Special Scientific Session of the International Skeletal Society, San Diego, California, September 2011

Abstracts

Special Scientific Session of the International Skeletal Society, San Diego, California, September 2011     

Evaluation of pericardial sinuses and recesses with 2-, 4-, 16-, and 64-row multidetector CT

Purpose

The aim of this study was to describe visualisation rate and appearance of all pericardial sinuses and recesses and to evaluate whether there is a significant difference between visualisation of these sinuses and recesses on 2-, 4-, 16- and 64-slice multidetector computed tomography (MDCT).

Materials and methods

We retrospectively analysed 588 MDCT scans of the chest obtained with a protocol for pulmonary embolism.

Results

The visualisation rate of any pericardial recess was 85.2%. The rates on 2-, 4-, 16- and 64-slice MDCT were 74.7%, 90.6%, 90.3% and 88.7%, respectively. There was a statistically significant difference in visualisation rates of pericardial recesses between 2-slice MDCT and other MDCT systems (p<0.01). Age, and 4-, 16- and 64-slice MDCT versus 2-slice MDCT and the presence of pleural effusion appeared as significant predictors of the presence of any recess.

Conclusions

Visualisation rates of pericardial recesses are higher with 4-, 16- and 64-slice MDCT than with 2-slice MDCT. Therefore, radiologists need to be familiar with the different appearances of pericardial recesses on MDCT to avoid misdiagnosis.     

Correlation of single leg vertical jump, single leg hop for distance, and single leg hop for time

Objectives

To determine the correlation among three functional tests: single leg vertical jump (SLVJ), single leg hop for distance (SLHD), and single leg hop for time (SLHT).

Design

Prospective correlational investigation.

Setting

University research laboratory.

Participants

Forty healthy men (n = 19) and women (n = 21) between the ages of 18 and 30 (23.9 ± 2.0 years).

Main outcome measures

SLVJ was measured using the Vertec. SLHD was measured using a standard tape measure. SLHT was measured over a 10-m course using a standard stopwatch.

Results

The strongest correlation was between SLHT and SLHD, −0.89 and −0.89 for dominant and non-dominant lower extremities (LE), respectively. The weakest pairwise correlation was between SLVJ and SLHT, −0.71 and −0.63 for dominant and non-dominant LE, respectively. The correlation between SLVJ and SLHD was 0.74 and 0.71 for dominant and non-dominant LE, respectively.

Conclusion

There is a strong correlation between SLHT and SLHD, suggesting that each test measures similar constructs of function, while the modest correlation between SLVJ and SLHT suggest these two tests do not measure the same functional components, and could be paired as outcome measures for the clinical assessment of lower extremity function.     

32nd Annual Meeting of The Japanese Society of Neuroradiology 26-28 February 2003, Tsukuba,Ibaraki, Japan

Abstracts

32nd Annual Meeting of The Japanese Society of Neuroradiology 26-28 February 2003, Tsukuba, Ibaraki, Japan     

Choline metabolism, proliferation, and angiogenesis in nonenhancing grades 2 and 3 astrocytoma

Purpose:

To study choline metabolism in biopsies from nonenhancing Grade 2 (AS2) and Grade 3 (AS3) astrocytomas to determine whether (1) phosphocholine (PC) dominates in AS3, and (2) PC is associated with proliferation or angiogenesis. PC and glycerophosphocholine (GPC) are involved in phospholipid metabolism that accompanies mitosis. PC is the predominant peak in Grade 4 astrocytoma (GBM) while GPC dominates in AS2.

Materials and Methods:

We used high resolution magic angle spinning magnetic resonance spectroscopy to compare the concentrations of 10 metabolites in 41 biopsies (16 AS2 and 25 AS3) from 24 tumors. Immunohistochemistry was performed on paired biopsies to determine the cell density, Ki‐67 proliferation index, and vascular endothelial growth factor (VEGF) angiogenic marker expression.

Results:

AS3 had higher PC than AS2; however, the PC:GPC was less than 1 in all cases irrespective of tumor grade. Within tumors, GPC increased with Ki‐67 and PC and tCho increased with cell density. There was no association between any choline compound and VEGF.

Conclusion:

These data suggest that PC:GPC less than 1 is not unique to low grade glioma. Furthermore, the PC concentration that is a marker of aggressive glial tumors is not tightly linked to cell proliferation or angiogenesis in nonenhancing astrocytomas. J. Magn. Reson. Imaging 2011;33:808–816. © 2011 Wiley‐Liss, Inc.     

MRI findings in the lumbar spines of asymptomatic, adolescent, elite tennis players

Objective

To describe magnetic resonance imaging (MRI) findings in the lumbar spine in asymptomatic elite adolescent tennis players, to serve as the baseline for a future prospective longitudinal cohort study.

Design

Observational study.

Setting

Institutional, national tennis centre.

Participants

33 asymptomatic elite adolescent tennis players, mean (SD) age, 17.3 (1.7) years (18 male, 15 female).

Methods

Sagittal T1, T2, STIR, and axial T2 weighted MRI images were reviewed for the presence of abnormalities by two radiologists in consensus. Abnormalities included disc degeneration, disc herniation, pars lesions (fracture or stress reaction), and facet joint arthropathy.

Results

Five players (15.2%) had a normal MRI examination and 28 (84.8%) had an abnormal examination. Nine players showed pars lesions (10 lesions; one at two levels) predominately at the L5 level (9/10, L5; 1/10, L4). Three of the 10 lesions were complete fractures; two showed grade 1 and one grade 2 spondylolisthesis, both of which resulted in moderate narrowing of the L5 exit foramen. There were two acute and five chronic stress reactions of the pars. Twenty three patients showed signs of early facet arthropathy occurring at L5/S1 (15/29 joints) and L4/5 (12/29 joints). These were classified as mild degeneration (20/29) and moderate degeneration (9/29), with 20/29 showing sclerosis and 24/29 showing hypertrophy of the facet joint. Synovial cysts were identified in 14 of the 29 joints. Thirteen players showed disc desiccation and disc bulging (mild in 13; moderate in two) most often at L4/5 and L5/S1 levels (12 of 15 discs).

Conclusions

Abnormalities were frequent, predominately in the lower lumbar spine, almost exclusively at L4/5 and L5/S1 levels. Pars injuries and facet joint arthroses were relatively common.     

Assessment of iron distribution between liver,spleen, pancreas,bone marrow,and myocardium by means of R2 relaxometry with MRI in patients with β‐thalassemia major

Purpose

To investigate the correlation between the degree of hepatic, splenic, pancreatic, vertebral bone marrow (VBM), and myocardial siderosis, as expressed by relaxation rate (R2 = 1/T2) values, in patients with thalassemia.

Materials and Methods

R2 relaxation rate values of liver, spleen, VBM, pancreas, and myocardium were estimated in 68 consecutive transfusion‐dependent patients with β‐thalassemia major and 10 healthy controls using a respiratory triggered 16‐echo Carr‐Purcell‐Meiboom‐Gill (CPMG) spin echo sequence.

Results

Hepatic R2 values were significantly increased in all 68 patients; VBM, pancreatic, and myocardial R2 values were increased in 67/68, 35/47, and 47/61 patients, whereas five patients showed decreased pancreatic R2 attributed to fatty degeneration. Of the 39 nonsplenectomized patients, splenic R2 values were decreased in 30 and normal in nine patients. Hepatic R2 values correlated with splenic (r = 0.63, P < 0.001), VBM (r = 0.52, P < 0.001), but not with myocardial and pancreatic R2 values.

Conclusion

Despite positive correlations between the degree of hepatic, splenic, and VBM siderosis, as expressed by respective R2 values, there was variability of iron distribution patterns in thalassemic patients. Unpredictable patterns of iron distribution may be seen, such as normal signal of the spleen in the presence of siderotic liver, resembling primary hemochromatosis. Fatty degeneration of the pancreas was not uncommon. J. Magn. Reson. Imaging 2009;29:853–859. © 2009 Wiley‐Liss, Inc.     

NMR properties of human median nerve at 3 T: Proton density,T1, T2, and magnetization transfer

Purpose

To measure the proton density (PD), the T1 and T2 relaxation time, and magnetization transfer (MT) effects in human median nerve at 3 T and to compare them with the corresponding values in muscle.

Materials and Methods

Measurements of the T1 and T2 relaxation time were performed with an inversion recovery and a Carr‐Purcell‐Meiboom‐Gill (CPMG) imaging sequence, respectively. The MT ratio was measured by acquiring two sets of 3D spoiled gradient‐echo images, with and without a Gaussian saturation pulse.

Results

The median nerve T1 was 1410 ± 70 msec. The T2 decay consisted of two components, with average T2 values of 26 ± 2 msec and 96 ± 3 msec and normalized amplitudes of 78 ± 4% and 22 ± 4%, respectively. The dominant component is likely to reflect myelin water and connective tissue, and the less abundant component originates possibly from intra‐axonal water protons. The value of proton density of MRI‐visible protons in median nerve was 81 ± 3% that of muscle. The MT ratio in median nerve (40.3 ± 2.0%) was smaller than in muscle (45.4 ± 0.5%).

Conclusion

MRI‐relevant properties, such as PD, T1 and T2 relaxation time, and MT ratio were measured in human median nerve at 3 T and were in many respects similar to those of muscle. J. Magn. Reson. Imaging 2009;29:982–986. © 2009 Wiley‐Liss, Inc.     

Myocardial T2* is not affected by ageing, myocardial fibrosis, or impaired left ventricular function

Purpose

To evaluate the influence of alterations in myocardial structure and function from increasing age, myocardial fibrosis, or impaired left ventricular function on myocardial T2*.

Materials and Methods

Myocardial T2* was measured in 126 subjects without cardiac iron loading, of whom 63 were normals of varying ages, 39 were patients with impaired left ventricular function from various nonsiderotic cardiac causes, and 24 were patients with chronic myocardial infarction affecting the interventricular septum (where myocardial T2* measurements are normally made).

Results

The median (Q1, Q3) of myocardial T2* in the normals was 36.3 ms (31.6, 45.4). There was no significant correlation between myocardial T2* and age (R² = 0.04; P = 0.11). In the patients with impaired left ventricular function, the median myocardial T2* was 35.5 ms (31, 42.2) (P = 0.34 versus normals). There was no significant correlation between ejection fraction and T2* in patients with left ventricular impairment (R² = 0.03; P = 0.33). In the patients with septal infarction, the median septal myocardial T2* was 35.4 ms (32.7, 43) (P = 0.81 vs normals).

Conclusion

There was no significant change in myocardial T2* associated with any alterations of myocardial structure and function occurring with increasing age, impairment of left ventricular function or septal fibrosis from chronic myocardial infarction. These results indicate that myocardial T2* measurements are robust to these potential confounding parameters. J. Magn. Reson. Imaging 2010;32:1095–1098. © 2010 Wiley‐Liss, Inc.     

Magnetic Resonance Cisternographic Evaluation of Glossopharyngeal,Vagus, and Accessory Nerves

Purpose

The individual visualization of the glossopharyngeal, vagus, and accessory nerves has been a troublesome issue. After the recent developments in the microsurgical field, the detailed knowledge of the relationship of these nerves and the tumour has gained importance. The purpose of this study is to compare the visibility of each of these nerves.

Methods

Thirty patients (M/F: 14/16; mean age 52.46 years) with complaints of vertigo, tinnitus, and hearing loss were examined with routine temporal magnetic resonance imaging (MRI) study. The imaging protocol consisted of 3-dimensional fast imaging with steady state acquisition in axial and sagittal oblique planes in addition to routine sequences. These images were transferred to a workstation and reformatted. Visibility of the nerves was evaluated by consensus of 2 radiologists who used an evaluation scale of 2 (excellently visible), 1 (partially visible), to 0 (not visible).

Results

In 26 patients, both sides were scanned; in 4 patients, only one side was scanned. A total of 168 nerves were investigated. The rates for visualization for each nerve were as follows: glossopharyngeal nerve, 100% and 100%; vagus nerve, 67.9% and 100%; and accessory nerve, 10.8% and 83.85% on axial and sagittal oblique 3-dimensional fast imaging with steady state acquisition, respectively.

Conclusions

Glossopharyngeal, vagus, and accessory nerve assessment improved when images were obtained in the sagittal oblique plane to the jugular foramen.     

Evaluation of the prevalence, lesion, and depth of osteoarthritic changes in the patella

Purpose

The aim of this study was to determine the prevalence, type of lesion, and depth of osteoarthritic (OA) changes in the patella.

Methods

One hundred and forty-six cadaveric knees were included in this study with an median age of 83?years (54?C97). Patella OA lesion was classified using Han??s method: Type 1, no or minimal lesion; Type 2, medial facet lesion without involvement of the ridge; Type 3, lateral facet lesion without involvement of the ridge; Type 4, lesion involvement of the ridge; Type 5, medial facet lesion with involvement of the ridge, Type 6, lateral facet lesion with involvement of the ridge; and Type 7, Global lesion. The depth of OA evaluation was performed following Outerbridge??s classification.

Results

OA lesions were observed as follows: (Type 1) 31%, (Type 2) 16%, (Type 3) 3%, (Type 4) 12%, (Type 5) 22%, (Type 6) 2%, and (Type 7) 14%. Outerbridge??s classification of over Grade 2 OA depth was observed in 63.7% of subjects. A significant difference of patella OA type in gender was observed. Severe patella OA occurred in female subjects. Greater depth of OA was observed in Types 5 and 7. Most OA occurred in the medial facet of the patella including the ridge. Isolated OA in the lateral facet of the patella was observed in only 2% of all knees.

Conclusion

There is a risk of patella OA in female subjects. Patella OA occurred mainly on the medial side. Isolated OA in the lateral facet of the patella was rare. 63.7% of subjects had patella OA.

Level of evidence

Controlled laboratory study, Level III.     

Developmental associations with muscle morphology,physical performance,and asymmetry in youth judo athletes

Purpose

This study evaluated the contributions of somatic maturity (years from estimated peak height velocity) and training experience as developmental indicators of muscle morphology, biomechanical parameters, and bilateral asymmetries in youth judo athletes.

Methods

Twenty-six judo athletes aged 8–18 years (mean?±?SD; age?=?12.9?±?2.6 years, maturity offset = ? 0.6?±?2.2 years, training experience?=?6.1?±?2.9 years) completed anthropometric measurements, performance testing, and ultrasound evaluation of the vastus lateralis.

Results

Somatic maturity had the greatest relationship with handgrip performance (r²?=?0.76–0.80; p?<?0.01) and lower-body plyometric ability (r²?=?0.23–0.72; p?<?0.05). Somatic maturity and training experience accounted for 72% of the variance in hopping power. Bilateral asymmetries in average/peak force and 1-/2-s force–time integration during isometric handgrip increased with training experience (r²?=?0.17–0.46 p?<?0.05). Muscle morphology (r²?=?0.29–0.75; p?<?0.01) was best related to somatic maturity. Significant differences were found between child and adolescent judo athletes in force–time curve parameters, muscle morphology, and plyometric ability.

Conclusions

These results indicate that somatic maturity and training experience exert unique influences on muscle morphology, biomechanical parameters, and bilateral asymmetries in youth judo athletes.

     

Graded associations between cardiorespiratory fitness, fatness, and blood pressure in children and adolescents

Objective

To measure the graded relation between cardiorespiratory fitness and sum of skinfolds, waist circumference, and blood pressure in children and adolescents participating in the European youth heart study.

Methods

The participants were 4072 children and adolescents (aged 9 and 15) from Denmark, Portugal, Estonia, and Norway. Cardiorespiratory fitness was indirectly determined using a maximal ergometer cycle test. The sum of four skinfolds, waist circumference, and blood pressure were assessed with a standardised protocol. Linear regression analysis was used to test the graded relation between cardiorespiratory fitness and the dependent variables adjusted for pubertal stage, sex, and country.

Results

A significant curvilinear graded relation was found between cardiorespiratory fitness and waist circumference and sum of skinfolds (partial r² for cardiorespiratory fitness was 0.09–0.26 for the different sexes and age groups). Systolic and diastolic blood pressure also showed a curvilinear relation with cardiorespiratory fitness, and fitness explained 2% of the variance in systolic blood pressure. The difference in systolic blood pressure between the least and most fit was 6 mm Hg.

Conclusion

A curvilinear graded relation was found between cardiorespiratory fitness and waist circumference, sum of skinfolds, and systolic blood pressure. The greatest difference in these health variables was observed between low and moderate fitness levels.     

Consistency of signal intensity and T2* in frozen ex vivo heart muscle,kidney, and liver tissue

Purpose:

To investigate tissue dependence of the MRI‐based thermometry in frozen tissue by quantification and comparison of signal intensity and T2* of ex vivo frozen tissue of three different types: heart muscle, kidney, and liver.

Materials and Methods:

Tissue samples were frozen and imaged on a 0.5 Tesla MRI scanner with ultrashort echo time (UTE) sequence. Signal intensity and T2* were determined as the temperature of the tissue samples was decreased from room temperature to approximately ?40°C. Statistical analysis was performed for (?20°C, ?5°C) temperature interval.

Results:

The findings of this study demonstrate that signal intensity and T2* are consistent across three types of tissue for (?20°C, ?5°C) temperature interval.

Conclusion:

Both parameters can be used to calculate a single temperature calibration curve for all three types of tissue and potentially in the future serve as a foundation for tissue‐independent MRI‐based thermometry. J. Magn. Reson. Imaging 2010;31:719–724. © 2010 Wiley‐Liss, Inc.

     

IAEA Quality Control Atlas for Scintillation Camera Systems, 2003

Book Reviews

IAEA Quality Control Atlas for Scintillation Camera Systems, 2003     

Measurement of T1, T2, and magnetization transfer properties during embryonic development at 7 Tesla using the chicken model

Purpose

To evaluate whether techniques of high field magnetic resonance imaging may be used to characterize embryonic tissue during proliferation and differentiation.

Materials and Methods

Thirteen chicken embryos with incubation times between 5 days and 16 days have been measured in a small animal magnetic resonance imager (ClinScan, Bruker) at 7 Tesla using the built‐in resonator. T1, T2‐, and magnetization transfer imaging was performed using fast spin‐echo with inversion recovery, half acquisition single shot turbo spin‐echo, and spoiled gradient‐echo sequences with and without off‐resonance pulse, respectively. T1, T2, and magnetization transfer ratio (MTR) maps were calculated on a pixel‐by‐pixel basis.

Results

T1‐, T2‐, and MTR maps showed good image quality allowing for delineation of embryonic organs. During embryonic development, a decrease of T1 and T2 relaxation times was found, whereas, embryonic tissue typically showed an increase of magnetization transfer, for example, liver properties at day 5: T1 = 2431 ± 163 ms, T2 = 122 ± 12 ms, MTR = 9.2 ± 4.2%; liver properties at day 16: T1 = 1763 ± 89 ms, T2 = 71 ± 4 ms, MTR = 16.9 ± 2.2%.

Conclusion

Embryonic tissues show changing relaxation and magnetization transfer properties during development, therefore, high field MRI seems suitable for characterization of tissue replacement derived from embryonic stem cells. J. Magn. Reson. Imaging 2008;28:1510–1514. © 2008 Wiley‐Liss, Inc.     

Two-Dimensional sixteen channel transmit/receive coil array for cardiac MRI at 7.0 T: Design, evaluation, and application

Purpose:

To design, evaluate, and apply a 2D 16‐channel transmit/receive (TX/RX) coil array tailored for cardiac magnetic resonance imaging (MRI) at 7.0 T.

Materials and Methods:

The cardiac coil array consists of two sections each using eight elements arranged in a 2 × 4 array. Radiofrequency (RF) safety was validated by specific absorption rate (SAR) simulations. Cardiac imaging was performed using 2D CINE FLASH imaging, T mapping, and fat–water separation imaging. The characteristics of the coil array were analyzed including parallel imaging performance, left ventricular chamber quantification, and overall image quality.

Results:

RF characteristics were found to be appropriate for all subjects included in the study. The SAR values derived from the simulations fall well within the limits of legal guidelines. The baseline signal‐to‐noise ratio (SNR) advantage at 7.0 T was put to use to acquire 2D CINE images of the heart with a very high spatial resolution of (1 × 1 × 4) mm³. The proposed coil array supports 1D acceleration factors of up to R = 4 without significantly impairing image quality.

Conclusion:

The 16‐channel TX/RX coil has the capability to acquire high contrast and high spatial resolution images of the heart at 7.0 T. J. Magn. Reson. Imaging 2012;36:847–857. © 2012 Wiley Periodicals, Inc.     

Safety of sonographically guided aspiration of intramuscular, bursal, articular and subcutaneous hematomas

Objective

To evaluate the safety and efficacy of sonographically guided aspiration of intramuscular, bursal and subcutaneous hematomas.

Materials and methods

One hundred eleven interventions were performed in 75 patients at a single institution from January 2005 to December 2009. In all cases the target of interest was identified with ultrasonography.

Results

Ninety-six procedures (87.3%) were successful, 14 procedures (12.7%) were unsuccessful due to excessive density and/or viscosity of the content. No significant complications were encountered during or immediately after any procedure. Clinical follow-up records were available for 73 (75%) procedures in 45 (66%) patients, 30 patients did not return for follow-up after hematoma evacuation. No septic or hemorrhagic complications or cases of neurovascular compromise were recorded.

Conclusions

Sonographically guided hematoma evacuation is a safe procedure. However, the proportion of unsuccessful evacuations and hematoma recurrence is substantial.     

MRI analysis of single-, double-, and triple-bundle anterior cruciate ligament grafts

Purpose

The purpose of the study was to evaluate the entire course of ACL grafts on coronal oblique MR images, focusing on differences in graft morphology and graft-to-tunnel healing among single-bundle (SB), double-bundle (DB), and triple-bundle (TB) reconstructions.

Methods

Eighty-three patients underwent anatomical ACL reconstruction using the semitendinosus tendon. SB reconstruction was performed on 20 patients, DB on 29 patients, and TB on 34 patients. The anteromedial-bundle (AMB) and posterolateral-bundle (PLB) images were extracted from coronal oblique images of grafts at 6 months to visualize their entire course. Signal intensity of grafts was measured independently in three regions: (1) intra-femoral tunnel region, (2) intra-articular region, and (3) intra-tibial tunnel region, followed by calculation of the signal-to-noise quotient (SNQ). To evaluate graft-to-tunnel healing, T2-weighted images were examined for the presence of a high signal-intensity lesion between the graft and bone tunnel around the tunnel aperture.

Results

AMB images showed that SB graft was thick throughout the entire course, while DB graft was thinner than SB graft. TB graft showed a fan shape approaching the tibial tunnels. The SNQ in the femoral tunnel of SB graft was significantly lower than in the DB and TB grafts. High signal-intensity lesions were frequently observed around the femoral tunnel aperture in PLB images of DB and TB grafts compared to SB grafts.

Conclusion

Gross morphology of TB grafts resembled that of the natural ACL. However, the graft-to-tunnel healing around the femoral tunnel seemed to be insufficient in PLB images of DB and TB compared to SB grafts.

Level of evidence

III.     

A return to basics, a focus on the future

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A return to basics, a focus on the future