Browsing by Subject "CT"

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  • Bebbington, Natalie A.; Haddock, Bryan T.; Bertilsson, Henrik; Hippeläinen, Eero; Husby, Ellen M.; Tunninen, Virpi I.; Söderberg, Marcus (2019)
    Background Computed tomography (CT) scans are routinely performed in positron emission tomography (PET) and single photon emission computed tomography (SPECT) examinations globally, yet few surveys have been conducted to gather national diagnostic reference level (NDRL) data for CT radiation doses in positron emission tomography/computed tomography (PET/CT) and single photon emission computed tomography/computed tomography (SPECT/CT). In this first Nordic-wide study of CT doses in hybrid imaging, Nordic NDRL CT doses are suggested for PET/CT and SPECT/CT examinations specific to the clinical purpose of CT, and the scope for optimisation is evaluated. Data on hybrid imaging CT exposures and clinical purpose of CT were gathered for 5 PET/CT and 8 SPECT/CT examinations via designed booklet. For each included dataset for a given facility and scanner type, the computed tomography dose index by volume (CTDIvol) and dose length product (DLP) was interpolated for a 75-kg person (referred to as CTDIvol,75kg and DLP75kg). Suggested NDRL (75th percentile) and achievable doses (50th percentile) were determined for CTDIvol,75kg and DLP75kg according to clinical purpose of CT. Differences in maximum and minimum doses (derived for a 75-kg patient) between facilities were also calculated for each examination and clinical purpose. Results Data were processed from 83 scanners from 43 facilities. Data were sufficient to suggest Nordic NDRL CT doses for the following: PET/CT oncology (localisation/characterisation, 15 systems); infection/inflammation (localisation/characterisation, 13 systems); brain (attenuation correction (AC) only, 11 systems); cardiac PET/CT and SPECT/CT (AC only, 30 systems); SPECT/CT lung (localisation/characterisation, 12 systems); bone (localisation/characterisation, 30 systems); and parathyroid (localisation/characterisation, 13 systems). Great variations in dose were seen for all aforementioned examinations. Greatest differences in DLP75kg for each examination, specific to clinical purpose, were as follows: SPECT/CT lung AC only (27.4); PET/CT and SPECT/CT cardiac AC only (19.6); infection/inflammation AC only (18.1); PET/CT brain localisation/characterisation (16.8); SPECT/CT bone localisation/characterisation (10.0); PET/CT oncology AC only (9.0); and SPECT/CT parathyroid localisation/characterisation (7.8). Conclusions Suggested Nordic NDRL CT doses are presented according to clinical purpose of CT for PET/CT oncology, infection/inflammation, brain, PET/CT and SPECT/CT cardiac, and SPECT/CT lung, bone, and parathyroid. The large variation in doses suggests great scope for optimisation in all 8 examinations.
  • Kwak, Gloria Hyunjung; Kwak, Eun-Jung; Song, Jae Min; Park, Hae Ryoun; Jung, Yun-Hoa; Cho, Bong-Hae; Hui, Pan; Hwang, Jae Joon (2020)
    The practicability of deep learning techniques has been demonstrated by their successful implementation in varied fields, including diagnostic imaging for clinicians. In accordance with the increasing demands in the healthcare industry, techniques for automatic prediction and detection are being widely researched. Particularly in dentistry, for various reasons, automated mandibular canal detection has become highly desirable. The positioning of the inferior alveolar nerve (IAN), which is one of the major structures in the mandible, is crucial to prevent nerve injury during surgical procedures. However, automatic segmentation using Cone beam computed tomography (CBCT) poses certain difficulties, such as the complex appearance of the human skull, limited number of datasets, unclear edges, and noisy images. Using work-in-progress automation software, experiments were conducted with models based on 2D SegNet, 2D and 3D U-Nets as preliminary research for a dental segmentation automation tool. The 2D U-Net with adjacent images demonstrates higher global accuracy of 0.82 than naïve U-Net variants. The 2D SegNet showed the second highest global accuracy of 0.96, and the 3D U-Net showed the best global accuracy of 0.99. The automated canal detection system through deep learning will contribute significantly to efficient treatment planning and to reducing patients’ discomfort by a dentist. This study will be a preliminary report and an opportunity to explore the application of deep learning to other dental fields.
  • Almada-Correia, Inês; Neves, Pedro Miguel; Mäkitie, Antti; Ravasco, Paula (2019)
    Introduction: Head and neck cancer (HNC) patients show a high risk of malnutrition due to the lifestyle habits adopted prior to the diagnosis as well as to the compromising impact of both the anatomical location of the tumor and the treatment modalities on food intake. Weight change, measurement of skinfold thickness, biochemical parameters, bioelectrical impedance analysis (BIA), computed tomography (CT), magnetic resonance (MRI), or dual-energy x-ray absorptiometry (DXA) are available techniques to evaluate nutritional status and/or body composition in the clinical practice. Evaluating body composition alterations in HNC patients is essential to be able to offer the best therapeutical interventions. In this paper, we review the existing literature regarding body composition evaluation in HNC patients to determine, which is the most suitable method for this population, regarding availability in the day-to-day practice, patient burden, cost, sensibility, and specificity.Methodology: A literature search for relevant papers indexed in MEDLINE, Cochrane Library and Scielo was conducted, with no publication date restriction and for all published articles until the 31 January, 2019. All the papers written in English, with interventions in humans, exclusively considering HNC patients were selected.Results: A total of 41 studies with different methodologies were included in this review. In 15 studies BIA was the used assessment method and three of them also evaluated skinfold thickness and one was a bioelectric impedance vector analysis (BIVA). Body composition assessment was made with DXA in eight studies, one of which also included muscle biopsies. In two studies the chosen method was both BIA and DXA. CT/ positron emission tomography-CT was applied in 11 studies and one also included MRI. In two studies body composition was assessed with skinfold measurements alone and one study only used BIVA.Conclusions: Despite the different existing body composition assessment tools, it seems that skeletal muscle mass (SMM) measurement at the level of cervical spine C3 vertebra may be a reliable method for SMM assessment as it strongly correlates with cross-sectional area measures at the level of L3 and it allows a cost-effective body composition assessment without the need for additional radiation exposure.
  • Arvola, Samuli; Seppänen, Marko; Malaspina, Simona; Mätzke, Sorjo; Raiko, Juho; Timonen, Kirsi L.; Ettala, Otto; Jambor, Ivan; Anttinen, Mikael; Kuisma, Anna; Löyttyniemi, Eliisa; Boström, Peter J.; Sohlberg, Antti; Noponen, Tommi (2022)
    Objective The aim of this study was to compare reprojected bone SPECT/CT (RBS) against planar bone scintigraphy (BS) in the detection of bone metastases in breast and prostate cancer patients. Methods Twenty-six breast and 105 prostate cancer patients with high risk for bone metastases underwent Tc-99m-HMDP BS and whole-body SPECT/CT, 1.5-T whole-body diffusion-weighted MRI and F-18-NaF or F-18-PSMA-1007 PET/CT within two prospective clinical trials (NCT01339780 and NCT03537391). Consensus reading of all imaging modalities and follow-up data were used to define the reference standard diagnosis. The SPECT/CT data were reprojected into anterior and posterior views to produce RBS images. Both BS and RBS images were independently double read by two pairs of experienced nuclear medicine physicians. The findings were validated against the reference standard diagnosis and compared between BS and RBS on the patient, region and lesion levels. Results All metastatic patients detected by BS were also detected by RBS. In addition, three metastatic patients were missed by BS but detected by RBS. The average patient-level sensitivity of two readers for metastases was 75% for BS and 87% for RBS, and the corresponding specificity was 79% for BS and 39% for RBS. The average region-level sensitivity of two readers was 64% for BS and 69% for RBS, and the corresponding specificity was 96% for BS and 87% for RBS. Conclusion Whole-body bone SPECT/CT can be reprojected into more familiar anterior and posterior planar images with excellent sensitivity for bone metastases, making additional acquisition of planar BS unnecessary.
  • Paajanen, Juuso; Laaksonen, Sanna; Ilonen, Ilkka; Wolff, Henrik; Husgafvel-Pursiainen, Kirsti; Kuosma, Eeva; Ollila, Hely; Myllärniemi, Marjukka; Vehmas, Tapio (2018)
    Objectives: Appropriate clinical staging of malignant pleural mesothelioma (MPM) is critical for correct treatment decisions. Newly revised TNM staging protocol has been released for MPM. We investigated baseline computed tomography (CT) characteristics of MPM patients, the new staging system and a simple tumor size (TS) assessment in terms of survival. Materials and methods: As part of our study that included all MPM patients diagnosed in Finland 2000-2012, we retrospectively reviewed 161 CT scans of MPM patients diagnosed between 2007 and 2012 in the Hospital District of Helsinki and Uusimaa. TS was estimated by using the maximal tumor thickness and grading tumor extension along the chest wall. Cox Regression models were used to identify relationships between survival, clinicopathological factors and CT-findings. Results: The median length of follow-up was 9.7 months and the median survival 9.1 months. The right sided tumors tended to be more advanced at baseline and had worse prognosis in the univariate analyses. In the multivariate survival model, TS, pleural effusion along with non-epithelioid histology were predictors of poor survival. Tumor size correlated significantly with a sarcomatoid histopathological finding and several parameters linked to a more advanced TNM stage. Most patients were diagnosed with locally advanced stage, while 12 (7%) had no sign of the tumor in CT. Conclusion. In this study, we demonstrate a novel approach for MPM tumor size evaluation that has a strong relationship with mortality, sarcomatoid histology and TNM stage groups. TS could be used for prognostic purposes and it may be a useful method for assessing therapy responses.
  • Nummela, Mari T.; Pyhältö, Tuomo T.; Bensch, Frank V.; Heinänen, Mikko T.; Koskinen, Seppo K. (2022)
    Purpose To assess the healing of costal cartilage fractures (CCFX) in patients with blunt polytrauma with follow-up imaging and clinical examination. Effect on physical performance and quality of life (QoL) was also evaluated. Methods The study group comprised twenty-one patients with diagnosed CCFX in trauma CT. All the patients underwent MRI, ultrasound, ultra-low-dose CT examinations, and clinical status control. The patients completed QoL questionnaires. Two radiologists evaluated the images regarding fracture union, dislocation, calcifications, and persistent edema at fracture site. An attending trauma surgeon clinically examined the patients, with emphasis on focal tenderness and ribcage mobility. Trauma registry data were accessed to evaluate injury severity and outcome. Results The patients were imaged at an average of 34.1 months (median 36, range 15.8-57.7) after the initial trauma. In 15 patients (71.4%), CCFX were considered stable on imaging. Cartilage calcifications were seen on healed fracture sites in all the patients. The fracture dislocation had increased in 5 patients (23.8%), and 1 patient (4.8%) showed signs of a non-stable union. Four patients (19.0%) reported persistent symptoms from CCFX. Conclusion Non-union in CCFX is uncommon but may lead to decreased stability and discomfort. Both clinical and radiological examinations play an important part in the post-traumatic evaluation of CCFX. CT and MRI visualize the healing process, while dynamic ultrasound may reveal instability. No significant difference in QoL was detected between patients with radiologically healed and non-healed CCFX. Post-traumatic disability was mostly due to other non-thoracic injuries.
  • Podda, M; Andersson, R; Boermeester, M; Coccolini, F; Sartelli, M; Moore, EE; Sugrue, M; Abu-Zidan, F; Tolonen, M; Damaskos, D; Kluger, Y; Soreide, K; Pisanu, A; Augustin, G; Latifi, R; Kelly, M; Leppaniemi, A; Fraga, GP; Ten Broek, R; Tan, E; Van Goor, H; Chiara, O; Maier, RV; Pata, F; De Simone, B; Ordonez, CA; Ansaloni, L; Catena, F; Di Saverio, S (2021)
  • Bajc, Marika; Schümichen, Carl; Grüning, Thomas; Lindqvist, Ari; Le Roux, Pierre-Yves; Alatri, Adriano; Bauer, Ralf W.; Dilic, Mirza; Neilly, Brian; Verberne, Hein J.; Delgado Bolton, Roberto C.; Jonson, Bjorn (2019)
    These guidelines update the previous EANM 2009 guidelines on the diagnosis of pulmonary embolism (PE). Relevant new aspects are related to (a) quantification of PE and other ventilation/perfusion defects; (b) follow-up of patients with PE; (c) chronic PE; and (d) description of additional pulmonary physiological changes leading to diagnoses of left ventricular heart failure (HF), chronic obstructive pulmonary disease (COPD) and pneumonia. The diagnosis of PE should be reported when a mismatch of one segment or two subsegments is found. For ventilation, Technegas or krypton gas is preferred over diethylene triamine pentaacetic acid (DTPA) in patients with COPD. Tomographic imaging with V/P-SPECT has higher sensitivity and specificity for PE compared with planar imaging. Absence of contraindications makes V/P-SPECT an essential method for the diagnosis of PE. When V/P-SPECT is combined with a low-dose CT, the specificity of the test can be further improved, especially in patients with other lung diseases. Pitfalls in V/P-SPECT interpretation are discussed. In conclusion, V/P-SPECT is strongly recommended as it accurately establishes the diagnosis of PE even in the presence of diseases like COPD, HF and pneumonia and has no contraindications.
  • Pitkänen, Johanna; Koikkalainen, Juha; Nieminen, Tuomas; Marinkovic, Ivan; Curtze, Sami; Sibolt, Gerli; Jokinen, Hanna; Rueckert, Daniel; Barkhof, Frederik; Schmidt, Reinhold; Pantoni, Leonardo; Scheltens, Philip; Wahlund, Lars-Olof; Korvenoja, Antti; Lötjönen, Jyrki; Erkinjuntti, Timo J; Melkas, Susanna (2020)
    Purpose Severity of white matter lesion (WML) is typically evaluated on magnetic resonance images (MRI), yet the more accessible, faster, and less expensive method is computed tomography (CT). Our objective was to study whether WML can be automatically segmented from CT images using a convolutional neural network (CNN). The second aim was to compare CT segmentation with MRI segmentation. Methods The brain images from the Helsinki University Hospital clinical image archive were systematically screened to make CT-MRI image pairs. Selection criteria for the study were that both CT and MRI images were acquired within 6 weeks. In total, 147 image pairs were included. We used CNN to segment WML from CT images. Training and testing of CNN for CT was performed using 10-fold cross-validation, and the segmentation results were compared with the corresponding segmentations from MRI. Results A Pearson correlation of 0.94 was obtained between the automatic WML volumes of MRI and CT segmentations. The average Dice similarity index validating the overlap between CT and FLAIR segmentations was 0.68 for the Fazekas 3 group. Conclusion CNN-based segmentation of CT images may provide a means to evaluate the severity of WML and establish a link between CT WML patterns and the current standard MRI-based visual rating scale.
  • Harloff-Helleberg, Stine; Fliervoet, Lies A. L.; Fano, Mathias; Schmitt, Mechthild; Antopolski, Maxim; Urtti, Arto; Nielsen, Hanne Morck (2019)
    Oral drug delivery is an attractive noninvasive alternative to injectables. However, oral delivery of biopharmaceuticals is highly challenging due to low stability during transit in the gastrointestinal tract (GIT), resulting in low systemic bioavailability. Thus, novel formulation strategies are essential to overcome this challenge. An interesting approach is increasing retention in the GIT by utilizing mucoadhesive biomaterials as excipients. Here, we explored the potential of the GRAS excipient sucrose acetate isobutyrate (SAIB) to obtain mucoadhesion in vivo. Mucoadhesive properties of a 90% SAIB/10% EtOH (w/w) drug delivery system (DDS) were assessed using a biosimilar mucus model and evaluation of rheological behavior after immersion in biosimilar intestinal fluid. To ease readability of this manuscript, we will refer to this as SAIB DDS. The effect of SAIB DDS on cell viability and epithelial membrane integrity was tested in vitro prior to in vivo studies that were conducted using SPECT/CT imaging in rats. When combining SAIB DDS with biosimilar mucus, increased viscosity was observed due to secondary interactions between biosimilar mucus and sucrose ester predicting considerable mucoadhesion. Mucoadhesion was confirmed in vivo, as radiolabeled insulin entrapped in SAIB DDS, remained in the small intestine for up to 22 h after administration. Moreover, the integrity of the system was investigated using the dynamic gastric model under conditions simulating the chemical composition of stomach fluid and physical shear stress in the antrum under fasted conditions. In conclusion, SAIB is an interesting and safe biomaterial to promote high mucoadhesion in the GIT after oral administration.
  • Ketola, Juuso H. J.; Heino, Helinä; Juntunen, Mikael A. K.; Nieminen, Miika T.; Siltanen, Samuli; Inkinen, Satu I. (2021)
    In interior computed tomography (CT), the x-ray beam is collimated to a limited field-of-view (FOV) (e.g. the volume of the heart) to decrease exposure to adjacent organs, but the resulting image has a severe truncation artifact when reconstructed with traditional filtered back-projection (FBP) type algorithms. In some examinations, such as cardiac or dentomaxillofacial imaging, interior CT could be used to achieve further dose reductions. In this work, we describe a deep learning (DL) method to obtain artifact-free images from interior CT angiography. Our method employs the Pix2Pix generative adversarial network (GAN) in a two-stage process: (1) An extended sinogram is computed from a truncated sinogram with one GAN model, and (2) the FBP reconstruction obtained from that extended sinogram is used as an input to another GAN model that improves the quality of the interior reconstruction. Our double GAN (DGAN) model was trained with 10 000 truncated sinograms simulated from real computed tomography angiography slice images. Truncated sinograms (input) were used with original slice images (target) in training to yield an improved reconstruction (output). DGAN performance was compared with the adaptive de-truncation method, total variation regularization, and two reference DL methods: FBPConvNet, and U-Net-based sinogram extension (ES-UNet). Our DGAN method and ES-UNet yielded the best root-mean-squared error (RMSE) (0.03 +/- 0.01), and structural similarity index (SSIM) (0.92 +/- 0.02) values, and reference DL methods also yielded good results. Furthermore, we performed an extended FOV analysis by increasing the reconstruction area by 10% and 20%. In both cases, the DGAN approach yielded best results at RMSE (0.03 +/- 0.01 and 0.04 +/- 0.01 for the 10% and 20% cases, respectively), peak signal-to-noise ratio (PSNR) (30.5 +/- 2.6 dB and 28.6 +/- 2.6 dB), and SSIM (0.90 +/- 0.02 and 0.87 +/- 0.02). In conclusion, our method was able to not only reconstruct the interior region with improved image quality, but also extend the reconstructed FOV by 20%.
  • Taimen, Kirsi; Heino, Samu; Kohonen, Ia; Relas, Heikki; Huovinen, Riikka; Hänninen, Arno; Pirilä, Laura (2020)
    Objective. Patients receiving chemotherapy are prone to neutropoenic infections, presenting with non-specific symptoms such as a high fever and elevated inflammatory parameters. Large-vessel vasculitis (LVV) may have a similar clinical presentation and should be included in differential diagnostics. A few published case reports and adverse event reports suggest a causal association between LVV and the use of granulocyte colony-stimulating factor (G-CSF) and chemotherapy. Our objective was to evaluate the relationship between LVV, G-CSF and chemotherapy. Methods. Between 2016 and 2018, we identified six patients in Finland with probable drug-induced LVV associated with G-CSF and chemotherapy. All six patients had breast cancer. A systematic literature review was performed according to PRISMA guidelines using comprehensive search terms for cancer, chemotherapy, G-CSF and LVV. Results. The literature search identified 18 similar published case reports, of which most were published after 2014. In all patients combined (n = 24), the time delay from the last drug administration to the LVV symptoms was on average 5 days with G-CSF (range = 1-8 days) and 9 days with chemotherapy (range = 1-21 days). Common symptoms were fever (88%), neck pain (50%) and chest pain (42%). Based on imaging, 17/24 (71%) had vascular inflammation in the thoracic aorta and supra-aortic vessels, but 5/24 (21%) reportedly had inflammation limited to the carotid area. Conclusion. This review suggests that LVV may be a possible serious adverse event associated with G-CSF and chemotherapy. Successful management of drug-induced LVV requires early identification, through diagnostic imaging, and discontinuation of the drug.
  • Suomela, Jenni; Suhonen, Heikki; Räisänen, Riikka; Wright, Krista (2022)
    In Finland, the earliest remains of a Christian church and cemetery date to the Late Iron Age (800-1150/1300 AD) and have been excavated in Ravattula Ristimaki, in Kaarina, southwestern Finland. In this study, seven assumingly plant fibre textile samples from individual inhumation graves were analysed to identify their materials. The aim of the study was to investigate the possibilities of identifying archaeological plant fibre samples using a three-stage procedure by observing the surface characteristics, microfibrillar orientation and cross section of the fibres via transmitted light microscopy (TLM). The identification process was based on such a TLM characterisation. Additionally, parts of the samples were studied with X-ray microtomography (micro-CT) and wide-angle X-ray scattering (WAXS) to test the possibilities of using the X-ray methods in research and to identify bast fibre textiles. Both flax and nettle were found in the samples, indicating a preference for these two fibre plants in Late Iron Age Finland.
  • Julkunen, Anna; Terna, Emma; Numminen, Jura; Markkola, Antti; Dastidar, Prasun; Karjalainen, Matti; Huhtala, Heini; Rautiainen, Markus; Meurman, Jukka; Toppila-Salmi, Sanna (2017)
    Conclusion: The study demonstrated considerable inter-observer variation in certain surgically important structures. This would indicate the significance for consultation when evaluating sinus CT scans of CRS patients for planned advanced sinus surgery. Objectives: After the failure of medical treatment of chronic rhinosinusitis (CRS), the need for surgery and the pre-operative planning of safe surgery is based on computed tomography (CT) findings. The aim of this prospective study was to compare inter-observer agreement of anatomical and surgical structures of sinus CT scans. The hypothesis was that the agreement between observers is good. Methods: Of these 57 CRS patients, Lund-Mackay (LM) scores and 43 other structural parameters were analyzed blinded. The reproducibility of the findings between three observers, a radiologist, an Ear, nose and throat (ENT) surgeon, and an ENT resident, were compared. Results: In general, there was moderate inter-observer agreement of the structures by Cohen's kappa coefficient. Poor reproducibility was observed in the following structures: optic nerve, insertion of the uncinated process, anterior ethmoidal artery, and Keros class.
  • Pakbaznejad Esmaeili, Elmira; Ilo, Anne-Mari; Waltimo-Sirén, Janna; Ekholm, Marja (2020)
    Objectives In children and adolescents, cone-beam computed tomography (CBCT) is frequently used for localization of unerupted or impacted teeth in the anterior maxilla. CBCT causes a higher radiation dose than conventional intraoral and panoramic imaging. The objective was to analyze the location of impacted canines in a three-dimensional coordinate and thereby optimize the CBCT field-of-view (FOV), for radiation dose reduction. Materials and methods Location of 50 impacted maxillary canines of children under 17 years was retrospectively evaluated from CBCT scans. The minimum and maximum distances of any part of the right- and left-side canines to three anatomic reference planes were measured to assess the adequate size and position of a cylindrical image volume. Results A cylinder sized 39.0 (diameter)x33.2 (height) mm, with its top situated 13.8 mm above the hard palate, its medial edge 8.4 mm across the midline, and anterior edge 2.5 mm in front of the labial surface of maxillary central incisors fitted all the analyzed canines. Conclusions In this sample, the FOV required for imaging maxillary impacted canines was smaller than the smallest FOV offered by common CBCT devices. We encourage development of indication-specific CBCT imaging programs and aids to facilitate optimum patient positioning.
  • Jadhav, A. P.; Desai, S. M.; Panczykowski, D. M.; Rangaraju, S.; Campbell, D.; Ritvonen, J. K.; Schreiner, M.; Silvennoinen, H.; Gerber, J.; Puetz, Volker; Raza, S. A.; Haussen, D. C.; Nogueira, R. G.; Strbian, D.; Jovin, T. G.; Lindsberg, P. J. (2020)
    Background and purpose Basilar artery occlusion (BAO) leads to high rates of morbidity and mortality, despite successful recanalization. The discordance between flow restoration and long-term functional status clouds clinical decision-making regarding further aggressive care. We sought to develop and validate a practical, prognostic tool for the prediction of 3-month favorable outcome after acute reperfusion therapy for BAO. Methods This retrospective, multicenter, observational study was conducted at four high-volume stroke centers in the USA and Europe. Multivariate regression analysis was performed to identify predictors of favorable outcome (90-day modified Rankin scale scores 0-2) and derive a clinically applicable prognostic model (the Pittsburgh Outcomes after Stroke Thrombectomy-Vertebrobasilar (POST-VB) score). The POST-VB score was evaluated and internally validated with regard to calibration and discriminatory ability. External validity was assessed in patient cohorts at three separate centers. Results In the derivation cohort of 59 patients, independent predictors of favorable outcome included smaller brainstem infarct volume on post-procedure magnetic resonance imaging (P <0.01) and younger age (P = 0.01). POST-VB score was calculated as: age + (10 x brainstem infarct volume). POST-VB score demonstrated excellent discriminatory ability [area under the receiver-operating characteristic curve (AUC) = 0.91] and adequate calibration (P = 0.88) in the derivation cohort (Center A). It performed equally well across the three external validation cohorts (Center B, AUC = 0.89; Center C, AUC = 0.78; Center D, AUC = 0.80). Overall, a POST-VB score <49 was associated with an 88% likelihood of favorable outcome, as compared to 4% with a score >= 125. Conclusions The POST-VB score effectively predicts 3-month functional outcome following acute reperfusion therapy for BAO and may aid in guiding post-procedural care.
  • Movahedi, Mahshid; Jamee, Mahnaz; Ghaffaripour, Hosseinali; Noori, Farzad; Ghaini, Mehdi; Eskandarzadeh, Shabnam; Enayat, Javad; Eslamian, Golnaz; Pourdowlat, Guitti; Sharifinejad, Niusha; Poorabdollah, Mihan; Nadji, Seyed Alireza; Fallahi, Mazdak; Daneshmandi, Zahra; Heshmatnia, Jalal; Eslaminejad, Alireza; Fakharian, Atefeh; Vasheghani, Maryam; Moniri, Afshin; Mirenayat, Maryam Sadat; Tabarsi, Payam; Marjani, Majid; Rezaei, Nima; Seppänen, Mikko R. J.; Mansouri, Davood; Mahdaviani, Seyed Alireza; Velayati, Ali Akbar (2022)
    Background: Inborn errors of immunity (IEIs) are a group of congenital diseases caused by genetic defects in the development and function of the immune system. The involvement of the respiratory tract is one of the most common presentations in IEIs. Methods: Overall, 117 patients with diagnosed IEIs were followed-up within 8 years at the National Research Institute of Tuberculosis and Lung Diseases (NRITLD). Demographic, clinical, and laboratory data were collected in a questionnaire. Pulmonary function test (PFT), chest X-ray (CXR), and high-resolution computed tomography (HRCT) scans were obtained where applicable. Results: Our study population consisted of 48 (41%) patients with predominantly antibody deficiencies (PADs), 39 (32%) patients with congenital defects of phagocytes, 14 (11.9%) patients with combined immunodeficiency (CID), and 16 (14%) patients with Mendelian susceptibility to mycobacterial diseases (MSMD).. Recurrent pneumonia was the most common manifestation, while productive cough appeared to be the most common symptom in almost all diseases. PFT showed an obstructive pattern in patients with PAD, a restrictive pattern in patients with CID, and a mixed pattern in patients with CGD. HRCT findings were consistent with bronchiectasis in most PAD patients, whereas consolidation and mediastinal lesions were more common in the other groups. Conclusions: Pulmonary manifestations vary among different groups of IEIs. The screening for lung complications should be performed regularly to reveal respiratory pathologies in early stages and follow-up on already existing abnormalities. (C) 2022 Codon Publications. Published by Codon Publications.
  • Kangasmaa, Tuija S.; Constable, Chris; Sohlberg, Antti O. (2021)
    Background Bone SPECT/CT has been shown to offer superior sensitivity and specificity compared to conventional whole-body planar scanning. Furthermore, bone SPECT/CT allows quantitative imaging, which is challenging with planar methods. In order to gain better quantitative accuracy, Bayesian reconstruction algorithms, including both image derived and anatomically guided priors, have been utilized in reconstruction in PET/CT scanning, but they have not been widely used in SPECT/CT studies. Therefore, the aim of this work was to evaluate the performance of CT-guided reconstruction in quantitative bone SPECT. Methods Three Bayesian reconstruction methods were evaluated against the conventional ordered subsets expectation maximization (OSEM) reconstruction method. One of the studied Bayesian methods was the relative difference prior (RDP), which has recently gained popularity in PET reconstruction. The other two methods, anatomically guided smoothing prior (AMAP-S) and anatomically guided relative difference prior (AMAP-R), utilized anatomical information from the CT scan. The reconstruction methods were evaluated in terms of quantitative accuracy with artificial lesions inserted in clinical patient studies and with 20 real clinical patients. Maximum and mean standardized uptake values (SUVs) of the lesions were defined. Results The analyses showed that all studied Bayesian methods performed better than OSEM and the anatomical priors also outperformed RDP. The average relative error in mean SUV for the artificial lesion study for OSEM, RDP, AMAP-S, and AMAP-R was - 53%, - 35%, - 15%, and - 10%, when the CT study had matching lesions. In the patient study, the RDP method gave 16 +/- 9% higher maximum SUV values than OSEM, while AMAP-S and AMAP-R offered increases of 36 +/- 8% and 36 +/- 9%, respectively. Mean SUV increased for RDP, AMAP-S, and AMAP-R by 18 +/- 9%, 26 +/- 5%, and 33 +/- 5% when compared to OSEM. Conclusions The Bayesian methods with anatomical prior, especially the relative difference prior-based method (AMAP-R), outperformed OSEM and reconstruction without anatomical prior in terms of quantitative accuracy.
  • Rosenblatt, Alana Jayne; Lappalainen, Anu Katriina; James, Nina Alice; Webster, Natalie Siu Ling; Caraguel, Charles Gregoire Benedict (2018)
    BackgroundThe Dachshund is a chondrodystrophic breed of dog predisposed to premature degeneration and calcification, and subsequent herniation, of intervertebral discs (IVDs). This condition is heritable in Dachshunds and breeding candidates are screened for radiographically detectable intervertebral disc calcification (RDIDC), a feature of advanced disc degeneration and a prognostic factor for clinical disease. RDIDC scoring has been previously shown to be consistent within scorers; however, strong scorer effect (subjectivity) was also reported. The aim of this study was to estimate the within- and between-scorer agreement (repeatability and reproducibility, respectively) of computed tomography (CT) scanning and magnetic resonance imaging (MRI) for scoring IVD calcification, and to compare these modalities with radiographic scoring.ResultsTwenty-one Dachshund dogs were screened for IVD calcification using the three imaging modalities. Three scorers scored each case twice, independently. Repeatability was highest for radiography (95.4%), and significantly higher than for CT (90.4%) but not MRI (93.8%). Reproducibility was also highest for radiography (92.9%), but not significantly higher than for CT or MRI (89.4% and 86.4%, respectively). Overall, CT scored IVDs differently than radiography and MRI (64.8% and 62.7% agreement, respectively), while radiography and MRI scored more similarly (85.7% agreement).ConclusionsDespite high precision for radiography, previous evidence of scorer subjectivity was confirmed, which was not generally observed with CT and MRI. The increased consistency of radiography may be related to prior scorer experience with the modality and RDIDC scoring. This study does not support replacing radiography with CT or MRI to screen for heritable IVD calcification in breeding Dachshunds; however, evaluation of dog-level precision and the accuracy of each modality is recommended.