3D Ultrashort Echo Time Cones Research Articles

Assessment of lung density in pediatric patients using three-dimensional ultrashort echo-time and four-dimensional zero echo-time sequences

PurposeLung magnetic resonance imaging (MRI) using conventional sequences is limited due to strong signal loss by susceptibility effects of aerated lung. Our aim is to assess lung signal intensity in children on ultrashort echo-time (UTE) and zero echo-time (ZTE) sequences. We hypothesize that lung signal intensity can be correlated to lung physical density.Materials and methodsLung MRI was performed in 17 children with morphologically normal lungs (median age: 4.7 years, range 15 days to 17 years). Both lungs were manually segmented in UTE and ZTE images and the average signal intensities were extracted. Lung-to-background signal ratios (LBR) were compared for both sequences and between both patient groups using non-parametric tests and correlation analysis. Anatomical region-of-interest (ROI) analysis was performed for the normal cohort for assessment of the anteroposterior lung gradient.ResultsThere was no significant difference between LBR of normal lungs using UTE and ZTE (p < 0.05). Both sequences revealed a LBR age-dependency with a high negative correlation for UTE (Rs = – 0.77; range 2.98–1.41) and ZTE (Rs = – 0.82; range 2.66–1.38)). Signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were age-dependent for both sequences. SNR was higher for children up to 2 years old with 3D UTE Cones while for the rest it was higher with 4D ZTE. CNR was similar for both sequences. Posterior lung areas exhibited higher signal intensity compared to anterior ones (UTE 9.4% and ZTE 12% higher), both with high correlation coefficients (R2UTE = 0.94, R2ZTE = 0.97).ConclusionThe ZTE sequence can measure signal intensity similarly to UTE in pediatric patients. Both sequences reveal an age- and gravity-dependency of LBR.

High-contrast osteochondral junction imaging using a 3D dual adiabatic inversion recovery-prepared ultrashort echo time cones sequence.

While conventional MRI sequences cannot visualize tissues from the osteochondral junction (OCJ) due to these tissues' short transverse T2 /T2 * relaxations, ultrashort echo time (UTE) sequences can overcome this limitation. A 2D UTE sequence with a dual adiabatic inversion recovery preparation (DIR-UTE) for selective imaging of short T2 tissues with high contrast has previously been developed, but high sensitivity to eddy currents and aliased out-of-slice excitation make it difficult to image the thin layer of the OCJ in vivo. Here, we combine the DIR scheme with a 3D UTE cones sequence for volumetric imaging of OCJ tissues in vivo, aiming to generate higher OCJ contrast compared with a recently developed single IR-prepared UTE sequence with a fat saturation module (IR-FS-UTE). All sequences were implemented on a 3-T clinical scanner. The DIR-UTE cones sequence combined a 3D UTE cones sequence with two narrow-band adiabatic IR preparation pulses centered on water and fat spectrum frequencies, respectively. The 3D DIR-UTE cones sequence was first applied to a phantom, then to the knees of four healthy volunteers and four patients diagnosed with osteoarthritis and compared with the IR-FS-UTE sequence. In both phantom and volunteer studies, the proposed DIR-UTE cones sequence showed much higher contrast for OCJ imaging than the IR-FS-UTE sequence did. The 3D DIR-UTE cones sequence showed a significantly higher contrast-to-noise ratio between the OCJ and subchondral bone fat (mean, standard deviation [SD]: 25.7 ± 2.3) and between the OCJ and superficial layers of cartilage (mean, SD: 22.2 ± 3.5) compared with the IR-FS-UTE sequence (mean, SD: 10.8 ± 2.5 and 16.3 ± 2.6, respectively). The 3D DIR-UTE cones sequence is feasible for imaging of the OCJ region of the knee in vivo and produces both high resolution and high contrast.

Automated cartilage segmentation and quantification using 3D ultrashort echo time (UTE) cones MR imaging with deep convolutional neural networks.

To develop a fully automated full-thickness cartilage segmentation and mapping of T1, T1ρ, and T2*, as well as macromolecular fraction (MMF) by combining a series of quantitative 3D ultrashort echo time (UTE) cones MR imaging with a transfer learning-based U-Net convolutional neural networks (CNN) model. Sixty-five participants (20 normal, 29 doubtful-minimal osteoarthritis (OA), and 16 moderate-severe OA) were scanned using 3D UTE cones T1 (Cones-T1), adiabatic T1ρ (Cones-AdiabT1ρ), T2* (Cones-T2*), and magnetization transfer (Cones-MT) sequences at 3T. Manual segmentation was performed by two experienced radiologists, and automatic segmentation was completed using the proposed U-Net CNN model. The accuracy of cartilage segmentation was evaluated using the Dice score and volumetric overlap error (VOE). Pearson correlation coefficient and intraclass correlation coefficient (ICC) were calculated to evaluate the consistency of quantitative MR parameters extracted from automatic and manual segmentations. UTE biomarkers were compared among different subject groups using one-way ANOVA. The U-Net CNN model provided reliable cartilage segmentation with a mean Dice score of 0.82 and a mean VOE of 29.86%. The consistency of Cones-T1, Cones-AdiabT1ρ, Cones-T2*, and MMF calculated using automatic and manual segmentations ranged from 0.91 to 0.99 for Pearson correlation coefficients, and from 0.91 to 0.96 for ICCs, respectively. Significant increases in Cones-T1, Cones-AdiabT1ρ, and Cones-T2* (p<0.05) and a decrease in MMF (p<0.001) were observed in doubtful-minimal OA and/or moderate-severe OA over normal controls. Quantitative 3D UTE cones MR imaging combined with the proposed U-Net CNN model allows a fully automated comprehensive assessment of articular cartilage. • 3D UTE cones imaging combined with U-Net CNN model was able to provide fully automated cartilage segmentation. • UTE parameters obtained from automatic segmentation were able to reliably provide a quantitative assessment of cartilage.

Assessment of mechanical properties of articular cartilage with quantitative three-dimensional ultrashort echo time (UTE) cones magnetic resonance imaging

Conventional magnetic resonance imaging (MRI) is not capable of detecting signal from the deep cartilage due to its short transverse relaxation time (T2). Moreover, several quantitative MRI techniques are significantly influenced by the magic angle effect. The combinations of ultrashort echo time (UTE) MRI with magnetization transfer (UTE-MT) and Adiabatic T1ρ (UTE-AdiabT1ρ) imaging allow magic angle-insensitive assessments of all regions of articular cartilage. The purpose of this study was to investigate the correlations between quantitative three-dimensional UTE MRI biomarkers and mechanical properties of human tibiofemoral cartilage specimens. In total, 40 human tibiofemoral cartilage specimens were harvested from three male and four female donors (64 ± 18 years old). Cartilage samples were scanned using a series of quantitative 3D UTE Cones T2* (UTE-T2*), T1 (UTE-T1), UTE-AdiabT1ρ, and UTE-MT sequences in a standard knee coil on a clinical 3T scanner. UTE-MT data were acquired with a series of MT powers and frequency offsets to calculate magnetization transfer ratio (MTR), as well as macromolecular fraction (MMF) and macromolecular T2 (T2mm) through modeling. Cartilage stiffness and Hayes elastic modulus were measured using indentation tests. Correlations of 3D UTE Cones MRI measurements in the superficial layer, deep layer, and global regions of interest (ROIs) with mechanical properties were investigated. Cartilage mechanical properties demonstrated highest correlations with UTE measures of the superficial layer of cartilage. AdiabT1ρ, MTR, and MMF in superficial layer ROIs showed significant correlations with Hayes elastic modulus (p < 0.05, R = −0.54, 0.49, and 0.66, respectively). These UTE measures in global ROIs showed significant, though slightly lower, correlations with Hayes elastic modulus (p < 0.05, R = −0.37, 0.52, and 0.60, respectively). Correlations between other UTE MRI measurements (T2*, T1, and T2mm) and mechanical properties were non-significant. The 3D UTE-AdiabT1ρ and UTE-MT sequences were highlighted as promising surrogates for non-invasive assessment of cartilage mechanical properties. MMF from UTE-MT modeling showed the highest correlations with cartilage mechanics.

Abstract LB-024: Development of a non-invasive clinically applicable real time cell tracking platform for evaluating cell-based cancer therapy using magnetic resonance imaging (MRI)

Abstract While advancement in chimeric antigen receptors (CARs) has greatly improved the anti-tumor activity of immune cell-based therapies utilizing modified T lymphocytes (CAR-T) and natural killer cells (CAR-NK), there remains a critical unmet need for diagnostic technologies to help evaluate their biological performance effectively and efficiently after injecting into the body.The ability to better understand the biodistribution of injected cells and devise dosing strategies are key determinants to the success or failure of cell therapy. However, clinicians are limited by the available technology for real time in-vivo tracking of cell therapy products in clinical settings. Here we present a clinically applicable novel magnetic agent that can effectively label a variety of cell types used in cancer cell therapy development including T cells, NK cells, and neural stem cells (NSCs), and when combined with the 3D ultrashort echo time Cones (3D UTE-Cones) sequence, can enable quantitative assessment of cell therapy products using MRI. In this study, we optimized loading of our tracking agent into T cells, NK cells, and NSCs, evaluated the morphology and viability of the labeled cells, and confirmed internalization of the labeling agent by Prussian blue staining and TEM. The in vitro MRI properties of the labeled cells were quantitated by the 3D UTE-Cones sequence. Ex vivo MRI analysis was performed by injecting labeled cells into harvested mouse livers and brains to ascertain their MRI visibility in tissues using a clinical MRI scanner. We confirmed that our magnetic labeling agent efficiently labeled each cell line tested, and the morphology or viability of the labeled cells were unaffected. The MRI detectability of labeled cells were confirmed by in vitro MRI phantoms. Further, using quantitative susceptibility mapping (QSM), T1, and T2* mapping based on 3D UTE-Cones sequences, we found near perfect correlations between cell density and MRI properties. By applying the parameters established in the MRI phantoms, we were able to detect and quantity the number of labeled cells injected into mouse livers and brains ex vivo. In summary, we have developed a clinically applicable imaging-based platform that empowers cell therapy researchers to better understand the results of their biodistribution and dosing studies through real-time cell tracking and quantitative assessments using MRI. Citation Format: Johnny C. Akers, Zhao Wei, Hyungseok Jang, Eric Chang, Jiang Du, Mya S. Thu. Development of a non-invasive clinically applicable real time cell tracking platform for evaluating cell-based cancer therapy using magnetic resonance imaging (MRI) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-024.

Fast quantitative three-dimensional ultrashort echo time (UTE) Cones magnetic resonance imaging of major tissues in the knee joint using extended sprial sampling.

The purpose of this study is to investigate the effect of extending the spiral sampling window on quantitative 3D ultrashort echo time (UTE) Cones imaging of major knee joint tissues including articular cartilage, menisci, tendons and ligaments at 3 T. Nine cadaveric human whole knee specimens were imaged on a 3 T clinical MRI scanner. A series of quantitative 3D UTE Cones imaging biomarkers including T2 *, T1 , adiabatic T1ρ , magnetization transfer ratio (MTR) and macromolecular fraction (MMF) were estimated using spiral sampling trajectories with various durations. Errors in UTE MRI biomarkers as a function of sampling time were evaluated using a nonstretched spiral trajectory as a reference standard. No significant differences were observed by increasing the spiral sampling window from 1116 to 2232 μs in the calculated T2 *, T1 , adiabatic T1ρ , MTR and MMF, as all P-values were over .05 as assessed by ANOVA with two-sided Dunnett's test. Although extending the sampling window results in signal loss for short T2 components, there was limited effect on the calculated quantitative biomarkers, with error percentages typically smaller than 5% in all the evaluated tissues. The total scan time can be reduced by up to 54% with quantification errors of less than 5% in any evaluated major tissue in the knee joint, suggesting that 3D UTE Cones MRI techniques can be greatly accelerated by using a longer spiral sampling window without causing additional quantitative bias.

Knee menisci segmentation and relaxometry of 3D ultrashort echo time cones MR imaging using attention U-Net with transfer learning.

To develop a deep learning-based method for knee menisci segmentation in 3D ultrashort echo time (UTE) cones MR imaging, and to automatically determine MR relaxation times, namely the T1, T1ρ , and parameters, which can be used to assess knee osteoarthritis (OA). Whole knee joint imaging was performed using 3D UTE cones sequences to collect data from 61 human subjects. Regions of interest (ROIs) were outlined by 2 experienced radiologists based on subtracted T1ρ -weighted MR images. Transfer learning was applied to develop 2D attention U-Net convolutional neural networks for the menisci segmentation based on each radiologist's ROIs separately. Dice scores were calculated to assess segmentation performance. Next, the T1, T1ρ , relaxations, and ROI areas were determined for the manual and automatic segmentations, then compared. The models developed using ROIs provided by 2 radiologists achieved high Dice scores of 0.860 and 0.833, while the radiologists' manual segmentations achieved a Dice score of 0.820. Linear correlation coefficients for the T1, T1ρ , and relaxations calculated using the automatic and manual segmentations ranged between 0.90 and 0.97, and there were no associated differences between the estimated average meniscal relaxation parameters. The deep learning models achieved segmentation performance equivalent to the inter-observer variability of 2 radiologists. The proposed deep learning-based approach can be used to efficiently generate automatic segmentations and determine meniscal relaxations times. The method has the potential to help radiologists with the assessment of meniscal diseases, such as OA.

Volumetric mapping of bound and pore water as well as collagen protons in cortical bone using 3D ultrashort echo time cones MR imaging techniques.

Cortical bone assessment using magnetic resonance imaging (MRI) has recently received great attention in an effort to avoid the potential harm associated with ionizing radiation-based techniques. Ultrashort echo time MRI (UTE-MRI) techniques can acquire signal from major hydrogen proton pools in cortical bone, including bound and pore water, as well as from the collagen matrix. This study aimed to develop and evaluate the feasibility of a technique for mapping bound water, pore water, and collagen proton densities in human cortical bone ex vivo and in vivo using three-dimensional UTE Cones (3D-UTE-Cones) MRI. Eight human tibial cortical bone specimens (63 ± 19 years old) were scanned using 3D-UTE-Cones sequences on a clinical 3 T MRI scanner and a micro-computed tomography (μCT) scanner. Total, bound, and pore water proton densities (TWPD, BWPD, and PWPD, respectively) were measured using UTE and inversion recovery UTE (IR-UTE) imaging techniques. Macromolecular proton density (MMPD), a collagen representation, was measured using TWPD and macromolecular fraction (MMF) obtained from two-pool UTE magnetization transfer (UTE-MT) modeling. The correlations between proton densities and μCT-based measures were investigated. The 3D-UTE-Cones techniques were further applied on ten young healthy (34 ± 3 years old) and five old (78 ± 6 years old) female volunteers to evaluate the techniques' feasibility for translational clinical applications. In the ex vivo study, PWPD showed the highest correlations with bone porosity and bone mineral density (BMD) (R = 0.79 and - 0.70, p < 0.01). MMPD demonstrated moderate to strong correlations with bone porosity and BMD (R = -0.67 and 0.65, p < 0.01). MMPD showed strong correlation with age in specimens from female donors (R = -0.91, p = 0.03, n = 5). The presented comprehensive 3D-UTE-Cones imaging protocol allows quantitative mapping of protons in major pools of cortical bone ex vivo and in vivo. PWPD and MMPD can serve as potential novel biomarkers to assess bone matrix and microstructure, as well as bone age- or injury-related variations.

Evaluation of normal cadaveric Achilles tendon and enthesis with ultrashort echo time (UTE) magnetic resonance imaging and indentation testing.

Entheses are regions where tendons and ligaments attach to bone, and are the primary target in seronegative and other diseases of the musculoskeletal (MSK) system. MRI has been widely used for visualizing features of inflammatory and degenerative MSK disease; however, normal tendons and entheses have short transverse relaxation times (T2 ), and show little or no signal with conventional clinical MRI pulse sequences, making it difficult to investigate their MR properties. In this study we examined the normal MR morphology of the cadaveric Achilles tendon and enthesis at 3T using novel three-dimensional ultrashort echo time (3D UTE) Cones sequences, and at 11.7T using conventional MRI sequences. We also studied the MR properties of the Achilles tendon and enthesis including T2 *, T1 , and magnetization transfer ratio (MTR). In addition, MT modeling of macromolecular proton fractions was investigated using 3D UTE Cones sequences at 3T. Indentation testing was performed to investigate the mechanical properties of the tendons and entheses, and this was followed by histological examination. In total five specimens (<50years) were investigated. On average, tendons and entheses respectively had T2 * values of 0.93±0.48ms and 2.77±0.79ms, T1 values of 644±22ms and 780±55ms, MTRs of 0.373±0.03 and 0.244±0.009 with an MT power of 1000° and frequency offset of 2kHz, and macromolecular proton fractions of 18.0±2.2% and 13.9±1.9%. Compared with the tendon, the enthesis generally had a longer T2 *, a longer T1 , a lower MTR, and a lower macromolecular proton fraction as well as both a higher Young's modulus and stiffness. Results from this study are likely to provide a useful baseline for identifying deviations from the normal in seronegative arthritis and other disease of the entheses.

Whole knee joint T1 values measured in vivo at 3T by combined 3D ultrashort echo time cones actual flip angle and variable flip angle methods.

To measure T1 relaxations for the major tissues in whole knee joints on a clinical 3T scanner. The 3D UTE-Cones actual flip angle imaging (AFI) method was used to map the transmission radiofrequency field (B1 ) in both short and long T2 tissues, which was then used to correct the 3D UTE-Cones variable flip angle (VFA) fitting to generate accurate T1 maps. Numerical simulation was carried out to investigate the accuracy of T1 measurement for a range of T2 values, excitation pulse durations, and B1 errors. Then, the 3D UTE-Cones AFI-VFA method was applied to healthy volunteers (N = 16) to quantify the T1 of knee tissues including cartilage, meniscus, quadriceps tendon, patellar tendon, anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), marrow, and muscles at 3T. Numerical simulation showed that the 3D UTE-Cones AFI-VFA technique can provide accurate T1 measurements (error <1%) when the tissue T2 is longer than 1 ms and a 150 μs excitation RF pulse is used and therefore is suitable for most knee joint tissues. The proposed 3D UTE-Cones AFI-VFA method showed an average T1 of 1098 ± 67 ms for cartilage, 833 ± 47 ms for meniscus, 800 ± 66 ms for quadriceps tendon, 656 ± 43 ms for patellar tendon, 873 ± 38 ms for ACL, 832 ± 49 ms for PCL, 379 ± 18 ms for marrow, and 1393 ± 46 ms for muscles. The 3D UTE-Cones AFI-VFA method allows volumetric T1 measurement of the major tissues in whole knee joints on a clinical 3T scanner.

Feasibility of quantitative ultrashort echo time (UTE)-based methods for MRI of peripheral nerve.

Peripheral nerves are a composite tissue consisting of neurovascular elements packaged within a well-organized extracellular matrix. Their composition, size, and anatomy render nerves a challenging medical imaging target. In contrast to morphological MRI, which represents the predominant approach to nerve imaging, quantitative MRI sequences can provide information regarding tissue composition. Here, we applied standard clinical Carr-Purcell-Meiboom-Gill (CPMG) and experimental three-dimensional (3D) ultrashort echo time (UTE) Cones sequences for quantitative nerve imaging including T2 measurement with single-component analysis, T2 * measurement with single-component and bi-component analyses, and magnetization transfer ratio (MTR) analysis. We demonstrated the feasibility and the high quality of single-component T2 *, bi-component T2 *, and MTR approaches to analyze nerves imaged with clinically deployed 3D UTE Cones pulse sequences. For 24 single fascicles from eight nerves, we measured a mean single-component T2 * of 22.6 ±8.9ms, and a short T2 * component (STC) with a mean T2 * of 1.7 ±1.0ms and a mean fraction of (6.74 ±4.31)% in bi-component analysis. For eight whole nerves, we measured a mean single-component T2 * of 16.7 ±2.2ms, and an STC with a mean T2 * of 3.0 ±1.0ms and a mean fraction of (15.56 ±7.07)% in bi-component analysis. For nine fascicles from three healthy nerves, we measured a mean MTR of (25.2 ±1.9)% for single fascicles and a mean MTR of (23.6 ±0.9)% for whole nerves. No statistically significant correlation was observed between any MRI parameter and routine histological outcomes, perhaps due to the small sample size and lack of apparent sample pathology. Overall, we have successfully demonstrated the feasibility of measuring quantitative MR outcomes ex vivo, which might reflect features of nerve structure and macromolecular content. These methods should be validated comprehensively on a larger and more diverse set of nerve samples, towards the interpretation of in vivo outcomes. These approaches have new and broad implications for the management of nerve disease, injury, and repair.

Theoretical analysis and optimization of ultrashort echo time (UTE) imaging contrast with off-resonance saturation

PurposeOff-resonance saturation (ORS) is a tool which can be used in ultrashort echo time (UTE) magnetic resonance imaging to selectively reduce short T2 signals. When these ORS prepared UTE images are subtracted from a non-suppressed UTE acquisition, the short T2 signals are highlighted. The aim of this paper is to develop a theoretical ORS model and optimize short T2 contrast. TheoryUsing a theoretical model the sequence parameters such as saturation flip angle and off-resonance frequency were optimized to maximize short T2 contrast. Bloch simulations were performed to demonstrate the accuracy of the theoretical model. MethodsVolunteer imaging was performed on the knee using different saturation flip angles and off-resonance frequencies using a Fermi RF pulse with a 3D UTE Cones acquisition. ResultsThe off-resonance saturation method showed good long T2 suppression, and highlighted short T2 signals such as the patella tendon. The theoretical signal curves generally agreed with simulated and experimentally measured signals. ConclusionOff-resonance saturation 3D UTE imaging can be used to effectively suppress long T2 signals and highlight short T2 signals. Theoretical modeling can be used to optimize sequence parameters to maximize long T2 suppression and short T2 contrast. Experimental results confirmed the theoretical predictions.

Rotator cuff tendon assessment using magic-angle insensitive 3D ultrashort echo time cones magnetization transfer (UTE-Cones-MT) imaging and modeling with histological correlation.

Rotator cuff tendons (RCTs) are challenging to image due to the "magic angle effect" and their short T2 . To assess the degree of magic angle sensitivity of human RCTs and to utilize a 3D ultrashort echo time Cones sequence with magnetization transfer preparation (UTE-Cones-MT) and two-pool quantitative MT modeling with histological correlation. We hypothesized that MT parameters would be less sensitive to the magic angle compared with conventional T2 measurements. Prospective imaging pathologic correlation. Twenty cadaveric rotator cuff tendons were imaged at five sample orientations ranging from 0-90° relative to the B0 field. 3T/3D UTE-Cones-MT and Carr-Purcell-Meiboom-Gill (CPMG). Two-pool quantitative MT modeling parameters and T2 values were calculated in regions of interest drawn by a medical physicist. Histopathological analysis was performed and mild and severe tendinopathy groups were assigned by a histopathologist and histotechnician. Coefficients of variations (CVs) were calculated for measures between the different orientations and group means were compared for each measure. CVs of T2 and macromolecular fractions between orientations were 26.14 ± 16.82% and 6.18 ± 2.77% (mean ± SD), respectively. T2 measurements at 0°, 27°, 70°, and 90° showed significant differences between the two histological groups (P = 0.004, 0.008, 0.003, and 0.015, respectively), but not at 55° (P = 0.611). Mean T2 value ranges between orientations for the mild and severe tendinopathy groups were 15.27-30.32 msec and 20.81-35.85 msec, respectively, showing overlap despite statistically significant differences (P = 0.003). Macromolecular fractions at all angles showed significant differences between the two groups (P < 0.0001). Mean fraction ranges between orientations for the mild and severe tendinopathy groups were 14.32-17.17% and 10.00-13.75% respectively (P < 0.0001) with no overlap. Compared with T2 , macromolecular fraction obtained with the 3D UTE-Cones-MT technique is resistant to the magic angle effect and is more sensitive to RCT degeneration. 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017.

Measurement of bound and pore water T1 relaxation times in cortical bone using three-dimensional ultrashort echo time cones sequences.

We present three-dimensional ultrashort echo time Cones (3D UTE Cones) techniques for quantification of total water T1 ( T1TW), bound water T1 ( T1BW), and pore water T1 ( T1PW) in vitro and in vivo using a 3 Tesla (T) scanner. T1TW, T1BW, and T1PW were measured with three-dimensional (3D) Cones and adiabatic inversion recovery Cone (IR-Cone) sequences. Two-dimensional (2D) nonselective ultrashort echo time (UTE) techniques, including saturation recovery, variable repetition times (TRs), and inversion recovery (IR) preparation approaches were compared with 3D-Cones techniques on bovine cortical bone samples (n = 8). The 3D Cones sequences were used to measure T1TW, T1BW, and T1PW in the tibial midshaft of healthy volunteers (n = 8). Comparable T1 images were achieved for cortical bone between 3D Cones and 2D UTE techniques as well as those published in the literature. The 3D Cones sequences showed a mean T1TW of 208 ± 22 ms, a mean T1PW of 545 ± 28 ms, and a mean T1BW of 131 ± 12 ms for bovine cortical bone; and a mean T1TW of 246 ± 32 ms, a mean T1PW of 524 ± 46 ms, and a mean T1BW of 134 ± 11 ms for the tibial midshaft of healthy volunteers. The 3D Cones sequences can be used for fast volumetric assessment of bound and pore water T1 images in vitro and in vivo. Magn Reson Med 77:2136-2145, 2017. © 2016 International Society for Magnetic Resonance in Medicine.