3D 3He diffusion MRI as a local in vivo morphometric tool to evaluate emphysematous rat lungs

In this work, we investigate 3He magnetic resonance imaging as a noninvasive morphometric tool to assess emphysematous disease state on a local level. Emphysema was induced intratracheally in rats with 25 U/100 g body wt of porcine pancreatic elastase dissolved in 200 μl saline. Rats were then paired with saline-dosed controls. Nine three-dimensional (3D) 3He diffusion-weighted images were acquired at 1, 2, or 3 wk postdose, after which the lungs were harvested and prepared for histological analysis. Recently introduced indexes sensitive to the heterogeneity of the air space size distribution were calculated. These indexes, D1 and D2, were derived from the moments of the mean equivalent airway diameters. Averaged over the entire lung, it is shown that the average 3He diffusivity ( Dave) correlates well with histology ( R = 0.85, P < 0.0001). By matching small (0.046 cm2) regions in 3He images with corresponding regions in histological slices, Dave correlates significantly with both D 1 and D 2 ( R = 0.88 and R = 0.90, respectively, with P < 0.0001). It is concluded that 3He MRI is a viable noninvasive morphometric tool for localized in vivo emphysema assessment.

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Alteration within the Hippocampal Volume in Patients with LHON Disease—7 Tesla MRI Study

Journal of Clinical Medicine ◽

10.3390/jcm10010014 ◽

2020 ◽

Vol 10 (1) ◽

pp. 14

Author(s):

Cezary Grochowski ◽

Kamil Jonak ◽

Marcin Maciejewski ◽

Andrzej Stępniewski ◽

Mansur Rahnama-Hezavah

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Molecular Layer ◽

Three Dimensional ◽

Hippocampal Volume ◽

7 Tesla ◽

Diagnostic Process ◽

Resonance Imaging ◽

The Right

Purpose: The aim of this study was to assess the volumetry of the hippocampus in the Leber’s hereditary optic neuropathy (LHON) of blind patients. Methods: A total of 25 patients with LHON were randomly included into the study from the national health database. A total of 15 patients were selected according to the inclusion criteria. The submillimeter segmentation of the hippocampus was based on three-dimensional spoiled gradient recalled acquisition in steady state (3D-SPGR) BRAVO 7T magnetic resonance imaging (MRI) protocol. Results: Statistical analysis revealed that compared to healthy controls (HC), LHON subjects had multiple significant differences only in the right hippocampus, including a significantly higher volume of hippocampal tail (p = 0.009), subiculum body (p = 0.018), CA1 body (p = 0.002), hippocampal fissure (p = 0.046), molecular layer hippocampus (HP) body (p = 0.014), CA3 body (p = 0.006), Granule Cell (GC) and Molecular Layer (ML) of the Dentate Gyrus (DG)–GC ML DG body (p = 0.003), CA4 body (p = 0.001), whole hippocampal body (p = 0.018), and the whole hippocampus volume (p = 0.023). Discussion: The ultra-high-field magnetic resonance imaging allowed hippocampus quality visualization and analysis, serving as a powerful in vivo diagnostic tool in the diagnostic process and LHON disease course assessment. The study confirmed previous reports regarding volumetry of hippocampus in blind individuals.

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Three-dimensional distribution of CT attenuation in the lumbar spine pedicle wall

Scientific Reports ◽

10.1038/s41598-020-80676-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tomoyo Y. Irie ◽

Tohru Irie ◽

Alejandro A. Espinoza Orías ◽

Kazuyuki Segami ◽

Norimasa Iwasaki ◽

...

Keyword(s):

Lumbar Spine ◽

Age Groups ◽

Three Dimensional ◽

Hounsfield Unit ◽

Lateral Wall ◽

Ct Attenuation ◽

Dimensional Distribution ◽

The Mean ◽

Pedicle Wall

AbstractThis study investigated in vivo the three-dimensional distribution of CT attenuation in the lumbar spine pedicle wall measured in Hounsfield Unit (HU). Seventy-five volunteers underwent clinical lumbar spine CT scans. Data was analyzed with custom-written software to determine the regional variation in pedicle wall attenuation values. A cylindrical coordinate system oriented along the pedicle’s long axis was used to calculate the pedicular wall attenuation distribution three-dimensionally and the highest attenuation value was identified. The pedicular cross-section was divided into four quadrants: lateral, medial, cranial, and caudal. The mean HU value for each quadrant was calculated for all lumbar spine levels (L1–5). The pedicle wall attenuation was analyzed by gender, age, spinal levels and anatomical quadrant. The mean HU values of the pedicle wall at L1 and L5 were significantly lower than the values between L2–4 in both genders and in both age groups. Furthermore, the medial quadrant showed higher HU values than the lateral quadrant at all levels and the caudal quadrant showed higher HU values at L1–3 and lower HU values at L4–5 than the cranial quadrant. These findings may explain why there is a higher incidence of pedicle screw breach in the pedicle lateral wall.

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In vivo three-dimensional magnetic resonance imaging of rat knee osteoarthritis model induced using meniscal transection

Journal of Orthopaedic Translation ◽

10.1016/j.jot.2015.06.002 ◽

2015 ◽

Vol 3 (3) ◽

pp. 134-141 ◽

Cited By ~ 2

Author(s):

Yi-Xiang J. Wang ◽

Junqing Wang ◽

Min Deng ◽

Gang Liu ◽

Ling Qin

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Knee Osteoarthritis ◽

Three Dimensional ◽

Resonance Imaging

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In Vivo Tracking of the Human Patella Using Cine Phase Contrast Magnetic Resonance Imaging

Journal of Biomechanical Engineering ◽

10.1115/1.2800868 ◽

1999 ◽

Vol 121 (6) ◽

pp. 650-656 ◽

Cited By ~ 86

Author(s):

F. T. Sheehan ◽

F. E. Zajac ◽

J. E. Drace

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Knee Joint ◽

Phase Contrast ◽

Three Dimensional ◽

Resonance Imaging ◽

Contrast Magnetic Resonance ◽

Knee Joint Kinematics ◽

Cine Phase Contrast

Improper patellar tracking is often considered to be the cause of patellar-femoral pain. Unfortunately, our knowledge of patellar-femoral-tibial (knee) joint kinematics is severely limited due to a lack of three-dimensional, noninvasive, in vivo measurement techniques. This study presents the first large-scale, dynamic, three-dimensional, noninvasive, in vivo study of nonimpaired knee joint kinematics during volitional leg extensions. Cine-phase contrast magnetic resonance imaging was used to measure the velocity profiles of the patella, femur, and tibia in 18 unimpaired knees during leg extensions, resisted by a 34 N weight. Bone displacements were calculated through integration and then converted into three-dimensional orientation angles. We found that the patella displaced laterally, superiorly, and anteriorly as the knee extended. Further, patellar flexion lagged knee flexion, patellar tilt was variable, and patellar rotation was fairly constant throughout extension.

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A Cadaveric and Magnetic Resonance Imaging Investigation of the Salpingopharyngeus

Journal of Speech Language and Hearing Research ◽

10.1044/2021_jslhr-20-00483 ◽

2021 ◽

pp. 1-11

Author(s):

Karen Perta ◽

Eileen Kalmar ◽

Youkyung Bae

Keyword(s):

Magnetic Resonance Imaging ◽

Body Weight ◽

Magnetic Resonance ◽

Three Dimensional ◽

Hierarchical Regression ◽

Resonance Imaging ◽

Before And After ◽

Velopharyngeal Function ◽

The Relationship

Purpose The aim of the study was to update our information regarding the salpingopharyngeus (SP) muscle using cadaveric and in vivo magnetic resonance imaging (MRI) data. Primary objectives were to (a) observe the presence/absence of the muscle and (b) quantify and describe its dimensions and course. Method SP specimens from 19 cadavers (10 women, nine men) were analyzed. Following head bisection, measurements of SP, including width of the cartilaginous attachment (CW) and width of the superior muscle base (SMW), were taken before and after removal of the overlying mucosa. In addition, SP was analyzed in 15 healthy subjects (eight men, seven women) using high-resolution three-dimensional MRI data. CW and SMW measures were replicated in the paraxial MRI view. Results The presence of the salpingopharyngeal fold and muscle was confirmed bilaterally in all cadaveric and living subjects. Following mucosa removal, mean cadaveric CW and SMW measurements were 5.6 and 3.8 mm, respectively. Mean in vivo CW and SMW were 6.1 and 3.7 mm, respectively. Results from the hierarchical regression analyses revealed that, in both cadaveric and living groups, SMW is dependent on the relationship between age and body weight, after controlling for sex. Conclusions The salpingopharyngeal fold and SP muscle are always present bilaterally and can be quantified at the superior origin using both cadaveric and in vivo three-dimensional MRI data. Though both the superior origin and inferior course of SP are highly variable, the size of the SP muscle is dependent on characteristics known to affect muscle fibers, such as the relationship between age and body weight. Given the consistent and quantifiable presence of the SP muscle, its potential role in velopharyngeal function for speech and swallowing is reconsidered. Supplemental Material https://doi.org/10.23641/asha.14347859

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Method for Calibration of Left Ventricle Material Properties Using Three-Dimensional Echocardiography Endocardial Strains

Journal of Biomechanical Engineering ◽

10.1115/1.4044215 ◽

2019 ◽

Vol 141 (9) ◽

Cited By ~ 4

Author(s):

Yaghoub Dabiri ◽

Kevin L. Sack ◽

Nuno Rebelo ◽

Peter Wang ◽

Yunjie Wang ◽

...

Keyword(s):

Mechanical Properties ◽

Left Ventricle ◽

Diffusion Tensor ◽

Diastolic Pressure ◽

Three Dimensional ◽

Heart Association ◽

Mean Difference ◽

Imaging Data ◽

The Mean

We sought to calibrate mechanical properties of left ventricle (LV) based on three-dimensional (3D) speckle tracking echocardiographic imaging data recorded from 16 segments defined by American Heart Association (AHA). The in vivo data were used to create finite element (FE) LV and biventricular (BV) models. The orientation of the fibers in the LV model was rule based, but diffusion tensor magnetic resonance imaging (MRI) data were used for the fiber directions in the BV model. A nonlinear fiber-reinforced constitutive equation was used to describe the passive behavior of the myocardium, whereas the active tension was described by a model based on tissue contraction (Tmax). isight was used for optimization, which used abaqus as the forward solver (Simulia, Providence, RI). The calibration of passive properties based on the end diastolic pressure volume relation (EDPVR) curve resulted in relatively good agreement (mean error = −0.04 ml). The difference between the experimental and computational strains decreased after segmental strain metrics, rather than global metrics, were used for calibration: for the LV model, the mean difference reduced from 0.129 to 0.046 (circumferential) and from 0.076 to 0.059 (longitudinal); for the BV model, the mean difference nearly did not change in the circumferential direction (0.061) but reduced in the longitudinal direction from 0.076 to 0.055. The calibration of mechanical properties for myocardium can be improved using segmental strain metrics. The importance of realistic fiber orientation and geometry for modeling of the LV was shown.

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ECG-gated dynamic magnetic resonance imaging method for examination of the pig heart

Acta Veterinaria Hungarica ◽

10.1556/004.49.2001.3.3 ◽

2001 ◽

Vol 49 (3) ◽

pp. 275-284

Author(s):

Zs. Petrási ◽

R. Romvári ◽

G. Bajzik ◽

B. Fenyves ◽

I. Repa ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Three Dimensional ◽

Dynamic Magnetic Resonance Imaging ◽

Imaging Method ◽

Resonance Imaging ◽

Dynamic Magnetic Resonance ◽

Heart Cycle ◽

The Right

A dynamic magnetic resonance imaging (MRI) method was developed for in vivo examination of the pig heart. Measurements were carried out on 15 meat-type pigs of different liveweight using a 1.5 T equipment. Inhalation anaesthesia was applied, then data acquisition was synchronised by ECG gating. Depending on the heart rate and heart size, in each case 8 to 10 slices and in each slice 8 to 14 phases were acquired prospectively according to one heart cycle. During the post-processing of the images the left and the right ventricular volumes were determined. The values measured at 106 kg liveweight are 2.5 times higher than those obtained at 22 kg, while the ejection fractions are equal. The calculated cardiac output values were 3.5 l (22 kg, 132 beats/min.), and 6.0 l (106 kg, 91 beats/min.), respectively. After measuring the wall thickness, the contraction values were also determined for the septum (70%), and for the anterior (61%), posterior (41%) and lateral (54%) walls of the left ventricle. Three-dimensional animated models of the ventricles were constructed. Based on the investigations performed, the preconditioning, the anaesthetic procedure, the specific details of ECG measurement and the correct MR imaging technique were worked out.

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