Browsing by Subject "VOLUME"

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  • Imangholiloo, Mohammad; Yrttimaa, Tuomas; Mattsson, Teppo; Junttila, Samuli; Holopainen, Marjut; Saarinen, Ninni; Savolainen, P.; Hyyppä, J.; Vastaranta, Mikko (2022)
    Silvicultural tending of seedling stands is important to producing quality timber. However, it is challenging to allocate where and when to apply these silvicultural tending actions. Here, we tested and evaluated two methodological modifications of the ordinary area-based approach (ABAOrdinary) that could be utilized in the airborne laser scanning-based forest inventories and especially seedling stand characterization. We hypothesize that ABA with added individual tree detection-derived features (ABAITD) or correcting edge-tree effects (ABAEdge) would display improved performance in estimating the tree density and mean tree height of seedling stands. We tested this hypothesis using single-photon laser (SPL) and linear-mode laser (LML) scanning data covering 89 sample plots.The obtained results supported the hypothesis as the methodological modifications improved seedling stand characterization. Compared to the performance of ABAordinary, relative bias in tree density estimation decreased from 17.2% to 10.1% when we applied ABAITD. In the case of mean height estimation, the relative root mean square error decreased from 19.5% to 16.3% when we applied ABAEdgeITD. The SPL technology provided practically comparable or, in some cases, enhanced performance in seedling stand characterization when compared to conventional LML technology. Based on the obtained findings, it seems that the tested methodological improvements should be carefully considered when ALS-based inventories supporting forest management and silvicultural decision-making are developed further.
  • Murtola, Tiina; Malinen, Jarmo; Geneid, Ahmed; Alku, Paavo (2019)
    A multichannel dataset comprising high-speed videoendoscopy images, and electroglottography and free-field microphone signals, was used to investigate phonation onsets in vowel production. Use of the multichannel data enabled simultaneous analysis of the two main aspects of phonation, glottal area, extracted from the high-speed videoendoscopy images, and glottal flow, estimated from the microphone signal using glottal inverse filtering. Pulse-wise parameterization of the glottal area and glottal flow indicate that there is no single dominant way to initiate quasi-stable phonation. The trajectories of fundamental frequency and normalized amplitude quotient, extracted from glottal area and estimated flow, may differ markedly during onsets. The location and steepness of the amplitude envelopes of the two signals were observed to be closely related, and quantitative analysis supported the hypothesis that glottal area and flow do not carry essentially different amplitude information during vowel onsets. Linear models were used to predict the phonation onset times from the characteristics of the subsequent steady phonation. The phonation onset time of glottal area was found to have good predictability from a combination of the fundamental frequency and the normalized amplitude quotient of the glottal flow, as well as the gender of the speaker. For the phonation onset time of glottal flow, the best linear model was obtained using the fundamental frequency and the normalized amplitude quotient of the glottal flow as predictors.
  • Ng, Wai Tong; But, Barton; Choi, Horace C. W.; de Bree, Remco; Lee, Anne W. M.; Lee, Victor H. F.; Lopez, Fernando; Mäkitie, Antti A.; Rodrigo, Juan P.; Saba, Nabil F.; Tsang, Raymond K. Y.; Ferlito, Alfio (2022)
    Introduction: Nasopharyngeal carcinoma (NPC) is endemic to Eastern and South-Eastern Asia, and, in 2020, 77% of global cases were diagnosed in these regions. Apart from its distinct epidemiology, the natural behavior, treatment, and prognosis are different from other head and neck cancers. With the growing trend of artificial intelligence (AI), especially deep learning (DL), in head and neck cancer care, we sought to explore the unique clinical application and implementation direction of AI in the management of NPC. Methods: The search protocol was performed to collect publications using AI, machine learning (ML) and DL in NPC management from PubMed, Scopus and Embase. The articles were filtered using inclusion and exclusion criteria, and the quality of the papers was assessed. Data were extracted from the finalized articles. Results: A total of 78 articles were reviewed after removing duplicates and papers that did not meet the inclusion and exclusion criteria. After quality assessment, 60 papers were included in the current study. There were four main types of applications, which were auto-contouring, diagnosis, prognosis, and miscellaneous applications (especially on radiotherapy planning). The different forms of convolutional neural networks (CNNs) accounted for the majority of DL algorithms used, while the artificial neural network (ANN) was the most frequent ML model implemented. Conclusion: There is an overall positive impact identified from AI implementation in the management of NPC. With improving AI algorithms, we envisage AI will be available as a routine application in a clinical setting soon.
  • FINNAKI Study Grp (2019)
    Background Injury to endothelium and glycocalyx predisposes to vascular leak, which may subsequently lead to increased fluid requirements and worse outcomes. In this post hoc study of the prospective multicenter observational Finnish Acute Kidney Injury (FINNAKI) cohort study conducted in 17 Finnish intensive care units, we studied the association of Syndecan-1 (SDC-1), Angiopoetin-2 (Ang-2), soluble thrombomodulin (sTM), vascular adhesion protein-1 (VAP-1) and interleukin-6 (IL-6) with fluid administration and balance among septic critical care patients and their association with development of acute kidney injury (AKI) and 90-day mortality. Results SDC-1, Ang-2, sTM, VAP-1 and IL-6 levels were measured at ICU admission from 619 patients with sepsis. VAP-1 decreased (p <0.001) and IL-6 increased (p <0.001) with increasing amounts of administered fluid, but other biomarkers did not show differences according to fluid administration. In linear regression models adjusted for IL-6, only VAP-1 was significantly associated with fluid administration on day 1 (p <0.001) and the cumulative fluid balance on day 5/ICU discharge (p = 0.001). Of 415 patients admitted without AKI, altogether 112 patients (27.0%) developed AKI > 12 h from ICU admission (AKI(>12 h)). They had higher sTM levels than patients without AKI, and after multivariable adjustment log, sTM level was associated with AKI(>12 h) with OR (95% CI) of 12.71 (2.96-54.67), p = 0.001). Ninety-day non-survivors (n = 180; 29.1%) had higher SDC-1 and sTM levels compared to survivors. After adjustment for known confounders, log SDC-1 (OR [95% CI] 2.13 [1.31-3.49], p = 0.002), log sTM (OR [95% CI] 7.35 [2.29-23.57], p <0.001), and log Ang-2 (OR [95% CI] 2.47 [1.44-4.14], p = 0.001) associated with an increased risk for 90-day mortality. Finally, patients who had high levels of all three markers, namely, SDC-1, Ang-2 and sTM, had an adjusted OR of 5.61 (95% CI 2.67-11.79; p <0.001) for 90-day mortality. Conclusions VAP-1 and IL-6 associated with fluid administration on the first ICU day. After adjusting for confounders, sTM was associated with development of AKI after 12 h from ICU admission. SDC-1, Ang-2 and sTM were independently associated with an increased risk for 90-day mortality.
  • Kangas, Annika; Raty, Minna; Korhonen, Kari T.; Vauhkonen, Jari; Packalen, Tuula (2019)
    Forest information is needed at global, national and local scales. This review aimed at providing insights of potential of national forest inventories (NFIs) as well as challenges they have to cater to those needs. Within NFIs, the authors address the methodological challenges introduced by the multitude of scales the forest data are needed, and the challenges in acknowledging the errors due to the measurements and models in addition to sampling errors. Between NFIs, the challenges related to the different harmonization tasks were reviewed. While a design-based approach is often considered more attractive than a model-based approach as it is guaranteed to provide unbiased results, the model-based approach is needed for downscaling the information to smaller scales and acknowledging the measurement and model errors. However, while a model-based inference is possible in small areas, the unknown random effects introduce biased estimators. The NFIs need to cater for the national information requirements and maintain the existing time series, while at the same time providing comparable information across the countries. In upscaling the NFI information to continental and global information needs, representative samples across the area are of utmost importance. Without representative data, the model-based approaches enable provision of forest information with unknown and indeterminable biases. Both design-based and model-based approaches need to be applied to cater to all information needs. This must be accomplished in a comprehensive way In particular, a need to have standardized quality requirements has been identified, acknowledging the possibility for bias and its implications, for all data used in policy making.
  • Turunen, Antti; Partanen, Anu; Valtola, Jaakko; Ropponen, Antti; Siitonen, Timo; Kuittinen, Outi; Kuitunen, Hanne; Putkonen, Mervi; Sankelo, Marja; Keskinen, Leena; Savolainen, Eeva-Riitta; Pyörälä, Marja; Kuittinen, Taru; Silvennoinen, Raija; Penttilä, Karri; Sikiö, Anu; Vasala, Kaija; Mäntymaa, Pentti; Pelkonen, Jukka; Varmavuo, Ville; Jantunen, Esa (2020)
    BACKGROUND Autologous stem cell transplantation is an established treatment option for patients with multiple myeloma (MM) or non-Hodgkin?s lymphoma (NHL). STUDY DESIGN AND METHODS In this prospective multicenter study, 147 patients with MM were compared with 136 patients with NHL regarding the mobilization and apheresis of blood CD34+ cells, cellular composition of infused blood grafts, posttransplant recovery, and outcome. RESULTS Multiple myeloma patients mobilized CD34+ cells more effectively (6.3???106/kg vs. 3.9???106/kg, p?=?0.001). The proportion of poor mobilizers (peak blood CD34+ cell count 100?days) nonrelapse mortality (NRM; 6% vs. 0%, p?=?0.003). CONCLUSIONS Non-Hodgkin?s lymphoma and MM patients differ in terms of mobilization of CD34+ cells, graft cellular composition, and posttransplant recovery. Thus, the optimal graft characteristics may also be different.
  • Söderström, Henna K.; Rasanen, Jari; Saarnio, Juha; Toikkanen, Vesa; Tyrväinen, Tuula; Rantanen, Tuomo; Valtola, Antti; Ohtonen, Pasi; Pääaho, Minna; Kokkola, Arto; Kallio, Raija; Karttunen, Tuomo J.; Pohjanen, Vesa-Matti; Ristimäki, Ari; Laine, Simo; Sihvo, Eero; Kauppila, Joonas H. (2020)
    Purpose The Finnish National Esophago-Gastric Cancer Cohort (FINEGO) was established to combine the available registry data with detailed patient information to form a comprehensive, retrospective, population-based research platform of surgically treated oesophageal and gastric cancer in Finland. This cohort profile describes the 2045 surgically treated patients with oesophageal cancer included in the FINEGO cohort. Participants Registry data were collected from the National Cancer, Patient, Education and Death Registries from 1 January 1987 to 31 December 2016. All patients over 18 years of age, who had either curative surgery, palliative surgery or salvage surgery for primary cancer in the oesophagus are included in this study. Findings to date 2045 patients had surgery for oesophageal cancer in the selected time period. 67.2% were man, and the majority had only minor comorbidities. The proportions of adenocarcinomas and squamous cell carcinomas were 43.1% and 44.4%, respectively, and 12.5% had other or missing histology. Only about 23% of patients received neoadjuvant therapy. Oesophagectomy was the treatment of choice and most patients were treated at low-volume centres, but median annual hospital volume increased over time. Median overall survival was 23 months, 5-year survival for all patients in the cohort was 32.9% and cancer-specific survival was 36.5%. Future plans Even though Finland only has a population of 5.5 million, surgery for oesophageal carcinoma has not been centralised and therefore previously reported results have mostly been small, single-centre cohorts. Because of FINEGO, we now have a population-based, unselected cohort of surgically treated patients, enabling research on national trends over time regarding oesophageal cancer, including patient characteristics, tumour histology, stage and neoadjuvant treatment, surgical techniques, hospital volumes and patient mortality. Data collection is ongoing, and the cohort will be expanded to include more detailed data from patient records and national biobanks.
  • Satopaa, Jarno; Mustanoja, Satu; Meretoja, Atte; Putaala, Jukka; Kaste, Markku; Niemela, Mika; Tatlisumak, Turgut; Strbian, Daniel (2017)
    Background and aims: We evaluated the accuracy of 19 published prognostic scores to find the best tool for predicting mortality after intracerebral hemorrhage (ICH). Methods: A retrospective single-center analysis of consecutive patients with ICH (n = 1013). After excluding patients with missing data (n = 131), we analyzed 882 patients for 3-month (primary outcome), in-hospital, and 12-month mortality. We analyzed the strength of the individual score components and calculated the c-statistics, Youden index, sensitivity, specificity, negative and positive predictive value (NPV and PPV) for the scores. Finally, we included every score component in a multivariable model to analyze the maximum predictive value of the data elements combined. Results: Observed in-hospital mortality was 23.6%, 3-month mortality was 31.0%, and 12-month mortality was 35.3%. For in-hospital mortality, the National Institutes of Health Stroke Scale (NIHSS) performed equally good as the best score for the other outcomes, the ICH Functional Outcome Score (ICH-FOS). The c-statistics of the scores varied from 0.6293 (95% CI 0.587-0.672) to 0.8802 (0.855-0.906). With all variables from all the scores in a multivariable regression model, the c-statistics did not improve, being 0.89 (0.867-0.913). Using the Youden index cutoff for the ICH-FOS score, the sensitivity (73%), specificity (90%), PPV (76%), and NPV (88%) for the primary outcome were good. Conclusions: A plethora of scores exists to help clinicians estimate the prognosis of an acute ICH patient. The NIHSS can be used to quantify the risk of in-hospital death while the ICH-FOS performed best for the other outcomes. (C) 2017 Elsevier B.V. All rights reserved.
  • Terho, Petra; Sallinen, Ville; Leppäniemi, Ari; Mentula, Panu (2020)
    Background: This study investigated how annual caseloads and the surgeon's previous experience influence the outcome in laparoscopic cholecystectomy (LCC) for acute cholecystitis. Methods: A total of 892 patients treated in Helsinki University Hospital in 2013-2016 were retrospectively analyzed. Surgeons were compared regarding volume-over 5 LCCs for acute cholecystitis a year versus 5 or fewer LCCs a year, and experience-attendings versus residents. Results: High-volume surgeons (n=14) operated faster than low-volume surgeons (n=62) (91 vs. 108 min, P5 LCCs for acute cholecystitis a year, have shorter operative times and lower conversion rates.
  • Budtz-Lilly, Jacob; Bjorck, Martin; Venermo, Maarit; Debus, Sebastian; Behrendt, Christian-Alexander; Altreuther, Martin; Beiles, Barry; Szeberin, Zoltan; Eldrup, Nikolaj; Danielsson, Gudmundur; Thomson, Ian; Wigger, Pius; Khashram, Manar; Loftus, Ian; Mani, Kevin (2018)
    Objectives: Current management of ruptured abdominal aortic aneurysms (RAAA) varies among centres and countries, particularly in the degree of implementation of endovascular aneurysm repair (EVAR) and levels of vascular surgery centralisation. This study assesses these variations and the impact they have on outcomes. Materials and methods: RAAA repairs from vascular surgical registries in 11 countries, 2010-2013, were investigated. Data were analysed overall, per country, per treatment modality (EVAR or open aortic repair [OAR]), centre volume (quintiles IV), and whether centres were predominantly EVAR (>= 50% of RAAA performed with EVAR [EVAR(p)]) or predominantly OAR [OAR(p)]. Primary outcome was peri-operative mortality. Data are presented as either mean values or percentages with 95% CI within parentheses, and compared with chi-square tests, as well as with adjusted OR. Results: There were 9273 patients included. Mean age was 74.7 (74.5-74.9) years, and 82.7% of patients were men (81.9-83.6). Mean AAA diameter at rupture was 7.6 cm (7.5-7.6). Of these aneurysms, 10.7% (10.0-11.4) were less than 5.5 cm. EVAR was performed in 23.1% (22.3-24.0). There were 6817 procedures performed in OAR(p) centres and 1217 performed in EVAR(p) centres. Overall peri-operative mortality was 28.8% (27.9-29.8). Peri-operative mortality for OAR was 32.1% (31.0-33.2) and for EVAR 17.9% (16.3-19.6), p <.001, and the adjusted OR was 0.38 (0.31-0.47), p <.001. The peri-operative mortality was 23.0% in EVAR(p) centres (20.6-25.4), 29.7% in OAR(p) centres (28.6-30.8), p <.001; adjusted OR = 0.60 (0.46-0.78), p <.001. Perioperative mortality was lower in the highest volume centres (QI > 22 repairs per year), 23.3% (21.2-25.4) than in QII-V, 30.0% (28.9-31.1), p <.001. Peri-operative mortality after OAR was lower in high volume centres compared with the other centres, 25.3% (23.0-27.6) and 34.0% (32.7-35.4), respectively, p <.001. There was no significant difference in peri-operative mortality after EVAR between centres based on volume. Conclusions: Peri-operative mortality is lower in centres with a primary EVAR approach or with high case volume. Most repairs, however, are still performed in low volume centres and in centres with a primary OAR strategy. Reorganisation of acute vascular surgical services may improve outcomes of RAAA repair. (C) 2018 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.
  • Karalis, Elina; Gissler, Mika; Tapper, Anna-Maija; Ulander, Veli-Matti (2016)
    Objective: To evaluate the influence of delivery unit size and on-call staffing in the performance of low-risk deliveries in Finland. Study design: A population-based study of hospital size and level based on Medical Birth Register data. Population was all hospital births in Finland in 2005-2009. Inclusion criteria were singleton births (birth weight 2500 g or more) without major congenital anomalies or birth defects. Additionally, only intrapartum stillbirths were included. Birthweights and maternal background characteristics were adjusted for by logistic regression. Main outcome measures were intrapartum or early neonatal mortality, neonatal asphyxia and newborns' need for intensive care or transfer to other hospital and longer duration of care. On-call arrangements were asked from each of the hospitals. Results: Intrapartum mortality was higher in units where physicians were at home when on-call (OR 1.25; 95% CI 1.02-1.52). A tendency to a higher mortality was also recorded in non-university hospitals (OR 1.18; 95% CI 0.99-1.40). Early neonatal mortality was twofold in units with less than 1000 births annually (OR 2.11; 95% CI 0.97-4.56) and in units where physicians were at home when on-call (OR 1.85; 95% CI 0.91-3.76). These results did not reach statistical significance. No differences between the units were found regarding Apgar scores or umbilical cord pH. Conclusion: The differences in mortality rates between different level hospitals suggest that adverse outcomes during delivery should be studied in detail in relation to hospital characteristics, such as size or level, and more international studies determining obstetric patient safety indicators are required. (C) 2016 Elsevier Ireland Ltd. All rights reserved.
  • Huhtakangas, Juha; Tetri, Sami; Juvela, Seppo; Saloheimo, Pertti; Bode, Michaela K.; Hillbom, Matti (2011)
  • Zhou, P.; Luukkanen, O.; Tokola, T.; Nieminen, Juhana (2008)
  • Taskinen, Seppo; Leskinen, Outi; Lohi, Jouko; Koskenvuo, Minna; Taskinen, Mervi (2019)
    Purpose: To evaluate the association between Wilms tumor histology at diagnosis and the change in Wilms' tumor volume during preoperative chemotherapy. Methods: We included all the 52 patients operated for Wilms tumor at 1988-2015, who had both pathology samples and either CT or MRI-images before and after preoperative chemotherapy, available for reevaluation. Results: The median tumor volume was 586 ml (IQR 323-903) at diagnosis. The median change in tumor volume was -68% (IQR -85 to -40, p <0.001) and the proportion of tumor necrosis 85% (IQR 24-97), after preoperative chemotherapy. There was a correlation between blastemal cell content in prechemotherapy cutting needle biopsy (CNB) sample and the reduction in tumor volume (Rho = -0.452, p = 0.002). High stromal and epithelial cell contents in CNB samples were associated with the lesser change in tumor volume (Rho = 0.279, p = 0.053 and Rho = 0.300, p = 0.038 respectively). Reduction of tumor volume and the proportion of tumor necrosis after chemotherapy were associated (Rho = -0.502, p <0.001). The actual viable tumor volume decreased in median by 97% (IQR 65-100), and the decrease could be seen in all cellular components. In three patients, the tumor volume increased more than 10% during the preoperative chemotherapy. Two of them had anaplastic tumor in the nephrectomy specimen. Conclusion: Wilms tumor total and viable tumor volumes were reduced by 68% and 97% with preoperative chemotherapy, respectively. High proportion of blastemal cells in CNB was associated with greatest decrease in Wilms tumor volume. Increase in tumor volume during preoperative chemotherapy may indicate anaplastic tumor and prolonging of preoperative therapy should be avoided. Type of study: Retrospective review. (C) 2018 Elsevier Inc. All rights reserved.
  • McInerney, Daniel; Barrett, Frank; McRoberts, Ronald E.; Tomppo, Erkki (2018)
  • Luoma, Ville; Vastaranta, Mikko; Eyvindson, Kyle; Kankare, Ville; Saarinen, Ninni; Holopainen, Markus; Hyyppa, Juha (Springer International Publishing AG, 2017)
    Lecture Notes in Geoinformation and Cartography
    Currently the forest sector in Finland is looking towards the next generation's forest resource information systems. Information used in forest planning is currently collected by using an area-based approach (ABA) where airborne laser scanning (ALS) data are used to generalize field-measured inventory attributes over an entire inventory area. Inventories are typically updated at 10-year interval. Thus, one of the key challenges is the age of the inventory information and the cost-benefit trade-off between using the old data and obtaining new data. Prediction of future forest resource information is possible through growth modelling. In this paper, the error sources related to ALS-based forest inventory and the growth models applied in forest planning to update the forest resource information were examined. The error sources included (i) forest inventory, (ii) generation of theoretical stem distribution, and (iii) growth modelling. Error sources (ii) and (iii) stem from the calculations used for forest planning, and were combined in the investigations. Our research area, Evo, is located in southern Finland. In all, 34 forest sample plots (300 m(2)) have been measured twice tree-by-tree. First measurements have been carried out in 2007 and the second measurements in 2014 which leads to 7 year updating period. Respectively, ALS-based forest inventory data were available for 2007. The results showed that prediction of theoretical stem distribution and forest growth modelling affected only slightly to the quality of the predicted stem volume in short-term information update when compared to forest inventory error.
  • MRIGENIE GISCOME Invest Int Stroke; Hong, Sungmin; Giese, Anne-Katrin; Schirmer, Markus D.; Strbian, Daniel; Tatlisumak, Turgut; Wu, Ona (2021)
    Objective: To personalize the prognostication of post-stroke outcome using MRI-detected cerebrovascular pathology, we sought to investigate the association between the excessive white matter hyperintensity (WMH) burden unaccounted for by the traditional stroke risk profile of individual patients and their long-term functional outcomes after a stroke. Methods: We included 890 patients who survived after an acute ischemic stroke from the MRI-Genetics Interface Exploration (MRI-GENIE) study, for whom data on vascular risk factors (VRFs), including age, sex, atrial fibrillation, diabetes mellitus, hypertension, coronary artery disease, smoking, prior stroke history, as well as acute stroke severity, 3- to-6-month modified Rankin Scale score (mRS), WMH, and brain volumes, were available. We defined the unaccounted WMH (uWMH) burden via modeling of expected WMH burden based on the VRF profile of each individual patient. The association of uWMH and mRS score was analyzed by linear regression analysis. The odds ratios of patients who achieved full functional independence (mRS < 2) in between trichotomized uWMH burden groups were calculated by pair-wise comparisons. Results: The expected WMH volume was estimated with respect to known VRFs. The uWMH burden was associated with a long-term functional outcome (beta = 0.104, p < 0.01). Excessive uWMH burden significantly reduced the odds of achieving full functional independence after a stroke compared to the low and average uWMH burden [OR = 0.4, 95% CI: (0.25, 0.63), p < 0.01 and OR = 0.61, 95% CI: (0.42, 0.87), p < 0.01, respectively]. Conclusion: The excessive amount of uWMH burden unaccounted for by the traditional VRF profile was associated with worse post-stroke functional outcomes. Further studies are needed to evaluate a lifetime brain injury reflected in WMH unrelated to the VRF profile of a patient as an important factor for stroke recovery and a plausible indicator of brain health.
  • Yrttimaa, Tuomas; Luoma, Ville; Saarinen, Ninni; Kankare, Elina; Junttila, Samuli; Holopainen, Markus; Hyyppa, Juha; Vastaranta, Mikko (2022)
    Tree growth is a physio-ecological phenomena of high interest among researchers across disciplines. Observing changes in tree characteristics has conventionally required either repeated measurements of the characteristics of living trees, retrospective measurements of destructively sampled trees, or modelling. The use of close-range sensing techniques such as terrestrial laser scanning (TLS) has enabled non-destructive approaches to reconstruct the three-dimensional (3D) structure of trees and tree communities in space and time. This study aims at improving the understanding of tree allometry in general and interactions between tree growth and its neighbourhood in particular by using two-date point clouds. We investigated how variation in the increments in basal area at the breast height (Delta g(1.3)), basal area at height corresponding to 60% of tree height (Delta g(0)(6h)), and volume of the stem section below 50% of tree height (Delta v(05h) ) can be explained with TLS point cloud-based attributes characterizing the spatiotemporal structure of a tree crown and crown neighbourhood, entailing the competitive status of a tree. The analyses were based on 218 trees on 16 sample plots whose 3D characteristics were obtained at the beginning (2014, T1) and at the end of the monitoring period (2019, T2) from multi-scan TLS point clouds using automatic point cloud processing methods. The results of this study showed that, within certain tree communities, strong relationships (vertical bar r vertical bar > 0.8) were observed between increments in the stem dimensions and the attributes characterizing crown structure and competition. Most often, attributes characterizing the competitive status of a tree, and the crown structure at T1, were the most important attributes to explain variation in the increments of stem dimensions. Linear mixed-effect modelling showed that single attributes could explain up to 35-60% of the observed variation in Delta g(1.3), Delta g(0)(6h) and Delta V-0(5h), depending on the tree species. This tree-level evidence of the allometric relationship between stem growth and crown dynamics can further be used to justify landscape-level analyses based on airborne remote sensing technologies to monitor stem growth through the structure and development of crown structure. This study contributes to the existing knowledge by showing that laser-based close-range sensing is a feasible technology to provide 3D characterization of stem and crown structure, enabling one to quantify structural changes and the competitive status of trees for improved understanding of the underlying growth processes.
  • Kelaranta, A.; Mäkelä, T.; Kaasalainen, T.; Kortesniemi, M. (2017)
    Purpose: To determine fetal doses in different stages of pregnancy in three common computed tomography (CT) examinations: pulmonary CT angiography, abdomino-pelvic and trauma scan with Monte Carlo (MC) simulations. Methods: An adult female anthropomorphic phantom was scanned with a 64-slice CT using pulmonary angiography, abdomino-pelvic and trauma CT scan protocols. Three different sized gelatin boluses placed on the phantom's abdomen simulated different stages of pregnancy. Intrauterine dose was used as a surrogate to a dose absorbed to the fetus. MC simulations were performed to estimate uterine doses. The simulation dose levels were calibrated with volumetric CT dose index (CTDIvol) measurements and MC simulations in a cylindrical CTDI body phantom and compared with ten point doses measured with metal-oxide-semiconductor field-effect-transistor dosimeters. Intrauterine volumes and uterine walls were segmented and the respective dose volume histograms were calculated. Results: The mean intrauterine doses in different stages of pregnancy varied from 0.04 to 1.04 mGy, from 4.8 to 5.8 mGy, and from 9.8 to 12.6 mGy in the CT scans for pulmonary angiography, abdomino-pelvic and trauma CT scans, respectively. MC simulations showed good correlation with the MOSFET measurement at the measured locations. Conclusions: The three studied examinations provided highly varying fetal doses increasing from sub-mGy level in pulmonary CT angiography to notably higher levels in abdomino-pelvic and trauma scans where the fetus is in the primary exposure range. Volumetric dose distribution offered by MC simulations in an appropriate anthropomorphic phantom provides a comprehensive dose assessment when applied in adjunct to point-dose measurements.
  • Csonka, Peter; Tapiainen, Terhi; Mäkelä, Mika J.; Lehtimäki, Lauri (2021)
    Aim Our aim was to survey treatment practices used for preschool children with wheezing in emergency rooms (ER) focussing on inhalation device choice and handling, face mask use, salbutamol dosing and written instructions. We sought to assess whether current protocols are in line with published evidence and guidelines. Methods This is a cross-sectional survey done in paediatric ER units located in Finnish municipalities with more than 10 000 inhabitants. Results Of the 100 units contacted, 50% responded. More than 50% of the units used nebulisers. Only 13% of the units administered salbutamol in single puffs. More than 30% of the units lacked criteria on face mask use. Poor co-operation had no effect on the dose of salbutamol in 62% of the units. Ensuring tight mask-to-face seal was included in the training in 20% of the units. A written action plan was provided to the caregivers in 28% of the units. Conclusion ER treatment guidelines for preschool children with wheezing are poorly endorsed. Research is needed to identify approaches to guideline implementation that are specific for primary care. Clinical research should focus on strengthening recommendations that are currently not embraced. ER treatment protocols need to be updated and adherence to guidelines should be re-evaluated.