Linea alba 3D morphometric variability by CT scan exploration.

PURPOSE: The width of the Linea alba, which is often gauged by inter-rectus distance, is a key risk factor for incisional hernia and recurrence. Previous studies provided limited descriptions with no consideration for width, location variability, or curvature. We aimed to offer a comprehensive 3D anatomical analysis of the Linea alba, emphasizing its variations across diverse demographics. METHODS: Using open source software, 2D sagittal plane and 3D reconstructions were performed on 117 patients' CT scans. Linea alba length, curvature assessed by the sagitta (the longest perpendicular segment between xipho-pubic line and the Linea alba), and continuous width along the height were measured. RESULTS: The Linea alba had a rhombus shape, with a maximum width at the umbilicus of 4.4 ± 1.9 cm and a larger width above the umbilicus than below. Its length was 37.5 ± 3.6 cm, which increased with body mass index (BMI) (p < 0.001), and was shorter in women (p < 0.001). The sagitta was 2.6 ± 2.2 cm, three times higher in the obese group (p < 0.001), majorated with age (p = 0.009), but was independent of gender (p = 0.212). Linea alba width increased with both age and BMI (p < 0.001-p = 0.002), being notably wider in women halfway between the umbilicus and pubis (p = 0.007). CONCLUSION: This study provides an exhaustive 3D description of Linea alba's anatomical variability, presenting new considerations for curvature. This method provides a patient-specific anatomy description of the Linea alba. Further studies are needed to determine whether 3D reconstruction correlates with pathologies, such as hernias and diastasis recti.

Fetal facial bone growth: Post-mortem CT analysis.

OBJECTIVE: To describe and model the normal growth of fetal facial bones and angles. MATERIAL AND METHODS: A total of 118 fetal CT scans obtained at 19 to 41 weeks gestation after in utero fetal death or late miscarriage were analyzed. CT scan was followed by autopsy and pathological examination and only fetuses free from brain disease or abnormal craniofacial development were included. The measurements were taken using software for frontal, sagittal and 3D reconstruction from native axial sections. The optimal plane for bone analysis was chosen and the measurements made by multiplanar reconstruction. RESULTS: There was a statistically significant increase (P<0.001) in all measurements regardless of gestational age (GA) except those of the mandibulo-fronto-maxillary angle (P=0.412), the naso-mandibulo-maxillary angle (P=0.828) and mandibular width (P=0.86). There was no significant difference according to fetal sex. Based on these results, the corresponding growth curves were created. The anteroposterior mandibular diameter (APD) was very strongly correlated with GA (R=0.926, P<0.001). The following equation: GA=(8.187×APD)+4.257 can be used to estimate GA with a confidence interval (CI) of±2.42. The same applies to maxillary width (MW) (R=0.922; P<0.001). The equation GA=(11.059×MW)+7.571 can be used to estimate GA with a CI of 2.17. CONCLUSION: The growth of the mandible, maxilla, zygomatic bone and orbits was measured and the corresponding growth curves were established. Several measurements were strongly correlated with gestational age.

Study of the growth and shape of the brain and cranial base during the first two years of life.

Ontogeny of the cranial base and the brain integrates data on growth, maturation and ontogenetic allometry of these two systems in the course of development. The aim of our work was to study the ontogeny of the cranial base and the brain in order to understand their growth dynamic and shape changes using a traditional morphometric approach in individuals with normal (non-pathological) development. MATERIEL AND METHOD: Forty-seven infants having been included in the unexpected infant death french protocol were analyzed. Medical imaging (CT and MRI) exams, followed by an autopsy and pathology examination allowed us to include only infants free from brain disease or pathology affecting growth. RESULTS: Testing of measurement reliability validated 12 distances and 3 angles as well as the positioning of the landmarks that had been used to obtain the distances and the angles. No correlation between sex and the various variables studied was found. However, a correlation was observed between these variables and age, making it possible to propose a growth curve. A medium to strong correlation was found between brain variables and the bone variables of the cranial base, underlining the parallel development of the two systems. CONCLUSION: Our study, carried out in a rigorously selected population of infants, presents a fundamental approach to the study of ontogenesis.

Biomechanical study of the thyroid cartilage: A model of bi-digital strangulation.

The presence of fracture on neck elements is an indication of violence. Both the hyoid bone and the larynx can be damaged by a strangulation mechanism. Thyroid cartilage, more specifically, may present lesions in response to this mechanical stress. These lesions result in fractures at the bases of the horns of the thyroid cartilage. This study focuses on the thyroid cartilage behavior in cases of bi-digital strangulation, using an anthropometric and biomechanical approach. To develop a biomechanical model, we performed an anthropometric study taking into account 14 distances measurements as well as 3 measurements of angles. These measures allowed us to determine a significant sexual dimorphism between individuals. Then, we define 6 morphologies models, composed of 3 females and 3 males individuals. In order to visualize the ossification of the cartilage, each model has been tested with bone properties. Strangulation cases were simulated by applying an imposed velocity of 0.4m/s then 1m/s. We observed different behaviors of the thyroid cartilage according to the sex and the morphology.

Value of early repeated abdominal CT in selective non-operative management for blunt bowel and mesenteric injury.

OBJECTIVES: To evaluate the performance of an early repeated computed tomography (rCT) in initially non-operated patients with blunt bowel and mesenteric injuries (BBMI). METHODS: This was a monocentric retrospective observational study from 2009 to 2017 of patients with a BBMI on initial CT (iCT). Patients initially non-operated on were scheduled for a rCT within 48 h. Initial CT and rCT diagnostic performance were compared based on a surgical injury prediction score previously described. For statistical analysis, we used the chi-square analyses for paired data (McNemar test). RESULTS: Eighty-four patients (1.9% of trauma) had suspected BBMI on iCT. Among these patients, 22 (26.2%) were initially operated on, 18 (21.4%) were later operated on, and 44 (52.4%) were not operated on. The therapeutic laparotomy rate was 85%. Thirty-four patients initially non-operated on had a rCT. The absolute value of the CT scan score increased for 15 patients (44.1%). The early rCT diagnostic performance, compared with iCT, showed an increase in sensitivity (from 63.6 to 91.7%), in negative predictive value (from 77.4 to 94.7%), and in AUC (from 0.77 to 0.94). CONCLUSION: In initially non-operated patients with BBMI lesions, the performance of an early rCT improved the sensitivity of lesion detection requiring surgical repair and the security of patient selection for non-operative treatment. KEY POINTS: • Selective non-operative treatment for hemodynamically stable patients with blunt bowel and/or mesenteric injuries on CT is developing but remains controversial. • An early repeated CT improved the sensitivity of lesion detection requiring surgical repair and the security of patient selection for conservative treatment.

[Duplication of the acromioclavicular joint: A case dating from the end of the 19th century]. / Duplication de l'articulation acromio-claviculaire : un cas datant de la fin du 19e siècle.

The duplication of the acromioclavicular joint is a very rare anomaly of shoulder girdle. Here, we present a new case of unilateral duplication of the acromioclavicular joint observed on an individual from the 19th century. In the literature, two hypotheses are proposed to explain the origin of this anomaly. The first is a congenital origin that could be explained by in utero displacement of one of the clavicle's primary ossification centers, or the existence of an additional ossification center. The second is a traumatic origin resulting from an acromioclavicular fracture that occurred during the growth period of the individual. Our macroscopic observations and CT-scan images show no sign of a healed fracture, of complications, or of a bone callus after healing. The hypothesis of a congenital origin for this acromioclavicular duplication is therefore preferred.

Ex vivo optimisation of a heterogeneous speed of sound model of the human skull for non-invasive transcranial focused ultrasound at 1 MHz.

Transcranial brain therapy has recently emerged as a non-invasive strategy for the treatment of various neurological diseases, such as essential tremor or neurogenic pain. However, treatments require millimetre-scale accuracy. The use of high frequencies (typically ≥1 MHz) decreases the ultrasonic wavelength to the millimetre scale, thereby increasing the clinical accuracy and lowering the probability of cavitation, which improves the safety of the technique compared with the use of low-frequency devices that operate at 220 kHz. Nevertheless, the skull produces greater distortions of high-frequency waves relative to low-frequency waves. High-frequency waves require high-performance adaptive focusing techniques, based on modelling the wave propagation through the skull. This study sought to optimise the acoustical modelling of the skull based on computed tomography (CT) for a 1 MHz clinical brain therapy system. The best model tested in this article corresponded to a maximum speed of sound of 4000 m.s-1 in the skull bone, and it restored 86% of the optimal pressure amplitude on average in a collection of six human skulls. Compared with uncorrected focusing, the optimised non-invasive correction led to an average increase of 99% in the maximum pressure amplitude around the target and an average decrease of 48% in the distance between the peak pressure and the selected target. The attenuation through the skulls was also assessed within the bandwidth of the transducers, and it was found to vary in the range of 10 ± 3 dB at 800 kHz and 16 ± 3 dB at 1.3 MHz.

Morphological Analysis of Healthy Aortic Arch.

OBJECTIVE/BACKGROUND: This study aimed to describe an arch morphology protocol in a healthy population, and to assess the impact of age and sex. METHODS: A retrospective morphology evaluation was conducted in a population with no personal history of thoracic aorta surgery or pathology, through computed tomography (CT) imaging analysis, using a standardised protocol. Based on centreline three dimensional coordinates, a single investigator calculated a series of parameters in the arch zones and in the total arch, using Matlab scripts. These were categorized as: (i) morphometric data: diameter, length and aortic angle of each zone, total arch angle, and length; (ii) geometric data: tortuosity index (TI), arch width, assimilated curvature radius (CRi), and attachment zone angles. Student or Mann-Whitney tests were used to compare parameter means. Their variability with age and sex was assessed through univariate and multivariate regression analysis. RESULTS: CT images from 123 subjects (mean ± SD age 53 ± 19 years) were reviewed. Significant correlation between age and morphology was found. The aorta expanded homogeneously and stretched heterogeneously with age because of posterior arch elongation. TI decrease, CRi, and attachment zone angle increase were also observed with aging. Age remained significantly associated with these morphological parameters, independently of body surface area and hypertension. Sex also affected morphology: longer total arch length and higher CRarch in men; lower zone 3 attachment angle in women CONCLUSION: Using mathematical algorithms, and with a view to improving endovascular arch treatment, this study provides a standardised arch morphology protocol and objectively identifies both age related evolution and sex related variation in the different zones.

Forensic use of the Greulich and Pyle atlas: prediction intervals and relevance.

OBJECTIVE: The Greulich and Pyle (GP) atlas is one of the most frequently used methods of bone age (BA) estimation. Our aim is to assess its accuracy and to calculate the prediction intervals at 95% for forensic use. METHODS: The study was conducted on a multi-ethnic sample of 2614 individuals (1423 boys and 1191 girls) referred to the university hospital of Marseille (France) for simple injuries. Hand radiographs were analysed using the GP atlas. Reliability of GP atlas and agreement between BA and chronological age (CA) were assessed and prediction intervals at 95% were calculated. RESULTS: The repeatability was excellent and the reproducibility was good. Pearson's linear correlation coefficient between CA and BA was 0.983. The mean difference between BA and CA was -0.18 years (boys) and 0.06 years (girls). The prediction interval at 95% for CA was given for each GP category and ranged between 1.2 and more than 4.5 years. CONCLUSION: The GP atlas is a reproducible and repeatable method that is still accurate for the present population, with a high correlation between BA and CA. The prediction intervals at 95% are wide, reflecting individual variability, and should be known when the method is used in forensic cases. KEY POINTS: • The GP atlas is still accurate at the present time. • There is a high correlation between bone age and chronological age. • Individual variability must be known when GP is used in forensic cases. • Prediction intervals (95%) are large; around 4 years after 10 year olds.

An anatomic and morphometric analysis of splenic variability using 3D reconstruction and spatial orientation from computed tomography.

INTRODUCTION: In terms of frequency, the spleen is the first organ affected in abdominal trauma, resulting even today in a high rate of mortality (10%). Nevertheless, very few studies have investigated splenic quantitative morphometry as to shape and spatial orientation. Therefore, we analysed healthy spleen variability in order to integrate it in its environment and to correlate its morphometric parameters to anthropometric characteristics. METHODS: Ninety abdominopelvic CT-scans performed on patients over 16 years with no splenic pathology were retrospectively selected among a Mediterranean population. Three age groups ([16-30], [30-60] and [over 60 years]), equally distributed among genders, were created. Parameters, such as volume, characteristic checkpoints, orientation, and morphology, were measured on the spleen, the 11th thoracic vertebra and the 10th ribs in three-dimensional reconstructions. Anthropometric parameters were characterised by waist circumference, costo-xiphoid angle, abdominal height and chest depth. RESULTS: Observed variations in splenic morphology were divided into three groups: cupped (66.7%), coiled (17.8%), and flat (15.5%). Splenic morphometry tends to be abdominal-shaped (54.5%) or dorsal-shaped (45.5%). The mean of the angle between the main axis of the spleen and the CT-scan horizontal axis was 40±14°. Correlations were highlighted between volume and gender (p<0.05), splenic morphology and liver morphometry (p<0.05) as well as between orientation of hilar surface and splenic morphometry (p<0.01). Moreover, the spleen is more horizontal in women (p<0.05), in the elderly (p<0.05) and in the obese (p<0.01). CONCLUSION: This study defines three groups based on shape and highlights correlations between parameters describing healthy splenic variability and its anthropometric characteristics, which are of great importance for numerical modelling in splenic studies.

Pelvic trauma and vascular emergencies.

Pelvic ring injuries carry a high mortality rate, the main cause of which, in the first 24hours, is exsanguination. Injured patients are managed by a multidisciplinary damage-control strategy. Unstable patients should have instrumentalized hemostasis without delay. Arterial embolization is an effective way of achieving this and justifies this approach being permanently available in level 1 trauma-centers. After CT assessment of injuries, stable patients can undergo arterial embolization if active arterial bleeding or vascular damage is present. The embolization methods (selective or unselective) and agents used depend on the patient's hemodynamic stage and assessment of the injury whenever possible.

Implementation of lung ultrasound in polyvalent intensive care unit: Impact on irradiation and medical cost.

OBJECTIVE: To determine the effect of implementing a daily lung ultrasound round on the number of chest radiographs and chest computed tomography (CT) scans in a polyvalent intensive care unit (ICU). STUDY DESIGN: Retrospective study comparing two consecutive periods. PATIENTS: All patients hospitalized for longer than 48 hours in a polyvalent ICU. METHODS: Implementation of a daily lung ultrasound round after a short educational program. The number of chest radiographs and chest CT scans and the patient outcome were measured before (group PRE) and after (group POST) the implementation of a daily lung ultrasound round. RESULTS: No demographic difference was found between the two groups, with the exception of a higher severity score in the group POST. For each ICU stay, the number of chest radiographs was 10.3 ± 12.4 in the group PRE and 7.7 ± 10.3 in the group POST, respectively (P<0.005) The number of chest CT scans was not reduced in the group POST, as compared with the group PRE (0.5 ± 0.7 CT scan/patient/ICU stay versus 0.4 ± 0.6 CT scan/patient/ICU stay, P=0.01). The ICU mortality was similar in both groups (21% versus 22%, P=0.75) CONCLUSION: The implementation of a daily lung ultrasound round was associated with a reduction in radiation exposure and medical cost without altering patient outcome.

Fetal skeletal computed tomography: when? How? Why?

PURPOSE: To study the additional role of fetal skeletal computed tomography in suspected prenatal bone abnormalities. MATERIALS AND METHODS: Two centers included in a retrospective study all fetuses who benefited from skeletal computed tomography for a suspected constitutional bone disease or focal dysostosis. RESULTS: A total of 198 patients were included. CT was performed in 112 patients (56%) for an isolated short femur below the third percentile (group A), in 15 patients (8%) for bowed or fractured femur (group B), in 23 patients (12%) for biometric discrepancy between a short femur and increased head circumference (group C) and in 48 patients (24%) for suspected focal dysostosis (group D). CT was interpreted as normal in 126 cases (64%), i.e. 87% in group A, 0% in group B, 65% in group C and 25% in group D. When including only cases with postnatal or postmortem clinical and/or radiological confirmation was available, CT provided additional and/or more accurate information than ultrasound in 20% of cases in group A, 66% in group B, 30% in group C and 72% in group D. Sixty-seven percent of patients in whom CT was interpreted as normal were lost to follow-up. CONCLUSION: In isolated short femur, fetal skeletal CT is normal in the great majority of cases although protocolized follow-up of these babies is absolutely compulsory, as a large proportion is lost to follow-up. Fetal skeletal CT can confirm or improve imaging for the suspected diagnosis in suspected focal dysostosis or constitutional bone disease.

Blunt bowel and mesenteric injuries detected on CT scan: who is really eligible for surgery?

BACKGROUND: There is no consensually accepted approach to the management of blunt bowel and mesenteric injuries. Surgery is required urgently in the case of bowel perforation or haemodynamic instability, but several patients can be treated non-operatively. This study aimed to identify the risk factors for surgery in an initial assessment. METHODS: We retrospectively reviewed the medical charts and computed tomography (CT) scans of adult patients presenting with a blunt abdominal trauma to our centre between the years 2004 and 2011. We included only patients with a CT scan showing suspected injury to the mesentery or bowel. RESULTS: There were 43 patients (33 males and 10 females), with a mean Injury Severity Score (ISS) of 22. The most frequently suspected injuries based on a CT scan were mesenteric infiltrations in 40 (93 %) patients and bowel wall thickening in 22 (51 %) patients. Surgical therapy was required for 23 (54 %) patients. Four factors were independently associated with surgical treatment: a free-fluid peritoneal effusion without solid organ injury [adjusted odds ratio (OR) = 14.4, 95 % confidence interval (CI) [1.9-111]; p = 0.015], a beaded appearance of the mesenteric vessels (OR = 9 [1.3-63]; p = 0.027), female gender (OR = 14.2 [1.3-159]; p = 0.031) and ISS >15 (OR = 6.9 [1.1-44]; p = 0.041). Surgery was prescribed immediately for 11 (26 %) patients and with delay, after the failure of initially conservative treatment, for 12 (28 %) patients. The presence of a free-fluid peritoneal effusion without solid organ injury was also an independent risk factor for delayed surgery (OR = 9.8 [1-95]; p = 0.048). CONCLUSIONS: In blunt abdominal trauma, the association of a bowel and/or mesenteric injury with a peritoneal effusion without solid organ injury on an initial CT scan should raise the suspicion of an injury requiring surgical treatment. Additionally, this finding should lead to a clinical discussion of the benefit of explorative laparotomy to prevent delayed surgery. However, these findings need validation by larger studies.

Emergency ultrasound: a prospective study on sufficient adequate training for military doctors.

PURPOSE: To evaluate the feasibility of "accelerated" training for military doctors in front line ultrasound. To establish the number of ultrasounds required to validate the doctor's training. To assess the average acquisition time for each ultrasound target. MATERIALS AND METHODS: Prospective study on 10 novice generalist military doctors to assess training for five urgent ultrasound targets: focused assessment with sonography in trauma (FAST), pleura, bladder, abdominal aorta and gallbladder. Each student received theoretical and practical training on "healthy" people and then performed 10 timed ultrasounds in an emergency situation, the result of which was either confirmed or rejected by a nationally qualified ultrasound expert. RESULTS: Some targets were easier to acquire (bladder, aorta and pleura) with excellent diagnostic performance after 10 ultrasounds on healthy people (sensitivity = 100%; specificity = 100%). The overall number of ultrasound errors fell over time. The median investigation time also fell significantly for all targets, reaching a plateau. Twenty ultrasounds including 10 "real life" appear to be needed for FAST. A minimum number of 30 ultrasounds is required to diagnose acute cholecystitis. CONCLUSION: "Accelerated" training for generalist military doctors in front line ultrasound is achievable. The recommended number of 25 ultrasounds per target is not appropriate for all ultrasound targets.

[Cerebral hemorrhage in a mechanically ventilated asthmatic child: multifactorial mechanisms]. / Hémorragie cérébrale chez un enfant asthmatique ventilé : mécanismes multifactoriels.

We report the case of a 7-year-old boy with acute status asthmaticus requiring mechanic ventilation in the pediatric intensive care unit. He developed a brain hemorrhage during the course of his illness. We discuss the mechanisms that may have precipitated this neurological complication.