arch and the extra thoracic trachea being normal. It is most commonly seen in males and is considered to be a diagnostic sign of Chronic obstructive pulmonary disease.

Pelvic bone structures in free-ranging Eurasian lynx (Lynx lynx) from Switzerland: a radiological pelvimetry study

The observation of severe pelvic malformations in Eurasian lynx (Lynx lynx) from a population reintroduced to Switzerland raised the question as to whether inbreeding may contribute to the development of congenital pelvic malformations. We aimed at providing baseline data on the pelvic morphology of Eurasian lynx from the reintroduced populations in Switzerland, at assessing potential differences in pelvic conformation between the two main Swiss populations, among age classes and between sexes, and at detecting pelvic anomalies. We performed measurements of 10 pelvic parameters on the radiographs of 57 lynx of both sexes and different ages taken from 1997-2015. We calculated two ratios (vertical diameter/acetabula; sagittal diameter/transversal diameter) and two areas (pelvic outlet and inlet) to describe the shape of the pelvis. Our results showed that the Eurasian lynx is a mesatipelvic species, with a pelvis length corresponding to approximatively 20% of the body length. We found no statistically significant differences between the two examined populations but observed growth-related pelvis size differences among age groups. Sexual dimorphism was obvious in the adult age group only: two parameters reflecting pelvic width were larger in females, likely to meet the physiological requirements of parturition. By contrast, pelvis length, conjugata vera, diagonal conjugata, vertical diameter and sagittal diameter were larger in males, in agreement with their larger body size. Accordingly, the ratio between the sagittal and transversal diameters was significantly larger in males, i.e. adult males have a different pelvic shape than adult females. Furthermore, pelvimetry highlighted one adult individual with values outside the calculated reference range, suggesting a possible congenital or developmental pathological morphology of the internal pelvis. Our work generated baseline data of the pelvic morphology including growth and sexual dimorphism of the Eurasian lynx. These data could also be useful for estimating age and sex in skeletal remains.

A study of lesser pelvic parameters and their correlation with age by reformatted computed tomography in western Indian Gujarati female population

Background & aims: Pelvic parameters vary according to age, race and population. The study is aimed at assessing female pelvic parameters using reformatted 3D CT images, compare the obtained values with other studies and correlate these parameters with age. Material & Methods: Reformatted three-dimensional CT images were obtained from stored abdominopelvic computed tomography [CT] scan images. Image analysis software was used to determine various diameters of the lesser pelvis. Data were analysed to derive mean ± SD, SE, 95% Cl, paired t test and Pearson correlation test were used for comparison and correlation of variables. Results: Mean± standard deviation of obstetric conjugate diameter was 10.94±1.18 cm, transverse diameter of inlet was 12.46±0.81 cm, sagittal diameter of midplane wasl 1.74±0.80 cm, interspinous diameter was 9.78±0.75 cm, sagittal diameter of outlet was 8.99±1.02 cm and intertuberous diameter was 10.69±0.86. All the parameters except sagittal diameter of midplane and interspinous diameter showed correlation with age. Conclusion: The present study provides reference values for various pelvic parameters in western Indian Gujarati female population. Parameters obtained in present study vary greatly from previous studies from other populations. The results demonstrated that significant age-related changes occurred in pelvic inlet and outlet parameters.

Sagittal Normal Limits of Lumbosacral Spine in a Large Adult Population: A Quantitative Magnetic Resonance Imaging Analysis

Objectives: The objective of this study was to determine, using magnetic resonance imaging (MRI) of the lumbosacral spine from L1 to S1, the values of the normal sagittal diameter of the spinal canal (SCD), sagittal diameter of the dural sac (DSD), and the normal values of dural sac ratio (DSR) in a large nonsymptomatic adult population and to discriminate whether a vertebral canal is pathological or nonpathological for dural ectasia and/or stenosis. Materials and Methods: Six hundred and four patients were prospectively enrolled. All measurements were performed on MRI sagittal T1- and T2-weighted images. The 95% confidence interval (95% CI), defined as mean ± 1.96 standard deviation, was determined for each metric. The upper limit of 95% CI was considered the cutoff value for the normal DSR; the lower limit of 95% CI was considered the cutoff value for the normal SCD. Results: SCD cutoff values from L1 to S1 ranged from 14.5–10.1 mm (males) to 15.0–9.9 mm (females). DSD ratios at S1 and L4 level show a significant difference in male and female groups: 11% of S1/L4 values exceeded 1 in male group while only 4% of S1/L4 values exceeded 1 in female group. Mean DSR at each level was significantly higher in female patients than in male patients (P < 0.001), ranging from 0.70 to 0.56 (male) and from 0.82 to 0.63 (female). Conclusions: We determined the cutoff values for the normal DSR and for the normal SCD. Our findings show the relevant discrepancies with respect to literature data for diagnosis of lumbar stenosis and/or dural ectasia.