High Prevalence of Spinal Magnetic Resonance Imaging Findings in Asymptomatic Young Adults (18-22 Yrs) Candidate to Air Force Flight.

STUDY DESIGN: Cross-sectional, retrospective, magnetic resonance (MR) imaging study, performed during cadets' selection procedures of the Italian Air Force Academy. OBJECTIVE: To assess the prevalence of spinal MR imaging findings in asymptomatic young adults (18-22 yrs) candidate to Air Force Flight. SUMMARY OF BACKGROUND DATA: Spinal MR imaging findings are frequently detected in asymptomatic subjects. Literature prevalence data come from studies that analyze different patient populations, in a wide age range and in different spinal tracts. Chronic degenerative disease of the vertebral column often occurs in pilots exposed to high flight acceleration forces, thus resulting crucial for Air Force Academy to exclude vertebral disease in cadets. METHODS: Three hundred fifty asymptomatic young adults underwent a 3T MR examination of the entire spine. A structured radiological report was set up to classify and calculate the prevalence of spinal MR imaging findings. RESULTS: Two hundred seventy of 350 subjects (77%) presented spinal MR findings, while 80 of 350 candidates (23%) had no detectable MR imaging findings. One hundred six of 350 (30%) candidates had at least one disc desiccation and 47 of 350 (13%) presented at least one disc narrowing. Disc bulging was found in 176 of 350 (49%) cadets. Sixty-two of 350 (18%) subjects showed disc protrusion while 28 of 350 (8%) had disc extrusion. Forty-five of 350 (13%) candidates presented low grade intervertebral spondylosis and of these 12 had also facet joints spondylosis. Asymptomatic vertebral fractures were observed in 2 of 350 (<1%) cadets. CONCLUSION: A high rate of MR spinal imaging findings, similar to that of the adult population, was detected in our population of young asymptomatic subjects. Our results suggest that the process of aging spine, which is supposed to begin in the second decade of life, is morphologically appreciable in the immediate postadolescent period and this issue is of crucial importance when selecting military pilots. LEVEL OF EVIDENCE: 4.

Simultaneous PET/MRI in assessing the response to chemo/radiotherapy in head and neck carcinoma: initial experience.

The purpose of the study was to assess by simultaneous positron emission tomography/magnetic resonance imaging (PET/MRI) the response to chemotherapy (CHT) and/or radiotherapy (RT) in patients with head and neck squamous cell carcinoma (HNSCC). Five patients with HNSCC underwent simultaneous PET/MRI examination before and after CHT and/or RT. Standard uptake volume (SUV), apparent diffusion coefficient (ADC), Ktrans, Kep, Ve, and iAUC pre- and post-treatment values were extracted and compared. The response to treatment was assessed according to RECIST criteria and classified as complete response (CR), partial response (PR), stable disease (SD), and progression disease (PD). In patient 1, PR was observed with increased ADC, Ktrans, and Ve values and reduction of SUV, iAUC, and Kep values; during clinical and instrumental follow-up, the patient experienced disease progression. Patient 2, classified as PR, showed increased ADC values and reduction of SUV and all perfusion parameters; follow-up demonstrated disease stability. Patient 3, considered as SD, showed increase of ADC and all perfusion values with a mild decrease of SUV; PD was observed during clinical and instrumental follow-up. Patients 4 and 5 showed a CR with no detectable tumor lesions at post-treatment PET/MRI examination, confirmed by 1-year follow-up. Multiparametric evaluation with simultaneous PET/MRI could be a useful tool to assess and predict the response to CHT and/or RT in patients with HNSCC.

Clinical impact of coronal-STIR sequence in a routine lumbar spine MR imaging protocol to investigate low back pain.

Aim of this study is to assess the clinical impact of coronal short tau inversion recovery (STIR)-weighted magnetic resonance (MR) sequence, when acquired in a lumbar spine MR imaging protocol, in detecting significant extraspinal imaging findings in patients with low back pain (LBP).We retrospectively evaluated 931 lumbar spine MR examinations of patients with LBP. Extraspinal MR imaging findings were categorized as: probably related to LBP (Category 1), not related to LBP but with relevant implications on patient's care (Category 2), and not related to LBP without significant implications on patient's care (Category 3). For each MR imaging finding was also assessed if it was detectable or not on the conventional sagittal and axial acquisition planes.Of the 931 evaluated MR examinations, 60 (6.4%) showed additional extraspinal MR imaging findings, categorized as follows: 55% (33/60) probably related to LBP (Category 1), 22% (13/60) not related to LBP but with relevant implications on patient's care (Category 2), and 23% (14/60) not related to LBP and without significant implications on patient's care (Category 3). Among categories 1 and 2 (n = 46), the 72% (33/46) of imaging findings were detected only on coronal plane. Coronal-STIR sequence significantly changed patients' diagnostic work-flow in 3.5% (33/931) of cases.Coronal STIR sequence, acquired in a lumbar spine MR imaging protocol to investigate LBP, may aid radiologists in detecting additional extraspinal MR imaging findings that could be related to LBP, addressing to the most appropriate clinical management.

An Evaluation of the Benefits of Simultaneous Acquisition on PET/MR Coregistration in Head/Neck Imaging

Coregistration of multimodal diagnostic images is crucial for qualitative and quantitative multiparametric analysis. While retrospective coregistration is computationally intense and could be inaccurate, hybrid PET/MR scanners allow acquiring implicitly coregistered images. Aim of this study is to assess the performance of state-of-the-art coregistration methods applied to PET and MR acquired as single modalities, comparing the results with the implicitly coregistration of a hybrid PET/MR, in complex anatomical regions such as head/neck (HN). A dataset consisting of PET/CT and PET/MR subsequently acquired in twenty-three patients was considered: performance of rigid (RR) and deformable (DR) registration obtained by a commercial software and an open-source registration package was evaluated. Registration accuracy was qualitatively assessed in terms of visual alignment of anatomical structures and qualitatively measured by the Dice scores computed on segmented tumors in PET and MRI. The resulting scores highlighted that hybrid PET/MR showed higher registration accuracy than retrospectively coregistered images, because of an overall misalignment after RR, unrealistic deformations and volume variations after DR. DR revealed superior performance compared to RR due to complex nonrigid movements of HN district. Moreover, simultaneous PET/MR offers unique datasets serving as ground truth for the improvement and validation of coregistration algorithms, if acquired with PET/CT.

An Evaluation of the Benefits of Simultaneous Acquisition on PET/MR Coregistration in Head/Neck Imaging.

Coregistration of multimodal diagnostic images is crucial for qualitative and quantitative multiparametric analysis. While retrospective coregistration is computationally intense and could be inaccurate, hybrid PET/MR scanners allow acquiring implicitly coregistered images. Aim of this study is to assess the performance of state-of-the-art coregistration methods applied to PET and MR acquired as single modalities, comparing the results with the implicitly coregistration of a hybrid PET/MR, in complex anatomical regions such as head/neck (HN). A dataset consisting of PET/CT and PET/MR subsequently acquired in twenty-three patients was considered: performance of rigid (RR) and deformable (DR) registration obtained by a commercial software and an open-source registration package was evaluated. Registration accuracy was qualitatively assessed in terms of visual alignment of anatomical structures and qualitatively measured by the Dice scores computed on segmented tumors in PET and MRI. The resulting scores highlighted that hybrid PET/MR showed higher registration accuracy than retrospectively coregistered images, because of an overall misalignment after RR, unrealistic deformations and volume variations after DR. DR revealed superior performance compared to RR due to complex nonrigid movements of HN district. Moreover, simultaneous PET/MR offers unique datasets serving as ground truth for the improvement and validation of coregistration algorithms, if acquired with PET/CT.

Multiparametric evaluation by simultaneous PET-MRI examination in patients with histologically proven laryngeal cancer.

OBJECTIVES: To evaluate the relationship between metabolic 18Fluoro-Deoxyglucose-Positron Emission Tomography (18FDG/PET) and morpho-functional parameters derived by Magnetic Resonance Imaging (MRI) in patients with histologically proven laryngeal cancer. To assess the clinical impact of PET/MRI examination on patient's staging and treatment planning. METHODS: 16 patients with histologically proven laryngeal cancer were enrolled and underwent whole body PET/CT followed by a dedicated PET/MRI of the head/neck region. Data were separately evaluated by two blinded groups: metabolic (SUV and MTV), diffusion (ADC) and perfusion (Ktrans, Ve, kep and iAUC) maps were obtained by positioning regions of interest (ROIs). Tumoral local extension assessed on PET/MRI was compared to endoscopic findings. RESULTS: A good inter-observer agreement was found in anatomical location and local extension of PET/MRI lesions (Cohen's kappa 0.9). PET/CT SUV measures highly correlate with ones derived by PET/MRI (e.g., p=0.96 for measures on VOI). Significant correlations among metabolic, diffusion and perfusion parameters have been detected. PET/MRI had a relevant clinical impact, confirming endoscopic findings (6 cases), helping treatment planning (9 cases), and modifying endoscopic primary staging (1 case). CONCLUSIONS: PET/MRI is useful for primary staging of laryngeal cancer, allowing simultaneous collection of metabolic and functional data and conditioning the therapeutic strategies.