Machine learning based analytics of micro-MRI trabecular bone microarchitecture and texture in type 1 Gaucher disease.

Type 1 Gaucher disease (GD) is an autosomal recessive lysosomal storage disease, affecting bone metabolism, structure and strength. Current bone assessment methods are not ideal. Semi-quantitative MRI scoring is unreliable, not standardized, and only evaluates bone marrow. DXA BMD is also used but is a limited predictor of bone fragility/fracture risk. Our purpose was to measure trabecular bone microarchitecture, as a biomarker of bone disease severity, in type 1 GD individuals with different GD genotypes and to apply machine learning based analytics to discriminate between GD patients and healthy individuals. Micro-MR imaging of the distal radius was performed on 20 type 1 GD patients and 10 healthy controls (HC). Fifteen stereological and textural measures (STM) were calculated from the MR images. General linear models demonstrated significant differences between GD and HC, and GD genotypes. Stereological measures, main contributors to the first two principal components (PCs), explained ~50% of data variation and were significantly different between males and females. Subsequent PCs textural measures were significantly different between GD patients and HC individuals. Textural measures also significantly differed between GD genotypes, and distinguished between GD patients with normal and pathologic DXA scores. PCA and SVM predictive analyses discriminated between GD and HC with maximum accuracy of 73% and area under ROC curve of 0.79. Trabecular STM differences can be quantified between GD patients and HC, and GD sub-types using micro-MRI and machine learning based analytics. Work is underway to expand this approach to evaluate GD disease burden and treatment efficacy.

Diagnostic utility of MRI and MR arthrography for detection of ligamentum teres tears: a retrospective analysis of 187 patients with hip pain.

OBJECTIVE: The purpose of this study was to compare the diagnostic utility of MRI and MR arthrography for ligamentum teres tears in patients with hip pain. MATERIALS AND METHODS: This is a retrospective study involving 187 patients who underwent MRI or MR arthrography for hip pain. This study included 103 male and 84 female patients with average age of 39 years. Three experienced musculoskeletal radiologists reviewed the MRI and MR arthrography studies to assess the ligamentum teres tears. The criteria for diagnosing normal or abnormal (i.e., ligament), partial or degenerative or complete tear of ligamentum teres were defined on the basis of several imaging characteristics. The MRI and MR arthrography results were correlated with arthroscopy, which served as the reference standard. Statistical analysis was performed to calculate the diagnostic yield, diagnostic accuracy, and diagnostic performance of MRI and MR arthrography in detecting partial or degenerative and complete ligamentum teres tears. Overall comparative performance of MRI and MR arthrography was assessed using Kruskal-Wallis test. RESULTS: For partial ligamentum teres tears, MRI showed lower sensitivity, specificity, and positive predictive value (0.41, 0.75, and 0.32, respectively) as compared to MR arthrography (0.83, 0.93, and 0.76, respectively), whereas the negative predictive value of MRI (0.82) was comparable to that of MR arthrography (0.95). No statistically significant difference (p < 0.05) could be identified between MRI and MR arthrography for diagnosing complete ligamentum teres tears. CONCLUSION: Hip MRI is equally suited for diagnosis of complete ligamentum teres tears when compared with MR arthrography. By contrast, for partial or degenerative ligamentum teres tears, MR arthrography offers the advantage of better arthroscopic correlation.

Tarsal navicular bone size in diabetics: radiographic assessment.

OBJECTIVE: To test the anecdotal observation that isolated navicular collapse is associated with diabetes mellitus, we quantified the size of the tarsal navicular bone in subjects with and without diabetes and tested for association of size with age, height, weight, body mass index (BMI), gender, smoking, bone mineral density (BMD), duration, and level of control of diabetes. MATERIALS AND METHODS: Ankle radiographs of 200 patients (122 female; 78 male; mean age 58 years [27-89]), 100 with type II diabetes and 100 age- and gender-matched controls were selected and reviewed. The anteroposterior (AP) dimension of the mid-navicular bone was measured from lateral radiographs. For standardization, the supero-inferior (SI) dimension of the calcaneal was measured and the navicular-calcaneus ratio calculated. Statistical evaluation included independent sample t tests and linear regression analyses. RESULTS: Diabetic subjects had a significantly smaller navicular AP dimension and navicular-calcaneus ratio compared with controls (p = 0.02 and p = 0.0001 respectively). Age, gender, height and duration of diabetes had no association with the navicular-calcaneus ratio. The navicular-calcaneus ratio was inversely correlated with weight (p = 0.01) and BMI (p < 0.001) and directly correlated with smoking (p = 0.04). Reliability of the radiographic measurements was excellent (ICC 0.80-0.97; SEM 0.3-1.7 mm). CONCLUSION: The anteroposterior dimension of the navicular is smaller in type II diabetic subjects than in age- and gender-matched controls. We hypothesize that this might be due to navicular collapse of multifactorial causes.

Radiographic evaluation of INBONE total ankle arthroplasty: a retrospective analysis of 30 cases.

OBJECTIVES: The objectives of this work were to retrospectively describe the radiographic assessment of INBONE total ankle arthroplasty in 30 patients using validated linear and angular measurements and to correlate these findings with the final surgical outcome over a 2-year follow-up period. MATERIALS AND METHODS: Thirty consecutive patients (21 females, nine males; mean age, 64.8 years) underwent INBONE total ankle arthroplasty during 2007-2011. After IRB approval, a retrospective pre- and post-operative radiographic analysis was performed using validated linear and angular measurements. The pre- and post-operative assessment included the tibial angle, talar angle, tibial slope, and coronal deformity. Post-operative measurements also included the talocalcaneal angle, joint space height, talar height, lateral tibial component angle, lateral talar component angle, and anteroposterior tibial component angle. The post-operative bone loss, subluxation, positioning, and subsidence were also assessed. Statistical analysis was performed using two-sample t test and Fisher's exact test. RESULTS: Out of 30 patients, 23 had a successful clinical outcome with intact prosthesis at a 2-year follow-up. The only variables with significant correlation (p < 0.05) to the post-surgical outcome were the lateral talar component angle (p = 0.002) and the mean difference between pre- and post-operative tibial slope (p = 0.001). The coronal deformity had significant mean difference between pre- and post-operative values (p < 0.001); however, it lacked a significant correlation to the final surgical outcome. None of the categorical variables had a significant correlation with post-surgical outcome. CONCLUSIONS: In our retrospective study, only the lateral talar component angle and the mean difference between the pre- and post-operative tibial slope had significant correlation with post-surgical outcome in INBONE ankle arthroplasty. These measurements may be helpful in radiographic assessment of the INBONE ankle arthroplasty.

Bilateral spontaneous rupture of the flexor digitorum superficialis and the flexor digitorum profundus in a diabetic patient.

Closed flexor tendon rupture is an unusual condition that has been described in association with distinct underlying disease processes. Several theories have been implicated in the pathogenesis, including labor-associated forceful usage, gender, and age. The effect of diabetes on the native tendon tissue is not yet fully understood; however, the metabolic perturbations of diabetes have been shown to result in detrimental changes to the musculoskeletal system. We report an unusual case of bilateral spontaneous rupture of the flexor digitorum superficialis and flexor digitorum profundus in a 58-year-old woman with Type 2 diabetes mellitus. The clinical course, radiographic findings, and the biomechanical factors and mechanisms through which diabetes may affect the native tendon are presented.

MRI of the cuboid bone: analysis of changes in diabetic versus non-diabetic patients and their clinical significance.

OBJECTIVES: (1) To investigate the association between diabetes and marrow changes in the cuboid; and (2) to evaluate the influence of age, gender, body mass index (BMI) and use of insulin in the occurrence of marrow changes in the cuboid. RESEARCH DESIGN AND METHODS: MR and X-ray foot examinations of 237 patients [94 males, 143 females; mean age, 47.1 years (range 16-93 years)], five of whom underwent bilateral examinations, were reviewed. MR and radiographic studies were analyzed for the presence of marrow edema and fractures in the cuboid. Findings were correlated with demographic data (age, gender) and clinical information (BMI and use of insulin). RESULTS: Two hundred and forty two feet - 69 diabetic and 173 non-diabetic - were retrospectively evaluated. There was a higher prevalence of marrow edema and fractures in the diabetic cuboid (n=31, 45%) compared to non-diabetic cuboid (n=25, 14%, p=0.02). A fracture line was seen in fourteen (20%) diabetic cuboid bones compared to 4 (2%) in non-diabetic cuboid bones (p<0.0001). Eleven (79%) cases of cuboid fractures in the diabetic population were radiographically occult. Multivariate data analysis revealed an adjusted odds ratio of 4.416 (95% CI; 2.307, 8.454) for the relationship between marrow changes (edema and fractures) in the cuboid and diabetes. For each year of age, the odds of changes in the cuboid increased by 2.2% (95% CI; 1.001, 1.044). CONCLUSION: Despite not bearing weight, the cuboid bone is more vulnerable to marrow edema and fractures in diabetic patients compared to non-diabetic patients. Age seems to be an influential factor.

The Guyon's canal in perspective: 3-T MRI assessment of the normal anatomy, the anatomical variations and the Guyon's canal syndrome.

PURPOSES: (1) To revisit the anatomical boundaries of the canal, its contents and its two channels, (2) to describe the anatomical variations of the canal's borders and the variations of its contents, and (3) to discuss the clinical relevance of the Guyon's canal syndrome. METHODS: Two hundred and fifty MR wrists examinations were reviewed. MR spin echo T1-weighted axial slices were used to analyze the Guyon's canal. The anatomical boundaries, the cross-sectional area and length of the canal were calculated. The anatomical variations of the canal's walls and contents and their prevalence were sought. Changes related to Guyon's canal syndrome were also evaluated. RESULTS: From the 250 wrists, the anatomy of the Guyon's canal was normal in 168 (67.2%) wrists; 73 (29.2%) wrists presented with anatomical variations; and 9 (3.6%) wrists had derangements causing Guyon's canal syndrome. The cross-sectional area of the canal was 33 ± 11 mm² proximally and 45 ± 19 mm² distally. The canal's length was approximately 40 ± 4 mm. Among the 73 wrists with anatomical variations, there were aberrant muscles in 39 (53.4%) wrists, multiple ulnar nerve branching in 22 (30%) cases, increased amount of fat tissue inside the canal in 9 (12.3%) cases and hypoplastic hamulus in 3 (4.1%) cases. There were 9 (3.6%) symptomatic wrists with clinical and radiological features attributed to Guyon's canal syndrome. CONCLUSION: MRI is an excellent modality for the evaluation of the Guyon's canal.

Interaction between dietary conjugated linoleic acid and calcium supplementation affecting bone and fat mass.

Dietary conjugated linoleic acid (CLA) has shown wide biologically beneficial effects, such as anticancer, antiatherosclerotic, antidiabetic, immunomodulating, and antiobesity effects. However, the effects of CLA on total body ash, reflective of bone mineral content, have not been consistent. We hypothesized that the inconsistency of the CLA effect on ash may be linked to interaction between CLA and dietary calcium levels. Thus, we investigated the effects of CLA on body ash in conjunction with various calcium levels. Male ICR mice were fed three different levels of calcium (0.01, 0.5, and 1%) with or without 0.5% CLA for 4 weeks for Experiment 1 and separate CLA isomers at 0.22% level with 1% calcium in Experiment 2. CLA feeding reduced body fat regardless of dietary calcium level, whereas CLA supplementation increased body ash compared to control only in animals fed the 1% calcium. In Experiment 2 it was confirmed that this observation was associated with the trans-10, cis-12 CLA isomer, but not with the cis-9, trans-11 isomer. CLA administration with 1% dietary calcium significantly improved total ash percent (%) in femurs, confirming that CLA has the potential to be used to improve bone mass.

Tibial subacute osteomyelitis with intraosseous abscess: an unusual complication of intraosseous infusion.

Intravenous (IV) access is a critical step in patient care, especially in the emergency and/or trauma setting. Recently, intraosseous (IO) infusion has re-emerged as a recommended alternative to central venous access in both the pediatric and the adult patient. We present the case of an older adult male patient several months after emergency tibial IO infusion, now with left shin pain, and the MRI and culture findings diagnostic of subacute osteomyelitis with IO abscess, an unusual complication of IO infusion.

MRI of the Achilles tendon: a comprehensive review of the anatomy, biomechanics, and imaging of overuse tendinopathies.

The Achilles tendon is the largest tendon in the body; it plays an important role in the biomechanics of the lower extremity. It can withstand great forces, especially during sporting exercises and pivoting. The pathologies related to the Achilles tendon are diverse and many carry undesirable consequences. We retrospectively analyzed the images of patients who underwent examinations of the ankle/foot region to review the anatomy of the Achilles tendon and its surroundings and to search for pathologies consistent with overuse injuries. The anatomy of the tendon is described from origin to insertion. The imaging characteristics of the Achilles tendon including pitfalls are reviewed. We also describe the Achilles overuse injuries: paratenonitis, tendinosis, tendon tear, atypical tear, tendon re-tear, retrocalcaneal bursitis, retro-Achilles bursitis, Haglund's deformity, and tendon calcification. We present other entities like tendon ossification and failed transplanted Achilles tendon, with emphasis on MRI.

Recombinant human bone morphogenetic protein 2-induced heterotopic ossification of the retroperitoneum, psoas muscle, pelvis and abdominal wall following lumbar spinal fusion.

A 45-year-old man presented with vertebral collapse at L5 as an initial manifestation of multiple myeloma and underwent spinal fusion surgery using recombinant human bone morphogenetic protein-2 (rhBMP-2). Subsequent computed tomography (CT) scans and X-rays revealed heterotopic ossification of the left psoas muscle, pelvis, and anterior abdominal wall. While the occurrence of heterotopic ossification has previously been reported when rhBMP-2 has been used for spinal fusion surgery, this case demonstrates that it can occur to a much greater degree than previously seen.

Analysis of the patellofemoral region on MRI: association of abnormal trochlear morphology with severe cartilage defects.

OBJECTIVE: The objective of our study was to assess patellofemoral measurements on MRI and to correlate the measurements with different grades of cartilage defect. MATERIALS AND METHODS: Axial and sagittal MR images of 100 patients with various pathologic knee conditions were analyzed. The patients were divided into two age groups: < 40 years and > or = 40 years. Patellar measurements of facet asymmetry, the patella-to-patellar tendon ratio, and the amount of patellotrochlear cartilage overlap were obtained in each subject. Similarly, trochlear measurements of the ventral trochlear prominence, trochlear depth, facet asymmetry, sulcus angle, and lateral inclination were obtained. Axial and sagittal MR images were reviewed to grade the severity of focal cartilage defects in the patellofemoral region on the basis of the depth of the lesion. Measurements in knees without a chondral defect were compared with knees with mild and severe chondral defects. RESULTS: There was a statistically significant difference in the trochlear measurements of the ventral prominence (p = 0.012), trochlear depth (p = 0.001), sulcus angle (p = 0.208), and lateral inclination (p = 0.154) between normal knees and knees with severe cartilage defects in patients younger than 40 years. No significant difference was seen in the patellar measurements between normal knees and knees with severe cartilage defects. CONCLUSION: There is an association between abnormal trochlear morphology and severe patellofemoral cartilage defects in patients younger than 40 years.

Multiple occult wrist bone injuries and joint effusions: prevalence and distribution on MRI.

This study aims (1) to assess the prevalence and distribution of multiple occult injuries of the carpal bones and the distal forearm in patients with wrist pain and negative radiographs following trauma and (2) to evaluate the distribution and significance of joint effusions in the wrists with multiple osseous injuries. One hundred and thirty-one subjects, 74 men and 57 women, were consecutively examined in two institutions. All were acute trauma patients with negative X-rays whose clinical examination suggested possible fracture at the wrist or the distal forearm. Magnetic resonance (MR) wrist imaging was performed with and without fat saturation sequences. The MR images were analysed for detection of occult trabecular contusions and cortical discontinuity in the carpus, the distal forearm and the metacarpal bases. The prevalence and distribution of the injuries were assessed along with the distribution of joint effusions. Eight patients were excluded due to inadequate image quality. Two patients had bilateral injury. A total of 125 wrists were analysed. Seventy-eight (62.4%) wrists had occult bone injuries. Among these 78, 53 (68%) wrists had more than one injured bone. Twenty-five wrists (32%) had one injured bone. The highest number of injured bones per wrist was six. Injuries with a visible fracture line were seen in 29 (37.1%) wrists on MRI. The distal radius was the most frequent location for occult fracture line (11 cases). The injuries without a fracture line (contusion) were present in 49 (63%) wrists; they were detected more frequently in the scaphoid (35 cases). The lunate (29 cases) and the triquetrum (26 cases) were almost equally affected. The bone that was less frequently injured was the pisiform (four cases). Joint effusions were present in all 53 wrists with multiple bone lesions but more often situated in the ulnocarpal space [27 (50.3%) wrists]. There was no correlation between effusions in multiple locations (grades III and IV) and multiple bone injuries. This study revealed the presence of multifocal trabecular contusions without correlation with increased joint effusions in patients with negative radiographs and persistent pain. The clinical significance of these findings deserves further investigation.

Congenital absence of the semimembranosus muscle: case report.

Congenital anomalies of the muscles of the lower extremity are rare. A case of complete absence of the semimembranosus muscle incidentally found with magnetic resonance imaging is reported. The patient was a 55-year-old female presenting with knee pain and no previous history of trauma. Clinical and imaging findings were consistent with meniscal tears. Two cases of uncommon distal insertion of the semimembranosus tendon are also described to illustrate the anatomical variations in this area. The anatomical and biomechanical relations between the semimembranosus muscle and the posteromedial corner of the knee are examined in this case report.

MRI of the median nerve and median artery in the carpal tunnel: prevalence of their anatomical variations and clinical significance.

OBJECTIVE: Anatomical variations of the median nerve and the persistent median artery (PMA) in the carpal tunnel (CT) are important to understand for their clinical and surgical significance. The aim of this cohort retrospective study was to investigate the prevalence of aberrant median nerve branches and persistent median artery in the CT in a selected population using magnetic resonance imaging (MRI). MATERIALS AND METHODS: MR wrist images of 194 patients, 77 males and 117 females, aged 12-80 years were randomly selected and retrieved from our clinical and radiology data base. The MR examinations were performed using either 1.5-T or 3.0-T magnet using a cylindrical receive-transmit wrist coil for all cases. The course of the bifurcation of the median nerve was followed on axial T2-weighted and axial proton density fat saturated images and classified as either proximal, within, or distal to the CT. The flexor retinaculum proximally and the metacarpal bases were used as anatomic landmarks to subdivide these three categories. In addition, the median artery was searched in order to assess the prevalence of its presence inside the CT. A total of 194 wrists were analyzed by two musculoskeletal-trained radiologists. They were blinded on the population age, gender, and the sides of the wrists. Agreement was reached by consensus. RESULTS: Among the 194 wrists, there was bifurcation of the nerve proximal to the CT in 12 (6.1%) wrists. There was nerve bifurcation within the CT in 36 (18%) wrists. Nerve bifurcation distal to the CT was more frequently observed, occurring in 147 (75%) wrists. Only one nerve trifurcation was seen within the CT. There was no gender predominance for the nerve bifurcation within the tunnel. There were 107 right wrists and 87 left wrists. On the right side, bifurcation of the nerve within the CT was seen in 21 (19.6%) wrists; and on the left side bifurcation of the nerve was present in 15 (17.2%) wrists. Statistically, we found no significant difference in the prevalence of the bifid nerve within the tunnel in the subgroups based on age, gender, or side of the wrists. A persistent median artery (PMA) within the tunnel was observed in 21 (11%) wrists--10 males and 11 females. Of these, four (19%) cases were presented with coexistent PMA and bifid median nerve within the tunnel. Statistically, we found that the two variations are not independent traits, and their covariance is not null. CONCLUSION: There was a high prevalence of bifid median nerve (19%) and PMA (11%) within the tunnel regardless of gender or age. The PMA was more frequent on the left side.

Patella alta: lack of correlation between patellotrochlear cartilage congruence and commonly used patellar height ratios.

OBJECTIVE: The purposes of this study were to assess the degree of patellotrochlear chondral overlap (patellotrochlear index), correlate it with the Insall-Salvati and modified Insall-Salvati indexes, and determine the association between these measurements and patellofemoral chondral defects. MATERIALS AND METHODS: Sagittal 1.5-T and 3-T MR images of 100 consecutively registered patients with symptoms were analyzed, and the Insall-Salvati index, modified Insall-Salvati index, patellotrochlear index, and patellophyseal index (ratio of the height of patella above the physeal line to the length of the patellar articular cartilage) were calculated. The upper and lower limits of 2 SDs were used to define patella alta and baja, and the correlation coefficient curves were plotted to compare techniques. The indexes in normal knees were compared with those in knees with severe chondral defects. RESULTS: The mean patellotrochlear index was 0.49 +/- 0.15 (SD) (range, 0-0.88). On the basis of calculation of 2 SDs, patella alta was determined to have a patellotrochlear index less than 0.18 and patella baja, an index greater than 0.80. Weak correlation was found between the measured patellotrochlear index and Insall-Salvati index (r = -0.224) and between the patellotrochlear index and modified Insall-Salvati index (r = -0.073). A strong correlation was found between the patellotrochlear index and patellophyseal index (r = -0.813). A statistically significant (p < 0.05) difference in the modified Insall-Salvati index and patellophyseal index was found between knees with normal and those with severe cartilage defects. CONCLUSION: Our results indicate that the commonly used Insall-Salvati and modified Insall-Salvati indexes do not correlate with patellotrochlear articular cartilage congruence. We did find an association between the modified Insall-Salvati and patellophyseal indexes and the presence of severe chondral defects.

Adult onset glycogen storage disease type II (adult onset Pompe disease): report and magnetic resonance images of two cases.

Glycogen storage disease type II (GSDII), also referred to as Pompe disease or acid maltase deficiency, is a rare inherited condition caused by a deficiency in acid alpha-glucosidase (GAA) enzyme activity (Tinkle andLeslie. GeneReviews, 2008. http://www.genetests.org). The condition is often classified by age of presentation,with infantile and late onset variants (Laforet et al. J Neurology 55:1122-8, 2000). Late onset tends to present with progressive proximal muscle weakness and respiratory insufficiency (Winkel et al. J Neurology 252:875-84, 2005). We report two cases of biopsy confirmed adulto nset GSDII, along with key Magnetic Resonance (MR) images.

Variations in normal sternoclavicular joints; a retrospective study to quantify SCJ asymmetry.

OBJECTIVE: A wide degree of normal anatomical variation can occur at the sternoclavicular joint (SCJ). On occasion, this has led to concern for a pathological process, potentially resulting in a costly work-up, unnecessary patient worry and invasive diagnostic procedures such as biopsy. The purpose of this study was to determine the normal range of anatomical variation at sternoclavicular joints. MATERIALS AND METHODS: One hundred four consecutive patients with chest CT done at our institution were selected. Patients with clear SCJ pathology, chest wall abnormality, CT slice thickness greater than 5 mm and sternotomy wires, were excluded. Chart review was done and showed no SCJ symptoms/signs. We measured the SCJ space, maximum clavicular head diameter within the joint and the distance from manubrium to the anterior margin of the clavicular head. RESULTS: Left and right SCJ space ranged from 0.2 to 1.37 cm. The difference (delta or asymmetry) between left SCJ space and right SCJ space ranged from 0 (symmetrical) to 0.57 cm in 104 cases. Left and right clavicular head diameter ranged from 1.2 to 3.7 cm with left/right asymmetry (delta) ranging from 0 (symmetrical) to 1 cm. Manubrium to anterior margin of clavicular head ranged from 0.1 to 2.13 cm with delta ranging from 0 to 0.8 cm. Thirty-three patients demonstrated gas in the joint, five had poor articulation and four had calcification in the joint. CONCLUSION: Greater than 10% of patients show substantial asymmetry in the sternoclavicular joints, which may be misinterpreted as pathological. Gas in the joint is a common phenomenon therefore should not be an indication for further work-up in asymptomatic patients and likely excludes the presence of effusion.

Cement Pulmonary Embolus Complicating Percutaneous Vertebroplasty.

We present the case of a 63-year-old woman who suffered a cement pulmonary embolus that resulted from methylmethacrylate extravasation into the paravertebral venous plexus during percutaneous vertebroplasty. We discuss the radiographic diagnosis and strategies for prevention and treatment.