Three-dimensional magnetic resonance imaging-based statistical shape analysis and machine learning-based prediction of patellofemoral instability.

This study performed three-dimensional (3D) magnetic resonance imaging (MRI)-based statistical shape analysis (SSA) by comparing patellofemoral instability (PFI) and normal femur models, and developed a machine learning (ML)-based prediction model. Twenty (19 patients) and 31 MRI scans (30 patients) of femurs with PFI and normal femurs, respectively, were used. Bone and cartilage segmentation of the distal femurs was performed and subsequently converted into 3D reconstructed models. The pointwise distance map showed anterior elevation of the trochlea, particularly at the central floor of the proximal trochlea, in the PFI models compared with the normal models. Principal component analysis examined shape variations in the PFI group, and several principal components exhibited shape variations in the trochlear floor and intercondylar width. Multivariate analysis showed that these shape components were significantly correlated with the PFI/non-PFI distinction after adjusting for age and sex. Our ML-based prediction model for PFI achieved a strong predictive performance with an accuracy of 0.909 ± 0.015, and an area under the curve of 0.939 ± 0.009 when using a support vector machine with a linear kernel. This study demonstrated that 3D MRI-based SSA can realistically visualize statistical results on surface models and may facilitate the understanding of complex shape features.

Non-exercise Activity Thermogenesis Correlated With Clinical Parameters in Patients With or At-Risk for Chronic Obstructive Pulmonary Disease (COPD): A Pilot Study.

BACKGROUND: Attention to physical activity has grown in patients with chronic obstructive pulmonary disease (COPD), as it serves as a robust indicator for mortality associated with COPD. Non-exercise activity thermogenesis (NEAT) is the energy expenditure due to physical activities besides active sports-like exercises and resistance training in daily life, and decreased NEAT may be related to physical inactivity in patients with COPD. We examined whether NEAT assessed using a questionnaire reflects clinical parameters in patients with or at risk for COPD. METHODS: The study participants consisted of 36 male patients (COPD=28; stage1=6, stage2=14, stage3/4=8, and at-risk for COPD=8) older than 50 years of age. The participants underwent anthropometric measurements, lung function testing, a six-minute walk test, muscle strength testing, and questionnaires, e.g., the COPD assessment test (CAT), modified Medical Research Council (mMRC) dyspnea scale, and Hospital Anxiety and Depression Scale. Image analysis with chest computed tomography (CT) included the number of trunk muscles, bronchial wall thickening, and emphysema (percentage of the lung field occupied by low attenuation area <-950 HU). We evaluated the relationship between these clinical parameters and NEAT questionnaire scores using Pearson correlation analysis and the Tukey-Kramer test. RESULTS: The NEAT score was correlated with the severity of airflow limitation and airway wall thickness measured by chest CT, symptoms evaluated by the mMRC dyspnea scale and CAT, and inspiratory muscle strength and pectoralis muscle area assessed by CT. CONCLUSION: Our study revealed the significance of NEAT as a valuable indicator in assessing the health status of patients with or at risk for COPD. The NEAT score was correlated with various clinical traits, suggesting that incorporating NEAT assessments using a questionnaire can contribute to a comprehensive understanding of the clinical condition in these patients. Further large-scale studies are warranted to validate and generalize these findings across diverse COPD populations.

Magnetic resonance imaging findings related to sacroiliac joint pain in high-performance athletes.

BACKGROUND: Sacroiliac joint (SIJ) dysfunction in athletes affects competitiveness. However, the pathology and imaging features have not been clarified. OBJECTIVE: To clarify the association between SIJ pain and MRI findings in high-performance athletes. METHODS: Fifty-two Japanese high-performance athletes with or without SIJ pain were recruited. MRI short tau inversion recovery (STIR) semi-coronal and semi-axial images of their SIJs were taken. The relationships between high-signal changes in MRI-STIR and SIJ pain and pain duration were investigated. Six athletes with continuous SIJ pain were prospectively followed. RESULTS: The proportion of athletes with high-signal changes in the SIJ was significantly higher among athletes with SIJ pain for one month or more (76.9%, 10/13) than among athletes with SIJ pain for less than one month (18.2%, 2/11) and among athletes without SIJ pain (28.6%, 8/28). High-signal changes on painful SIJs were most often present in the sacrum. In three of the six athletes who were prospectively followed, the high-signal area and intensity on MRI both diminished as their symptoms improved. CONCLUSIONS: High-signal changes of the SIJ on MRI-STIR images in high-performance athletes may reflect their SIJ pain.

Motion-robust MR imaging of the shoulder using compressed SENSE MultiVane.

Purpose: Motion artifacts caused by breathing or involuntary motion of patients, which may lead to reduced image quality and a loss of diagnostic information, are a major problem in shoulder magnetic resonance imaging (MRI). The MultiVane (MV) technique decreases motion artifacts; however, it tends to prolong the acquisition time. As a parallel imaging technique, SENSitivity Encoding (SENSE) can be combined with the compressed sensing method to produce compressed SENSE (C-SENSE), resulting in a markedly reduced acquisition time. This study aimed to evaluate the use of C-SENSE MV for MRI of the shoulder joint. Methods: Thirty-one patients who were scheduled to undergo MRI of the shoulder were included. This prospective study was approved by our institution's medical ethics committee, and written informed consent was obtained from all 31 patients. Two sets of oblique coronal images derived from the standard protocol were acquired without (standard) or with C-SENSE MV: proton-density weighted imaging (PDWI), PDWI with C-SENSE MV, T2-weighted imaging (T2WI) with fat suppression (fs), and T2WI fs with C-SENSE MV. Two radiologists graded motion artifacts and the detectability of anatomical shoulder structures on a 4-point scale (3, no artifacts/excellent delineation; 0, severe artifacts/difficulty with delineation). The Wilcoxon signed-rank test was used to compare the data for the standard and C-SENSE MV images. Results: Motion artifacts were significantly reduced on the C-SENSE MV images (p < 0.001). Regarding the detectability of anatomical structures, the ratings for the C-SENSE MV sequences were significantly better (p < 0.001).In conclusion, in shoulder MRI the newly developed C-SENSE MV technique reduces motion artifacts and increases the detectability of anatomical structures compared with standard sequences.

Possible association of high-density lipoprotein cholesterol levels with trunk muscle deficits and decrease in energy expenditure in patients with or at risk for COPD: A pilot study.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with low muscle mass and function caused by malnutrition and physical inactivity. We aimed to investigate possible associations between serum biomarkers and clinical traits including computed tomography-derived muscle measurements and energy expenditure indices in COPD. METHODS: Total energy expenditure (TEE) was measured by the doubly labeled water method, while physical activity level (PAL) was calculated as TEE/basal metabolic rate. Cross-sections and densities of pectoralis, rectus abdominis, and erector spinae muscles were measured. Serum biomarkers included adiponectin, insulin-like growth factor-1, and high-density lipoprotein (HDL)- and low-density lipoprotein (LDL)-cholesterol (C). RESULTS: HDL-C levels were significantly correlated with all muscle areas, densities, and TEE. Only LDL-C levels were correlated with PAL. CONCLUSIONS: HDL-C level was a potential biomarker for trunk muscle volumes and functions, as well as total energy expenditure in COPD.

Contrast Enhancement of the Normal Infundibular Recess Using Heavily T2-weighted 3D FLAIR.

PURPOSE: The purpose of the present study was to evaluate contrast enhancement of the infundibular recess in the normal state using heavily T2-weighted 3D fluid-attenuated inversion recovery (FLAIR) (HT2-FLAIR). METHODS: Twenty-six patients were retrospectively recruited. We subjectively assessed overall contrast enhancement of the infundibular recess between postcontrast, 4-hour (4-h) delayed postcontrast, and precontrast HT2-FLAIR images. We also objectively conducted chronological and spatial comparisons by measuring the signal intensity (SI) ratio (SIR). Chronological comparisons were performed by comparing SI of the infundibular recess/SI of the midbrain (SIRIR-MB). Spatial comparisons were conducted by comparing SI on postcontrast HT2-FLAIR/SI on precontrast HT2-FLAIR (SIRPost-Pre) of the infundibular recess with that of other cerebrospinal fluid (CSF) spaces, including the superior part of the third ventricle, lateral ventricles, fourth ventricle, and interpeduncular cistern. RESULTS: In the subjective analysis, all cases showed contrast enhancement of the infundibular recess on both postcontrast and 4-h delayed postcontrast HT2-FLAIR, and showed weaker contrast enhancement of the infundibular recess on 4-h delayed postcontrast HT2-FLAIR than on postcontrast HT2-FLAIR. In the objective analysis, SIRIR-MB was the highest on postcontrast images, followed by 4-h delayed postcontrast images. SIRPost-Pre was significantly higher in the infundibular recess than in the other CSF spaces. CONCLUSION: The present results demonstrated that the infundibular recess was enhanced on HT2-FLAIR after an intravenous gadolinium injection. The infundibular recess may be a potential source of the leakage of intravenously administered gadolinium into the CSF.

Comparison of multiparametric magnetic resonance imaging sequences with laboratory parameters for prognosticating renal function in chronic kidney disease.

Magnetic resonance imaging (MRI) is playing an increasingly important role in evaluating chronic kidney disease (CKD). It has the potential to be used not only for evaluation of physiological and pathological states, but also for prediction of disease course. Although different MRI sequences have been employed in renal disease, there are few studies that have compared the different sequences. We compared several multiparametric MRI sequences, and compared their results with the estimated glomerular filtration rate. Principal component analysis showed a similarity between T1 values and tissue perfusion (arterial spin labelling), and between fractional anisotropy (diffusion tensor imaging) and apparent diffusion coefficient values (diffusion-weighted imaging). In multiple regression analysis, only T2* values, derived from the blood oxygenation level-dependent (BOLD) MRI sequence, were associated with estimated glomerular filtration rate slope after adjusting for degree of proteinuria, a classic prognostic factor for CKD. In receiver operating characteristic curve analysis, T2* values were a good predictor of rapid deterioration, regardless of the degree of proteinuria. This suggests further study of the use of BOLD-derived T2* values in the workup of CKD, especially to predict the disease course.

Signal and morphological changes in the endolymph of patients with vestibular schwannoma on non-contrast 3D FLAIR at 3 Tesla.

BACKGROUND: Non-contrast FLAIR revealed increased signal within the inner ear in patients with vestibular schwannoma, which is generally assumed to occur in the perilymph; however, the majority of previous studies did not differentiate between the endolymph and perilymph. Therefore, endolymph signal changes have not yet been investigated in detail. The purpose of the present study was three-fold: (1) to assess perilymph signal changes in patients with vestibular schwannoma on heavily T2-weighted (T2W) 3D FLAIR, also termed positive perilymphatic images (PPI), (2) to evaluate signal and morphological changes in the endolymph on PPI, and (3) to establish whether vertigo correlates with the signal intensity ratios (SIR) of the vestibular perilymph or vestibular endolymphatic hydrops. METHODS: Forty-two patients with unilateral vestibular schwannoma were retrospectively recruited. We semi-quantitatively and qualitatively evaluated the perilymph signal intensity on the affected and unaffected sides. We also quantitatively examined the signal intensity of the vestibular perilymph and assessed the relationship between vertigo and the SIR of the vestibular perilymph on the affected side. We semi-quantitatively or qualitatively evaluated the endolymph, and investigated whether vestibular hydrops correlated with vertigo. RESULTS: The perilymph on the affected side showed abnormal signal more frequently (signal intensity grade: overall mean 1.45 vs. 0.02; comparison of signal intensity: overall mean 36 vs. 0 cases) and in more parts (the entire inner ear vs. the basal turn of the cochlea and vestibule) than that on the unaffected side. No significant difference was observed in the SIR of the vestibular perilymph with and without vertigo (5.54 vs. 5.51, p = 0.18). The endolymph of the vestibule and semicircular canals showed the following characteristic features: no visualization (n = 4), signal change (n = 1), or vestibular hydrops (n = 10). A correlation was not observed between vestibular hydrops and vertigo (p = 1.000). CONCLUSIONS: PPI may provide useful information on signal and morphological changes in the endolymph of patients with vestibular schwannoma. Further research is warranted to clarify the relationship between vertigo and the MR features of the inner ear.

Texture analysis of muscle MRI: machine learning-based classifications in idiopathic inflammatory myopathies.

To develop a machine learning (ML) model that predicts disease groups or autoantibodies in patients with idiopathic inflammatory myopathies (IIMs) using muscle MRI radiomics features. Twenty-two patients with dermatomyositis (DM), 14 with amyopathic dermatomyositis (ADM), 19 with polymyositis (PM) and 19 with non-IIM were enrolled. Using 2D manual segmentation, 93 original features as well as 93 local binary pattern (LBP) features were extracted from MRI (short-tau inversion recovery [STIR] imaging) of proximal limb muscles. To construct and compare ML models that predict disease groups using each set of features, dimensional reductions were performed using a reproducibility analysis by inter-reader and intra-reader correlation coefficients, collinearity analysis, and the sequential feature selection (SFS) algorithm. Models were created using the linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), support vector machine (SVM), k-nearest neighbors (k-NN), random forest (RF) and multi-layer perceptron (MLP) classifiers, and validated using tenfold cross-validation repeated 100 times. We also investigated whether it was possible to construct models predicting autoantibody status. Our ML-based MRI radiomics models showed the potential to distinguish between PM, DM, and ADM. Models using LBP features provided better results, with macro-average AUC values of 0.767 and 0.714, accuracy of 61.2 and 61.4%, and macro-average recall of 61.9 and 59.8%, in the LDA and k-NN classifiers, respectively. In contrast, the accuracies of radiomics models distinguishing between non-IIM and IIM disease groups were low. A subgroup analysis showed that classification models for anti-Jo-1 and anti-ARS antibodies provided AUC values of 0.646-0.853 and 0.692-0.792, with accuracy of 71.5-81.0 and 65.8-78.3%, respectively. ML-based TA of muscle MRI may be used to predict disease groups or the autoantibody status in patients with IIM and is useful in non-invasive assessments of disease mechanisms.

Intravenous enhanced 3D FLAIR imaging to identify CSF leaks in spontaneous intracranial hypotension: Comparison with MR myelography.

PURPOSE: To evaluate the clinical utility of intravenous gadolinium-enhanced heavily T2-weighted 3D fluid-attenuated inversion recovery (HT2-FLAIR) imaging for identifying spinal cerebrospinal fluid (CSF) leaks in patients with spontaneous intracranial hypotension (SIH). METHODS: Patients with SIH underwent MR myelography and post-contrast HT2-FLAIR imaging after an intravenous gadolinium injection. Two types of CSF leaks (epidural fluid collection and CSF leaks around the nerve root sleeve) at each vertebral level were compared between the 2 sequences. The total numbers of CSF leaks and vertebral levels involved were recorded for the whole spine. The sequence that was superior for the overall visualization of epidural and paraspinal fluid collection was then selected. RESULTS: Nine patients with SIH were included in the present study. HT2-FLAIR imaging was equivalent or superior to MR myelography at each level for detecting the 2 types of CSF leaks. In the 2 types of CSF leaks, the total numbers of CSF leaks and levels involved were higher on HT2-FLAIR images than on MR myelography, while no significant difference was observed for CSF leaks around the nerve root sleeve. In all 9 patients, HT2-FLAIR imaging was superior to MR myelography for the overall visualization of epidural and paraspinal fluid collection. CONCLUSION: Intravenous gadolinium-enhanced HT2-FLAIR imaging was superior to MR myelography for the visualization of CSF leaks in patients with SIH. This method can be useful for identifying spinal CSF leaks.

Energy expenditure and physical activity in COPD by doubly labelled water method and an accelerometer.

Although weight loss suggests poor prognosis of COPD, only a few studies have examined total energy expenditure (TEE) or physical activity level (PAL) using the doubly labelled water (DLW) method. We evaluated TEE and PAL using the DLW method together with a triaxial accelerometer to elucidate the relationships between TEE, PAL and clinical parameters leading to a practical means of monitoring COPD physical status. This study evaluated 50- to 79-year-old male patients with mild to very severe COPD (n=28) or at risk for COPD (n=8). TEE, activity energy expenditure for 2 weeks and basal metabolic rate were measured by DLW, an accelerometer and indirect calorimetry, respectively. All patients underwent pulmonary function, chest-computed tomography, 6-min walk test, body composition and grip strength tests. Relationships between indices of energy expenditure and clinical parameters were analysed. Bland-Altman analysis was used to examine the agreement of TEE and PAL between the DLW method and the accelerometer. TEE and PAL using DLW in the total population were 2273±445 kcal·day-1 and 1.80±0.20, respectively. TEE by DLW correlated well with that from the accelerometer and grip strength (p<0.0001), and PAL by DLW correlated well with that from the accelerometer (p<0.0001), grip strength and 6-min walk distance (p<0.001) among various clinical parameters. However, the accelerometer underestimated TEE (215±241 kcal·day-1) and PAL (0.18±0.16), with proportional biases in both indices. TEE and PAL can be estimated by accelerometer in patients with COPD if systematic errors and relevant clinical factors such as muscle strength and exercise capacity are accounted for.

The product of trunk muscle area and density on the CT image is a good indicator of energy expenditure in patients with or at risk for COPD.

BACKGROUND: Physical inactivity due to cachexia and muscle wasting is well recognized as a sign of poor prognosis in chronic obstructive pulmonary disease (COPD). However, there have been no reports on the relationship between trunk muscle measurements and energy expenditure parameters, such as the total energy expenditure (TEE) and physical activity level (PAL), in COPD. In this study, we investigated the associations of computed tomography (CT)-derived muscle area and density measurements with clinical parameters, including TEE and PAL, in patients with or at risk for COPD, and examined whether these muscle measurements serve as an indicator of TEE and PAL. METHODS: The study population consisted of 36 male patients with (n = 28, stage 1-4) and at risk for (n = 8) COPD aged over 50 years. TEE was measured by the doubly labeled water method, and PAL was calculated as the TEE/basal metabolic rate estimated by the indirect method. The cross-sectional areas and densities of the pectoralis muscles, rectus abdominis muscles, and erector spinae muscles were measured. We evaluated the relationship between these muscle measurements and clinical outcomes, including body composition, lung function, muscle strength, TEE, and PAL. RESULTS: All the muscle areas were significantly associated with TEE, severity of emphysema, and body composition indices such as body mass index, fat-free mass, and trunk muscle mass. All trunk muscle densities were correlated with PAL. The product of the rectus abdominis muscle area and density showed the highest association with TEE (r = 0.732) and PAL (r = 0.578). Several trunk muscle measurements showed significant correlations with maximal inspiratory and expiratory pressures, indicating their roles in respiration. CONCLUSIONS: CT-derived measurements for trunk muscles are helpful in evaluating physical status and function in patients with or at risk for COPD. Particularly, trunk muscle evaluation may be a useful marker reflecting TEE and PAL.

Imaging evaluation of the cartilage in rheumatoid arthritis patients with an x-ray phase imaging apparatus based on Talbot-Lau interferometry.

X-ray Talbot-Lau interferometry is one of the x-ray phase imaging methods that has high sensitivity in depicting soft tissues. Unlike earlier x-ray phase imaging methods that required particular types of x-ray sources, such as a synchrotron or a micro-focus x-ray tube, x-ray Talbot-Lau interferometry enables to perform clinical x-ray phase imaging using a conventional x-ray source with a relatively compact configuration. We developed an apparatus to depict cartilage in the metacarpophalangeal joints of the hands. In addition, we examined the apparatus performance by applying it to healthy volunteers and patients with rheumatoid arthritis (RA). Cartilage deformation, which is thought to be a precursor of destruction of the joints, was successfully depicted by the apparatus, suggesting a potential early diagnosis of RA.

An Unusual Ovarian Mucinous Borderline Tumor with a Large Solid Component.

Herein, we report magnetic resonance imaging (MRI) findings of a mucinous borderline tumor of the ovary, which we observed as a mainly solid tumor with large solid components in the lower pelvic cavity. The appearance of ovarian epithelial tumors on imaging is often complex. Cystic to solid appearing masses may be observed, and they often resemble epithelial carcinoma. Due to mucinous or hemorrhage components of packed small or microcystic components, MRI depicts slightly high signal intensity on T1-weighted images and low signal intensity on T2-weighted images. Mucinous borderline tumor of the ovary with a large solid component is very rare, but it is clinically important to recognize the possibility of mucinous borderline tumor to avoid unnecessary surgical intervention.

Development of anisotropic phantoms using wood and fiber materials for diffusion tensor imaging and diffusion kurtosis imaging.

OBJECTIVE: Several studies have demonstrated that anisotropic phantoms can be utilized for diffusion magnetic resonance imaging. The purpose of our study was to examine whether wood is suitable as an anisotropic phantom material from the viewpoints of affordability and availability. In the current study, wood was used for restricted diffusion, and fibers were used for hindered diffusion. MATERIALS AND METHODS: Wood and fiber phantoms were made. Diffusion kurtosis images were acquired with three magnetic resonance scanners. Fractional anisotropy, radial diffusivity, axial diffusivity, radial kurtosis and axial kurtosis values were measured. The wood phantom was imaged, and its durability was confirmed. The phantoms were imaged in varying orientations within the magnetic field. The wood was observed using an optical microscope. RESULTS: Ten kinds of wood and the fiber had a diffusion metrics. The wood diffusion metrics suggested low variation over a period of 9 months. Changing the orientation of the phantoms within the magnetic field resulted in changes in diffusion metrics. Observation of wood vessels and fibers was conducted. DISCUSSION: Wood and fibers have anisotropy and are promising as phantom materials. The development of anisotropic phantoms that anyone can use is useful for diffusion magnetic resonance imaging research and clinical applications.

High-speed scanning of planar images showing 123I-MIBG uptake using a whole-body CZT camera: a phantom and clinical study.

BACKGROUND: The heart-to-mediastinum ratio (HMR) obtained in myocardial sympathetic innervation imaging using 123I-metaiodobenzylguanidine (MIBG) is used for heart failure or Lewy body diseases (LBD). Discovery NM/CT 670 CZT, a novel whole-body scanner, enables direct HMR measurements in planar images, in contrast to cardiac-dedicated CZT-based cameras which require specific post-processing reconstruction. We sought to investigate the clinical utility of the Discovery NM/CT 670 CZT for myocardial innervation imaging and the potential time reduction. RESULTS: Following preliminary phantom examinations, 123I-MIBG planar imaging was performed in 36 patients with suspected or known LBD to measure HMRs with a collection time of 300 s. Images for different collection times were subsequently reframed using already acquired data, and changes in HMRs were evaluated. The HMRs for patients with versus without clinically diagnosed LBD were 1.63 ± 0.08 versus 2.21 ± 0.08 at early phase (p < 0.001) and 1.54 ± 0.09 versus 2.08 ± 0.09 at delayed phase (p < 0.001). The difference of HMRs (300 s - other collection time) became greater as the collection time became shorter. There was good consistency in HMRs between the 300-s images (reference) and the 200-s (intra-class correlation (ICC) coefficients > 0.99), 100-s (ICC coefficients > 0.97), and 50-s (ICC coefficients > 0.89) images. CONCLUSIONS: In planar images with a whole-body CZT-based camera, the HMRs of patients with LBD were significantly lower than those without. HMRs with the collection time of 50 s and longer showed good consistency with those of 300 s in the ICC analysis. These findings indicate a clinical utility of this novel scanner for HMR measurements and potential time reductions.

Development of a Surface Marker for Fractional Anisotropy Maps Using Wood in a Phantom Study.

PURPOSE: To improve imaging, a reliable setup method is critical for the accurate localization of lesions and surface markers. Because an anisotropic marker has not yet been validated for MRI, direct localization of surface markers is not yet feasible in fractional anisotropy (FA) maps. This study aimed to develop an anisotropic surface marker using wood for an FA map and to determine whether a wood marker is useful for various sequences. METHODS: Wood infiltrated with water was used to develop an anisotropic surface marker. The wood marker was compared with phantoms composed of clinically available markers, including MR-SPOTS Packets (Beekley Medical, Bristol, CT, USA), Breath Care Oral Refreshing Capsules (Kobayashi Pharmaceutical Co., Ltd., Osaka, Japan), and baby oil (Johnson & Johnson, New Brunswick, NJ, USA). Magnetic resonance images were acquired using the Achieva 3T TX MRI System (Philips HealthCare, Best, Netherlands) equipped with a QD head coil including T1- and T2-weighted imaging, proton-density-weighted imaging, T2*-weighted imaging, T1-weighted imaging spectral pre-saturation with inversion recovery, T2-weighted imaging spectral attenuated inversion recovery, proton-density-weighted imaging spectral attenuated inversion recovery, diffusion weighted imaging, and diffusion tensor imaging. Apparent diffusion coefficient, FA values, and signal-to-noise ratio (SNR) were measured and recorded, and the coefficient of variation was calculated for two consecutive imaging scans. The wood was observed using a microscope. RESULTS: Breath Care Oral Refreshing Capsules and baby oil were not observed in the FA map. The FA value of the MR-SPOTS Packets was 0.18. The FA value of the wood marker was 0.80. The coefficient of variation of the MR-SPOTS Packets and the wood marker were 0.0263 and 0.0013, respectively, in the FA map. Microscopic observation revealed a wood anisotropic structure. CONCLUSION: The wood maker enabled direct localization in the FA map. Hence, wood markers may be useful to radiologists and contribute to obtaining useful findings.

Simultaneous multi-slice MR imaging of the hip at 3 T to reduce acquisition times and maintain image quality.

BACKGROUND: Newly developed simultaneous multi-slice (SMS) scans are now being introduced as a clinical application in neuroimaging. We examined the feasibility of SMS scans for joint imaging. The purpose of the present study was to prospectively compare the resolution and specific absorption rate (SAR) obtained using SMS to those of conventional methods in hip joint magnetic resonance imaging (MRI) and establish whether imaging times may be reduced using SMS in 3 T MRI and if image quality is affected. METHODS: Twenty-one patients (4 men and 17 women, average age, 51.5 years, range: 22 to 76 years) with hip pain underwent MR examinations of the unilateral hip joint. Three board-certified radiologists independently and blindly evaluated the images obtained with and without SMS using window and level settings and magnification according to personal preferences. Individual SAR values were measured for each protocol. A Wilcoxon signed-rank test and a t-statistic test were used for statistical analyses. Signal-to-noise ratio (SNR) was also compared using a phantom. RESULTS: SMS imaging maintained equivalent image quality to conventional imaging for evaluating the morphology of the hip joint, and also reduced imaging times by approximately 40%. SMS images had significantly higher SAR values than conventional images. The rate of difference (SMS/conventional) in SNR ranged between 80 and 111%. CONCLUSIONS: Based on its significantly lower acquisition times and the maintenance of similar image quality to conventional imaging, SMS may be applied to morphological evaluations of hip joint disorders without significantly increasing SAR.

Complete Circumferential Osseous Extension in the Acetabular Rim Occurs Regardless of Acetabular Coverage.

BACKGROUND: Complete circumferential osseous extension in the acetabular rim has been reported to occur in the deep hip with pincer impingement. However, this phenomenon occasionally is observed in dysplastic hips without pincer impingement, and the degree to which this finding might or might not be associated with hip pain, and how often it occurs bilaterally among patients, are not well characterized. QUESTIONS/PURPOSES: (1) To determine the proportion of patients with complete circumferential osseous extension in the acetabular rim using three-dimensional (3-D) CT in patients with and without hip pain who had CT scans obtained for various reasons. (2) To elucidate how often this complete circumferential osseous extension occurred bilaterally among those patients. (3) To investigate the relationship between the proportions of patients with complete circumferential osseous extension observed on CT scans among three different acetabular coverage groups: dysplasia, normal, and overcoverage. (4) To determine how often the finding of hip pain was associated with complete circumferential osseous extension. PATIENTS AND METHODS: Between September 2011 to July 2016, we evaluated 3788 patients with pelvic complaints such as hip, groin, thigh, buttock, or sacroiliac joint pain. We obtained consent from 26% (992 of 3788) of them, and obtained 3-D CT scans as part of that evaluation. For the current retrospective study, we excluded patients younger than 20 years or 80 years or older (181 patients), patients who had previous hip surgery (185 patients), patients with severe osteoarthritis with Tönnis Grades 2 or 3 (301 patients), and patients who could not have an accurate lateral center-edge (LCE) angle measured owing to poor-quality radiographs (24 patients), leaving 301 patients (602 hips) for this analysis. In this study population, patients reported pain in 131 hips (22%), defined as all types of hip pain except for trauma, including activity pain, pain with sports, pain on motion, and impingement pain; the others did not report hip pain. The mean age of the patients was 56 ± 16 years, and the mean LCE angle was 26° ± 8° (range, -9° to 47°). We first determined the proportion of patients with complete circumferential osseous extension in the acetabular rim using 3-D CT for those with and without hip pain who had CT obtained for various reasons. We next elucidated how often this complete circumferential osseous extension occurred bilaterally among the patients, and finally we investigated the relationship between the proportion of patients with complete circumferential osseous extension observed on CT scans among the three groups: dysplasia (defined as LCE angles of 22° or smaller), normal, and overcoverage (defined as LCE angles of 34° or larger) groups. We finally determined how often the finding was associated with hip pain attributable to complete circumferential osseous extension. RESULTS: The proportion of patients with complete circumferential osseous extension was 6% (18 of 301 patients). Eighty-nine percent (16 of 18) of the patients had bilateral complete circumferential osseous extension. There were no differences in the proportions of patients with complete circumferential osseous extension among the three groups: 5.3% (odds ratio [OR], 1.02; 95% CI, 0.45-2.31; p = 0.97), 5.3%, and 7.4% (OR, 0.70; 95% CI, 0.28-1.73; p = 0.44) in the dysplasia, normal, and overcoverage groups, respectively, with the numbers available. Eighteen percent (six of 34) of the hips with complete circumferential osseous extension had pain. CONCLUSIONS: Complete circumferential osseous extension in the acetabular rim is relatively uncommon. When it occurs, it usually is bilateral, it occurs regardless of acetabular coverage, and it is associated with pain in a minority of patients. LEVEL OF EVIDENCE: Level III, prognostic study.

Comparison of Dopamine Transporter SPECT and 123I-MIBG Myocardial Scintigraphy to Assess Clinical Severity in Patients With Parkinson Disease.

PURPOSE: The aim of our study was to evaluate the use of dopamine transporter (DAT) SPECT and I-MIBG myocardial scintigraphy to determine the clinical severity of Parkinson disease (PD), with a focus on motor impairments affecting activities of daily living (ADLs). METHODS: Data for 65 consecutive PD patients who underwent both DAT and MIBG imaging were reviewed. Associations between imaging variables and Hoehn and Yahr (H&Y) staging or self-supportive care ratings were investigated. Univariate and multivariate regression analyses were performed to determine the factors associated with ADLs. RESULTS: After applying the exclusion criteria, 45 patients were analyzed (age, 73.1 ± 9.3 years; 23 males; H&Y stage 1: n = 12, stage 2: n = 14, stage 3: n = 10, stage 4: n = 5, and stage 5: n = 4; self-supportive care rating-dependent ADLs: n = 29). Dopamine transporter variables were significantly associated with the clinical severity of PD as assessed by H&Y staging, whereas MIBG variables were not. Dopamine transporter variables gradually decreased throughout progressive stages, whereas the MIBG variables changed only in the advanced stages. In a multivariate analysis including clinical and imaging variables, both lower DAT and MIBG uptakes were significantly associated with dependent ADL status (P = 0.028 and 0.034, respectively). CONCLUSIONS: In patients with PD, DAT SPECT and MIBG myocardial scintigraphy were associated with ADL status; DAT SPECT was a stronger indicator of severity than MIBG myocardial scintigraphy in the early and middle stages.