Papers by Sheronda Statum
Journal of Computer Assisted Tomography, 2015
The aim of the study was to determine whether quantitative ultrashort echo time (UTE) -T1ρ magnet... more The aim of the study was to determine whether quantitative ultrashort echo time (UTE) -T1ρ magnetic resonance (MR) measurements are sensitive to proteoglycan degradation in human menisci by trypsin digestion. Conventional and quantitative UTE-T1ρ MR sequences were performed on 4 meniscal samples using a 3T scanner. Magnetic resonance imaging was performed before and after 4, 8, and 12 hours of trypsin solution immersion, inducing proteoglycan loss. One sample was used as a control. Digest solutions were analyzed for glycosaminoglycan (GAG) content. The UTE-T1ρ studies were analyzed for quantitative changes. Images showed progressive tissue swelling, fiber disorganization, and increase in signal intensity after GAG depletion. The UTE-T1ρ values tended to increase with time after trypsin treatment (P = 0.06). Cumulative GAG loss into the bath showed a trend of increased values for trypsin-treated samples (P = 0.1). Ultrashort echo time T1ρ measurements can noninvasively detect and quantify severity of meniscal degeneration, which has been correlated with progression of osteoarthritis.
Journal de Radiologie, 2009
Journal of magnetic resonance imaging : JMRI, Jan 23, 2015
To determine if off-saturation ratio (OSR) measured with the ultrashort echo time magnetization t... more To determine if off-saturation ratio (OSR) measured with the ultrashort echo time magnetization transfer (UTE-MT) sequence could differentiate between tendons under different states of tensile load and to compare these changes between normal versus degenerated tendons. Fourteen tendons were imaged at 3 Tesla before and during the application of 0.5-1 kg tension. A two-dimensional (2D) -UTE-MT sequence with 1.5, 3, and 5 kHz frequency offsets was used on nine tendons and a 3D-UTE-MT sequence with 1.5 kHz frequency offset was used on five tendons. OSR was calculated and compared for each condition. Histologic correlation was performed using light microscopy. In general, OSR increased after the application of tension. Mean increase of 2D OSR was 0.035 (95% confidence interval [CI], 0.013-0.056) at 1.5 kHz offset (P < 0.01), 0.031 (95% CI, 0.023-0.040) at 3 kHz offset (P < 0.01), and 0.013 (95% CI, -0.013-0.027) at 5 kHz offset (P = 0.07) from pre- to posttension states. Mean incr...
Osteoarthritis and cartilage / OARS, Osteoarthritis Research Society, 2013
To develop ultrashort echo time (UTE) magnetic resonance imaging (MRI) techniques to image the zo... more To develop ultrashort echo time (UTE) magnetic resonance imaging (MRI) techniques to image the zone of calcified cartilage (ZCC), and quantify its T2*, T1 and T1ρ. In this feasibility study a dual inversion recovery UTE (DIR-UTE) sequence was developed for high contrast imaging of the ZCC. T2* of the ZCC was measured with DIR-UTE acquisitions at progressively increasing TEs. T1 of the ZCC was measured with saturation recovery UTE acquisitions at progressively increasing saturation recovery times. T1ρ of the ZCC was measured with spin-locking prepared DIR-UTE acquisitions at progressively increasing spin-locking times. The feasibility of the qualitative and quantitative DIR-UTE techniques was demonstrated on phantoms and in six cadaveric patellae using a clinical 3 T scanner. On average the ZCC has a short T2* ranging from 1.0 to 3.3 ms (mean ± standard deviation = 2.0 ± 1.2 ms), a short T1 ranging from 256 to 389 ms (mean ± standard deviation = 305 ± 45 ms), and a short T1ρ ranging ...
PURPOSE/AIM The purpose of this study is to define the anatomy of the metacarpophalangeal and int... more PURPOSE/AIM The purpose of this study is to define the anatomy of the metacarpophalangeal and interphalangeal joints of the thumb and fingers with images obtained using an 11.7T MR scanner. Commonly encountered pathologic lesions involving these joints will be depicted with clinical protocols at 1.5 and 3.0T, emphasizing diagnostic criteria. CONTENT ORGANIZATION The anatomy and structure of the thumb and fingers will be profiled using high resolution MR imaging at 11.7T in human cadaveric donors. Commonly encountered pathologic lesions will then be demonstrated and characterized, reviewing diagnostic criteria and pertinent grading systems. Lesions will include commonly encountered injuries such as collateral ligament injuries, pseudo-Stener lesions, sagittal band injuries, central slip extensor tendon tears, pulley lesions, and Boutonniere and pseudo-Boutonniere deformities. SUMMARY Review of the complex anatomic structures of the thumb and fingers with high resolution imaging will ...
PURPOSE To provide a non-invasive quantitative means of evaluating Achilles tendon T2* values usi... more PURPOSE To provide a non-invasive quantitative means of evaluating Achilles tendon T2* values using 3T MR UTE techniques in asymptomatic volunteers. METHOD AND MATERIALS Left ankles of 10 asymptomatic volunteers (43±14.2 yrs, mean±sd) underwent MR imaging at 3T. Measurements were taken from 1.5 to 6 cm above the posterior superior margin of the calcaneus in the region of the mid-tensile tendon. A constant TR–variable TE 2D ultrashort TE (UTE) sequence with a minimum TE of 8 us was employed to image and quantify the Achilles tendon of asymptomatic volunteers. Typical imaging parameters included: field of view (FOV)=10 cm, slice thickness = 2 mm, readout = 512, 355 projections, TR = 200 ms, number of excitation=2, bandwidth=±62.5 kHz, flip angle=45°, scan time=2.4 min (x4 scans total). T2* was quantified using Matlab, employing voxel-wise mono exponential fitting of fat saturated axial UTE images taken at 4 TEs (8 us, 600 us, 2.2 ms, 6.6 ms). For each sample, the region of interest wa...
PURPOSE To compare T1ρ measurements using a 2D multi-slice spiral and 3D MAPS technique. METHOD A... more PURPOSE To compare T1ρ measurements using a 2D multi-slice spiral and 3D MAPS technique. METHOD AND MATERIALS Four phantoms (agarose concentration: 1%, 2%, 3%, 4%) and five axially sliced cadaveric patella chips were scanned in a 3T MRI-system using a single-channel, transmit and receive, custom-built quadrature birdcage coil. T1ρ sequences were acquired using a 2D multi-slice spiral technique and 3D MAPS technique. Measurements were performed in the phantoms and in the radial and transitional zones of the cartilage. T1ρ values were compared with respect to the imaging technique, orientation of the cartilage surface compared to the direction of the main magnetic field B0, and localization in the medial or lateral patellar facet. RESULTS On the phantom images (agarose concentration: 1% / 2% / 3% / 4%), average T1ρ values were 75.3 / 30.2 / 22.9 / 21.5 msec using 2D technique, and 61.2 / 46.6 / 27.7 / 18.2 msec using 3D technique. The differences between the measurement techniques wer...
PURPOSE Determine if quantitative conventional and Ultrashort Time-to-Echo (UTE) MR imaging is se... more PURPOSE Determine if quantitative conventional and Ultrashort Time-to-Echo (UTE) MR imaging is sensitive to meniscus degeneration, in an in vitro model using enzymatic collagen degradation. METHOD AND MATERIALS Cadaveric knees (n=3, 1F, 80±6.1 yrs) were sectioned sagittally to obtain ~mid-medial 5-mm slices. Triangular meniscus samples were taken, and submerged in saline (n=1) or collagenase (n=3) solution for 0, 4, 8 or 12 hrs. At each time point, samples were imaged using conventional multi-echo T2 (TR=2000 ms, TE=10-90 ms) and novel UTE T2* (TR=300 ms, TE=0.012 to 20 ms) techniques. MR properties were normalized to values at time 0 to determine percent increase in value with time. Bathing solutions were collected and analyzed for collagen content using Sircol assay. RESULTS Collagenase treatment resulted in increasing loss of collagen with time (Fig.A). SE T2 and UTE T2* values of the meniscus samples were 14~21 ms and 3~16 ms, respectively, prior to the collagenase treatment. Af...
Journal of orofacial pain
To use the ultrashort time-to-echo magnetic resonance imaging (UTE MRI) technique to quantify sho... more To use the ultrashort time-to-echo magnetic resonance imaging (UTE MRI) technique to quantify short T2* properties (obtained through gradient echo) of a disc from the human temporomandibular joint (TMJ) and to corroborate regional T2* values with biomechanical properties and histologic appearance of the discal tissues. A cadaveric human TMJ was sliced sagittally and imaged by conventional and UTE MRI techniques. The slices were then subjected to either biomechanical indentation testing or histologic evaluation, and linear regression was used for comparison to T2* maps obtained from UTE MRI data. Feasibility of in vivo UTE MRI was assessed in two human volunteers. The UTE MRI technique of the specimens provided images of the TMJ disc with greater signal-to-noise ratio (~3 fold) and contrast against surrounding tissues than conventional techniques. Higher T2* values correlated with lower indentation stiffness (softer) and less collagen organization as indicated by polarized light micr...
The importance of the menisci in the biomechanics of the knee joint, particularly with respect to... more The importance of the menisci in the biomechanics of the knee joint, particularly with respect to load distribution, is well established. Its noninvasive evaluation has been emphasized more recently in an attempt to consider the joint as a whole with respect to the pathogenesis of osteoarthrosis (OA). To fulfill the function of load distribution and shock absorption in the knee, the meniscus has a complex infrastructure that affords it hoop strength. This structure includes a collagen fibrillar pattern comprised of 5 different fiber orientations (circumferential, radial, tie, vertical and lamella fibers). Four functional and anatomical zones are also distinguished within meniscal substance: 1) a central fibrocartilaginous portion, 2) a peripheral fibrous portion, 3) a central vascular white zone, and 4) a peripheral vascularized red zone. Knowledge of this structure is intrinsic to the diagnosis and characterization of meniscal pathology, the understanding of injury patterns, as well as their management. The noninvasive MR imaging analysis of meniscal infrastructure has not yet been described due to the intrinsic MR properties of this tissue, its relatively short T2 properties, resulting in lack of signal and contrast with conventional MR techniques. We aimed at using a tailored MR sequence to demonstrate the infrastructure of cadaveric menisci, including the fibrillar pattern, the fibrous and the fibrocartilaginous as well as the red and the white zones on a 3T clinical scanner.
PURPOSE The purpose of this study was to investigate the free and bound water components in human... more PURPOSE The purpose of this study was to investigate the free and bound water components in human cadaveric meniscus using ultrashort TE (UTE) imaging and bi-component analysis. METHOD AND MATERIALS A two-dimensional (2D) UTE imaging sequence was implemented on a 3T Signa TwinSpeed scanner (GE Healthcare Technologies, Milwaukee, WI). The 2D UTE sequence employed half-pulse radiofrequency (RF) excitation, radial ramp sampling and fast transmit/receive switching to reduce nominal TE to 8 μs. 12 fresh lateral and medial menisci were collected one to two days after death. Each meniscus was placed in a plastic container filled with perfluorooctyl bromide (PFOB) solution to minimize susceptibility effects at tissue air interface. The following UTE imaging parameters were used: TR=200 ms, FOV = 6-8 cm, matrix=512x512, flip angle = 45°, BW = 62.5 kHz, slice = 1.7 mm, 16 TEs ranged from 8 μs to 40 ms. In-house developed bi-component fitting software was used to calculate T2* and the fraction...
PURPOSE/AIM To review the rationale, imaging techniques, normal appearances, and often subtle com... more PURPOSE/AIM To review the rationale, imaging techniques, normal appearances, and often subtle complications of current generation total hip arthroplasty utilizing various bearings including metal-on-polyethylene, metal-on-metal, ceramic-on-polyethylene, ceramic-on-ceramic, and ceramic-on-metal. CONTENT ORGANIZATION 1) Briefly summarize biomechanical literature with regards to bearing tribology 2) Review conventional imaging techniques utilized in postoperative patients with emphasis on CT and MR image optimization with metal artifact reduction sequences (MARS) 3) Discuss principles behind more novel MR sequences including SEMAC, MAVRIC, and UTE-MSI 4) Show examples of complications specific to each bearing system using conventional multimodality imaging as well as novel MR sequences SUMMARY Comprehensive knowledge of imaging techniques and appearances of current generation total hip arthroplasty systems is crucial for radiologists to be useful to their referring orthopaedic surgeons.
PURPOSE Excellent anatomical studies on clinical systems have been done to demonstrate the detail... more PURPOSE Excellent anatomical studies on clinical systems have been done to demonstrate the detail of the digital pulleys and plates at fields up to 7T. In our study, using an 11.7T system with high-performance gradients and micro-array coils, we attempted to visualize details of these structures which have previously been refractory to MR imaging. METHOD AND MATERIALS Human fingers and thumbs were collected per institutional policy, firmly immobilized, and placed into the bore of an 11.7T Bruker BioSpec 117/16USR system (Bruker BioSpin, Billerica, MA) fitted with a 750 mT/m gradient system. Ten fields of view (finger: proximal, middle, distal phalanx, PIP, DIP and MCP; thumb: proximal, distal phalanx, IP and MCP) were independently imaged with both gradient and spin echo sequences (FLASH: 90-120um3 isotropic resolution, TE 6ms, TR 25ms, fat sat, NEX 9-25, 4-6 hour scans; Multislice Spin Echo: 35x35x250um to 60x60x500um resolution, TE 7-14ms, TR 5000ms, 2 echoes, fat sat, NEX 5-15, 4...
PURPOSE Anatomic studies have shown that few fibers of the anteromedial and posterolateral bundle... more PURPOSE Anatomic studies have shown that few fibers of the anteromedial and posterolateral bundles of the anterior cruciate ligament (ACL) partially blend with the anterior horn of the lateral meniscus root ligament (AHLMR) fibers. This close relationship between the ACL and the AHLMR through these blended fibers (BF) might be a pathway for spread of lesions affecting the ACL. We sought to systematically evaluate the prevalence and association of ACL degenerative and traumatic lesions with abnormal MR appearance of AHLMR. METHOD AND MATERIALS In a single cadaveric knee, the tibial attachment of the AHLM root ligament and ACL was imaged on an 11.7T MR system with a 3D GRE (TR20ms, TE7ms) sequence (112x112x120μm resolution). Two blinded readers retrospectively reviewed 500 consecutive knee MRI examinations (6 month period). Studies were searched for the presence of ACL lesions (degenerative mucoid lesions or traumatic tears), abnormal appearance of AHLMR (degeneration or tear) and inc...
PURPOSE To determine quantitative MR properties of menisci and articular cartilage in the human k... more PURPOSE To determine quantitative MR properties of menisci and articular cartilage in the human knee, when stratified by meniscal morphology as determined by clinical MR grading. METHOD AND MATERIALS Cadaveric knees (n=6, 4F, 78±10.7 yrs) were sectioned sagittally through central weight bearing region of lateral and medial condyles. Slices were imaged at 3T using intermediate-weighted spin echo fat-saturated sequence (TR=2500 ms, TE=35 ms, slice=1 mm, FOV=8 cm, matrix=512x512) and menisci were classified as being normal (Fig.A), torn (Fig.B) or degenerate (Fig.C). Regions of interest were created (Fig.D) on inner, middle and outer zones of each meniscus, and adjacent cartilage in superficial (S), middle (M) and deep (D) layers. Quantitative MR properties were assessed using Ultrashort Time-to-Echo T2 Star (UTE T2*; TR=100 ms, TE=0.012 to 60 ms), tailored for short T2 tissues, and long T2-tailored spin echo (SE T2; TR=2000 ms, TE=10 to 90 ms) techniques. RESULTS In the meniscus, UTE ...
PURPOSE MR studies of the anatomy of the tendons, pulleys and plantar plates of the toes have bee... more PURPOSE MR studies of the anatomy of the tendons, pulleys and plantar plates of the toes have been performed with clinical systems at field strengths up to 3T. In this study we used a high performance small bore 11.7T system to study the anatomy of the toes in detail. METHOD AND MATERIALS Following institutional policy human cadaveric great and lesser toes were collected and imaged with a 11.7T Bruker BioSpec 117/16USR system (Bruker BioSpin, Billerica, MA) fitted with a 750 mT/m gradient system, using resonators (60 and 72mm internal diameter) with and without receive-only four element semi-circular surface array coils. Both spin echo (80x80x400um resolution, TE 7-14ms, TR 5000ms, 2 echoes, fat sat, NEX 5-15, 4-6 hour scans) and gradient echo (90-150um3 isotropic resolution, TE 6ms, TR 25ms, fat sat, NEX 9-25, 4-6 hour scans) images were acquired. RESULTS Unprecedented spatial resolution and contrast was achieved, with well over 20 times greater spatial resolution than previous rep...
PURPOSE To evaluate the deep layer morphology of knee articular cartilage using Ultrashort Time-t... more PURPOSE To evaluate the deep layer morphology of knee articular cartilage using Ultrashort Time-to-Echo (UTE) MRI, and report the morphologic and quantitative MR properties of overlying cartilage. METHOD AND MATERIALS Cadaveric knees (n=5, 2 females, 76±11 yrs) were sectioned sagittally through central weight bearing region of lateral and medial condyles. Using UTE MRI (3T, 3” coil, TR=500 ms, TE=0.008 and 8 ms, slice=1 mm, FOV=8 cm, matrix=512x512) echo-subtraction images (Fig.A) were evaluated for focal abnormality (Fig.A, arrows) of the characteristic normal linear signal intensity (Fig.A, triangles), not discernable in conventional spin echo images (Fig.B). Regions of interest were created on superficial (S), middle (M) and deep (D) layer cartilage of UTE–abnormal and –normal regions (Fig.B). Four types of quantitative MR properties were assessed: UTE T2 Star (TR=100 ms, TE=0.012 to 60 ms), UTE T1rho (TR=400, TSL=0.02, 2, 5, 10 ms), Spiral Chopped Magnetization Preparation (SCMP...
PURPOSE To perform morphologic MR imaging of cartilaginous endplates (CEP) of intervertebral disc... more PURPOSE To perform morphologic MR imaging of cartilaginous endplates (CEP) of intervertebral discs (IVD) in healthy volunteers using ultrashort time-to-echo (UTE) technique. METHOD AND MATERIALS The lumbar spine of an asymptomatic male (29 yrs) and female (20 yrs) was imaged using a conventional fat saturated fast spin echo (FOV=26 cm, slice=3 mm, TR=3500 ms, TE=120 ms, ETL=27, maxtrix=384x384, scan time=4 min) and 2D UTE MR (TR=300 ms, TE=0.012 and 8.8 ms, scan time=11 min) sequences at 3T, using a clinical spine coil. UTE echo subtraction image was obtained by subtrating the 2nd echo image from the 1st echo image. Morphology of the IVD and CEP were evaluated by a board-certified radiologist. RESULTS In conventional T2-weighted FSE images, the nucleus pulposus (NP; Figure A, square) was seen with homogeneous high signal intensity as expected in healthy human subjects. However, the region of the CEP (Figure A, arrows) exhibited low signal intensity and could not be evaluated directl...
Skeletal Radiology, 2014
We obtained high-resolution 11.7-T MR images of the pulleys of the flexor tendons in cadaveric to... more We obtained high-resolution 11.7-T MR images of the pulleys of the flexor tendons in cadaveric toe specimens. A detailed understanding of toe pulley anatomy as seen with MR is likely to be of benefit in recognizing disease and the effects of trauma. Six cadaveric toes were imaged with an 11.7-T small-bore MR imaging system using optimized coils. Two-dimensional dual-echo SE scans were obtained in three planes (40 × 40 × 400-μm(3) voxel size, TE = 7/14 ms, TR = 3,500 ms, fat saturation). Three-dimensional spoiled gradient echo scans were obtained (90-150 μm(3) isotropic voxel size, TE = 6 ms, TR = 25 ms, with and without fat saturation). Specimen orientation was with the long axis of the toe either parallel or perpendicular to B0. All the annular (A) pulleys were demonstrated in the great and lesser toes. The A2 pulley in the great and lesser toes and the A4 pulley in the lesser toes were the most substantial pulleys. The A5 pulley, which has not previously been described in the toes, was demonstrated. The cruciform pulleys were also seen and were smaller and thinner. Three tissue layers were seen, and there was evidence of different fiber directions in annular pulleys producing different magic angle effects. Detailed anatomy of the pulley system of the flexor tendons was seen on the 11.7-T MR images showing new features and providing a basis for image interpretation. Similarities and differences between the pulley systems in the toes and the fingers were identified.
Radiology, 2012
To assess the ability of ultrashort echo time (UTE) magnetic resonance (MR) imaging techniques to... more To assess the ability of ultrashort echo time (UTE) magnetic resonance (MR) imaging techniques to enable morphologic assessment of different types of meniscal calcifications, to compare these sequences with standard clinical sequences, and to perform T2* measurements of meniscal calcifications. This study was exempted by the institutional review board, and informed consent was not required. Ten human cadaveric menisci were imaged with high-spatial-resolution radiography and 3.0-T MR imaging by using morphologic (T1-weighted fast spin-echo [FSE], T2-weighted FSE, proton density [PD]-weighted FSE, two-dimensional [2D] fast spoiled gradient-echo [FSPGR], three-dimensional [3D] FSPGR, and 3D UTE) and quantitative (2D inversion-recovery [IR] UTE and 3D UTE) sequences. The menisci were divided into thirds for regional analysis. Morphologic assessment was performed with MR imaging; MR imaging findings were correlated with radiographs. Calcifications were classified as punctate, linear, or ...
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Papers by Sheronda Statum