A rapid high-performance semi-automated tool to measure total kidney volume from MRI in autosomal dominant polycystic kidney disease.

OBJECTIVES: To develop a high-performance, rapid semi-automated method (Sheffield TKV Tool) for measuring total kidney volume (TKV) from magnetic resonance images (MRI) in patients with autosomal dominant polycystic kidney disease (ADPKD). METHODS: TKV was initially measured in 61 patients with ADPKD using the Sheffield TKV Tool and its performance compared to manual segmentation and other published methods (ellipsoidal, mid-slice, MIROS). It was then validated using an external dataset of MRI scans from 65 patients with ADPKD. RESULTS: Sixty-one patients (mean age 45 ± 14 years, baseline eGFR 76 ± 32 ml/min/1.73 m2) with ADPKD had a wide range of TKV (258-3680 ml) measured manually. The Sheffield TKV Tool was highly accurate (mean volume error 0.5 ± 5.3% for right kidney, - 0.7 ± 5.5% for left kidney), reproducible (intra-operator variability - 0.2 ± 1.3%; inter-operator variability 1.1 ± 2.9%) and outperformed published methods. It took less than 6 min to execute and performed consistently with high accuracy in an external MRI dataset of T2-weighted sequences with TKV acquired using three different scanners and measured using a different segmentation methodology (mean volume error was 3.45 ± 3.96%, n = 65). CONCLUSIONS: The Sheffield TKV Tool is operator friendly, requiring minimal user interaction to rapidly, accurately and reproducibly measure TKV in this, the largest reported unselected European patient cohort with ADPKD. It is more accurate than estimating equations and its accuracy is maintained at larger kidney volumes than previously reported with other semi-automated methods. It is free to use, can run as an independent executable and will accelerate the application of TKV as a prognostic biomarker for ADPKD into clinical practice. KEY POINTS: • This new semi-automated method (Sheffield TKV Tool) to measure total kidney volume (TKV) will facilitate the routine clinical assessment of patients with ADPKD. • Measuring TKV manually is time consuming and laborious. • TKV is a prognostic indicator in ADPKD and the only imaging biomarker approved by the FDA and EMA.

A study to quantify the effect of patient motion and develop methods to detect and correct for motion during myocardial perfusion imaging on a CZT solid-state dedicated cardiac camera.

BACKGROUND: Due to differences in the design and acquisition parameters on the solid-state CZT cardiac camera the effect of patient motion may vary compared to Anger cameras. This study evaluates the effect of motion, two new methods of three-dimensional (3D) motion detection and a method of motion correction. METHOD: Phantom acquisitions were offset in the X, Y, and Z directions and combined to simulate different types of motion. Motion artifacts were identified using the total perfusion defect and blinded visual interpretation. Motion was detected by registering planar and reconstructed 30 second images, and corrected by summing the aligned reconstructed images. Validation was performed on phantom data. These techniques were then applied to 40 patient studies. RESULTS: Motion ≥10 mm and ≥60 seconds in duration introduced significant artifacts. There was no significant difference (P = .258) between the two methods of motion detection. Motion correction removed artifacts from 9/10 phantom simulations. Superior-inferior motion ≥8 mm was measured on 10% of patient studies, and 5% were affected by motion. Motion in the lateral and anterior-posterior directions was <8 mm. CONCLUSION: Superior-inferior patient motion artifacts have been identified on myocardial perfusion images acquired on a CZT camera. Routine QC to identify studies with significant motion is recommended.

Development of two electronic bladder diaries: a patient and healthcare professionals pilot study.

AIMS: Assess patients' preferences in a pilot crossover study of two different electronic voiding diaries against a standard paper diary. Assess urological health professional (HP) opinions on the electronic bladder diary reporting system. METHODS: Two different electronic diaries were developed: (1) electronically read diary-a card with predefined slots read by a card reader and (2) e-diary-a handheld touch screen device. Data uploaded from either electronic diary produced an electronic report. We recruited 22 patients split into two cohorts for each electronic diary, 11 completed each type of electronic diary for 3 days either preceded or followed by a standard paper diary for 3 days. Both diaries were completed on the 7th day. Patients' perceptions of both diaries were recorded using a standardized questionnaire. A HP study recruited 22 urologists who were given the paper diary and the electronic reports. Time taken for analysis was recorded along with accuracy and HP preferences. RESULTS: The majority of patients (82%) preferred the e-diary and only 1/11 found it difficult to use. Patients had the same preference for the electronically read diary as the paper diary. The paper diary took 66% longer to analyze than the electronic report (P < 0.001) and was analyzed with an accuracy of 58% compared to 100%. Slightly more HP (9%) preferred the electronic report to the paper diary. CONCLUSIONS: This proposed e-diary with its intuitive interface has overcome previous deficiencies in electronic diaries with most patients finding the format user-friendly. Electronic reports make analysis and interpretation by HP quicker and more accurate.

Identifying individual enablers and barriers to the use of digital technology for the self-management of long-term conditions by older adults.

Evidence suggests that much of the digital technology available and provided to older adults to enable self-management of long-term conditions is under-utilised. This research focuses on three conditions prevalent amongst older adults: diabetes, dementia and chronic kidney disease and explores the individual enablers and barriers to the use of digital self-management technology. The paper reports findings from a series of three systematic reviews of qualitative research (qualitative evidence syntheses). These reviews informed the design of a Delphi study. The first round of the Delphi involving 15 expert interviews is reported. The findings highlight common themes across the three conditions: how technology is used; barriers to use; assessing individual needs when selecting technology; support requirements; multi-functional self-management technologies; trust, privacy and data sharing; achieving accessible and aspirational design. Some emerging recommendations have been suggested to guide the design, and provision of technology to older adults. These will extended and refined through subsequent rounds of the Delphi method.

Usability engineering in practice: developing an intervention for post-stroke therapy during a global pandemic.

This paper provides an overview of the usability engineering process and relevant standards informing the development of medical devices, together with adaptations to accommodate situations such as global pandemics where use of traditional face-to-face methods is restricted. To highlight some of those adaptations, a case study of a project developing a novel electronic rehabilitation device is referenced, which commenced in November 2020 amidst the COVID-19 pandemic. The Sheffield Adaptive Patterned Electrical Stimulation (SHAPES) project, led by Sheffield Teaching Hospitals NHS Foundation Trust (STH), aimed to design, manufacture and trial an intervention for use to treat upper arm spasticity after stroke. Presented is an outline and discussion of the challenges experienced in developing the SHAPES health technology intended for at-home use by stroke survivors and in implementing usability engineering approaches. Also highlighted, are the benefits that arose, which can offer easier involvement of vulnerable users and add flexibility in the ways that user feedback is sought. Challenges included: restricted travel; access to usual prototyping facilities; social distancing; infection prevention and control; availability of components; and changing work pressures and demands. Whereas benefits include: less travel; less time commitment; and greater scope for participants with restricted mobility to participate in the process. The paper advocates a more flexible approach to usability engineering and outlines the onward path for development and trialling of the SHAPES technology.

Fit for purpose? A cross-sectional study to evaluate the acceptability and usability of HeadUp, a novel neck support collar for neurological neck weakness.

The HeadUp collar (previously known as the Sheffield Support Snood) provides support for neck weakness caused by amyotrophic lateral sclerosis (ALS) and has shown to be superior to alternative options in a small cohort of patients from one single center. Here we report the assessment of the HeadUp collar in a larger cohort of patients, exploring the use in other neurological conditions and expanding to other centers across the UK and Ireland. An interventional cross-sectional study design was implemented to investigate the usability and acceptability of the HeadUp collar. A total of 139 patients were recruited for the study, 117 patients had a diagnosis of ALS and 22 patients presented with neck weakness due to other neurological conditions. Participants were assessed at baseline, fitted a HeadUp collar and followed-up one month later. The performance of the HeadUp collar was rated favorably compared to previously worn collars in terms of the ability to eat, drink and swallow. Findings suggest that the collar also permitted a more acceptable range of head movements whilst maintaining a good level of support. We conclude that the HeadUp collar is a suitable option for patients with neck weakness due to ALS and other neurological conditions.

Efficacy of the Head Up collar in facilitating functional head movements in patients with Amyotrophic Lateral Sclerosis.

BACKGROUND: The Head Up collar is a cervical orthosis designed to be adaptable to a patient's needs using adjustable removable supports. The aim of this study was to characterise the ability of this orthosis to provide head support and facilitate the control of head movements in people living with Amyotrophic Lateral Sclerosis. METHODS: Thirteen patients (6 females, age range: 45-74 years old, Amyotrophic Lateral Sclerosis Functional Rating Scale range: 13-44) with neck muscle weakness due to Amyotrophic Lateral Sclerosis were enrolled in the study. An additional inclusion criterion was the presence of enough residual muscle strength to enable the performance of the test procedure. Participants were asked to perform a series of head movements with and without wearing the collar. Two parameters (mean angular velocity and ratio of movement coupling) were extracted from recorded angular velocities, to quantify changes in the execution of the movement between the two conditions. FINDINGS: Participants exhibited different levels of impairment in performing different movements. When wearing the collar self-selected movement velocity was preserved and significant improvement in the control of lateral flexion movement was observed (median ratio of movement coupling value reduced from 1.1 to 0.84, P = 0.013). A lower ratio of movement coupling was also observed in 4 out of 7 individuals that were fitted with anterior supports. INTERPRETATION: The heterogeneity observed in the level of impairment and residual function highlights the need for personalized interventions. The Head Up was effective in enabling more controlled movements and maintaining the natural velocity of head movement.

Nonrigid image registration for head and neck cancer radiotherapy treatment planning with PET/CT.

PURPOSE: Head and neck radiotherapy planning with positron emission tomography/computed tomography (PET/CT) requires the images to be reliably registered with treatment planning CT. Acquiring PET/CT in treatment position is problematic, and in practice for some patients it may be beneficial to use diagnostic PET/CT for radiotherapy planning. Therefore, the aim of this study was first to quantify the image registration accuracy of PET/CT to radiotherapy CT and, second, to assess whether PET/CT acquired in diagnostic position can be registered to planning CT. METHODS AND MATERIALS: Positron emission tomography/CT acquired in diagnostic and treatment position for five patients with head and neck cancer was registered to radiotherapy planning CT using both rigid and nonrigid image registration. The root mean squared error for each method was calculated from a set of anatomic landmarks marked by four independent observers. RESULTS: Nonrigid and rigid registration errors for treatment position PET/CT to planning CT were 2.77 +/- 0.80 mm and 4.96 +/- 2.38 mm, respectively, p = 0.001. Applying the nonrigid registration to diagnostic position PET/CT produced a more accurate match to the planning CT than rigid registration of treatment position PET/CT (3.20 +/- 1.22 mm and 4.96 +/- 2.38 mm, respectively, p = 0.012). CONCLUSIONS: Nonrigid registration provides a more accurate registration of head and neck PET/CT to treatment planning CT than rigid registration. In addition, nonrigid registration of PET/CT acquired with patients in a standardized, diagnostic position can provide images registered to planning CT with greater accuracy than a rigid registration of PET/CT images acquired in treatment position. This may allow greater flexibility in the timing of PET/CT for head and neck cancer patients due to undergo radiotherapy.

An Objective Functional Characterisation of Head Movement Impairment in Individuals with Neck Muscle Weakness Due to Amyotrophic Lateral Sclerosis.

BACKGROUND: Neck muscle weakness and head drop are well recognised in patients with Amyotrophic lateral sclerosis (ALS), but an objective characterisation of the consequent head movement impairment is lacking. The aim of this study was to quantitatively characterise head movements in ALS compared to aged matched controls. METHODS: We evaluated two groups, one of thirteen patients with ALS and one of thirteen age-matched controls, during the execution of a series of controlled head movements, performed while wearing two inertial sensors attached on the forehead and sternum, respectively. We quantified the differences between the two groups from the sensor data using indices of velocity, smoothness and movement coupling (intended as a measure of undesired out of plane movements). FINDINGS: Results confirmed a general limitation in the ability of the ALS patients to perform and control head movements. High inter-patient variability was observed due to a wide range of observed functional impairment levels. The ability to extend the head backward and flex it laterally were the most compromised, with significantly lower angular velocity (P < 0.05, Cohen's d > 0.8), reduced smoothness and greater presence of coupled movements with respect to the controls. A significant reduction of angular velocity (P < 0.05, Cohen's d > 0.8) in extension, axial rotation and lateral flexion was observed when patients were asked to perform the movements as fast as possible. INTERPRETATION: This pilot study is the first study providing a functional objective quantification of head movements in ALS. Further work involving different body areas and correlation with existing methods of evaluating neuromuscular function, such as dynamometry and EMG, is needed to explore the use of this approach as a marker of disease progression in ALS.

Assessment of the Sheffield Support Snood, an innovative cervical orthosis designed for people affected by neck muscle weakness.

BACKGROUND: This study aimed at quantifying the biomechanical features of the Sheffield Support Snood, a cervical orthosis specifically designed for patients with neck muscle weakness. The orthosis is designed to be adaptable to a patient's level of functional limitation using adjustable removable supports, which contribute support and restrict movement only in desired anatomical planes. METHODS: The snood was evaluated along with two commercially available orthoses, the Vista and Headmaster, in a series of flexion, extension, axial-rotation and lateral flexion movements. Characterization was performed with twelve healthy participants with and without the orthoses. Two inertial-magneto sensors, placed on the forehead and sternum, were used to quantify the neck's range of motion. FINDINGS: In its less supportive configuration, the snood was effective in limiting movements to the desired planes, preserving free movement in other planes. The Headmaster was only effective in limiting flexion. The range of motion achieved with the snood in its rigid configuration was equivalent (P>0.05, effect size<0.4) to that achieved with the Vista, both in trials performed reaching the maximum amplitude (range of motion reduction: 25%-34% vs 24%-47%) and at maximum speed (range of motion reduction: 24%-29% vs 25%-43%). INTERPRETATION: The Sheffield Support Snood is effectively adaptable to different tasks and, in its most supportive configuration, offers a support comparable to the Vista, but providing a less bulky structure. The chosen method is suitable for the assessment of range of motions while wearing neck orthoses and is easily translatable in a clinical context.

Implications of the UK NHS consent policy for nuclear medicine practice.

To comply with government policy on consent, the Sheffield Teaching Hospitals (STH) National Health Service (NHS) Trust introduced a new consent policy in February 2002. Verbal or written consent (depending on the level of risk) must be obtained prior to each study. The patient must be fully informed and given time to reach a decision. Consideration needs to be given to the following: to whom, when and how to provide such information and obtain consent. Each study type and patient circumstance needs to be classified according to risk. Consideration of the risks resulted in a local policy in which written consent is required for the following: therapeutic procedures, studies on pregnant women, studies in which pregnancy needs to be avoided, research procedures, cardiac stress for myocardial perfusion scintigraphy and intrathecal administration. Patient information leaflets have been updated with new information about the study and any risks. Information is now available for both patients and hospital staff. Compliance with the consent policy in a service department provides logistic challenges, but it is possible to fully inform patients in advance about their treatment, allowing them to give informed consent.

Healthcare technology co-operatives: Innovative about innovation.

The paper provides an introduction to the National Institute for Health Research Devices for Dignity Healthcare Technology Co-operative. Embedded within the NHS, Devices for Dignity identifies areas of unmet clinical need and translates these into research and development projects to develop new medical technologies. It addresses the needs of people living with long-term conditions, helping them to live more dignified and independent lives. Through partnerships with patients, universities, the NHS and industry, Devices for Dignity has developed an innovation methodology for successful medical technology innovation.

Unmet needs: relevance to medical technology innovation?

This paper describes and discusses the role of unmet needs in the innovation of new medical technologies using the National Institute for Health Research Devices for Dignity (D4D) Healthcare Technology Co-operative as a case study. It defines an unmet need, providing a spectrum of classification and discusses the benefits and the challenges of identifying unmet need and its influence on the innovation process. The process by which D4D has captured and utilized unmet needs to drive technology innovation is discussed and examples given. It concludes by arguing that, despite the challenges, defining and reviewing unmet need is a fundamental factor in the success of medical technology innovation.

Head-Up; An interdisciplinary, participatory and co-design process informing the development of a novel head and neck support for people living with progressive neck muscle weakness.

This paper presents the Head-Up project, that aims to provide innovative head support to help improve posture, relieve pain and aid communication for people living with progressive neck muscle weakness. The initial focus is motor neurone disease. The case study illustrates collaborative, interdisciplinary research and new product development underpinned by participatory design. The study was initiated by a 2-day stakeholder workshop followed by early proof-of-concept modelling and patient need evidence building. The work subsequently led to a successful NIHR i4i application funding a 24-month iterative design process, patenting, CE marking and clinical evaluation. The evaluation has informed amendments to the proposed design refered to here as the Sheffield Support Snood (SSS). The outcome positively demonstrates use and performance improvements over current neck orthoses and the process of multidisciplinary and user engagement has created a sense of ownership by MND participants, who have since acted as advocates for the product.

Using a registration-based motion correction algorithm to correct for respiratory motion during myocardial perfusion imaging.

OBJECTIVE: The aim of the study was to develop and evaluate a registration-based motion correction algorithm as a method of reducing respiratory motion artefacts in myocardial perfusion imaging. MATERIALS AND METHODS: The NCAT software was used to build nine male and nine female computer simulations of myocardial perfusion imaging data, with different respiratory motions and left ventricular ejection fractions. Imaging data were generated at various time points throughout each cardiac cycle. The data were summed over each cardiac cycle, forward projected, normalized, noise added and reconstructed with and without motion correction. Motion correction was performed using an algorithm that aligns images within a projection using nonlinear registrations. A standard simulation with no respiratory motion was also generated for comparison. The algorithm was applied to the standard to determine its effect on images with no respiratory motion. RESULTS: The median difference in mean segmental counts compared with the standard was calculated for each simulation. The mean (range) of these values was 3% (1-6%), 14% (12-16%) and 28% (28-29%) for displacements of 1, 2 and 3 cm, respectively. The largest changes occurred inferiorly and anteriorly. Motion correction reduced these differences to 2% (0-4%), 5% (2-7%) and 7% (7-7%), respectively. The process of correcting for motion reduced the mean counts in all segments by 3% (1-5%). CONCLUSION: Artefacts resulting from respiratory motion are improved using our algorithm when motion is 2 cm or greater.

99mTc white-cell imaging in inflammatory bowel disease: a comparison of planar versus SPECT.

OBJECTIVE: 99mTc-labelled white-cell scintigraphy is sensitive and specific for detecting inflammatory bowel disease (IBD). A retrospective analysis was carried out on 99 consecutive studies to compare results from planar imaging and single photon emission computed tomography (SPECT). MATERIALS AND METHODS: Two observers blindly and independently reported all planar images followed by the SPECTs. Both sets of scans were reported in random order. All possible abnormalities were assigned a confidence rating and specific, preagreed bowel location and their extent measured. RESULTS: The observers disagreed on whether studies were normal in 17 of 99 planar scans (κ=0.56) but only eight of 99 SPECTs (κ=0.83). Consensus reporting, where there was disagreement between observers, yielded the following results: planar and SPECT normal in 56 of 99 cases; planar and SPECT positive in 29 of 99 cases; planar normal but SPECT positive in 13 of 99 cases; planar positive but SPECT normal in one of 99 cases. In the 14 of 99 cases where there was discordance between planar and SPECT, confirmation of active IBD was sought from other investigations (e.g. histology). Relevant other investigations were available in eight of these discordant cases and showed agreement with the SPECT result in seven of eight patients. Where the same abnormalities were identified in both planar and SPECT, there was a significant increase (P<0.001 mean: 57 mm) in the extent of abnormalities as measured from SPECT compared with planar. CONCLUSION: Reporting from SPECT improves inter-operator variability and appears to improve sensitivity for detecting IBD. Planar imaging also appears to underestimate the extent of active disease.

Correlation of left ventricular count rate with patient weight in Tc-99m myocardial perfusion imaging.

OBJECTIVES: The aim of this retrospective investigation was to devise a protocol for obtaining consistent myocardial counts for patients attending myocardial perfusion imaging. METHODS: A total of 229 patients were included in the study sample. For each rest single-photon emission computed tomography data set, a three-dimensional ellipse was manually defined to isolate the left ventricle. The count rate per voxel was measured from a threshold region of interest covering the normally perfused myocardium (70-100% of maximum counts). Data were normalized for net administered activity and plotted against patient weight. The correlation between the variables was used to derive a protocol for adjusting injected activity or scan time to obtain consistent counts from patient to patient. RESULTS: There was a significant correlation between counts per second per voxel per MBq and patient weight. The best fit was achieved with an inverse model. A correlation equation was derived for patients weighing more than 60 kg (combined R=0.79): [CPS/voxel/MBq=(0.0163/weight(kg)]-3.68×10+A in which A, a sex-dependent constant, was 0 for men and -2.920×10 for women. CONCLUSION: There was a significant inverse correlation between patient weight and CPS per voxel per MBq.