Fat-saturated Proton Density Research Articles

Reconstruction of 3D knee MRI using deep learning and compressed sensing: a validation study on healthy volunteers.

To investigate the potential of combining compressed sensing (CS) and artificial intelligence (AI), in particular deep learning (DL), for accelerating three-dimensional (3D) magnetic resonance imaging (MRI) sequences of the knee. Twenty healthy volunteers were examined using a 3-T scanner with a fat-saturated 3D proton density sequence with four different acceleration levels (10, 13, 15, and 17). All sequences were accelerated with CS and reconstructed using the conventional and a new DL-based algorithm (CS-AI). Subjective image quality was evaluated by two blinded readers using seven criteria on a 5-point-Likert-scale (overall impression, artifacts, delineation of the anterior cruciate ligament, posterior cruciate ligament, menisci, cartilage, and bone). Using mixed models, all CS-AI sequences were compared to the clinical standard (sense sequence with an acceleration factor of 2) and CS sequences with the same acceleration factor. 3D sequences reconstructed with CS-AI achieved significantly better values for subjective image quality compared to sequences reconstructed with CS with the same acceleration factor (p ≤ 0.001). The images reconstructed with CS-AI showed that tenfold acceleration may be feasible without significant loss of quality when compared to the reference sequence (p ≥ 0.999). For 3-T 3D-MRI of the knee, a DL-based algorithm allowed for additional acceleration of acquisition times compared to the conventional approach. This study, however, is limited by its small sample size and inclusion of only healthy volunteers, indicating the need for further research with a more diverse and larger sample. DRKS00024156. Using a DL-based algorithm, 54% faster image acquisition (178s versus 384s) for 3D-sequences may be possible for 3-T MRI of the knee. • Combination of compressed sensing and DL improved image quality and allows for significant acceleration of 3D knee MRI. •DL-based algorithm achieved better subjective image quality than conventional compressed sensing. •For 3D knee MRI at 3 T, 54% faster image acquisition may be possible.

Analisis Informasi Anatomi Pemeriksaan MRI Ankle Joint pada Penggunaan Foot Ankle Coil dan Flex Coil Proton Density Fat Saturation Irisan Sagital

Background: To get good MRI image quality, a special coil is designed according to the type of examination with various types and sizes so that it can be adjusted to the body to be examined so that the selection of coil is very important in MRI examination. At Dr.R.Soeharso Surakarta Orthopedi Hospital, it was found on an MRI examination of the ankle joint using a foot ankle coil and also sometimes also using a flex coil. The purpose of this study was to determine the difference in anatomical information of ankle joint MRI examination on Proton Density Fat Saturation Sagittal Slices using foot ankle coil and flex coil. Methods: This research is quantitative research with an experimental approach. This research was conducted on 10 volunteers. Respondents assessed image information on the anatomy of the Achilles tendon, talocalcaneal ligament, tibiofibular ligament, talofibular ligament, talotibial ligament, tenton flexor digitorum, extensor digitorum tendon, os calcaneus, os tallus, os tibia. Results: Ten probandus were performed MRI examination of ankle joint, proton density weighting, sagittal slice using foot ankle coil and flex coil. Images are produced that can show predetermined anatomical information, namely: Achilles tendon, talocalcaneal ligament, tibiofibular ligament, talofibular ligament, talotibial ligament, tenton flexor digitorum, extensor digitorum tendon, os calcaneus, os tallus, os tibia. Based on Wilcoxon's nonparametric statistical test in table shows that the resulting p value is 0.001 (p-value is 0.05) which means that there is a significant difference in the overall anatomical information of ankle joint MRI examination on the use of foot ankle coil and flex coil proton density fat saturation sagittal slices and mean rank results (28.50) foot ankle coil (0,001) flex coil.Conclusions: The anatomical information produced in the use of foot ankle coil is better than the anatomical information produced by flex coil on MRI examination of ankle joint proton density fat saturation sagittal slice.

Thin-slice 2D MR Imaging of the Shoulder Joint Using Denoising Deep Learning Reconstruction Provides Higher Image Quality Than 3D MR Imaging

This study was conducted to evaluate whether thin-slice 2D fat-saturated proton density-weighted images of the shoulder joint in three imaging planes combined with parallel imaging, partial Fourier technique, and denoising approach with deep learning-based reconstruction (dDLR) are more useful than 3D fat-saturated proton density multi-planar voxel images. Eighteen patients who underwent MRI of the shoulder joint at 3T were enrolled. The denoising effect of dDLR in 2D was evaluated using coefficient of variation (CV). Qualitative evaluation of anatomical structures, noise, and artifacts in 2D after dDLR and 3D was performed by two radiologists using a five-point Likert scale. All were analyzed statistically. Gwet's agreement coefficients were also calculated. The CV of 2D after dDLR was significantly lower than that before dDLR (P < 0.05). Both radiologists rated 2D higher than 3D for all anatomical structures and noise (P < 0.05), except for artifacts. Both Gwet's agreement coefficients of anatomical structures, noise, and artifacts in 2D and 3D produced nearly perfect agreement between the two radiologists. The evaluation of 2D tended to be more reproducible than 3D. 2D with parallel imaging, partial Fourier technique, and dDLR was proved to be superior to 3D for depicting shoulder joint structures with lower noise.

End-to-end deep learning model for segmentation and severity staging of anterior cruciate ligament injuries from MRI

PurposeThe purpose of this study was to develop a semi-supervised segmentation and classification deep learning model for the diagnosis of anterior cruciate ligament (ACL) tears on MRI based on a semi-supervised framework, double-linear layers U-Net (DCLU-Net). Materials and methodsA total of 297 participants who underwent of total of 303 MRI examination of the knee with fat-saturated proton density (PD) fast spin-echo (FSE) sequence in the sagittal plane were included. There were 214 men and 83 women, with a mean age of 37.46 ± 1.40 (standard deviation) years (range: 29–44 years). Of these, 107 participants had intact ACL (36%), 98 had partially torn ACL (33%), and 92 had fully ruptured ACL (31%). The DCLU-Net was combined with radiomic features for enhancing performances in the diagnosis of ACL tear. The different evaluation metrics for both classification (accuracy, sensitivity, accuracy) and segmentation (mean Dice similarity coefficient and root mean square error) were compared individually for each image class across the three phases of the model, with each value being compared to its respective value from the previous phase. Findings at arthroscopic knee surgery were used as the standard of reference. ResultsWith the addition of radiomic features, the final model yielded accuracies of 90% (95% CI: 83–92), 82% (95% CI: 73–86), and 92% (95% CI: 87–94) for classifying ACL as intact, partially torn and fully ruptured, respectively. The DCLU-Net achieved mean Dice similarity coefficient and root mean square error of 0.78 (95% CI: 0.71–0.80) and 0.05 (95% CI: 0.06–0.07), respectively, when segmenting the three ACL conditions with pseudo data (P < 0.001). ConclusionA dual-modules deep learning model with segmentation and classification capabilities was successfully developed. In addition, the use of semi-supervised techniques significantly reduced the amount of manual segmentation data without compromising performance.

Concurrent validity and reliability of a semi-automated approach to measuring the magnetic resonance imaging morphology of the knee joint in active youth.

Post-traumatic knee osteoarthritis is attributed to alterations in joint morphology, alignment, and biomechanics triggered by injury. While magnetic resonance (MR) imaging-based measures of joint morphology and alignment are relevant to understanding osteoarthritis risk, time consuming manual data extraction and measurement limit the number of outcomes that can be considered and deter widespread use. This paper describes the development and evaluation of a semi-automated software for measuring tibiofemoral and patellofemoral joint architecture using MR images from youth with and without a previous sport-related knee injury. After prompting users to identify and select key anatomical landmarks, the software can calculate 37 (14 tibiofemoral, 23 patellofemoral) relevant geometric features (morphology and alignment) based on established methods. To assess validity and reliability, 11 common geometric features were calculated from the knee MR images (proton density and proton density fat saturation sequences; 1.5 T) of 76 individuals with a 3-10-year history of youth sport-related knee injury and 76 uninjured controls. Spearman's or Pearson's correlation coefficients (95% CI) and Bland-Altman plots were used to assess the concurrent validity of the semi-automated software (novice rater) versus expert manual measurements, while intra-class correlation coefficients (ICC2,1; 95%CI), standard error of measurement (95%CI), 95% minimal detectable change, and Bland-Altman plots were used to assess the inter-rater reliability of the semi-automated software (novice vs resident radiologist rater). Correlation coefficients ranged between 0.89 (0.84, 0.92; Lateral Trochlear Inclination) and 0.97 (0.96, 0.98; Patellar Tilt Angle). ICC estimates ranged between 0.79 (0.63, 0.88; Lateral Patellar Tilt Angle) and 0.98 (0.95, 0.99; Bisect Offset). Bland-Altman plots did not reveal systematic bias. These measurement properties estimates are equal, if not better than previously reported methods suggesting that this novel semi-automated software is an accurate, reliable, and efficient alternative method for measuring large numbers of geometric features of the tibiofemoral and patellofemoral joints from MR studies.

Association of Mucoid Degeneration of the ACL with Medial Tibiofemoral Osteoarthritis Progression at MR Imaging

Abstract Background Using MRI, ACL mucoid degeneration is defined as a thickened ACL with increased signal intensity on all MR pulse sequences, with discrete fibers easily distinguished on fatsaturated T2-weighted or fat-saturated proton-density (PD)-weighted images but poorly differentiated on T1-weighted or non-fat-saturated PD-weighted images. Objective To assess the prevalence of ACL mucoid degeneration in a population of patients referred for routine knee MRI, and its association with age and structural joint damage. Patients and Methods Our study is a retrospective study conducted at the radiology department of Ain Shams University hospitals and Ain Shams University Specialized Hospital including 81 cases of knees with ACL mucoid degeneration by MRI and no sex predilection. Cases and controls were scored with respect to independent articular features: cartilage signal and morphology, subarticular bone marrow abnormality, subarticular cysts, subarticular bone attrition, marginal osteophytes and medial meniscal integrity. Results Patients with ACL mucoid degeneration were older than patients with a normal ACL, without statistically significant sex difference. Knees with ACL mucoid degeneration had statistically significant medial meniscal injuries and cartilage damage involving the central and posterior MTFC compared to control knees with a normal ACL frequency matched for age, sex and MR field strength. Conclusion Our study proved that there is a strong association between ACL mucoid degeneration and cartilage damage in MTFC.

Visualization of meniscus with 3D axial reconstructions

PurposeTo visualize the meniscus of the knee joint in the axial plane and identify injuries that cannot be visualized using conventional sequences. MethodsTwo hundred and two subjects underwent an improvised 3-Dimensional Proton Density Fat Saturation (3D-PD FS) Magnetic Resonance (MR) sequence on their meniscus. The transverse images were reconstructed and examined. Fifty-three of the subjects had a healthy meniscus and their images were used as part of a qualitative evaluation to verify that all parts of the meniscus were properly visualized. The evaluation was based on a four-level scale indicating the visualization of meniscal parts. The same evaluation was also performed on the 149 subjects with meniscal pathologies. Another qualitative evaluation was performed on all subjects concerning five image characteristics based on a five-level scale. Finally, images from 20 patients with meniscal pathologies were compared with arthroscopic images visualizing meniscal tears. ResultsIn all subjects, all parts of the meniscus were clearly visualized. The axial reformats provided ideal imaging of the meniscus, yielding high total image quality, satisfactory smoothing and sharpening, fewer artifacts, and successful fat saturation. The findings of the MR images from the 20 subjects with meniscal pathologies, concerning the topography of meniscal tears coincided at 100% with their arthroscopic findings. ConclusionThe use of the improvised 3D-PD FS sequence provides the possibility of axial reconstruction with a better depiction of the meniscus. These images can accurately illustrate the range of the meniscus and any meniscal tears along with their exact location with high image quality.

MRI Evaluation of Anterolateral Ligament of the Knee: A Cross-Sectional Study in Malaysia.

IntroductionAfter detailed anatomical delineation of the anterolateral ligament (ALL) of the knee, there is a surge in research on this anatomical structure. Owing to the anatomical variation and lack of experience in the identification of this structure, magnetic resonance (MR) evaluation of the ALL produces mixed results. It was aimed to evaluate the ALL using the routinely performed MR imaging of the knee and to determine any associated factors with ALL injuries.Materials and methodsThirty-six MR images of the knee from 31 patients from January 1, 2017, to June 30, 2017, are evaluated. MR sequences performed include T1-weighted, T2-weighted, proton density (PD), and PD fat saturation (FS). All MR images were double-read by two authors and approved by a consultant radiologist with more than 20 years of radiological experience. The ALL was divided into three portions: femoral, meniscal, and tibial, and the ALL was considered fully visualized when all three portions were seen on MR images.ResultsAt least a portion of the ALL was visualized in 27 scans (75%), and it was fully visualized in 20 scans (55.6%). The femoral portion was the most commonly identified (75%), followed by the meniscal portion (69.4%) and the tibial portion (58.3%). ALLs were best visualized on coronal view in PD FS with the lateral inferior genicular artery as a guide to locate the bifurcation of the meniscal and tibial components.ConclusionThe ALL can be visualized in routine 1.5-T MR imaging, either full delineation (55.6%) or partially visualized (75%). It is best characterized via a PD-weighted sequence with fat saturation on the coronal plane. The ALL injury was associated with an anterior cruciate ligament (ACL) injury.

Real-time assessment of temporomandibular joint using HASTE sequences: feasibility and comparison with standard static sequences.

To test real-time MRI (rtMRI) using HASTE sequences in patients with suspected internal disk derangement (IDD) of temporomandibular joint (TMJ) and to compare these sequences with standard static sequences. 99 TMJ were studied with both standard sequences (fat-saturated proton density) and HASTE sequences with high temporal resolution. Image quality was assessed using a 4-point Likert scale. Two radiologists analysed both standard and rtMRI sequences separately, randomly and blinded (by a third operator) to patients' names in order to assess inter-observer repeatability. One of the radiologists performed the analysis twice for assessing intra-observer repeatability. The same radiologists evaluated randomly and blinded to the previous assessment both the sequences and decided in consensus which was the most credible. Qualitative scores were compared using Friedman's test while concordance between radiologists and sequences was evaluated using the concordance correlation coefficient. At image quality analysis, mean score was 3.41 for static MRI and 3.82 for rtMRI, with a statistically significant difference in favour of rtMRI (p < 0.0001). Inter-rater concordance between operator 1 (Op1) and operator 2 (Op2) with regard to the same sequence was high for both static and rtMRI sequences (0.824 and 0.888, respectively). Inter-rater variability of Op1 and Op2 between static and rtMRI sequences was lower (0.647 for Op1 and 0.633 for Op2). Among 71 discordances between sequences, 60 were judged in favour of rtMRI, while 11 were in favour of static MRI. rtMRI with HASTE sequences is a robust technique and provide additional information in assessing IDD compared to static sequences.

7-T clinical MRI of the shoulder in patients with suspected lesions of the rotator cuff

BackgroundTo evaluate feasibility and diagnostic performance of clinical 7-T magnetic resonance imaging (MRI) of the shoulder.MethodsEight patients with suspected lesions of the rotator cuff underwent 7-T MRI before arthroscopy. Image quality was scored for artifacts, B1+ inhomogeneities, and assessability of anatomical structures. A structured radiological report was compared to arthroscopy. In four patients, a visual comparison with pre-existing 1.5-T examinations was performed.ResultsRegarding image quality, the majority of the sequences reached values above the middle of each scoring scale. Fat-saturated proton density sequences showed least artifacts and best structure assessability. The most homogenous B1+ field was reached with gradient-echo sequences. Arthroscopy did not confirm tendinopathy/partial tear of supraspinatus in 5/8 patients, of subscapularis in 5/6, and of infraspinatus in one patient; only a partial lesion of the subscapularis tendon was missed. Pathologic findings of long bicipital tendon, acromioclavicular joint, glenohumeral cartilage, labrum, and subacromial subdeltoideal bursa were mainly confirmed; exceptions were one lesion of the long bicipital tendon, one subacromial bursitis, and one superior glenoid labrum anterior-to-posterior lesion, missed on 7-T MRI. Evaluating all structures together, sensitivity was 86%, and specificity 74%. A better contrast and higher image resolution was noted in comparison to previous 1.5-T examinations.Conclusions7-T MRI of the shoulder with diagnostic image quality is feasible. Overrating of tendon signal alterations was the main limitation. Although the diagnostic performance did not reach the current results of 3-T MRI, our study marks the way to implement clinical 7-T MRI of the shoulder.

Role of diffusion-weighted magnetic resonance imaging in evaluation of bone marrow edema of the knee

Background Bone marrow edema (BME) has not been recognized as a significant pain generator or as a primary contributor to disease until recently. BME is characterized by a nonspecific pattern of ill-defined high signal intensity on short-tau inversion recovery and T2-weighted MRI and low signal intensity on T1-weighted images. Objective To assess the value of diffusion-weighted MRI in the diagnosis and evaluation of BME at the knee region. Patients and methods This study was conducted on 130 patients referred with clinical suspicion of knee edema with or without history of trauma. They were divided into group ‘A,’ with lesions less than 15 mm, and group ‘B,’ with lesions greater than 15 mm. Their ages ranged between 9 and 75 years, with a mean age of 42 years. There were 43 females and 87 males. Results Between groups A and B, we found that bone marrow lesions (BMLs) were approximately two times larger on apparent diffusion coefficient (ADC) maps than on fat-saturated (FS) proton density (PD)-weighted turbo spin echo images. The most important value of adding the ADC-derived maps in routine MRI examination of the knee is to show additional BMLs that only can be detected at the ADC maps but could not be detected at the FS PD. Approximately 27 more lesions in 27 patients and one patient with two more lesions were detected. These nonconcordant lesions accounted totally for 29 more BMLs. Conclusion MRI is the mainstay of diagnosis, staging, and management plan of knee traumatic and nontraumatic disorders. ADC maps are more sensitive than corresponding FS PD-weighted turbo spin echo images allowing for detection of significantly more and larger BMLs. In addition, they represent a valuable add-on in knee imaging protocols.

Magnetic Resonance Imaging of Osteochondral Lesions of the Talus: Comparison Between Small FOV Surface Coil with BLADE and Boot-Shape Coil Without BLADE

Background: It is common for osteochondral lesions of the talus (OLT) to be associated with ankle injury, residual ankle stiffness and pain after osteochondral injuries, and OLTs are most common in the dome of the talus. Before choosing the appropriate therapy based on diagnosis, it is necessary to determine if the OLT is a stabile lesion or not. More accurate diagnosis and classifications could be conducted to guide the clinical treatment. Objectives: To compare the accuracy rate and diagnostic indices of proton-density fat-saturation BLADE (proprietary name for periodically rotated overlapping parallel lines with enhanced reconstruction in magnetic resonance systems from Siemens Healthcare) sequences from a small field of view (FOV) surface coil and proton-density fat-saturation sequences without BLADE in a routine FOV using a boot-shaped coil on the magnetic resonance imaging (MRI) of OLT. Patients and Methods: One hundred and one patients with ankle pain for greater than 6 weeks and normal X-ray participated in this study. They were ready for diagnosis by arthroscopy and treatment following MR examination. All patients were scanned by two different methods: (a) a coronal proton-density fat-saturated sequence with BLADE using a small FOV surface coil and (b) a coronal proton-density fat-saturated sequence without BLADE using a routine FOV boot coil. In this study, the arthroscopic results were regarded as the gold standard for assessing OLTs and were used to directly compare the ability of the two different scanning methods to produce accurate findings with regard to MR imaging of OLTs. Results: Of the 101 patients, 57 patients with cartilaginous injury were confirmed by the results of arthroscopy, and 44 patients were without cartilaginous injury. Forty-eight lesions had the same grade with the small FOV BLADE sequence MRI and arthroscopy, while 37 lesions had the same grade on routine FOV MRI and arthroscopy among 57 patients with cartilaginous injury. Among MR findings of 101 patients, the results of weighted Kappa, accuracy, sensitivity and specificity were 0.803, 90.10%, 84.21%, and 97.73%, respectively between small FOV and arthroscopy; 0.515, 75.25%, 64.91%, and 88.64%, respectively between routine FOV and arthroscopy. The accuracy rate, sensitivity and specificity of small FOV with BLADE were higher than routine FOV. Mc Nemar’s test confirmed that the accuracy, sensitivity and specificity of small FOV BLADE were significantly better than routine FOV (P < 0.001). Greater values of small FOV compared to routine FOV appeared in sensitivity of 0.94 vs. 0.81 (MR normal and grade I), 0.89 vs. 0.77 (MR normal and grade I - IIA), 0.90 vs. 0.74 (MR normal and grade I-IIB), 0.91 vs. 0.75 (MR normal and grade I - III) and specificity of 0.98 vs. 0.92 (MR normal and grade I), the same in specificity of 0.91 vs. 0.91 (MR normal and grade I - IIA), 0.80 vs. 0.80 (MR normal and grade I - III), only smaller in specificity of 0.60 vs. 0.80 (MR normal and grade I - IIB). Conclusion: Small FOV surface coil with BLADE sequence grading of OLT demonstrated a promising accuracy rate compared with arthroscopic diagnosis.

Added value of thin axial MR cuts in the diagnosis of several meniscal tears: how far are they reliable?

BackgroundThe purpose of the study is to assess the added value of thin-cut (1 mm) axial magnetic resonance (MR) fat-saturated proton density (FS PD) weighted images (WIs) in the diagnosis of different types of meniscal tears. The study was conducted between January 2016 and August 2017 at a major private center group. This study included 28 patients with clinical suspicion of meniscal tear of age between 30 and 48 years including 19 males and 9 females. Axial 1-mm FS PD WIs were performed in addition to the conventional MR sequences. The type and classification of the meniscal tear were then diagnosed by a group of highly experienced musculoskeletal radiologists. The group assessed the morphology and classification of tears. The diagnosis was then confirmed by arthroscopy as a gold-standard reference.ResultsMeniscal tears were found in 23 out of 28 patients. Twenty-seven meniscal tears were found in the 23 patients: 2 root attachment radial tears (6.9%), 8 radial tears (27.6%), 7 longitudinal [vertical] tears (24%), 3 horizontal tears (10%), 5 displaced bucket handle tears (17%), 1 case of flab tear (3.4%), 1 case of meniscal fraying (3.4%), and 2 lesions which were diagnosed as artifacts and confirmed negative for tears by arthroscopy (6.8%). Diagnostic performance was as follows: sensitivity 96.3%, positive predictive value 100%, accuracy 96.6%, prevalence 93%, specificity 100%, and negative predictive value 66.67%.ConclusionThe study declared high diagnostic performance of thin-cut fat-saturated PD WIs in the diagnosis of different types of meniscal tears regarding their classifications and morphology which is crucial for further management.

Abbreviated MRI of the foot in patients with suspected osteomyelitis.

To determine the diagnostic accuracy of an abbreviated magnetic resonance imaging (MRI) protocol of the foot for the diagnosis of osteomyelitis in patients with acute foot infection. This retrospective study evaluated adult patients (age 18 and over) visiting an academic medical center from 1 January 2013 to 31 December 2015 who were imaged with MRI for suspected acute pedal osteomyelitis. Examinations were performed utilizing the departmental standard protocol. All examinations were retrospectively interpreted by five radiologists under two protocols: a reference standard protocol consisting of all non-contrast sequences obtained at initial acquisition and an abbreviated protocol consisting of only coronal T1-weighted and sagittal T2-weighted fast multiplanar inversion-recovery (FMPIR) sequences. Interpretation of the two imaging subsets was separated in time by at least 6weeks for each reader. Each examination was assigned a score to represent one of four diagnostic categories: normal; soft tissue infection without bone changes or bone changes specific to a non-infectious etiology; nonspecific bone marrow changes; or bone changes specific for osteomyelitis. Diagnostic accuracy of both protocols was determined based on clinical diagnosis and treatment of osteomyelitis, and histopathology when available. One hundred and two MRI examinations met inclusion criteria; participants ranged in age from 26 to 91years, with a mean age of 59years. Seventy examinations were performed for male participants (69%) and 32 for female participants (31%). Thirty-five had a confirmed diagnosis of osteomyelitis, while the remainder (n = 67) did not. An average of 6 non-contrast sequences was performed during each examination. The most common protocol (53/102 examinations) was comprised of the following 6 sequences: axial T1-weighted, axial fat-saturated proton density, sagittal T1-weighted, sagittal T2-weighted FMPIR, coronal T1-weighted, and coronal fat-saturated proton density. After patient positioning, the abbreviated protocol sequences (sagittal T2-weighted FMPIR and coronal T1-weighted) were performed in an average total of 8min. The reference standard protocol required an average of 22min to complete 6 sequences. Averaged across all readers, the AUC for the reference standard full protocol and the abbreviated protocols were 0.843 and 0.873, respectively. The difference in AUC between protocols was not statistically significant (p = 0.1297), with the abbreviated protocol showing a non-significantly greater AUC. An abbreviated MRI protocol, including only coronal T1-weighted and sagittal T2-weighted FMPIR images, is non-inferior to standard MRI protocol for the diagnosis of acute pedal osteomyelitis. It should be considered as a diagnostic alternative for reducing imaging time and improving patient access to MRI.

Anatomical Differences Between T2 WI FSE and Proton Density Fat Saturation Sequences in MRI Examination of Knee Joint with Sagittal Slice

Anatomical Differences Between T2 WI FSE and Proton Density Fat Saturation Sequences in MRI Examination of Knee Joint with Sagittal Slice

Reliability and Relationship Between HIP Osteoarthritis Synovitis-Effusion Measurements Using Different MRI Sequences

Purpose: Hip osteoarthritis (OA) is a complex disease and imaging can provide important insight into pathophysiology. For example, magnetic resonance imaging (MRI) can demonstrate bony and soft tissue pathology such as synovitis/effusion in a noninvasive test, with the unique ability to use various sequences to enhance or decrease signals from fat, fluid, and other tissues. However, there is currently little evidence as to which MRI sequences should be used to optimally image synovitis/effusion, and whether the use of contrast agent, which carries risks, is necessary at the hip. Though there are multiple areas to assess in hip OA pathophysiology, in this study we focused on scoring inflammation, particularly measurements of effusion-synovitis. The objective of this study was to compare effusion-synovitis measurements obtained using various MR sequences in terms of reader reliability and inter-sequence correlations Methods: With informed consent and institutional ethics approval, we recruited 97 patients with highly symptomatic hip OA just prior to their clinically requested fluoroscopically guided joint injection, and obtained sagittal hip MRI using Proton Density Fat Saturation (PD FS), T2 Fat Saturation (T2 FS), and post-gadolinium-enhanced VIBE sequences. PD FS was optimal for overall anatomic detail, while T2 FS emphasized fluid signal to directly visualize effusion, and VIBE was performed post gadolinium contrast injection to enhance hyperemic areas, such as in synovitis. To assess inflammation two readers AS and LS, both fellowship trained musculoskeletal radiologists with 8 and 6 years imaging experience respectively, separately measured i) effusion only, as the maximal depth of joint fluid including bright voxels only, on PDFS and T2FS sequences, and ii) synovitis/effusion, as distance from the bone surface to the outer edge of the joint capsule (i.e., effusion plus synovial thickness), on PDFS and post-gadolinium VIBE sequences. Note that the synovium is not well seen on T2FS and effusion is not readily directly visualized without synovium on VIBE. Measurements were performed at the point of widest effusion at the femoral neck (on any slice on which femoral neck marrow was visible). Results: Reliability: Measurements were highly reliable at the femoral neck on all sequences, with inter-observer intraclass correlation coefficients (ICC(3,1)) 0.843 (95% CI 0.798,0.879) for post-gadolinium VIBE synovitis/effusion, 0.873 (0.836,0.902) for PDFS effusion only, 0.846 (0.802,0.881) for PDFS synovitis/effusion, and 0.917 (0.892,0.937) for T2FS effusion only. Correlations: Measurements of effusion correlated highly to each other (PDFS vs. T2FS effusion only, r=0.883, p<0.0001), as did measurements of effusion-synovitis (PDFS vs. VIBE, r=0.762, p<0.0001). The correlation between effusion only and effusion-synovitis was very high on PDFS at r=0.930, p<0.0001). Conclusions: Hip joint effusion/synovial thickness can be measured with high reliability at the largest fluid pocket at the femoral neck. Measurements correlate highly between non-augmented and post-gadolinium sequences, and were more reliably performed on non-augmented PDFS scans than post-gadolinium VIBE. This may be due to higher in-plane resolution on PDFS scans. Future work includes correlation to clinical and imaging outcomes, and to ultrasound measurements of effusion. Overall, the data shows a promising degree of consistency among readers for several sagittal MRI sequences, highlights the importance of high resolution imaging in assessing hip OA with MRI, and raises doubt as to whether gadolinium adds value.

Role of MRI in a Series of Cases with Biceps Injuries of the Shoulder.

Dislocation and injury of the biceps is associated with acute and chronic trauma, degenerative changes, repetitive microtrauma, or injuries associated with recurrent and neglected cases of shoulder dislocation. The cases of displaced biceps injuries are relatively rare (only 1/6th of all rotator cuff injuries). The dislocation of biceps is manifested with pain and restriction of movements. The X-ray shoulder is not of much help in this condition barring for ruling out the fractures of humerus and scapula. Ultrasound is an important tool in the dislocation and shows empty bicipital groove which raises the suspicion of the soft tissue injures. Ultrasound is a problem solving tool when the equivocal findings in MRI (Magnetic Resonance Imaging) in other muscular injuries also. MRI is the modality of choice in these conditions. The bone and anatomy is better visualised on the T1WI images and the pathology is better visualised on the PDFS (Proton Density Fat Saturation) and the STIR (Short Tau Inversion Recovery) images. The role of Non Contrast Computed Tomography (NCCT) is important in associated suspicious bony abnormalities as highlighted in the article. The biceps region is a hidden area and challenging on arthroscopy due to poor visualisation of the extra-articular tendon part. MRI study helps the orthopaedicians for better management of the hidden areas. This series highlights the role of each modality in the diagnosis and management of the biceps lesions.

Detection of Traumatic Bone Marrow Lesions after Knee Trauma: Comparison of ADC Maps Derived from Diffusion-weighted Imaging with Standard Fat-saturated Proton Density-weighted Turbo Spin-Echo Sequences.

Purpose To compare single-shot echo-planar diffusion-weighted imaging-derived apparent diffusion coefficient (ADC) maps with fat-saturated (FS) proton density (PD)-weighted turbo spin-echo (TSE) imaging in the detection of bone marrow lesions (BMLs) after knee trauma. Materials and Methods Institutional review board approval was obtained from Leipzig University. Written informed consent was waived. Three radiologists retrospectively re-examined 97 consecutive patients with reported knee trauma who underwent 1.5-T magnetic resonance (MR) imaging within 90 days of knee trauma. The following sequences were used: (a) sagittal T1-weighted TSE and FS PD-weighted TSE and (b) sagittal T1-weighted TSE and single-shot echo-planar diffusion-weighted imaging-derived ADC mapping. BMLs on the lateral and medial femoral condyle, lateral and medial aspect of the tibial plateau, and patella were documented. Volumetry was performed on BMLs with a thickness of at least 15 mm (major BMLs). ADC values were measured in intact bone marrow and major BMLs. A McNemar test and t tests were used as appropriate to test for significant differences between BML number and volume at an α level of .05. Results Significantly more patients showed at least one BML on ADC maps (98%, 95 of 97 patients) than on FS PD-weighted TSE images (86%, 84 of 97 patients) (P < .001). Of the affected regions detected on FS PD-weighted TSE images, 97% (170 of 175 regions) were identified consistently on ADC maps. Only 58% of the affected regions detected on ADC maps (170 of 293 regions) were identified on FS PD-weighted TSE images (P < .001). Median volume of concordant major BML was approximately two times larger on ADC maps (81 cm3) than on FS PD-weighted TSE images (39 cm3) (P < .001). The ADC values of intact bone marrow and BMLs did not overlap. Conclusion ADC maps are more sensitive than corresponding FS PD-weighted TSE images for detection of BML after knee trauma and allow detection of significantly more and larger BMLs. ADC map evaluation improves diagnostic performance in regions with insufficient spectral fat saturation, such as the patella. © RSNA, 2016 Online supplemental material is available for this article.

A new MRI grading system for chondromalacia patellae.

Background Chondromalacia patellae is a very common disorder. Although magnetic resonance imaging (MRI) is widely used to investigate patellar cartilage lesions, there is no descriptive MRI-based grading system for chondromalacia patellae. Purpose To propose a new MRI grading system for chondromalacia patellae with corresponding high resolution images which might be useful in precisely reporting and comparing knee examinations in routine daily practice and used in predicting natural course and clinical outcome of the patellar cartilage lesions. Material and Methods High resolution fat-saturated proton density (FS PD) images in the axial plane with corresponding T2 mapping images were reviewed. A detailed MRI grading system covering the deficiencies of the existing gradings has been set and presented on these images. Two experienced observers blinded to clinical data examined 44 knee MR images and evaluated patellar cartilage changes according to the proposed grading system. Inter- and intra-rater validity testing using kappa statistics were calculated. Results A descriptive and detailed grading system with corresponding FS PD and T2 mapping images has been presented. Inter-rater agreement was 0.80 (95% confidence interval [CI], 0.71-0.89). Intra-rater agreements were 0.83 (95% CI, 0.74-0.91) for observer A and 0.79 (95% CI, 0.70-0.88) for observer B (k-values). Conclusion We present a new MRI grading system for chondromalacia patellae with corresponding images and good inter- and intra-rater agreement which might be useful in reporting and comparing knee MRI examinations in daily practice and may also have the potential for using more precisely predicting prognosis and clinical outcome of the patients.

Analisis Informasi Anatomi antara Sekuens T2WI FSE dan Proton Density Fat Saturation pada Pemeriksaan MRI Knee Joint Potongan Sagital (Studi pada Anterior Cruciate Ligament (ACL) dan Posterior Cruciate Ligament (PCL))

Background: There are clinical situations that radiology physicians need to assess Anterior Cruciate Ligament (ACL) and Posterior Cruciate Ligament (PCL) clearly with the two typical sequences (T2WI FSE sequence and Proton Density Fat Saturation). However, a slight difference in using the applied sequences will result different levels of image quality information. The aim of this study is to compare clinical manifest in anatomical information on the resulted images between T2WI FSE sequence and Proton Density Fat Saturation and to define the best sequence that fit to reveal ACL and PCL of the knee joint..Methods: The research was an experimental quasy. 20 sagital slices of the knee jointMRI were acquired from 10 volunteers who underwent MRI examinations with the two methods (T2WI FSE and Proton Density Fat Saturation). 3 experienced radiology physicians blended in the image scoring when review ACL and PCL appearances on knee MRI images. Inter-observer suitability was checked with Kappa test. A non-parametric Wilcoxon analyses was the statistical tool to test the null hypothesis.Results: The result showed a significant difference in anatomical information of ACL and PCL when T2WI FSE and Proton Density Fat Saturation sequences applied on the MRI of the knee jointsagital slices (p-value 0,05). The mean rank of T2WI FSE was better than Proton Density Fat Saturation which contributed to the value at 4,50. There was an increase in signals that lead to ACL and PCL appear to be more hyper-intens compared to sorrounding organs in general, except the border line of PCL. By this means, it was useful for evaluating the patient whose particularly with ACL post-grafting.Conclusion: There was the difference in anatomical information between T2WI FSE sequence and Proton Density Fat Saturation on MRI knee jointwith sagital slices for ACL and PCL studies. T2WI FSE sequence was the best method for showing anatomical information of ACL and PCL, although a relative low signal still occured from border line of PCL.