The potential for learning within hospital learning communities: the interplay between nursing practice and education to support research ability.

Objectives Nurses must contribute to the development of professional practice and thereby improve quality of care by using their research abilities. Therefore, learning communities comprised of nurses, students and teachers were created in a hospital. Methods A qualitative descriptive methodology was used. Three learning communities were purposefully selected, and members were asked open-ended questions about their learning and activities in multiple data collection sessions. Data were analyzed by means of an inductive process. Results Both individually and collectively, members learned about research in general, research terminology and methods. They learned about asking questions and critical thinking, and, specifically through collective learning, they learned about the differences between education practices. Activities were carried out primarily to continue personal learning. Conclusions Learning within the learning communities was mainly research-oriented and therefore potentially suitable for enhancing research ability. Implications are offered to support the formulation of community activities.

Iodine Maps from Subtraction CT or Dual-Energy CT to Detect Pulmonary Emboli with CT Angiography: A Multiple-Observer Study.

Background Dual-energy CT iodine maps are used to detect pulmonary embolism (PE) with CT angiography but require dedicated hardware. Subtraction CT, a software-only solution, results in iodine maps with high contrast-to-noise ratios. Purpose To compare the use of subtraction CT versus dual-energy CT iodine maps to CT angiography for PE detection. Materials and Methods In this prospective study ( https://clinicaltrials.gov , NCT02890706), 274 participants suspected of having PE underwent precontrast CT followed by contrast material-enhanced dual-energy CT angiography between July 2016 and April 2017. Iodine maps from dual-energy CT were derived. Subtraction maps (contrast-enhanced CT minus precontrast CT) were calculated after motion correction. Truth was established by expert consensus. A total of 75 randomly selected participants with and without PE (1:1 ratio) were evaluated by three radiologists and six radiology residents (blinded to final diagnosis) for the presence of PE using three types of CT: CT angiography alone, dual-energy CT, and subtraction CT. The partial area under the receiver operating characteristic curve (AUC) for the clinically relevant specificity region (maximum partial AUC, 0.11) was compared by using multireader multicase variance. A P value less than or equal to .025 was considered indicative of a significant difference due to multiple comparisons. Results There were 35 men and 40 women in the reader study (mean age, 63 years ± 12 [standard deviation]). The pooled sensitivities were not different (P ≥ .31 among techniques) (95% confidence intervals [CIs]: 67%, 89% for CT angiography; 72%, 91% for dual-energy CT; 70%, 91% for subtraction CT). However, pooled specificity was higher for subtraction CT (95% CI: 100%, 100%) than for CT angiography (95% CI: 89%, 97%) or dual-energy CT (95% CI: 89%, 98%) (P < .001). Partial AUCs for the average observer improved equally when adding iodine maps (subtraction CT [0.093] vs CT angiography [0.088], P = .03; dual-energy CT [0.094] vs CT angiography, P = .01; dual-energy CT vs subtraction CT, P = .68). Average reading times were equivalent (range, 97-101 seconds; P ≥ .41) among techniques. Conclusion Subtraction CT iodine maps had greater specificity than CT angiography alone in pulmonary embolism detection. Subtraction CT had comparable diagnostic performance to that of dual-energy CT, without the need for dedicated hardware. © RSNA, 2019 Online supplemental material is available for this article.

Image Quality of Iodine Maps for Pulmonary Embolism: A Comparison of Subtraction CT and Dual-Energy CT.

OBJECTIVE. The objective of this study was to compare the image quality of iodine maps derived from subtraction CT and from dual-energy CT (DECT) in patients with suspected pulmonary embolism (PE). SUBJECTS AND METHODS. In this prospective study conducted between July 2016 and April 2017, consecutive patients with suspected PE underwent unenhanced CT at 100 kV and dual-energy pulmonary CT angiography at 100 and 140 kV on a dual-source scanner. The scanner was set to generate subtraction and DECT iodine maps at similar radiation doses. In 55 patients (30 women, 25 men; mean age ± SD, 63.4 ± 11.9 years old), various subjective image quality criteria including diagnostic acceptability were rated on a 5-point scale by four radiologists and a radiology resident. In 29 patients (17 women, 12 men; mean age, 62.4 ± 11.7 years old) with confirmed perfusion defects, the signal-difference-to-noise ratio (SDNR) between perfusion defects and adjacent normally perfused parenchyma was measured in corresponding ROIs on subtraction and DECT iodine maps. McNemar and Wilcoxon signed-rank tests were used for statistical comparisons. RESULTS. Diagnostic acceptability was rated excellent or good in a mean of 67% (range, 31-80%) of subtraction CT studies and 36% (5-69%) of DECT studies (p < 0.05 for four of the five radiologists), mainly because of fewer artifacts on subtraction CT. Mean SDNR was marginally higher for subtraction CT than for DECT (18.6 vs 17.1, p = 0.06) and was significantly higher in the upper lobes (21.8 vs 17.9, p < 0.05). CONCLUSION. Radiologist-judged image quality of pulmonary iodine maps was higher for subtraction CT than for DECT with similar to higher SDNR. Subtraction CT is a software-only solution, so it may be an attractive alternative to DECT for depicting perfusion defects.

Long-Term Serial Follow-Up of Pulmonary Artery Size and Wall Shear Stress in Fontan Patients.

Pulmonary arterial (PA) flow is abnormal after the Fontan operation and is marked by a lack of pulsatility. We assessed the effects of this abnormal flow on the size and function of the PA's in Fontan patients in long-term serial follow-up. Twenty-three Fontan patients with serial follow-up were included. Median age was 11.1 (9.5-16.0) years at baseline and 15.5 (12.5-22.7) years at follow-up. Median follow-up duration was 4.4 (4.0-5.8) years. Flow and size of the left pulmonary artery were determined using phase-contrast MRI. From this wall shear stress (WSS), distensibility and pulsatility were determined. A group of healthy peers was included for reference. Flow and pulsatility were significantly lower in patients than in controls (p < 0.001). Mean area was comparable in patients and controls, but distensibility was significantly higher in controls (p < 0.001). Mean and peak WSS were significantly lower in Fontan patients (p < 0.001). Between baseline and follow-up, there was a significant increase in normalized flow (15.1 (14.3-19.1) to 18.7 (14.0-22.6) ml/s/m(2), p = 0.023). Area, pulsatility, distensibility and WSS did not change, but there was a trend toward a lower mean WSS (p = 0.068). Multivariable regression analysis showed that flow, area and age were important predictors for WSS. WSS in Fontan patients is decreased compared to healthy controls and tends to decrease further with age. Pulsatility and distensibility are significantly lower compared to healthy controls. Pulmonary artery size, however, is not significantly different from healthy controls and long-term growth after Fontan operation is proportionate to body size.

Nurturing Cultural Change in Care for Older People: Seeing the Cherry Tree Blossom.

There is a need for person-centred approaches and empowerment of staff within the residential care for older people; a movement called 'culture change'. There is however no single path for achieving culture change. With the aim of increasing understandings about cultural change processes and the promotion of cultural values and norms associated with person-centred practices, this article presents an action research project set on a unit in the Netherlands providing care for older people with dementia. The project is presented as a case study. This study examines what has contributed to the improvement of participation of older people with dementia in daily occupational and leisure activities according to practitioners. Data was collected by participant observation, interviews and focus groups. The results show that simultaneous to the improvement of the older people's involvement in daily activities a cultural transformation took place and that the care became more person-centred. Spontaneous interactions and responses rather than planned interventions, analysis and reflection contributed to this. Furthermore, it proved to be beneficial that the process of change and the facilitation of that process reflected the same values as those underlying the cultural change. It is concluded that changes arise from dynamic, interactive and non-linear processes which are complex in nature and difficult to predict and to control. Nevertheless, managers and facilitators can facilitate such change by generating movement through the introduction of small focused projects that meet the stakeholders' needs, by creating conditions for interaction and sense making, and by promoting the new desired cultural values.

Computer-aided detection improves detection of pulmonary nodules in chest radiographs beyond the support by bone-suppressed images.

PURPOSE: To evaluate the added value of computer-aided detection (CAD) for lung nodules on chest radiographs when radiologists have bone-suppressed images (BSIs) available. MATERIALS AND METHODS: Written informed consent was waived by the institutional review board. Selection of study images and study setup was reviewed and approved by the institutional review boards. Three hundred posteroanterior (PA) and lateral chest radiographs (189 radiographs with negative findings and 111 radiographs with a solitary nodule) in 300 subjects were selected from image archives at four institutions. PA images were processed by using a commercially available CAD, and PA BSIs were generated. Five radiologists and three residents evaluated the radiographs with BSIs available, first, without CAD and, second, after inspection of the CAD marks. Readers marked locations suspicious for a nodule and provided a confidence score for that location to be a nodule. Location-based receiver operating characteristic analysis was performed by using jackknife alternative free-response receiver operating characteristic analysis. Area under the curve (AUC) functioned as figure of merit, and P values were computed with the Dorfman-Berbaum-Metz method. RESULTS: Average nodule size was 16.2 mm. Stand-alone CAD reached a sensitivity of 74% at 1.0 false-positive mark per image. Without CAD, average AUC for observers was 0.812. With CAD, performance significantly improved to an AUC of 0.841 (P = .0001). CAD detected 127 of 239 nodules that were missed after evaluation of the radiographs together with BSIs pooled over all observers. Only 57 of these detections were eventually marked by the observers after review of CAD candidates. CONCLUSION: CAD improved radiologists' performance for the detection of lung nodules on chest radiographs, even when baseline performance was optimized by providing lateral radiographs and BSIs. Still, most of the true-positive CAD candidates are dismissed by observers.

Increase in perceived case suspiciousness due to local contrast optimisation in digital screening mammography.

OBJECTIVES: To determine the influence of local contrast optimisation on diagnostic accuracy and perceived suspiciousness of digital screening mammograms. METHODS: Data were collected from a screening region in the Netherlands and consisted of 263 digital screening cases (153 recalled,110 normal). Each case was available twice, once processed with a tissue equalisation (TE) algorithm and once with local contrast optimisation (PV). All cases had digitised previous mammograms. For both algorithms, the probability of malignancy of each finding was scored independently by six screening radiologists. Perceived case suspiciousness was defined as the highest probability of malignancy of all findings of a radiologist within a case. Differences in diagnostic accuracy of the processing algorithms were analysed by comparing the areas under the receiver operating characteristic curves (A(z)). Differences in perceived case suspiciousness were analysed using sign tests. RESULTS: There was no significant difference in A(z) (TE: 0.909, PV 0.917, P = 0.46). For all radiologists, perceived case suspiciousness using PV was higher than using TE more often than vice versa (ratio: 1.14-2.12). This was significant (P <0.0083) for four radiologists. CONCLUSIONS: Optimisation of local contrast by image processing may increase perceived case suspiciousness, while diagnostic accuracy may remain similar. KEY POINTS: Variations among different image processing algorithms for digital screening mammography are large. Current algorithms still aim for optimal local contrast with a low dynamic range. Although optimisation of contrast may increase sensitivity, diagnostic accuracy is probably unchanged. Increased local contrast may render both normal and abnormal structures more conspicuous.

The role of (18)F-FDG PET in the differentiation between lung metastases and synchronous second primary lung tumours.

PURPOSE: In lung cancer patients with multiple lesions, the differentiation between metastases and second primary tumours has significant therapeutic and prognostic implications. The aim of this retrospective study was to investigate the potential of (18)F-FDG PET to discriminate metastatic disease from second primary lung tumours. METHODS: Of 1,396 patients evaluated by the thoracic oncology group between January 2004 and April 2009 at the Radboud University Nijmegen Medical Centre, patients with a synchronous second primary lung cancer were selected. Patients with metastatic disease involving the lungs served as the control group. Maximum standardized uptake values (SUVs) measured with (18)F-FDG PET were determined for two tumours in each patient. The relative difference between the SUVs of these tumours (∆SUV) was determined and compared between the second primary group and metastatic disease group. Receiver-operating characteristic (ROC) curve analysis was performed to determine the sensitivity and specificity of the ∆SUV for an optimal cut-off value. RESULTS: A total of 37 patients (21 metastatic disease, 16 second primary cancer) were included for analysis. The ∆SUV was significantly higher in patients with second primary cancer than in those with metastatic disease (58 vs 28%, respectively, p < 0.001). The area under the ROC curve was 0.81 and the odds ratio for the optimal cut-off was 18.4. CONCLUSION: SUVs from (18)F-FDG PET images can be helpful in differentiating metastatic disease from second primary tumours in patients with synchronous pulmonary lesions. Further studies are warranted to confirm the consistency of these results.

Ventricular response to dobutamine stress cardiac magnetic resonance imaging is associated with adverse outcome during 8-year follow-up in patients with repaired Tetralogy of Fallot.

AIMS: The aim of this study was to evaluate the possible value of dobutamine stress cardiac magnetic resonance imaging (CMR) to predict adverse outcome in Tetralogy of Fallot (TOF) patients. METHODS AND RESULTS: In previous prospective multicentre studies, TOF patients underwent low-dose dobutamine stress CMR (7.5 µg/kg/min). Subsequently, during regular-care patient follow-up, patients were assessed for reaching the composite endpoint (cardiac death, arrhythmia-related hospitalization, or cardioversion/ablation, VO2 max ≤65% of predicted). A normal stress response was defined as a decrease in end-systolic volume (ESV) and increase in ejection fraction. The relative parameter change during stress was calculated as relative parameter change = [(parameterstress - parameterrest)/parameterrest] * 100. The predictive value of dobutamine stress CMR for the composite endpoint was determined using time-to-event analyses (Kaplan-Meier) and Cox proportional hazard analysis. We studied 100 patients [67 (67%) male, median age at baseline CMR 17.8 years (interquartile range 13.5-34.0), age at TOF repair 0.9 years (0.6-2.1)]. After a median follow-up of 8.6 years (6.7-14.1), 10 patients reached the composite endpoint. An abnormal stress response (30% vs. 4.4%, P = 0.021) was more frequently observed in composite endpoint patients. Also in endpoint patients, the relative decrease in right ventricular ESV decreased less during stress compared with the patients without an endpoint (-17 ± 15 vs. -26 ± 13 %, P = 0.045). Multivariable analyses identified an abnormal stress response (hazard ratio 10.4; 95% confidence interval 2.5-43.7; P = 0.001) as predictor for the composite endpoint. CONCLUSION: An abnormal ventricular response to dobutamine stress is associated with adverse outcome in patients with repaired TOF.

Validation, comparison, and combination of algorithms for automatic detection of pulmonary nodules in computed tomography images: The LUNA16 challenge.

Automatic detection of pulmonary nodules in thoracic computed tomography (CT) scans has been an active area of research for the last two decades. However, there have only been few studies that provide a comparative performance evaluation of different systems on a common database. We have therefore set up the LUNA16 challenge, an objective evaluation framework for automatic nodule detection algorithms using the largest publicly available reference database of chest CT scans, the LIDC-IDRI data set. In LUNA16, participants develop their algorithm and upload their predictions on 888 CT scans in one of the two tracks: 1) the complete nodule detection track where a complete CAD system should be developed, or 2) the false positive reduction track where a provided set of nodule candidates should be classified. This paper describes the setup of LUNA16 and presents the results of the challenge so far. Moreover, the impact of combining individual systems on the detection performance was also investigated. It was observed that the leading solutions employed convolutional networks and used the provided set of nodule candidates. The combination of these solutions achieved an excellent sensitivity of over 95% at fewer than 1.0 false positives per scan. This highlights the potential of combining algorithms to improve the detection performance. Our observer study with four expert readers has shown that the best system detects nodules that were missed by expert readers who originally annotated the LIDC-IDRI data. We released this set of additional nodules for further development of CAD systems.

[Severe inflammation during recovery from neutropenia: the immune reconstitution inflammatory syndrome following chemotherapy]. / Ernstige inflammatie tijdens herstel van neutropenia: het immuunreconstitutie-inflammatoir-syndroom na chemotherapie.

Immune reconstitution inflammatory syndrome (IRIS) occurs when a patient is recovering from a transient immunodeficiency and results in an uncontrolled inflammatory response to infectious agents and tissue damage. Symptoms such as fever and radiological signs seem to paradoxically appear or worsen, unmasking a previously unrecognized infection. The patient's clinical condition may then deteriorate as a result of increasing tissue damage and this may even lead to death. IRIS was initially described in patients suffering from a HIV infection who experienced immune recovery following the initiation of antiretroviral therapy. Increasingly, however, the syndrome is being reported in patients who are recovering from an episode of neutropenia following chemotherapy, hypomethylating agent use or a stem cell transplantation for the treatment of a solid tumour or haematological cancers. We describe two cases of IRIS following an episode of neutropenia in patients with a haematological malignancy and elaborate on the pathogenesis, diagnosis and treatment of IRIS in cancer patients.

Bone suppression increases the visibility of invasive pulmonary aspergillosis in chest radiographs.

OBJECTIVE: Chest radiographs (CXR) are an important diagnostic tool for the detection of invasive pulmonary aspergillosis (IPA) in critically ill patients, but their diagnostic value is limited by a poor sensitivity. By using advanced image processing, the aim of this study was to increase the value of chest radiographs in the diagnostic work up of neutropenic patients who are suspected of IPA. METHODS: The frontal CXRs of 105 suspected cases of IPA were collected from four institutions. Radiographs could contain single or multiple sites of infection. CT was used as reference standard. Five radiologists and two residents participated in an observer study for the detection of IPA on CXRs with and without bone suppressed images (ClearRead BSI 3.2; Riverain Technologies). The evaluation was performed separately for the right and left lung, resulting in 78 diseased cases (or lungs) and 132 normal cases (or lungs). For each image, observers scored the likelihood of focal infectious lesions being present on a continuous scale (0-100). The area under the receiver operating characteristics curve (AUC) served as the performance measure. Sensitivity and specificity were calculated by considering only the lungs with a suspiciousness score of greater than 50 to be positive. RESULTS: The average AUC for only CXRs was 0.815. Performance significantly increased, to 0.853, when evaluation was aided with BSI (p = 0.01). Sensitivity increased from 49% to 66% with BSI, while specificity decreased from 95% to 90%. CONCLUSION: The detection of IPA in CXRs can be improved when their evaluation is aided by bone suppressed images. BSI improved the sensitivity of the CXR examination, outweighing a small loss in specificity.

Bone suppressed images improve radiologists' detection performance for pulmonary nodules in chest radiographs.

OBJECTIVES: To assess the effect of bone suppression imaging on observer performance in detecting lung nodules in chest radiographs. MATERIALS AND METHODS: Posteroanterior (PA) and lateral digital chest radiographs of 111 (average age 65) patients with a CT proven solitary nodule (median diameter 15 mm), and 189 (average age 63) controls were read by 5 radiologists and 3 residents. Conspicuity of nodules on the radiographs was classified in obvious (n = 32), moderate (n = 32), subtle (n = 29) and very subtle (n = 18). Observers read the PA and lateral chest radiographs without and with an additional PA bone suppressed image (BSI) (ClearRead Bone Suppression 2.4, Riverain Technologies, Ohio) within one reading session. Multi reader multi case (MRMC) receiver operating characteristics (ROC) were used for statistical analysis. RESULTS: ROC analysis showed improved detection with use of BSI compared to chest radiographs alone (AUC = 0.883 versus 0.855; p = 0.004). Performance also increased at high specificities exceeding 80% (pAUC = 0.136 versus 0.124; p = 0.0007). Operating at a specificity of 90%, sensitivity increased with BSI from 66% to 71% (p = 0.0004). Increase of detection performance was highest for nodules with moderate and subtle conspicuity (p = 0.02; p = 0.03). CONCLUSION: Bone suppressed images improve radiologists' detection performance for pulmonary nodules, especially for those of moderate and subtle conspicuity.

Ipsilateral brachial plexus block and hemidiaphragmatic paresis as adverse effect of a high thoracic paravertebral block.

BACKGROUND: Thoracic paravertebral block is regularly used for unilateral chest and abdominal surgery and is associated with a low complication rate. CASE REPORTS: We describe 2 patients with an ipsilateral brachial plexus block with Horner syndrome after a high continuous thoracic paravertebral block at T2-3. One patient also developed an ipsilateral hemidiaphragmatic paresis, an adverse effect that has not been reported before. Subsequent radiologic examination revealed a limited thoracic cephalad spread of the radiopaque dye and a laterally ascending spread from the thoracic paravertebral space toward and around the brachial plexus. We offer potential explanations for these phenomena. CONCLUSIONS: Brachial plexus block can occur by a route parallel to a nerve connecting the second intercostal nerve and T1 nerve, that is, Kuntz nerve. The hemidiaphragmatic paresis was attributed to the ascending spread of local anesthetic toward the area where the phrenic nerve bypasses the subclavian artery and vein.