Comparison of morphing techniques to develop subject-specific finite element models of vertebrae.

This study compared two morphing techniques (and their serial combination) to create subject-specific finite element models of 15 astronaut vertebrae. Surface deviations of the morphed models were compared against subject geometries extracted from medical images. The optimal morphing process yielded models with minimal difference in root-mean-square (RMS) deviation (C3, 0.52 ± 0.14 mm; T3, 0.34 ± 0.04 mm; L1, 0.59 ± 0.16 mm) of the subject's vertebral geometry. <1% of model elements failed quality checks and compression simulations ran to completion. This research lays the foundation for the development of subject-specific finite element models to quantify musculoskeletal changes and injury risk from spaceflight.

Computed tomography assessment of pelvic bone density: Associations with age and pelvic fracture in motor vehicle crashes.

Motor vehicle crash (MVC) occupants routinely get a computed tomography (CT) scan to screen for internal injury, and this CT can be leveraged to opportunistically derive bone mineral density (BMD). This study aimed to develop and validate a method to measure pelvic BMD in CT scans without a phantom, and examine associations of pelvic BMD with age and pelvic fracture incidence in seriously injured MVC occupants from the Crash Injury Research and Engineering Network (CIREN) study. A phantom-less muscle-fat calibration technique to measure pelvic BMD was validated using 45 quantitative CT scans with a bone calibration phantom. The technique was then used to measure pelvic BMD from CT scans of 252 CIREN occupants (ages 16+) in frontal MVCs who had sustained either abdominal or pelvic injury. Pelvic BMD was analyzed in relation to age and pelvic fracture incidence. In the validation set, phantom-based calibration vs. phantom-less muscle-fat calibration yielded similar BMD values at the anterior superior iliac spine (ASIS; R2 = 0.95, p < 0.001) and iliac crest (R2 = 0.90, p < 0.001). Pelvic BMD was measured in 150 female and 102 male CIREN occupants aged 16-89, and 25% of these occupants sustained pelvic fracture. BMD at the ASIS and iliac crest declined with age (p < 0.001). For instance, iliac crest BMD decreased an average of 25 mg/cm3 per decade of age. The rate of iliac crest BMD decline was 7.6 mg/cm3 more per decade of age in occupants with pelvic fracture compared to those not sustaining pelvic fracture. Findings suggest pelvic BMD may be a contributing risk factor for pelvic fracture in MVCs.

Age-based differences in the disability of spine injuries in pediatric and adult motor vehicle crash occupants.

OBJECTIVE: The objective was to develop a disability-based metric for quantifying disability rates as a result of motor vehicle crash (MVC) spine injuries and compare functional outcomes between pediatric and adult subgroups. METHODS: Disability rate was quantified using Functional Independence Measure (FIM) scores within the National Trauma Data Bank-Research Data System for the top 95% most frequent Abbreviated Injury Scale (AIS) 3 spine injuries (14 unique injuries). Pediatric (7-18 years), young adult (19-45 years), middle-aged adult (46-65 years), and older adult (66+ years) MVC occupants with FIM scores available and at least one of the 14 spine injuries were included. FIM scores of 1 or 2 at time of discharge were used to define disability and correspond to full functional or modified dependence in self-feeding, locomotion, and/or verbal expression. Disability rate was evaluated on a per injury basis for each AIS 3 spine injury and calculated as the proportion of cases associated with disability (i.e. FIM of 1 or 2) out of the total cases of that particular injury. Disability rates were calculated with and without the exclusion of cases with severe co-injuries (AIS 4+) to minimize bias from additional non-spinal injuries that could have contributed to disability. Associations between adjusted disability rates and existing mortality rates were investigated. RESULTS: Locomotion impairment alone was the most frequent disability type for the top 14 AIS 3 spine injuries (7 cervical, 4 thoracic, and 3 lumbar) across all age groups and spine regions. Adjusted and unadjusted disability rates ranged from 0-69%. Adjusted disability rates increased with age: 14.8 ± 10% (mean ± SD) in pediatrics to 16.2 ± 6.6% (young adults), 29.2 ± 10.9% (middle-aged adults), and 45.0 ± 12.2% (older adults). Among all adult populations, adjusted mortality and disability rates were positively correlated (R2>0.24), with disability rates consistently greater than corresponding mortality rates. CONCLUSIONS: Older adults had significantly greater disability rates associated with MVC spine injuries across all spinal regions. MVC disability rates for pediatrics were considerably lower. Overall, rates of mortality were significantly lower than rates of disability. The adjusted disability rates developed can supplement existing injury metrics by accounting for age- and location-specific functional implications of MVC spine injuries.

Effects of muscle quantity and bone mineral density on injury and outcomes in older adult motor vehicle crash occupants.

Objectives: Quantify the independent and combined effects of abdominal muscle quantity and lumbar bone mineral density (BMD) on injury risk and in-hospital outcomes in severely injured motor vehicle crash (MVC) occupants ages 50 and older.Methods: Skeletal muscle area measurements of MVC occupants were obtained through semi-automated segmentation of an axial computed tomography (CT) slice at the L3 vertebra. An occupant height-normalized Skeletal Muscle Index (SMI) was calculated - a defining metric of sarcopenia and low muscle mass (sarcopenia thresholds: <38.5 cm2/m2 females; <52.4 cm2/m2 males). Lumbar BMD was obtained using a validated, phantomless CT calibration method (osteopenia threshold: <145 mg/cm3). SMI and BMD values were used to categorize occupants, and logistic regression was used to associate sarcopenia, osteopenia, and osteosarcopenia predictors to injury outcomes (e.g., Injury Severity Score (ISS), maximum Abbreviated Injury Scale (MAIS) score, fractures) and hospital outcomes (e.g., length of stay, ICU days).Results: Of the 336 occupants, 210 (63%) were female (mean ± SD: age 66.3 ± 10.6). SMI was 41.7 ± 8.0 cm2/m2 in females and 51.2 ± 10.8 cm2/m2 in males. Based on SMI, 40% of females and 55% of males were classified as sarcopenic. BMD was 163.2 ± 38.3 mg/cm3 in females and 164.1 ± 35.4 mg/cm3 in males, with 41% of females and 33% of males classified as osteopenic. Prevalence of both conditions (osteosarcopenia) was similar between females (21%) and males (22%). Incidence of low SMI and BMD increased with age. Sarcopenic individuals were less likely to sustain a MAIS 2+ thorax injury and had longer ICU stays. Osteopenic individuals were more likely to sustain upper extremity injuries and fractures, and were less likely to be discharged to a rehabilitation facility. Osteosarcopenic individuals were less likely to be ventilated or admitted to the ICU but tended to spend more time on the ventilator if placed on one.Conclusions: Osteosarcopenia was not associated with any injury outcomes, but sarcopenia was associated with thoracic injury and osteopenia was associated with upper extremity injury incidence. Sarcopenia was only associated with ICU length of stay, while osteopenia was only associated with discharge destination. Osteosarcopenia was associated with likelihood of being ventilated, being admitted to the ICU, and with increased length of ventilation.

Body mass index influence on lap belt position and abdominal injury in frontal motor vehicle crashes.

OBJECTIVE: As obesity rates climb, it is important to study its effects on motor vehicle safety due to differences in restraint interaction and biomechanics. Previous studies have shown that an abdominal seatbelt sign (referred hereafter as seatbelt sign) sustained from motor vehicle crashes (MVCs) is associated with abdominal trauma when located above the anterior superior iliac spine (ASIS). This study investigates whether placement of the lap belt causing a seatbelt sign is associated with abdominal organ injury in occupants with increased body mass index (BMI). We hypothesized that higher BMI would be associated with a higher incidence of superior placement of the lap belt to the ASIS level, and a higher incidence of abdominal organ injury. METHODS: A retrospective data analysis was performed using 230 cases that met inclusion criteria (belted occupant in a frontal collision that sustained at least one abdominal injury) from the Crash Injury Research and Engineering Network (CIREN) database. Computed tomography (CT) scans were rendered to visualize fat stranding to determine the presence of a seatbelt sign. 146 positive seatbelt signs were visualized. ASIS level was measured by adjusting the transverse slice of the CT to the visualized ASIS level, which was used to determine seatbelt sign location as superior, on, or inferior to the ASIS. RESULTS: Obese occupants had a significantly higher incidence of superior belt placement (52%) vs on-ASIS placement (24%) compared to their normal (27% vs 67%) BMI counterparts (p < 0.001). Notable trends included obese occupants with superior placement having less abdominal organ injury incidence than those with on-ASIS belt placement (42% superior placement vs 55% on-ASIS). In non-obese occupants, there was a higher incidence of abdominal organ injury with superior lap belt placement compared to on-ASIS placement counterparts (Normal BMI: 62% vs 41%, Overweight: 57% vs 43%). CONCLUSIONS: In CIREN occupants with abdominal injury, those with obesity are more prone to positioning the lap belt superior to the ASIS, though the impact on abdominal injury incidence remains a key point for continued exploration into how occupant BMI affects crash safety and belt design.

The relationship of body mass index, belt placement, and abdominopelvic injuries in motor vehicle crashes: A Crash Injury Research and Engineering Network (CIREN) study.

OBJECTIVE: Obesity has important implications for motor vehicle safety due to altered crash injury responses from increased mass and improper seatbelt placement. Abdominal seatbelt signs (ASBS) above the anterior superior iliac spine (ASIS) in motor vehicle crashes (MVCs) often correlate with abdominopelvic trauma. We investigated the relationship of body mass index (BMI), lap belt placement, and the incidence of abdominopelvic injury using computed tomography (CT) evaluation for subcutaneous ASBS mark and its location relative to the ASIS. METHODS: A retrospective analysis of 235 Crash Injury Research and Engineering Network (CIREN) cases and their associated abdominal injuries was conducted. CT Scans were analyzed to visualize fat stranding. 150 positive ASBS were found and their ASBS mark location was classified as superior, on, or inferior to the ASIS. RESULTS: Obese occupants had a higher incidence rate of belt placement superior to the ASIS, and occupants with normal BMI had a higher incidence of proper belt placement (p < 0.05). Trends of interest developed, notably that non-obese occupants with superior belt placement had increased incidence of internal abdominopelvic organ injury compared to those with proper belt placement (Normal BMI: 53.3% superior vs 39.4% On-ASIS, Overweight: 47.8% superior vs 34.7% On-ASIS). CONCLUSIONS: Utilizing CT scans to confirm ASBS and lap belt placement relative to the ASIS, superior belt placement above the ASIS was associated with elevated BMI and a trend of increasing incidence of internal abdominopelvic organ injury.

Pazopanib and Statin-Induced Rhabdomyolysis.

BACKGROUND: The VEGF inhibitor pazopanib is a widely used first-line therapy for the treatment of advanced renal cell carcinoma. Potential drug-drug interactions and toxicities may be underrecognized. CASE PRESENTATION: A 73-year-old woman with metastatic renal cell carcinoma on treatment with pazopanib presented with progressive inability to ambulate. The initial concern was for metastasis to the spine. However, MRI of the spine revealed diffuse muscle edema with no metastatic deposits or lytic lesions. Upon further evaluation, creatine kinase was significantly elevated and the diagnosis of rhabdomyolysis was made. With aggressive hydration and discontinuation of both pazopanib and rosuvastatin, the patient made a full recovery. CONCLUSION: This case of drug-induced rhabdomyolysis demonstrates an unexpected toxicity resulting from concomitant pazopanib and rosuvastatin therapy. This combination is predicted to be safe due to different, nonoverlapping effects on the cytochrome p450 enzymes. Discontinuation of statin therapy in patients with metastatic cancer should be considered when the risk of cancer-related death exceeds the risk of cardiovascular-related death.

Immunohistochemical analysis of embryonal sarcoma of the liver.

Embryonal sarcoma of the liver is a rare, aggressive malignant tumor that typically occurs in children and teenagers. Microscopic features include spindle, oval, or stellate cells with poorly defined cell borders, nuclear pleomorphism and multinucleation, and variable immunoreactivity to cytokeratin, vimentin, and alpha-1-antitrypsin. Intracellular and extracellular PAS-positive, diastase-resistant hyaline globules are commonly present. The authors evaluated a panel of IHC stains to better define the pattern of immunoreactivity in this tumor. Embryonal sarcomas of the liver were identified from archival files and were immunostained with antibodies: cytokeratin AE1/3, hepatocyte, SMMS, myogenin, calponin, h-caldesmon, desmin, S100, vimentin, CD34, C-kit (CD117), CD10, ALK-1, PE10, Bcl2, p53, and Ki-67. Six cases were identified. Patient age ranged from 6 to 24 years. Tumors ranged from 10 to 20 cm and contained spindled and epithelioid areas with PAS-positive, diastase-resistant globules and atypical cells with focal multinucleation. All cases showed immunoreactivity with vimentin and five showed immunoreactivity with Bcl2. Focal immunoreactivity was seen with cytokeratin AE1/3 in three cases, CD10 in four, calponin in two, desmin in one, and p53 in four. All tumors were negative with hepatocyte, myogenin, CD34, SMMS, h-caldesmon, PE10, ALK-1, and S100. No cytoplasmic staining was seen with C-kit. The proliferation index ranged from 30% to 95%. The diagnosis of embryonal sarcoma is based on typical morphologic features in a large liver tumor occurring in a young patient. The most useful IHC stains help to exclude tumors such as hepatoblastoma, hepatocellular carcinoma, embryonal rhabdomyosarcoma, and other sarcomas.

Endobronchial presentation of Hodgkin lymphoma: a review of the literature.

Endobronchial presentation of Hodgkin lymphoma is exceedingly rare and can be confused clinically with pulmonary small cell carcinoma. Because of the dramatic implications in treatment and prognosis, endobronchial Hodgkin lymphoma, despite its uncommon occurrence, should be considered in the differential of small cell carcinoma and necrotizing vasculitides with pulmonary involvement, especially in a relatively young patient with cough, hemoptysis, atelectasis, and hilar or mediastinal lymphadenopathy. The use of photodynamic laser therapy or stent placement for palliative treatment of life-threatening airway obstruction may be required prior to or as an initial adjunct to tumor-specific therapy.

Polypoid endobronchial Hodgkin lymphoma with an initial response to photodynamic therapy.

Endobronchial presentation of Hodgkin lymphoma is rare and can be confused clinically and radiographically with pulmonary small cell carcinoma. We present a case of an obstructive endobronchial presentation of nodular sclerosing classic Hodgkin lymphoma, initially misdiagnosed as small cell carcinoma, with endobronchial vasculitis and associated hemoptysis. Photodynamic therapy relieved the obstruction before induction of tumor-specific therapy. This case demonstrates the successful use of photodynamic therapy in obstructive endobronchial Hodgkin lymphoma.

MRI with Magnetic Resonance Spectroscopy of multiple brain abscesses secondary to Scedosporium apiospermum in two immunocompromised patients.

Scedosporium apiospermum is a deadly fungal infection that can infect the central nervous system, particularly in immunocompromised patients. We present two cases of Scedosporium brain abscesses. The first case was fatal and relevant conventional MRI and MR spectroscopy findings are discussed. To our knowledge, this is the first reported case of MR spectroscopy in Scedosporium apiospermum abscesses. In the second case, the patient recovered and conventional MR findings are followed over several months. In the appropriate clinical setting, conventional MR imaging and MR spectroscopy may facilitate diagnosis, earlier initiation of antifungal pharmacotherapy and surgical intervention in this frequently fatal infection.

Clonality in the setting of Sweet's syndrome and pyoderma gangrenosum is not limited to underlying myeloproliferative disease.

BACKGROUND: The neutrophilic dermatoses encompass, among others, Sweet's syndrome (SS) and pyoderma gangrenosum (PG), which are associated with underlying systemic diseases including myeloid dyscrasias. METHODS: On skin biopsies from 16 patients with biopsy-proven SS and/or PG, we performed an X-inactivation assay to detect clonal restriction of neutrophils. There were two patient categories based on known diseases at the time of diagnosis: patients with myeloproliferative disease and patients without myeloproliferative disease. RESULTS: Among seven patients with acute myelogenous leukemia and two with myelodysplastic syndrome, clonal restriction was found in five; three were homozygous, precluding analysis. Among the seven control patients, infiltrates were clonally restricted in five; one was polyclonal and the other was homozygous for the allele, precluding analysis. Of the five patients with clonally restricted infiltrates, one was subsequently diagnosed with myelodysplasia, one had unexplained neutropenia and an additional patient developed breast cancer. Overall, the incidence of clonality in both groups was the same, averaging 81%. CONCLUSION: These findings suggest that clonality in neutrophilic dermatoses, while characteristic of underlying myeloid dyscrasia, is not observed exclusively in the setting of myeloproliferative diseases. The significance of clonal neutrophilic infiltrates unassociated with myeloproliferative disease is unclear, but it may have some implications regarding the pathogenesis of sterile neutrophilic infiltrates. Clonality is well described in the setting of lymphomatoid hypersensitivity, reflecting an overzealous response to antigenic stimuli. One could speculate a similar mechanism operational in cases of apparently reactive SS/PG associated with monoclonality; a localized form of cutaneous neutrophilic dyscrasia is also possible.