Selective visualization of pelvic splanchnic nerve and pelvic plexus using readout-segmented echo-planar diffusion-weighted magnetic resonance neurography: A preliminary study in healthy male volunteers

PurposeTo evaluate the potential of readout-segmented echo-planar diffusion-weighted magnetic resonance neurography (RS-EPI DW-MRN) for the selective visualization of pelvic splanchnic nerve and pelvic plexus in healthy male volunteers.Materials and methodsInstitutional review board approval and written informed consent were obtained. RS-EPI DW-MRN images were acquired from thirteen healthy male volunteers aged 25–48 years between September 2013 and December 2013. For RS-EPI DW-MRN, the following parameters were used: spatial resolution, 1.1 × 1.1 × 2.5 mm; b-value, 250 s/mm²; number of readout-segments, seven; and acquisition time, 7 min 45 s. For qualitative assessment, two abdominal radiologists independently evaluated the visibility of the pelvic splanchnic nerves and pelvic plexuses bilaterally in each subject on oblique coronal thin-slab 10-mm-thick maximum intensity projection images and scored it with a 4-point grading scale (excellent, good, fair, poor). Both readers scored twice at 6-month intervals. Inter-observer and intra-observer variability were evaluated using Cohen’s quadratically weighted κ statistics. Image artifact level was scored on a 4-point grading scale by other two abdominal radiologists in order to evaluate the correlation between the nerve visibility and the severity of imaging artifacts using the Spearman’s correlation coefficient.ResultsQualitative grading showed the following success rate (number of nerves qualitatively scored as excellent or good divided by total number of nerves): reader 1 (first set), 73% (19/26); reader 2 (first set), 77% (20/26); reader 1 (second set), 81% (21/26); and reader 2 (second set), 77% (20/26). Inter-observer agreement between readers 1 and 2 was excellent: κ = 0.947 (first set) and 0.845 (second set). Intra-observer agreement was also excellent: κ = 0.810 (reader 1) and 0.946 (reader 2). The visibility of pelvic splanchnic nerve and pelvic plexus showed a moderate correlation with the image artifact level (ρ = 0.54, p = 0.004).ConclusionThis study demonstrated that RS-EPI DW-MRN is a promising approach for selectively visualizing the pelvic splanchnic nerve and pelvic plexus.     

Quantitative assessment of optic nerve in patients with Leber’s hereditary optic neuropathy using reduced field-of-view diffusion tensor imaging

PurposeTo quantitatively analyze the optic nerve alterations in chronic Leber’s hereditary optic neuropathy (LHON) using reduced field-of-view diffusion tensor imaging (rFOV-DTI) and evaluate the correlation of diffusion parameters with visual functional and peripapillary retinal nerve fiber layer (RNFL) thickness.MethodsTwenty-five patients (50 affected optic nerves) with chronic LHON and 28 healthy controls (56 normal optic nerves) were enrolled. The rFOV-DTI was performed in the bilateral optic nerves for all the subjects. The fractional anisotropy (FA), mean diffusivity (MD), principal eigenvalue (λ//), and orthogonal eigenvalue (λ⊥) were calculated for quantitative analysis. Visual field (VF) and visual acuity (VA) were measured in all subjects. The peripapillary RNFL thickness was assessed using optical coherence tomography (OCT). The correlation of DTI diffusion parameters with visual function and peripapillary RNFL thickness was evaluated.ResultsCompared with optic nerves in the control group, the mean FA was significant decreased (P < 0.005), and the mean MD, λ//and λ⊥ significant increased (P < 0.005). The average and temporal peripapillary RNFL thickness were significantly thinned in LHON patients. There was a significant correlation between optic nerve FA and VA, mean deviation of visual field (MD_VF) (P < 0.005). Also, optic nerve FA correlated significantly with average RNFL thickness (P < 0.05) but not with MD, λ//and λ⊥ (P > 0.05). However, none of the DTI parameters correlated with age and disease duration (P > 0.05).ConclusionsOur study has demonstrated that rFOV-DTI could provide information of optic nerve damage in chronic LHON, and can serve as technique for detecting and evaluating pathological changes in the optic nerve in LHON.     

Comparison of 3D bone models of the knee joint derived from CT and 3T MR imaging

PurposeTo examine whether magnetic resonance (MR) imaging can offer a viable alternative to computed tomography (CT) based 3D bone modeling.MethodsCT and MR (SPACE, TrueFISP, VIBE) images were acquired from the left knee joint of a fresh-frozen cadaver. The distal femur, proximal tibia, proximal fibula and patella were manually segmented from the MR and CT examinations. The MR bone models obtained from manual segmentations of all three sequences were compared to CT models using a similarity measure based on absolute mesh differences.ResultsThe average absolute distance between the CT and the various MR-based bone models were all below 1 mm across all bones. The VIBE sequence provided the best agreement with the CT model, followed by the SPACE, then the TrueFISP data. The most notable difference was for the proximal tibia (VIBE 0.45 mm, SPACE 0.82 mm, TrueFISP 0.83 mm).ConclusionsThe study indicates that 3D MR bone models may offer a feasible alternative to traditional CT-based modeling. A single radiological examination using the MR imaging would allow simultaneous assessment of both bones and soft-tissues, providing anatomically comprehensive joint models for clinical evaluation, without the ionizing radiation of CT imaging.     

Maturity-related developmental inequalities in age-group swimming: The testing of ‘Mat-CAPs’ for their removal

ObjectivesTo (1) examine the association between maturity timing and performance-based selection levels in (N = 708) Australian male 100-m Freestyle swimmers (12–17 years); (2) identify the relationship between maturation status and 100-m Freestyle performance; and (3) determine whether Maturation-based Corrective Adjustment Procedures (Mat-CAPs) could remove maturation-related differences in swimming performance.MethodsIn Part 1, maturity timing category distributions (‘Early’, ‘Early Normative’, ‘Late Normative’ and ‘Late’) for ‘All’, ‘Top 50%’ and ‘25%’ of raw swimming times were examined within and across age-groups. In Part 2, multiple regression analyses quantified the relationship between maturity offset (YPHV) and swimming performance. In Part 3, sample-based maturity timing category distributions were examined based on raw and correctively adjusted swim times for 12–17 year old age-groups.ResultsBased on raw swim times, a high prevalence of ‘Early-maturing’ swimmers, with large effect sizes was identified (e.g., 14 years ‘All’ — χ² (3, 151 = 111.98, p < 0.001; ‘Early’ v ‘Late’ OR = 82.0 95%CI = 4.77, 1409.9); while a complete absence of ‘Late-maturers’ was apparent in the sample (N = 708). When maturity categories were re-defined based on sample mean ± standard deviation, and when using the expected curvilinear trendline identified in Part 2, Mat-CAPs mitigated maturity timing biases across all age-groups and selection levels, and removed the Freestyle performance advantage afforded by advanced maturity timing and status.ConclusionsRemoving the influence of maturation-related developmental differences could help improve youth swimmer participation experiences and improve the accuracy of identifying genuinely skilled age-group swimmers.     

Removing relative age effects from youth swimming: The development and testing of corrective adjustment procedures

Objectives(1) Generate accurate estimates of the relationship between decimal age (i.e., chronological and relative) with swimming performance based on longitudinal data. (2) Determine whether corrective adjustment procedures can remove Relative Age Effects (RAEs) from junior/youth swimming.DesignLongitudinal and repeated years of cross-sectional performance data were examined.Methods(1) Participants were 553 male 100 m Freestyle swimmers (10–18 years) who participated in ≥five annual events between 1999–2017. Growth curve modelling quantified the relationship between age and swimming performance, permitting corrective adjustment calculations. (2) Participants were N = 2141 male 100 m Freestyle swimmers (13–16 years) who swam at state/national events in 2015–2017. Relative age distributions for ‘All’, ‘Top 50%’, ‘25%’ and ‘10%’ of swimming times were examined based on raw and correctively adjusted swim times. Chi-square, Cramer’s V and Odds Ratios (OR) determined whether relative age (quartile) inequalities existed according to age-groups, selection level and correctively adjusted swim times.ResultsBased on raw swim times, for ‘All’ swimmers RAEs was evident at 13 and 14 years-old and dissipated thereafter. But, RAE effect sizes substantially increased with selection level, with large-medium effects between 13–15 years-old (e.g., 15 years — Top 50% Q1 v Q4 OR = 2.28; Top 10% = 6.02). However, when correctively adjusted swim times were examined, RAEs were predominantly absent across age-group and selection levels.ConclusionsWith accurate longitudinal reference data, corrective adjustment procedures effectively removed RAEs from 100 m Freestyle swimming performance, suggesting the potential to improve swimming participation experience and performance evaluation.     

Intra- and interrater reliability of three different MRI grading and classification systems after acute hamstring injuries

ObjectiveTo assess and compare the intra- and interrater reliability of three different MRI grading and classification systems after acute hamstring injury.MethodsMale athletes (n = 40) with clinical diagnosis of acute hamstring injury and MRI ≤5 days were selected from a prospective cohort. Two radiologists independently evaluated the MRIs using standardised scoring form including the modified Peetrons grading system, the Chan acute muscle strain injury classification and the British Athletics Muscle Injury Classification. Intra-and interrater reliability was assessed with linear weighted kappa (κ) or unweighted Cohen's κ and percentage agreement was calculated.ResultsWe observed ‘substantial’ to ‘almost perfect’ intra- (κ range 0.65–1.00) and interrater reliability (κ range 0.77–1.00) with percentage agreement 83–100% and 88–100%, respectively, for severity gradings, overall anatomical sites and overall classifications for the three MRI systems. We observed substantial variability (κ range −0.05 to 1.00) for subcategories within the Chan classification and the British Athletics Muscle Injury Classification, however, the prevalence of positive scorings was low for some subcategories.ConclusionsThe modified Peetrons grading system, overall Chan classification and overall British Athletics Muscle Injury Classification demonstrated ‘substantial' to ‘almost perfect' intra- and interrater reliability when scored by experienced radiologists. The intra- and interrater reliability for the anatomical subcategories within the classifications remains unclear.     

Diffusion MRI for rectal cancer staging: ADC measurements before and after ultrasonographic gel lumen distension

ObjectivesTo compare Apparent Diffusion Coefficient (ADC) measurements in rectal neoplastic lesions before and after lumen distension obtained with sonography transmission gel.MethodsFrom January 2014 to July 2016, 25 patients (average age 63.7, range 41–85, 18 males) were studied for pre-treatment rectal cancer staging using a 1.5 T MRI. Diffusion MRI was obtained using echo-planar imaging with b = 800 value; all patients were studied acquiring diffusion sequences with and without rectal lumen distension obtained using sonography transmission gel. In both diffusion sequences, two blinded readers calculated border ADC values and small ADC values, drawing regions of interest respectively along tumour borders and far from tumour borders. Mean ADC values among readers − for each type of ADC measurement − were compared using Wilcoxon matched pairs signed rank test. Correlation was assessed using Pearson analysis.ResultsBorder ADC mean value for diffusion MR sequences without endorectal contrast was 1.122 mm²/sec, with 95% Confidence Interval (CI) = 1.02–1.22; using gel lumen distension, higher border ADC mean value of 1.269 mm²/s (95% CI = 1.16–1.38) was obtained. Wilcoxon matched pairs signed rank test revealed statistical difference (p < 0.01); a strong Pearson correlation was reported, with r value of 0.69. Small-ADC mean value was 1.038 mm²/s (95% CI = 0.91–1.16) for diffusion sequences acquired without endorectal distension and 1.127 mm²/s (95% CI = 0.98–1.27) for diffusion sequences obtained after endorectal gel lumen distension. Wilcoxon analysis did not show statistical difference (p = 0.13). A very strong positive correlation was observed, with r value of 0.81.ConclusionsADC measurements are slightly higher using endorectal sonographic transmission gel; ROI should be traced far from tumour borders, to minimize gel filled-pixel along the interface between lumen and lesion. Further studies are needed to investigate better reliability of ADC in rectal cancer MRI using sonographic gel intraluminal distension.     

Metal artifact reduction by dual-layer computed tomography using virtual monoenergetic images

ObjectiveThe aim of the study was to investigate the performance and diagnostic value of metal artifact reduction in virtual monoenergetic images generated from dual-layer computed tomography (DLCT).Methods35 patients that received a DLCT at the University Hospital Cologne and had an orthopedic implant in the examined region were included in this study. For each DLCT virtual monoenergetic images of different energy levels (64 keV, 70 keV, 105 keV, 140 keV, 200 keV and an optimized photon energy) were reconstructed and analyzed by three blinded observers. Images were analyzed with regard to subjective criteria (extent of artifacts, diagnostic image quality) and objective criteria (width and density of artifacts).Results21 patients had implants in the spine, 8 in the pelvis and 6 patients in the extremities. Diagnostic image quality improved significantly at high photon energies from a Likert-score of 4.3 (±0.83) to 2.3 (±1.02) and artifacts decreased significantly from a score of 4.3 (±0.66) to 2.6 (±2.57). The average optimized photon energy was 149.2 ± 39.4 keV. The density as well as the width of the most pronounced artifacts decreased from−374.6 ± 251.89 HU to −12.5 ± 205.84 HU and from 14.5 ± 8.74 mm to 6.4 ± 10.76 mm, respectively.ConclusionUsing virtual monoenergetic images valuable improvements of diagnostic image quality can be achieved by reduction of artifacts associated with metal implants. As preset for virtual monoenergetic images, 140 keV appear to provide optimal artifact reduction. In 20% of the patients, individually optimized keV can lead to a further improvement of image quality compared to 140 keV.     

Comparison between multi-shot gradient echo EPI and balanced SSFP in unenhanced 3T MRA of thoracic aorta in healthy volunteers

PurposeThe purpose of this study was to compare scan time and image quality between magnetic resonance angiography (MRA) of the thoracic aorta using a multi-shot gradient echo planar imaging (MSG-EPI) and MRA using balanced steady-state free precession (b-SSFP).Materials and methodsHealthy volunteers (n = 17) underwent unenhanced thoracic aorta MRA using balanced steady-state free precession (b-SSFP) and MSG-EPI sequences on a 3T MRI. The acquisition time, total scan time, signal-to-noise ratio (SNR) of the thoracic aorta, and the coefficient of variation (CV) of thoracic aorta were compared with paired t-tests. Two radiologists independently recorded the images’ contrast, noise, sharpness, artifacts, and overall quality on a 4-point scale.ResultsThe acquisition time was 36.2% shorter for MSG-EPI than b-SSFP (115.5 ± 14.4 vs 181.0 ± 14.9 s, p < 0.01). The total scan time was 40.4% shorter for MSG-EPI than b-SSFP (272 ± 78 vs 456 ± 144 s, p < 0.01). There was no significant difference in mean SNR between MSG-EPI and b-SSFP scans (17.3 ± 3.6 vs 15.2 ± 4.3, p = 0.08). The CV was significantly lower for MSG-EPI than b-SSFP (0.2 ± 0.1 vs. 0.5 ± 0.2, p < 0.01). All qualitative scores except for image noise were significantly higher in MSG-EPI than b-SSFP scans (p < 0.05).ConclusionThe MSG-EPI sequence is a promising technique for shortening scan time and yielding more homogenous image quality in MRA of thoracic aorta on 3T scanners compared with the b-SSFP.     

Effects of pure and hybrid iterative reconstruction algorithms on high-resolution computed tomography in the evaluation of interstitial lung disease

ObjectivesTo compare image quality characteristics of high-resolution computed tomography (HRCT) in the evaluation of interstitial lung disease using three different reconstruction methods: model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP).MethodsEighty-nine consecutive patients with interstitial lung disease underwent standard-of-care chest CT with 64-row multi-detector CT. HRCT images were reconstructed in 0.625-mm contiguous axial slices using FBP, ASIR, and MBIR. Two radiologists independently assessed the images in a blinded manner for subjective image noise, streak artifacts, and visualization of normal and pathologic structures. Objective image noise was measured in the lung parenchyma. Spatial resolution was assessed by measuring the modulation transfer function (MTF).ResultsMBIR offered significantly lower objective image noise (22.24 ± 4.53, P < 0.01 among all pairs, Student's t-test) compared with ASIR (39.76 ± 7.41) and FBP (51.91 ± 9.71). MTF (spatial resolution) was increased using MBIR compared with ASIR and FBP. MBIR showed improvements in visualization of normal and pathologic structures over ASIR and FBP, while ASIR was rated quite similarly to FBP. MBIR significantly improved subjective image noise (P < 0.01 among all pairs, the sign test), and streak artifacts (P < 0.01 each for MBIR vs. the other 2 image data sets).ConclusionMBIR provides high-quality HRCT images for interstitial lung disease by reducing image noise and streak artifacts and improving spatial resolution compared with ASIR and FBP.     

Diagnostic accuracy of different magnetic resonance imaging sequences for detecting local tumor progression after radiofrequency ablation of hepatic malignancies

ObjectiveTo evaluate the diagnostic accuracy of the individual sequences of a clinical routine liver MRI protocol for the detection of local tumour progression after radiofrequency (RF) ablation of hepatic malignancies.Material and methodsA cohort of 93 patients treated for 140 primary and secondary hepatic malignancies with RF ablation was assembled for this retrospective study. The cohort contained 31 cases of local tumour progression, which occurred 8.3 ± 6.2 months (range: 4.0–28.2 months) after treatment. All patients underwent clinical routine follow-up MRI at 1.5T including following sequences: unenhanced T1-weighted fast low angle shot (FLASH-2D), T2-weighted turbo-spin-echo sequence, contrast-enhanced (CE) T1-weighted volume-interpolated breath-hold examination (VIBE), diffusion-weighted imaging (DWI). Follow-up was 32.7 ± 22.5 months (range: 4.0–138.3 months). Two readers independently evaluated the individual sequences separately for signs of local tumour progression. Diagnostic confidence was rated on a 4-point scale. Inter-reader agreement was assessed with Coheńs kappa. Long-term follow-up and histological specimen served as standard of reference.ResultsBoth readers reached the highest sensitivity for detection of local tumour progression with unenhanced T1-FLASH 2D (88.2% and 94.1%, respectively) and the highest specificity with CE T1-VIBE (96.2% and 97.2%, respectively). Highest inter-reader agreement was reached with T1-FLASH-2D (kappa = 0.83). Typical pitfalls for false-positive diagnoses were focal cholestasis and vasculature adjacent to the ablation zone. Diagnostic confidence was highest with CE T1-VIBE for reader 1 and DWI for reader 2.ConclusionUnenhanced T1-FLASH-2D is an essential sequence for follow-up imaging after tumour ablation with a high sensitivity for detection of local progression and a high inter-reader agreement.     

Early myocardial gadolinium enhancement in patients with myocarditis: Validation of “Lake Louise consensus” criteria using a single bolus of 0.1 mmol/Kg of a high relaxivity gadolinium-based contrast agent

ObjectivesGlobal early gadolinium enhancement (EGE) is an accepted cardiac magnetic resonance (CMR) criterion for diagnosis of myocarditis. However, recommended enhancement thresholds are based specifically on standard-relaxivity Gd-chelates. We evaluated the performance of a high relaxivity MR contrast agent for detection of myocardial hyperemia in patients referred for endomyocardial biopsy (EMB).MethodsWe retrospectively enrolled 54 patients (mean age: 44.1 years [range = 18–77 years]; 72% men) with suspected myocarditis who underwent CMR and EMB within four weeks of clinical onset. CMR imaging protocol included T2-weighted short tau inversion-recovery sequence, EGE and late gadolinium enhanced (LGE) imaging.For EGE imaging, free-breathing ECG-gated turbo spin echo T1-weighted (TSE T1w) sequences were acquired before and within the first three minutes after gadobenate dimeglumine (0.1 mmol/Kg) administration. The ratio (EGEr) between myocardial and musculoskeletal early enhancement was calculated. Myocardial edema, EGE and late gadolinium enhancement (LGE) were correlated with EMB results. Receiver operating characteristic (ROC) curve analysis of EGE values was applied on the overall population.ResultsEMB revealed myocarditis in 34/54 patients. Sensitivity, specificity and accuracy values of 0.61, 0.85 and 0.70, respectively, were obtained for a standard EGE threshold (EGEr > 4.0). ROC analysis revealed an area under the curve of 0.701 for EGEr (IC95%:0.556–0.846, p = 0.014) and 0.706 for absolute enhancement (IC95%:0.563–0.849, p = 0.012).Sensitivity, specificity and accuracy values were 0.67, 0.80 and 0.72, respectively, for myocardial edema and 0.76, 0.75 and 0.76, respectively, for LGE.ConclusionsHigh relaxivity contrast agents provide comparable results to standard-relaxivity chelates for EGE assessment in diagnosing myocarditis.     

Magnetic resonance diffusion tensor imaging of the testis: Preliminary observations

IntroductionTo evaluate the feasibility of testis diffusion tensor imaging (DTI), to determine normative apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values and to assess the efficacy of DTI in characterizing testicular pathology.Materials and methodsFifty-six men underwent MRI of the scrotum, including DTI. Parametric and non-parametric statistical tests were used to compare the ADC and FA between the cranial, middle and lower thirds of normal testis and between the bilateral testicular thirds. Comparison between the ADC and FA of normal testis, malignant and benign testicular lesions was performed.ResultsNo significant differences of the ADC and FA in normal testis between the cranial, middle and lower thirds and between the bilateral testicular thirds were found. ADC was significantly lower in malignancies compared to normal testis (P = 0.006) and benign testicular lesions (P = 0.006). FA was significantly higher both in malignancies (P = 0.001) and benign lesions (P < 0.001) compared to normal testis. FA in malignancies did not differ from FA in benign lesions (P = 0.221)ConclusionsThis study shows the feasibility of testis DTI. Both ADC and FA significantly differ between testicular lesions and normal testis, although FA did not show an incremental diagnostic value compared to ADC in lesion differentiation.     

Implications of CT imaging for postplan quality assessment in prostate brachytherapy

PurposePostplan quality assurance using CT shows considerable interobserver contour variability. We examined CT postplans of four experienced brachytherapists for comparison with MR-determined prostate volumes.Methods and MaterialsSeventy-five patients had CT and MR scans 1 month post-¹²⁵I prostate brachytherapy. CT scans were contoured by the treating physician and dosimetry calculated. The prostate was contoured independently on MR by one observer with extensive MR experience, the scans were fused and dosimetric parameters compared.ResultsThe mean prostate volume on CT was 38.3 cc (17.5–78.6 cc), on MR 33.3 cc (16.3–66.1 cc). On average, the volume on CT was 16.1% larger than on MR (range, 8% smaller to 64% larger). Craniocaudal discordance of the CT vs. MR prostate contours ranged from 4 mm cranial to 10 mm caudal to MR base and from 6 mm cranial to 14 mm caudal to MR apex. The CT prostate volume not only included an average of 90% of the MR prostate (range, 75–99%) but also included normal tissue (mean, 8.3 cc; range, 2.9–17.1 cc). The average difference between the calculated D₉₀ from CT contours vs. MR contours was 10.0 Gy (standard deviation, 8.8; range, ?37.6 to +41.6 Gy).ConclusionsOn average, only 90% of the MR-defined prostate is included in CT contours, while a volume of normal tissue is erroneously designated as prostate. Lack of awareness of this deficiency in planning and/or operative technique gives a false sense of appreciation of the true conformality, delays implementation of corrective measures, and risks unnecessary side effects.     

Assessment of the test–retest reliability of a foot placement accuracy protocol in assisted-living older adults

IntroductionThis study assessed the test–retest reliability of a foot placement accuracy protocol in a population of assisted-living elderly. The goal was to evaluate the execution of foot placement performance with increasing complexity of the walking condition.MethodsTwenty-five elderly participants (5 males, 20 females, 80.4 ± 8.6 years) were assessed by one observer in two sessions with 48 h between the measurements. Participants walked at self-selected pace along a pathway with three different walking conditions composed of two rectangular foam target locations and an obstacle on the walking surface. The main outcome measures were foot placement distance error, intra-class correlation coefficients (ICC), and the smallest detectable difference (SDD).ResultsMean absolute values of the foot placement distance errors were 14.0 ± 4.5 mm for medio-lateral deviation and 27.2 ± 2.1 mm for anterior–posterior deviation, respectively. ICC values for test–retest reliability showed ‘fair to good’ to ‘excellent’ reliability across all conditions with values ranging from 0.63 to 0.94. SDD values were between 3.6 and 37.3 mm.ConclusionThe protocol showed good reliability for test–retest measurements of foot placement accuracy, thus making this protocol a reliable and location-independent tool to assess performance of foot placement in elderly in assisted-living settings. In the future, measurements with elderly fallers and non-fallers should be conducted to assess validity of the protocol.     

Exploring associations between neuromuscular performance,hypermobility, and children’s motor competence

ObjectivesTo evaluate if neuromuscular performance and hypermobility are factors associated with children’s motor competence.DesignCross-sectional observation study.MethodsData was collected on 60 children aged 6–12 years; motor competence was determined using the Movement Assessment Battery for Children-2 test, with children classified into 3 groups (Typically Developing n = 30; ‘At Risk’ of low motor competence (LMC) n = 9; LMC n = 21). Neuromuscular performance was determined utilising the Resistance Training Skills Battery for Children (RTSBc), 5-repetition maximum (5RM) leg press and Biodex dynamometry to assess isometric and isokinetic peak torque of the knee flexors and extensors. Hypermobility was measured using the Beighton and Lower Limb Assessment Score.ResultsBetween-groups MANCOVA revealed typically developing children scored significantly higher on the RTSBc than those ‘at risk’ of LMC (p = 0.021) and those in the LMC group (p < 0.001). 5RM scores also differed between groups, with typically developing children achieving significantly higher scores than the LMC group. No differences were found between groups for isometric or isokinetic measures of strength. Sequential regression analysis revealed neuromuscular performance variables explained 44.7% of the variance in motor competence, with RTSBc (p < 0.001) and 5RM (p = 0.019) emerging as positive significant predictors. Hypermobility failed to explain significant variance in motor competence beyond that explained by neuromuscular performance.ConclusionsNeuromuscular performance of children varies according to levels of motor competence, with those with LMC performing poorly on tasks requiring multi-joint movement. Furthermore, neuromuscular performance predicted almost half the variance observed in motor competence and highlights a novel intervention strategy.     

Qualitative and quantitative analysis of diffusion-weighted imaging of gestational trophoblastic disease: Can it predict progression of molar pregnancy to persistent form of disease?

PurposeTo describe the diffusion-weighted imaging (DWI) appearance of gestational trophoblastic disease (GTD) and to determine its apparent diffusion coefficient (ADC) values. To evaluate the feasibility of DWI to predict progression of hydatidiform mole (HM) to persistent disease.MethodsDuring a period of 6 months, women with preliminary diagnosis of GTD, based on ultrasound and ßhCG levels, underwent 1.5T MRI (T2 high-resolution and DWI; b values 50, 400, 800; sagittal and perpendicular to the endometrium; and T1, T2 Turbo Spin Echo [TSE] axial images). Patients were followed for 6–12 months to monitor progression to persistent form of the disease. ADC values and image characteristics were compared between HM and persistent neoplasia and between GTD and non-molar pregnancy using Mann–Whitney U and Fisher’s exact tests, respectively.ResultsAmong the 23 studied patients, 19 (83%) were classified as molar and 4 (17%) as non-molar, based on pathology reports. After 6–12 months of follow-up, 5 (26%) cases progressed to persistent disease and 14 (74%) cases were benign HM. There was no significant difference between ADC values for HM (1.93 ± 0.33 × 10⁻³ mm²/s) and persistent neoplasia (2.03 ± 0.28 × 10⁻³ mm²/s) (P = 0.69). The ADC of non-molar pregnancies was (0.96 ± 0.46 × 10⁻³ mm²/s), which was significantly different from GTD (1.96  ± 0.32 × 10⁻³ mm²/s) (P = 0.001). Heterogeneous snowstorm appearance, focal intratumoral hemorrhage, myometrial contraction, and prominent myometrial vascularity were more common in GTD compared to non-molar pregnancy (P < 0.05).ConclusionHeterogeneous snowstorm appearance, focal intratumoral hemorrhage, myometrial contraction, and prominent myometrial vascularity are among the imaging characteristics of GTD. We cannot use ADC values to predict progression to persistent disease.     

Does apparent diffusion coefficient predict the degree of liver regeneration of donor and recipient after living donor liver transplantation?

ObjectiveTo elucidate the relationship between the ADCs of the liver graft and the remnant liver and the degree of liver regeneration in LDLT.Materials and methods15 recipients and 15 corresponding donors underwent magnetic resonance imaging and computed tomography 1–2 weeks after living donor liver transplantation (LDLT). For diffusion-weighted imaging (DWI), a single-shot echo-planar sequence with b-factors of 0, 500, and 1000 s/mm² was scanned. ADCs of the liver parenchyma were calculated at b factors of 0 and 500 and 1000 (ADC 0–500–1000) or 0 and 500 (ADC 0–500) or 500 and 1000 (ADC 500–1000). The liver volume ratio at LDLT, the mean ADCs and the regeneration rate were compared between the graft and the remnant liver using paired-t tests.ResultsThe mean liver volume ratio of the recipients (41.3 ± 9.8%) tended to be smaller than that of the donors (51.8 ± 13.8%). The mean ADC 0–500 of the remnant liver (1.72 ± 0.33) was significantly higher than that of the graft (1.43 ± 0.32). The regeneration rate of the graft (2.07 ± 0.41) was significantly higher than that of the remnant liver (1.53 ± 0.49).ConclusionADC 0–500 can describe differences in blood perfusion between liver grafts and the remnant liver according to the degree of liver regeneration.     

Visualization of cranial nerves I–XII: value of 3D CISS and T2-weighted FSE sequences

The aim of this study was to evaluate the sensitivity of the three-dimensional constructive interference of steady state (3D CISS) sequence (slice thickness 0.7 mm) and that of the T2-weighted fast spin echo (T2-weighted FSE) sequence (slice thickness 3 mm) for the visualization of all cranial nerves in their cisternal course. Twenty healthy volunteers were examined using the T2-weighted FSE and the 3D CISS sequences. Three observers evaluated independently the cranial nerves NI–NXII in their cisternal course. The rates for successful visualization of each nerve for 3D CISS (and for T2-weighted FSE in parentheses) were as follows: NI, NII, NV, NVII, NVIII 40 of 40 (40 of 40), NIII 40 of 40 (18 of 40), NIV 19 of 40 (3 of 40), NVI 39 of 40 (5 of 40), NIX, X, XI 40 of 40 (29 of 40), and NXII 40 of 40 (4 of 40). Most of the cranial nerves can be reliably assessed when using the 3D CISS and the T2-weighted FSE sequences. Increasing the spatial resolution when using the 3D CISS sequence increases the reliability of the identification of the cranial nerves NIII–NXII. Received: 29 September 1999; Revised: 2 February 2000; Accepted: 21 March 2000