Periventricular Nodular Heterotopia: Detection of Abnormal Microanatomic Fiber Structures with Whole-Brain Diffusion MR Imaging Tractography.

Purpose To investigate whether it is possible in patients with periventricular nodular heterotopia (PVNH) to detect abnormal fiber projections that have only previously been reported in the histopathology literature. Materials and Methods Whole-brain diffusion-weighted (DW) imaging data from 14 patients with bilateral PVNH and 14 age- and sex-matched healthy control subjects were prospectively acquired by using 3.0-T magnetic resonance (MR) imaging between August 1, 2008, and December 5, 2012. All participants provided written informed consent. The DW imaging data were processed to generate whole-brain constrained spherical deconvolution (CSD)-based tractography data and super-resolution track-density imaging (TDI) maps. The tractography data were overlaid on coregistered three-dimensional T1-weighted images to visually assess regions of heterotopia. A panel of MR imaging researchers independently assessed each case and indicated numerically (no = 1, yes = 2) as to the presence of abnormal fiber tracks in nodular tissue. The Fleiss κ statistical measure was applied to assess the reader agreement. Results Abnormal fiber tracks emanating from one or more regions of heterotopia were reported by all four readers in all 14 patients with PVNH (Fleiss κ = 1). These abnormal structures were not visible on the tractography data from any of the control subjects and were not discernable on the conventional T1-weighted images of the patients with PVNH. Conclusion Whole-brain CSD-based fiber tractography and super-resolution TDI mapping reveals abnormal fiber projections in nodular tissue suggestive of abnormal organization of white matter (with abnormal fibers both within nodules and projecting to the surrounding white matter) in patients with bilateral PVNH. © RSNA, 2016.

Sonoelastography of the Achilles Tendon: Prevalence and Prognostic Value Among Asymptomatic Elite Australian Rules Football Players.

OBJECTIVE: To investigate the prevalence of sonographic abnormalities at the mid-Achilles tendon among a cohort of asymptomatic professional football players and to determine whether these sonographic abnormalities predict midportion Achilles tendon symptoms. DESIGN: Longitudinal study. SETTING: A single competitive season in the Australian Rules Football League. PARTICIPANTS: Forty-two elite Australian Rules football players. MAIN OUTCOME MEASURES: Using ultrasound and sonoelastography, 42 players were examined at baseline and again 9 months later (postseason) for the existence of intratendinous hypoechogenicity, delamination, softening, and neovascularization. The anterio-posterior (AP) thickness and cross-sectional area (CSA) were measured. Players reporting Achilles tendon pain or with Victorian Institute of Sports Assessment-Achilles scores below 80 at the end of the season were classified as symptomatic. RESULTS: At preseason, ultrasound and/or sonoelastographic abnormalities were found in 22 (22/42, 52.4%) asymptomatic players. Baseline AP thickness and CSA were significantly greater in symptomatic players at the end season than those in asymptomatic players (0.57 ± 0.05 cm vs 0.50 ± 0.03 cm; P < 0.001 and 0.67 ± 0.07 cm vs 0.57 ± 0.06 cm; P < 0.001, respectively). The presence of intratendinous softening and delaminations at baseline was associated with pain onset during the season (P = 0.046; P = 0.048, respectively). CONCLUSIONS: Ultrasound and sonoelastography-detected abnormalities were relatively common among the asymptomatic footballers. Greater AP thickness and CSA and also the presence of intratendinous softening and delaminations were associated with the increased risk of developing symptoms. CLINICAL RELEVANCE: Conventional ultrasound supplement with sonoelastography may be able to identify elite athletes at risk of Achilles tendon injury, which may, in turn, impact therapeutic decisions.

High-resolution imaging of pulmonary ventilation and perfusion with 68Ga-VQ respiratory gated (4-D) PET/CT.

PURPOSE: Our group has previously reported on the use of (68)Ga-ventilation/perfusion (VQ) PET/CT scanning for the diagnosis of pulmonary embolism. We describe here the acquisition methodology for (68)Ga-VQ respiratory gated (4-D) PET/CT and the effects of respiratory motion on image coregistration in VQ scanning. METHODS: A prospective study was performed in 15 patients with non-small-cell lung cancer. 4-D PET and 4-D CT images were acquired using an infrared marker on the patient's abdomen as a surrogate for breathing motion following inhalation of Galligas and intravenous administration of (68)Ga-macroaggregated albumin. Images were reconstructed with phase-matched attenuation correction. The lungs were contoured on CT and PET VQ images during free-breathing (FB) and at maximum inspiration (Insp) and expiration (Exp). The similarity between PET and CT volumes was measured using the Dice coefficient (DC) comparing the following groups; (1) FB-PET/CT, (2) InspPET/InspCT, (3) ExpPET/Exp CT, and (4) FB-PET/AveCT. A repeated measures one-way ANOVA with multiple comparison Tukey tests were performed to evaluate any difference between the groups. Diaphragmatic motion in the superior-inferior direction on the 4-D CT scan was also measured. RESULTS: 4-D VQ scanning was successful in all patients without additional acquisition time compared to the nongated technique. The highest volume overlap was between ExpPET and ExpCT and between FB-PET and AveCT with a DC of 0.82 and 0.80 for ventilation and perfusion, respectively. This was significantly better than the DC comparing the other groups (0.78-0.79, p < 0.05). These values agreed with a visual inspection of the images with improved image coregistration around the lung bases. The diaphragmatic motion during the 4-D CT scan was highly variable with a range of 0.4-3.4 cm (SD 0.81 cm) in the right lung and 0-2.8 cm (SD 0.83 cm) in the left lung. Right-sided diaphragmatic nerve palsy was observed in 3 of 15 patients. CONCLUSION: (68)Ga-VQ 4-D PET/CT is feasible and the blurring caused by respiratory motion is well corrected with 4-D acquisition, which principally reduces artefact at the lung bases. The images with the highest spatial overlap were the combined expiration phase or FB PET and average CT. With higher resolution than SPECT/CT, the PET/CT technique has a broad range of potential clinical applications including diagnostic algorithms for patients with suspected pulmonary embolism, preoperative evaluation of regional lung function and improving assessment or understanding of pulmonary physiology in the vast range of pulmonary diseases.

The effect of diabetes during pregnancy on fetal renal parenchymal growth.

AIMS/HYPOTHESIS: Diabetes in pregnancy is thought to adversely affect the developing fetal kidneys. The rate of gestational diabetes is increasing globally with major consequences for future renal function. Very little is known about the impact of hyperglycaemia on the fetal renal parenchyma which contains the developing nephrons. The aim of this study was to measure the fetal renal parenchymal thickness and evaluate whether diabetes during pregnancy affects the growth of the fetal kidneys. METHODS: This prospective, observational study used serial ultrasound measurements to evaluate the fetal renal parenchymal growth of 55 pregnancies with diabetes compared to 72 control pregnancies. Mixed effects modelling was used to analyse the data. RESULTS: The renal parenchyma of fetuses from mothers with gestational diabetes was significantly thicker than those from the control group (LR Chisq = 4.8, df = 1, p = 0.029), however, the difference was proportional to the larger size of these fetuses. Fetuses of pregestational diabetics demonstrated no significant difference in renal parenchymal thickness compared to the control group even though they were also larger fetuses. Parenchymal growth slowed with increasing abdominal circumference in the pregestational diabetic group, suggesting an adverse effect on nephrogenesis, however this did not reach statistical significance. CONCLUSIONS/INTERPRETATION: Our study provides unique data on how diabetes during pregnancy influences fetal kidney growth. Appropriate management of diabetic pregnancies may mitigate some of the adverse effects on the fetal kidneys. Increasing degrees of hyperglycaemia, as seen sometimes in pregestational diabetes, may affect nephrogenesis; however larger studies are needed.

Ultrasound Screening for Adverse Local Tissue Reaction after Hip Arthroplasty.

Early detection of adverse local tissue reaction (ALTR) to prosthetic hip wear debris is vital to improve the success of revision surgery. Magnetic resonance imaging with metal artefact reduction sequencing (MARS MRI) is considered the modality of choice to provide cross-sectional imaging of the soft tissues. The areas adjacent to the prosthesis are, however, not readily imaged using these protocols. Ultrasound has also been recommended as an imaging modality in the follow-up of hip replacement surgery. We decided to characterise the typical ultrasound findings in a group of patients undergoing routine biennial review of arthroplastic hips with particular reference to the hip capsule, femoral neck and iliopsoas bursa and tendon adjacent to the implant. Fifty-two patients with a mean (±SD) age of 60.4 (±12) y were prospectively recruited. Twelve patients had bilateral hip prostheses, giving 64 hips for analysis. Mean (±SD) age of the prosthesis in situ was 8.2 (±3.3) y. Data were grouped on the basis of the shape of the iliofemoral ligament. The median (range) maximal anteroposterior synovial thickness was 5 (2-8) mm in the normal concave iliofemoral ligament group and 7 (4-56) mm in the abnormal straight/convex iliofemoral ligament group (p = 0.001). The anteroposterior iliopsoas tendon measurement was 5 (3-8) mm in the normal group and 5 (4-8) mm in the abnormal group (p = 0.065). ALTR development in asymptomatic well-functioning prostheses may be recognised earlier using ultrasound rather than MARS MRI by carefully assessing the shape of the iliofemoral ligament. Ultrasound findings of an abnormal straight or convex ligament may be suggestive of early ALTR and warrant streaming of patients to a more frequent surveillance program.

Occupational burnout among radiographers, sonographers and radiologists in Australia and New Zealand: Findings from a national survey.

INTRODUCTION: Evidence demonstrates that health care professionals are more prone to burnout than other professionals due to the emotionally taxing interactions they have with their patients on a daily basis. The aims of this study were to measure occupational burnout levels among sonographers, radiographers and radiologists and to examine predictors of burnout according to demographic characteristics. METHODS: A cross-sectional online survey was administered in 2010 to radiographers, sonographers and radiologists who were members of the following professional bodies: Australian Institute of Radiography, Australian Sonographers Association and The Royal Australian and New Zealand College of Radiologists. The Maslach Burnout Inventory was used to measure burnout levels for each profession. Data were analysed using SPSS Ver 20 (IBM, Chicago, IL, USA) statistical software. RESULTS: A total of 613 radiographers, 121 sonographers and 35 radiologists participated in the survey. Radiographers, sonographers and radiologists had a high mean (±SD) burnout score for emotional exhaustion (39.9 ± 8.5, 42.2 ± 8.5 and 44.9 ± 7.1 respectively) and depersonalization (18.9 ± 5.5, 20.3 ± 5.8 and 20.6 ± 5.6) compared to MBI norms. Radiographers also had low personal achievement (30.8 ± 5.5) compared to MBI norms. Radiographers and sonographers who were male, worked >10 hours overtime and spent <10% of their time training students per week had significantly higher depersonalization scores (p < 0.05). CONCLUSION: Burnout levels among radiographers, sonographers and radiologists are high and likely to vary according to some demographic and work-related factors. Further research is needed to examine ways to alleviate burnout in these professions so that loss of experienced staff due to burnout can be minimized and quality of patient care can be maintained.

Brain Surface Heating After Exposure to Ultrasound: An Analysis Using Thermography.

Ultrasound is the imaging modality of choice to monitor brain pathologies in neonates after complicated deliveries. Animal studies have indicated that ultrasound may cause heating of brain tissues. To date, no study has explored brain surface heating by ultrasound during clinically relevant exposure. Hence, we investigated heating effects of B-mode and pulsed Doppler (PD) mode on ex vivo lamb brains using thermography. Five brains were scanned for 5 min in B-mode or for 3 min, 1 min, 30 s or 15 s in PD mode. Brain surface temperature was measured pre- and post-exposure using thermography. The highest mean temperature increase was recorded by B-mode (3.82 ± 0.43°C). All five PD exposure protocols were associated with surface temperature increases of 2.1-2.7°C. These outcomes highlight for the first time that B-mode ultrasound can contribute to brain surface heating during a routine cranial scan. Scan duration should be minimised whenever possible.

A soft patellar tendon on ultrasound elastography is associated with pain and functional deficit in volleyball players.

OBJECTIVES: To investigate the diagnostic performance of grey scale Ultrasound (US), power Doppler (PD) and US elastography for diagnosing painful patellar tendinopathy, and to establish their relationship with Victorian Institute of Sport Assessment-Patella (VISA-P) scores in a group of volleyball players with and without symptoms of patellar tendinopathy. DESIGN: Cross-sectional study. METHODS: Thirty-five volleyball players (70 patellar tendons) were recruited during a national university volleyball competition. Players were imaged with conventional US followed by elastography. The clinical findings of painful patellar tendons were used as the reference standard for diagnosing patellar tendinopathy. In addition, all participants completed the VISA-P questionnaires. RESULTS: Of the 70 patellar tendons, 40 (57.1%) were clinically painful. The diagnostic accuracy of grey scale US, PD and elastography were 60%, 50%, 62.9%, respectively, with sensitivity/specificity of 72.5%/43.3%, 12.5%/100%, and 70%/53.3%, respectively. Combined US elastography and grey scale imaging achieved 82.5% sensitivity, 33.3% specificity and 61.4% accuracy while routine combination technique of PD and grey scale imaging revealed 72.5% sensitivity, 43.3% specificity and 60.0% accuracy. Tendons in players categorized as soft on elastography had statistically significantly greater AP thickness (p<0.001) and lower VISA-P scores (p=0.004) than those categorized as hard. There was no significant association between grey scale US abnormalities (hypoechogenicities and/or fusiform swelling) and VISA-P scores (p=0.098). CONCLUSIONS: Soft tendon properties depicted by US elastography may be more related to patellar tendon symptoms compared to grey scale US abnormalities. The supplementation of US elastography to conventional US may enhance the sensitivity for diagnosing patellar tendinopathy in routine clinical practice.

An Online Survey Investigating Australian Radiation Therapists' Responses to Hypothetical Dilemmas Concerning Impaired Fitness to Practise.

INTRODUCTION: Impairment in health care professionals has been identified as one of the determinants of fitness to practise (FTP), and practitioners have a legal obligation to notify regulatory authorities if they experience it. However, there remains confusion as to how radiation therapists (RTs) discern what constitutes impaired practice and how they would respond to such dilemmas. The aim of this study was to identify the range of responses to hypothetical professional impairment dilemmas, which may inform an educational strategy for improving reporting occurrences. METHODS: A convenience sample of Australian RTs was invited to participate in an anonymous online survey that presented a range of FTP dilemmas relating to impairment, competence, and values/ethics. Participants were asked to describe how they would deal with such situations. Qualitative responses were coded using NVivo software. This article reports on the themes that emerged from the impairment dilemmas. RESULTS: One hundred eighty-two RTs responded to the survey. The emerging key theme and subthemes included dealing with the situation, removal of the practitioner from the situation, stop working, avoiding responsibility, giving the benefit of the doubt, and carrying on with the workload. CONCLUSIONS: Practitioners' interpretations of the impairment dilemmas varied, which, in turn, influenced their suggestions of how they would deal with them. The continuum of responses supports a key tenant of the interpretive paradigm-multiple interpretations of social phenomena exist. Those seeking to improve practitioner understanding of their obligations under national law should consider a scenario-based approach to raising awareness of FTP issues such as impairment.

A prospective investigation into the clinical impact of 4D-PET/CT in the characterisation of solitary pulmonary nodules.

BACKGROUND: While the effects of respiratory motion on measuring metabolic signal in PET/CT scanning are well known, it is still standard practice in most centres to scan patients while breathing freely with no correction for the effects of respiratory motion. The aim of this study was to investigate the impact of 4D-PET/CT in classifying lesions in patients with a radiologically-indeterminate solitary pulmonary nodule. METHODS: Twenty consecutive patients with a solitary pulmonary nodule for investigation were prospectively recruited and completed a whole-body (WB)-PET/CT and 4D-PET/CT in the same session. The reporting physician initially classified the nodule using a 5-point scale (Definitely Malignant, Probably Malignant, Indeterminate, Probably benign, Definitely Benign) on the WB-PET/CT. The physician was then shown the 4D-PET/CT and asked if they would re-classify the lesion. Frequency, sensitivity, specificity and accuracy values were calculated for WB-PET/CT alone and then with the addition of the 4D-PET/CT. RESULTS: There were no changes in the classification for nodules initially classed as either benign or malignant with the addition of a 4D-PET/CT. However changes were observed between WB and 4D-PET/CT scans in lesions initially classified as indeterminate. When indeterminate lesions were defined as malignant there was a minor increase in sensitivity (from 73% to 75%), in specificity (56%-63%) and in accuracy (65%-70%) but these results do not reach statistical significance. When the Indeterminate lesions were defined as benign there was an increase in sensitivity (from 55% to 67%) but there was a reduction in the specificity (100%-75%) and accuracy (75%-70%) with the addition of the 4D-PET/CT but again the results did not reach statistical significance. CONCLUSION: The addition of 4D-PET/CT is most likely to have an impact on those nodules initially classified as indeterminate on standard WB-PET/CT. In lesions classified as benign or malignant on standard WB-PET/CT the addition of a 4D-PET/CT is less likely to impact lesion classification. While 4D-PET/CT does improve the measurement of the metabolic signal, it does not overcome inherent limitations of FDG in differentiating a malignant lesion from inflammatory processes, correct for partial volume effects or compensate for the low intrinsic FDG-avidity of some malignancies.

Geographic miss of lung tumours due to respiratory motion: a comparison of 3D vs 4D PET/CT defined target volumes.

BACKGROUND: PET/CT scans acquired in the radiotherapy treatment position are typically performed without compensating for respiratory motion. The purpose of this study was to investigate geographic miss of lung tumours due to respiratory motion for target volumes defined on a standard 3D-PET/CT. METHODS: 29 patients staged for pulmonary malignancy who completed both a 3D-PET/CT and 4D-PET/CT were included. A 3D-Gross Tumour Volume (GTV) was defined on the standard whole body PET/CT scan. Subsequently a 4D-GTV was defined on a 4D-PET/CT MIP. A 5 mm, 10 mm, 15 mm symmetrical and 15×10 mm asymmetrical Planning Target Volume (PTV) was created by expanding the 3D-GTV and 4D-GTV's. A 3D conformal plan was generated and calculated to cover the 3D-PTV. The 3D plan was transferred to the 4D-PTV and analysed for geographic miss. Three types of miss were measured. Type 1: any part of the 4D-GTV outside the 3D-PTV. Type 2: any part of the 4D-PTV outside the 3D-PTV. Type 3: any part of the 4D-PTV receiving less than 95% of the prescribed dose. The lesion motion was measured to look at the association between lesion motion and geographic miss. RESULTS: When a standard 15 mm or asymmetrical PTV margin was used there were 1/29 (3%) Type 1 misses. This increased 7/29 (24%) for the 10 mm margin and 23/29 (79%) for a 5 mm margin. All patients for all margins had a Type 2 geographic miss. There was a Type 3 miss in 25 out of 29 cases in the 5, 10, and 15 mm PTV margin groups. The asymmetrical margin had one additional Type 3 miss. Pearson analysis showed a correlation (p < 0.01) between lesion motion and the severity of the different types of geographic miss. CONCLUSION: Without any form of motion suppression, the current standard of a 3D- PET/CT and 15 mm PTV margin employed for lung lesions has an increasing risk of significant geographic miss when tumour motion increases. Use of smaller asymmetric margins in the cranio-caudal direction does not comprise tumour coverage. Reducing PTV margins for volumes defined on 3D-PET/CT will greatly increase the chance and severity of a geometric miss due to respiratory motion. 4D-imaging reduces the risk of geographic miss across the population of tumour sizes and magnitude of motion investigated in the study.

Sonographic response in the liver and urinary bladder of children 14 months after treatment for schistosomiasis.

After praziquantel treatment for schistosomiasis, parasitological cure rates of 60%-90% are usual. Does this response to treatment correlate with the improvement in liver and bladder changes seen on ultrasound in children? This study shows that ultrasound is an effective way to evaluate liver and bladder changes caused by schistosomiasis infection in children and to assess treatment effects after mass treatment programmes.