Rotational assessment of distal femur and its relevance in total knee arthroplasty: analysis by magnetic resonance imaging

AbstractObjective:To define the distal femur rotation pattern in a Brazilian population, correlating such pattern with the one suggested by the arthroplasty instruments, and analyzing the variability of each anatomic parameter.Materials and Methods:A series of 101 magnetic resonance imaging studies were evaluated in the period between April and June 2012. The epidemiological data collection was performed with the aid of the institution's computed imaging system, and the sample included 52 male and 49 female patients. The measurements were made in the axial plane, with subsequent correlation and triangulation with the other plans. The posterior condylar line was used as a reference for angle measurements. Subsequently, the anatomical and surgical transepicondylar axes and the anteroposterior trochlear line were specified. The angles between the reference line and the studied lines were calculated with the aid of the institution's software.Results:The mean angle between the anatomical transepicondylar axis and the posterior condylar line was found to be 6.89°, ranging from 0.25° to 12°. For the surgical transepicondylar axis, the mean value was 2.89°, ranging from –2.23° (internal rotation) to 7.86°, and for the axis perpendicular to the anteroposterior trochlear line, the mean value was 4.77°, ranging from –2.09° to 12.2°.Conclusion:The anatomical transepicondylar angle showed mean values corresponding to the measurement observed in the Caucasian population. The utilized instruments are appropriate, but no anatomical parameter proved to be steady enough to be used in isolation.

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Does diffusion-weighted magnetic resonance imaging have a place in the differential diagnosis of brucella sacroiliitis and seronegative spondyloarthropathy?

Acta Radiologica ◽

10.1177/0284185120938370 ◽

2020 ◽

pp. 028418512093837

Author(s):

Sunay Sibel Karayol ◽

Kudret Cem Karayol

Keyword(s):

Magnetic Resonance Imaging ◽

Bone Marrow ◽

Differential Diagnosis ◽

Magnetic Resonance ◽

Control Group ◽

Resonance Imaging ◽

Visual Evaluation ◽

Mean Values ◽

Diffusion Weighted ◽

The Mean

Background The aim of this study is to investigate the role of diffusion-weighted imaging (DWI) in the differential diagnosis of sacroiliitis. Purpose To compare the sacroiliac magnetic resonance imaging (MRI) examinations of patients with suspected active sacroiliitis with patients with acute SpA MR findings and the DWI examinations of patients with acute brucella sacroiliitis, and thereby determine whether DWI can contribute to the differential diagnosis. Material and Methods A total of 84 patients were included in the study and were separated into three groups: group 1 (13 women, 6 men) comprised cases with brucella positive for sacroiliitis; group 2 (17 women, 19 men) comprised cases negative for brucella but with sacroiliitis; and group 3 (16 women, 13 men) comprised cases negative for brucella and sacroiliitis. Results The mean bone marrow apparent diffusion coefficient (ADC) values independently of edema were determined as 0.71 × 10−3 in sacroiliitis and brucella-positive patients, as 0.53 × 10−3 in brucella-negative and sacroiliitis-positive patients, and as 0.43 × 10−3 in the control group of brucella-negative sacroiliitis-negative patients. In the ADC measurements taken from areas of evident edema in patients with sacroiliitis, the mean values were 0.13 × 10−3 in the brucella-positive group and 0.12 × 10−3 in the brucella-negative group. Conclusion By adding DWI, which is a rapid MR sequence, to sacroiliac joint MR examination, normal bone marrow and bone marrow with sacroiliitis can be objectively differentiated with ADC measurements in addition to visual evaluation.

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Standing open magnetic resonance imaging improves detection and staging of pelvic organ prolapse

Canadian Urological Association Journal ◽

10.5489/cuaj.7244 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Lynn Stothers ◽

Jennifer A. Locke ◽

Marwa Abdulaziz ◽

Darren Lazare ◽

Alex Kavanagh ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Pelvic Organ Prolapse ◽

Magnetic Resonance ◽

Pelvic Organ ◽

Resonance Imaging ◽

Mean Values ◽

Open Magnetic Resonance Imaging ◽

Significant Difference ◽

The Mean ◽

The Impact

Introduction: The role of imaging in pelvic organ prolapse (POP) assessment is unclear. Open magnetic resonance imaging (MRI) systems have a configuration that allows for imaging women with POP in different positions. Herein, we use a 0.5 Tesla open MRI to obtain supine, seated, and standing images. We then compare these images to evaluate the impact of posture on detection and staging of POP. Methods: Women presenting with symptoms of POP at a tertiary care university hospital were asked to participate in this prospective cohort study. Symptom scores, POP-Q staging and three-position MRI imaging of the pelvis data were collected. The pubococcygeal line (PCL) was used to quantify within-patient changes in pelvic organ position as defined by: no displacement, <1 cm inferior to the PCL, mild (1–3 cm), moderate (3.1–6 cm), and severe (>6 cm) in the axial and sagittal T2-weighted images. Statistical analysis was completed (T-test; p<0.05 significant). Results: A total of 42 women, age range 40–78 years, participated. There was a significant difference in the mean values associated with anterior prolapse in the supine (0.7±1.8), seated (2.4±3.4), and upright (4.2±1.6) positions (p=0.015). There was a significant difference in the mean values associated with apical prolapse in the supine (0.5±1.5), seated (1.5±1.4), and upright (2.1±1.5) positions (p=0.036). Conclusions: Our findings suggest that POP is more readily detected and upstaged with standing MRI images as compared to supine and seated positions. The developed two-minute standing MRI protocol may enable clinicians to better assess the extent of POP.

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Normal range of clivoaxial angle in adults using flexion and extension cervical magnetic resonance imaging scans

The Neuroradiology Journal ◽

10.1177/1971400921998982 ◽

2021 ◽

pp. 197140092199898

Author(s):

Anousheh Sayah ◽

April D Farley ◽

Eric C Munoz ◽

Faheem A Sandhu ◽

Frank Berkowitz

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Prone Position ◽

Mean Value ◽

Resonance Imaging ◽

Normal Range ◽

Posterior Cortex ◽

Normal Ranges ◽

Significant Difference ◽

The Mean

Objective An abnormally decreased clivoaxial angle (CXA) is used during the clinical evaluation for corrective skull base surgery. Published normal ranges of CXA using x-ray, computed tomography, or magnetic resonance imaging (MRI) vary dramatically, especially with neck flexion or extension. The aim of this study was to use high-resolution MRI to determine the normal range of CXA in various neck positions using a reproducible measurement technique. Methods The CXA was measured in 10 healthy volunteers on sagittal T2 SPACE c-spine MRI in supine and prone positions and with the neck both neck and extended. CXA is strictly defined as the angle between a line along the inferior third of the dorsal clival cortex and a line from the superior/posterior cortex of the dens to the posterior/inferior corner of the C2 body. Statistical analysis was performed in all positions and included mean CXA, range, standard deviation ( SD), inter-reader agreement, and group comparisons. Results The mean CXA overall was 156.92° ( SD=4.23°; range 134–179°). The mean value for extension CXA was 169.20° ( SD=5.81°), and the mean value for flexion CXA was 144.73° ( SD=5.71°), the difference being statistically significant ( p<0.0001) regardless of supine or prone position. Concordant correlations of reader measurements showed substantial agreement in the supine position at 0.96, with lower agreement in the prone position at 0.87. Conclusions We report normal ranges for CXA in various neck positions based on 3D T2-weighted MRI, using a reproducible measurement method. There was a significant difference in the CXA values between neck extended and neck flexed positions but not between supine and prone positions.

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The Kaplan Fibers of the Iliotibial Band Can Be Identified on Routine Knee Magnetic Resonance Imaging

The American Journal of Sports Medicine ◽

10.1177/0363546519868219 ◽

2019 ◽

Vol 47 (12) ◽

pp. 2895-2903 ◽

Cited By ~ 5

Author(s):

Lachlan Batty ◽

Jerome Murgier ◽

Richard O’Sullivan ◽

Kate E. Webster ◽

Julian A. Feller ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Sagittal Plane ◽

Interobserver Reliability ◽

Joint Line ◽

Coronal Plane ◽

Iliotibial Band ◽

Resonance Imaging ◽

Lateral Gastrocnemius ◽

The Mean

Background: The Kaplan fibers (KFs) of the iliotibial band have been suggested to play a role in anterolateral rotational instability of the knee, particularly in the setting of an anterior cruciate ligament (ACL) rupture. Description of the normal magnetic resonance imaging (MRI) anatomy of the KFs may facilitate subsequent investigation into the MRI signs of injury. Purpose: To assess if the KF complex can be identified on 3-T MRI using standard knee protocols. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: 3-T MRI scans of 50 ACL-intact knees were reviewed independently by a musculoskeletal radiologist and 2 orthopaedic surgeons. Identification of the KFs was based on radiological diagnostic criteria developed a priori. Identification of the KFs in the sagittal, coronal, and axial planes was recorded. Interobserver reliability was assessed using the Kappa statistic. Detailed anatomy including distance to the joint line and relationship to adjacent structures was recorded. Results: The mean patient age was 43 years (range, 15-81 years), 58% were male, and 50% were right knees. The KFs were identified by at least 2 reviewers on the sagittal images in 96% of cases, on the axial images in 76% of cases, and on the coronal images in 4% of cases. The mean distance from the KF distal femoral insertion to the lateral joint line was 50.1 mm (SD, 6.6 mm) and the mean distance to the lateral gastrocnemius tendon origin was 10.8 mm (SD, 8.6 mm). The KFs were consistently identified immediately anterior to the superior lateral geniculate artery on sagittal imaging. Interobserver reliability for identification was best in the sagittal plane (Kappa 0.5) and worst in the coronal plane (Kappa 0.1). Conclusion: The KF complex can be identified on routine MRI sequences in the ACL-intact knee; however, there is low to moderate interobserver reliability. Imaging in the sagittal plane had the highest rate of identification and the coronal plane the lowest. There is a consistent relationship between the most distal KF femoral attachment and the lateral joint line, lateral gastrocnemius tendon, and superior lateral geniculate artery.

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5377679 Magnetic resonance imaging system

Magnetic Resonance Imaging ◽

10.1016/0730-725x(95)96642-o ◽

1995 ◽

Vol 13 (6) ◽

pp. VI-VII

Author(s):

Machida Yoshio ◽

Hatanaka Masahiko ◽

Kitane Shinichi

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Imaging System ◽

Magnetic Resonance Imaging System ◽

Resonance Imaging

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Demyelination and remyelination detected in an alternative cuprizone mouse model of multiple sclerosis with 7.0 T multiparameter magnetic resonance imaging

Scientific Reports ◽

10.1038/s41598-021-90597-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shuang Ding ◽

Yu Guo ◽

Xiaoya Chen ◽

Silin Du ◽

Yongliang Han ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Multiple Sclerosis ◽

Magnetic Resonance ◽

Mouse Model ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Blue Staining ◽

Resonance Imaging ◽

The Mean ◽

Underlying Mechanisms

AbstractThe aim of this study was to investigate the mechanisms underlying demyelination and remyelination with 7.0 T multiparameter magnetic resonance imaging (MRI) in an alternative cuprizone (CPZ) mouse model of multiple sclerosis (MS). Sixty mice were divided into six groups (n = 10, each), and these groups were imaged with 7.0 T multiparameter MRI and treated with an alternative CPZ administration schedule. T2-weighted imaging (T2WI), susceptibility-weighted imaging (SWI), and diffusion tensor imaging (DTI) were used to compare the splenium of the corpus callosum (sCC) among the groups. Prussian blue and Luxol fast blue staining were performed to assess pathology. The correlations of the mean grayscale value (mGSV) of the pathology results and the MRI metrics were analyzed to evaluate the multiparameter MRI results. One-way ANOVA and post hoc comparison showed that the normalized T2WI (T2-nor), fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) values were significantly different among the six groups, while the mean phase (Φ) value of SWI was not significantly different among the groups. Correlation analysis showed that the correlation between the T2-nor and mGSV was higher than that among the other values. The correlations among the FA, RD, MD, and mGSV remained instructive. In conclusion, ultrahigh-field multiparameter MRI can reflect the pathological changes associated with and the underlying mechanisms of demyelination and remyelination in MS after the successful establishment of an acute CPZ-induced model.

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Substantia nigra neuromelanin magnetic resonance imaging in patients with different subtypes of Parkinson disease

Journal of Neural Transmission ◽

10.1007/s00702-020-02295-8 ◽

2021 ◽

Author(s):

Lu Wang ◽

Yayun Yan ◽

Liyao Zhang ◽

Yan Liu ◽

Ruirui Luo ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Substantia Nigra ◽

Parkinson Disease ◽

Clinical Symptoms ◽

Dopamine Neurons ◽

Substantia Nigra Pars Compacta ◽

Resonance Imaging ◽

Mean Values

AbstractNeuromelanin (NM) is a dark pigment that mainly exists in neurons of the substantia nigra pars compacta (SNc). In Parkinson disease (PD) patients, NM concentration decreases gradually with degeneration and necrosis of dopamine neurons, suggesting potential use as a PD biomarker. We aimed to evaluate associations between NM concentration in in vivo SN and PD progression and different motor subtypes using NM magnetic resonance imaging (NM-MRI). Fifty-four patients with idiopathic PD were enrolled. Patients were divided into groups by subtypes with different clinical symptoms: tremor dominant (TD) group and postural instability and gait difficulty (PIGD) group. Fifteen healthy age-matched volunteers were enrolled as controls. All subjects underwent clinical assessment and NM-MRI examination. PD patients showed significantly decreased contrast-to-noise ratio (CNR) values in medial and lateral SN (P < 0.05) compared to controls. CNR values in lateral SN region decreased linearly with PD progression (P = 0.001). PIGD patients showed significant decreases in CNR mean values in lateral SN compared to TD patients (P = 0.004). Diagnostic accuracy of using lateral substantia nigra (SN) in TD and PIGD groups was 79% (sensitivity 76.5%, specificity 78.6%). NM concentration in PD patients decreases gradually during disease progression and differs significantly between PD subtypes. NM may be a reliable biomarker for PD severity and subtype identification.

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Multiple b values of diffusion-weighted magnetic resonance imaging in evaluation of solid head and neck masses

Egyptian Journal of Radiology and Nuclear Medicine ◽

10.1186/s43055-019-0054-3 ◽

2019 ◽

Vol 50 (1) ◽

Cited By ~ 1

Author(s):

Rania Sobhy Abou khadrah ◽

Haytham Haroon Imam

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Head And Neck ◽

Resonance Imaging ◽

Adc Value ◽

Neck Masses ◽

Adc Values ◽

Weighted Magnetic Resonance Imaging ◽

The Mean ◽

Head And Neck Masses

Abstract Background Differentiation between malignant and benign masses is essential for treatment planning and helps in improving the prognosis of malignant tumors; the aim of this work is to determine the role of diffusion-weighted magnetic resonance imaging (DW-MRI) and the apparent diffusion coefficient (ADC) in the differentiation between benign and malignant solid head and neck masses by comparing diagnostic performance of low b values (0.50 and 400 s/mm2) versus high b values (800 and 1000 s/mm2) and comparing the result with histopathological finding. Results The study included 60 patients (34 male and 26 female) with solid head and neck masses > 1 cm who referred to radiodiagnosis department for MRI evaluation. Multiple b values were used 50, 400, 800, and 1000 s/mm2 (at least 2 b values). DWI and ADC value of all 60 patients were acquired. Mean ADC values of both malignant and benign masses were statistically measured and compared, and cut off value was determined. Solid head and neck masses in our study DWI with the use of high b value 800 and 1000 s/mm2 were of higher significance (P value 0.001*). There was a significant difference in the mean ADC value between benign and malignant masses (P < 0.01); solid masses were divided into 2 categories: (a) malignant lesions 46.7% (n = 28) with mean ADC value (0.82 ± 0.19) × 10−3 s/mm2 and (b) benign lesions 53.3% (n = 32) with mean ADC value (2.05 ± 0.46) × 10−3 s/mm2) with ADC cutoff value of 1.0 × 10−3 s/mm2 and 94% sensitivity, 93% specificity, negative predictive value (NPV) = 94%, positive predictive value (PPV) 93%, and an accuracy of 93.5%. Conclusion The DWI with ADC mapping were valuable as non-invasive tools in differentiating between benign and malignant solid head and neck masses. The use of high b value 800 and 1000 s/mm2 was of higher significance (P value 0.001*) in differentiation between benign and malignant lesion than that with low b values 0, 50, and 400 s/mm2 (0.01). The mean ADC values were significantly lower in malignant solid masses. Attention had to be paid to the choice of b values in MRI-DWI in the head and neck region.

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“Yokoyama procedure” efficacy on non-highly myopic patients with acquired esotropia and hypotropia

European Journal of Ophthalmology ◽

10.1177/1120672119850684 ◽

2019 ◽

Vol 30 (4) ◽

pp. 676-679

Author(s):

Massimiliano Serafino ◽

Matteo Scaramuzzi ◽

Edoardo Villani ◽

Paolo Nucci

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Axial Length ◽

Lateral Rectus ◽

Inclusion Criteria ◽

Resonance Imaging ◽

Spherical Equivalent Refraction ◽

Before And After ◽

Weighted Magnetic Resonance Imaging ◽

The Mean

Objective: To assess the efficacy of “Yokoyama Procedure,” on non-highly myopic patients with acquired esotropia and hypotropia. Methods: The study involved 10 eyes of 5 patients with eso-hypotropia. Inclusion criteria were acquired esotropic-hypotropic strabismus with lateral rectus inferior displacement and superior rectus nasal displacement confirmed by magnetic resonance imaging, refractive errors between ±6 D, and axial length < 27 mm. Range of full duction movements and maximum angles of abduction-sursumduction was measured in each eye before and after surgery. All patients underwent T1- and T2-weighted magnetic resonance imaging. The surgery was aimed at creating a junction between the muscle bellies of the superior and lateral rectus muscles. This junction was made approximately 14 mm behind the insertions using a non-absorbable mersilene 5/0 suture (Yokoyama procedure). Results: Mean patient age was 64.8 ± 4.8 years. The mean globe axial length was 25.4 ± 0.76 mm and a mean corresponding spherical equivalent refraction of −3.7 ± 1.7 D was observed. Eight eyes on 10 had mild limitation in abduction, while the remaining 2 had no limitation. Three out of 10 eyes showed a moderate limited sursumduction, 5 eyes were categorized as mild, and the remaining 2 had no limitation. No evident post-operative limitation was present in any eye, in both abduction and sursumduction (p < 0.01). Pre-operative esotropia and hypotropia were, respectively, 32 ± 11 prismatic diopters and 25 ± 5 prismatic diopters, and they were significantly reduced after surgery as 9 ± 1.7 prismatic diopters and 6 ±1 prismatic diopters (p = 0.043), respectively. Conclusion: Yokoyama procedure is an effective, fast, reversible procedure to face eso-hypotropic acquired strabismus, even in patients with a clear magnetic resonance imaging displacement of superior and lateral rectus muscles, and absence of globe dislocation and of elevated myopia.

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