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Kolasa M, Hakulinen U, Brander A, Hagman S, Dastidar P, Elovaara I, Sumelahti ML. Diffusion tensor imaging and disability progression in multiple sclerosis: A 4-year follow-up study. Brain Behav 2019; 9:e01194. [PMID: 30588771 PMCID: PMC6346728 DOI: 10.1002/brb3.1194] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/26/2018] [Accepted: 12/05/2018] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVES Diffusion tensor imaging (DTI) is sensitive technique to detect widespread changes in water diffusivity in the normal-appearing white matter (NAWM) that appears unaffected in conventional magnetic resonance imaging. We aimed to investigate the prognostic value and stability of DTI indices in the NAWM of the brain in an assessment of disability progression in patients with a relapsing-onset multiple sclerosis (MS). METHODS Forty-six MS patients were studied for DTI indices (fractional anisotropy (FA), mean diffusivity (MD), radial (RD), and axial (AD) diffusivity) in the NAWM of the corpus callosum (CC) and the internal capsule at baseline and at 1 year after. DTI analysis for 10 healthy controls was also performed at baseline. Simultaneously, focal brain lesion volume and atrophy measurements were done at baseline for MS patients. Associations between DTI indices, volumetric measurements, and disability progression over 4 years were studied by multivariate logistic regression analysis. RESULTS At baseline, most DTI metrics differed significantly between MS patients and healthy controls. There was tendency for associations between baseline DTI indices in the CC and disability progression (p < 0.05). Changes in DTI indices over 1 year were observed only in the CC (p < 0.008), and those changes were not found to predict clinical worsening over 4 years. Clear-cut association with disability progression was not detected for baseline volumetric measurements. CONCLUSION Aberrant diffusivity measures in the NAWM of the CC may provide additional information for individual disability progression over 4 years in MS with the relapsing-onset disease. CC may be a good target for DTI measurements in monitoring disease activity in MS, and more studies are needed to assess the related prognostic potential.
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Affiliation(s)
- Marcin Kolasa
- Faculty of Medicine and Life Sciences, Tampere University, Tampere, Finland.,Department of Radiology, Medical Imaging Center of Pirkanmaa Hospital District, Tampere University Hospital, Tampere, Finland
| | - Ullamari Hakulinen
- Department of Radiology, Medical Imaging Center of Pirkanmaa Hospital District, Tampere University Hospital, Tampere, Finland.,Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, Tampere, Finland.,Department of Medical Physics, Medical Imaging Center, Tampere University Hospital, Tampere, Finland
| | - Antti Brander
- Department of Radiology, Medical Imaging Center of Pirkanmaa Hospital District, Tampere University Hospital, Tampere, Finland
| | - Sanna Hagman
- Faculty of Medicine and Life Sciences, Tampere University, Tampere, Finland
| | - Prasun Dastidar
- Department of Radiology, Medical Imaging Center of Pirkanmaa Hospital District, Tampere University Hospital, Tampere, Finland
| | - Irina Elovaara
- Faculty of Medicine and Life Sciences, Tampere University, Tampere, Finland
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Koskinen A, Numminen J, Markkola A, Karjalainen J, Karstila T, Seppälä M, Julkunen A, Lemmetyinen R, Pekkanen J, Rautiainen M, Dastidar P, Hytönen M, Toppila-Salmi S. Diagnostic Accuracy of Symptoms, Endoscopy, and Imaging Signs of Chronic Rhinosinusitis Without Nasal Polyps Compared to Allergic Rhinitis. Am J Rhinol Allergy 2018; 32:121-131. [PMID: 29644866 DOI: 10.1177/1945892418762891] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Objectives The diagnosis of chronic rhinosinusitis without nasal polyps (CRSsNP) and distinguishing it from allergic rhinitis is difficult. Yet, early detection of CRSsNP is important to prevent progressive and severe chronic rhinosinusitis. Our aim was to compare diagnostic accuracy of symptoms, endoscopy, and imaging signs of CRSsNP and allergic rhinitis -only phenotypes. Setting Prospective controlled follow-up study. Participants Forty-two nonsmoking patients visiting tertiary care due to CRSsNP and 19 nonsmoking volunteer controls with allergic rhinitis filled a symptoms questionnaire and underwent nasal endoscopy off-seasonally. All CRSsNP patients underwent computed tomography scans of paranasal sinuses. All the allergic rhinitis control subjects and 14 of the CRSsNP patients underwent sinus magnetic resonance imaging. Results Radiologic Lund-Mackay score, duration of symptoms, visual analogue scale scores of symptoms, and Sinonasal Outcome Test 22 were significantly higher in the CRSsNP group compared to allergic rhinitis control group. These factors also correlated in part with each other. Endoscopic score did not correlate with other factors, nor did it differ between CRSsNP and allergic rhinitis groups. The highest area under curve value was demonstrated for visual analogue scale score of facial pain/pressure (0.93) and score ≥4/10 showed 60% sensitivity and 95% specificity for detecting CRSsNP group ( P < .001). Radiologic sign of obstructed osteomeatal complex showed 100% specificity and 38% sensitivity for detecting CRSsNP group ( P < .001). Conclusions CRSsNP phenotype could be primarily distinguished from allergic rhinitis by higher facial pain/pressure score and secondarily by radiologic sings of obstructed ostiomeatal complex and higher Lund-Mackay score. Endoscopic score has limited value in distinguishing CRSsNP from allergic rhinitis.
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Affiliation(s)
- A Koskinen
- 1 Haartman Institute, Medicum, University of Helsinki, Helsinki, Finland.,2 Department of Otorhinolaryngology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - J Numminen
- 3 Department of Ear and Oral Diseases, Tampere University Hospital, Tampere, Finland
| | - A Markkola
- 4 University of Helsinki and HUS Imaging, Helsinki, Finland
| | - J Karjalainen
- 5 Allergy Centre, Tampere University Hospital, Tampere, Finland.,6 Terveystalo Healthcare Oyj, Helsinki, Finland
| | - T Karstila
- 6 Terveystalo Healthcare Oyj, Helsinki, Finland
| | - M Seppälä
- 1 Haartman Institute, Medicum, University of Helsinki, Helsinki, Finland
| | - A Julkunen
- 1 Haartman Institute, Medicum, University of Helsinki, Helsinki, Finland
| | - R Lemmetyinen
- 1 Haartman Institute, Medicum, University of Helsinki, Helsinki, Finland
| | - J Pekkanen
- 7 Department of Public Health, University of Helsinki, Helsinki, Finland.,8 Department of Health Protection, National Institute for Health and Welfare, Kuopio, Finland
| | - M Rautiainen
- 3 Department of Ear and Oral Diseases, Tampere University Hospital, Tampere, Finland.,9 Department of Otorhinolaryngology, University of Tampere, Tampere, Finland
| | - P Dastidar
- 10 Department of Radiology, Medical Imaging Centre, Tampere University Hospital, Tampere, Finland
| | - M Hytönen
- 2 Department of Otorhinolaryngology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - S Toppila-Salmi
- 1 Haartman Institute, Medicum, University of Helsinki, Helsinki, Finland.,11 Skin and Allergy Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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3
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Julkunen A, Terna E, Numminen J, Markkola A, Dastidar P, Karjalainen M, Huhtala H, Rautiainen M, Meurman J, Toppila-Salmi S. Inter-observer agreement of paranasal sinus computed tomography scans. Acta Otolaryngol 2017; 137:611-617. [PMID: 27981879 DOI: 10.1080/00016489.2016.1262552] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
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.
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Affiliation(s)
- Anna Julkunen
- Transplantation Laboratory, Haartman Institute, University of Helsinki, Helsinki, Finland
- Department of Oral and Maxillofacial Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Emma Terna
- Transplantation Laboratory, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Jura Numminen
- Department of Otorhinolaryngology, University of Tampere, Tampere, Finland
- Department of Ear and Oral diseases, Tampere University Hospital, Tampere, Finland
| | - Antti Markkola
- University of Helsinki and HUS Imaging, Helsinki, Finland
| | - Prasun Dastidar
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Finland
| | - Matti Karjalainen
- Department of Otorhinolaryngology, University of Tampere, Tampere, Finland
| | - Heini Huhtala
- School of Public Health, University of Tampere, Tampere, Finland
| | - Markus Rautiainen
- Department of Otorhinolaryngology, University of Tampere, Tampere, Finland
- Department of Ear and Oral diseases, Tampere University Hospital, Tampere, Finland
| | - Jukka Meurman
- Department of Oral and Maxillofacial Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Sanna Toppila-Salmi
- Transplantation Laboratory, Haartman Institute, University of Helsinki, Helsinki, Finland
- Department of Allergy, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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4
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Koivisto J, van Eijnatten M, Järnstedt J, Holli-Helenius K, Dastidar P, Wolff J. Impact of prone, supine and oblique patient positioning on CBCT image quality, contrast-to-noise ratio and figure of merit value in the maxillofacial region. Dentomaxillofac Radiol 2017; 46:20160418. [PMID: 28306334 DOI: 10.1259/dmfr.20160418] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To assess the impact of supine, prone and oblique patient imaging positions on the image quality, contrast-to-noise ratio (CNR) and figure of merit (FOM) value in the maxillofacial region using a CBCT scanner. Furthermore, the CBCT supine images were compared with supine multislice CT (MSCT) images. METHODS One fresh frozen cadaver head was scanned in prone, supine and oblique imaging positions using a mobile CBCT scanner. MSCT images of the head were acquired in a supine position. Two radiologists graded the CBCT and MSCT images at ten different anatomical sites according to their image quality using a six-point scale. The CNR and FOM values were calculated at two different anatomical sites on the CBCT and MSCT images. RESULTS The best image quality was achieved in the prone imaging position for sinus, mandible and maxilla, followed by the supine and oblique imaging positions. 12-mA prone images presented high delineation scores for all anatomical landmarks, except for the ear region (carotid canal), which presented adequate to poor delineation scores for all studied head positions and exposure parameters. The MSCT scanner offered similar image qualities to the 7.5-mA supine images acquired using the mobile CBCT scanner. The prone imaging position offered the best CNR and FOM values on the mobile CBCT scanner. CONCLUSIONS Head positioning has an impact on CBCT image quality. The best CBCT image quality can be achieved using the prone and supine imaging positions. The oblique imaging position offers inadequate image quality except in the sinus region.
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Affiliation(s)
- Juha Koivisto
- 1 Department of Oral and Maxillofacial Surgery/Oral Pathology and 3D Innovation Lab, VU University Medical Center, Amsterdam, Netherlands
| | - Maureen van Eijnatten
- 1 Department of Oral and Maxillofacial Surgery/Oral Pathology and 3D Innovation Lab, VU University Medical Center, Amsterdam, Netherlands
| | - Jorma Järnstedt
- 2 Medical Imaging Center, Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Kirsi Holli-Helenius
- 2 Medical Imaging Center, Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Prasun Dastidar
- 2 Medical Imaging Center, Department of Radiology, Tampere University Hospital, Tampere, Finland.,3 University of Tampere, Medical School, Tampere, Finland
| | - Jan Wolff
- 1 Department of Oral and Maxillofacial Surgery/Oral Pathology and 3D Innovation Lab, VU University Medical Center, Amsterdam, Netherlands
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Numminen S, Korpijaakko-Huuhka AM, Parkkila AK, Kulkas T, Numminen H, Dastidar P, Jehkonen M. Factors Influencing Quality of Life Six Months after a First-Ever Ischemic Stroke: Focus on Thrombolyzed Patients. Folia Phoniatr Logop 2016; 68:86-91. [DOI: 10.1159/000449218] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Wu X, Sikiö M, Pertovaara H, Järvenpää R, Eskola H, Dastidar P, Kellokumpu-Lehtinen PL. Differentiation of Diffuse Large B-cell Lymphoma From Follicular Lymphoma Using Texture Analysis on Conventional MR Images at 3.0 Tesla. Acad Radiol 2016; 23:696-703. [PMID: 26976622 DOI: 10.1016/j.acra.2016.01.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 01/25/2016] [Accepted: 01/26/2016] [Indexed: 01/18/2023]
Abstract
RATIONAL AND OBJECTIVES Diffuse large B-cell lymphoma (DLBCL) represents the most common type of aggressive non-Hodgkin lymphoma (NHL); follicular lymphoma (FL) is the most frequent indolent NHL. The aim of this study was to investigate whether texture-based analysis of conventional magnetic resonance imaging (MRI) allows discrimination of DLBCL from FL, and further, to correlate the MRI texture features with diffusion-weighted imaging apparent diffusion coefficient (ADC) value and tumor tissue cellularity. MATERIALS AND METHODS Forty-one patients with histologically proven NHL (30 DLBCL and 11 FL) underwent conventional MRI and diffusion-weighted imaging examination before treatment. Based on regions of interest, texture analysis was performed on T1-weighted images pre- and postcontrast enhancement and on T2-weighted images with and without fat suppression, and features derived from the run-length matrix- and co-occurrence matrix-based methods were analyzed. Receiver operating characteristic curves were performed for the three most discriminative texture features for the differentiation of the two most common types of lymphoma. The analyzed MRI texture features were correlated with the ADC value and the tumor tissue cellularity. RESULTS We found that on T1-weighted images postcontrast enhancement, run-length matrix-based texture analysis for lesion classification differentiated DLBCL from FL, with specificity and sensitivity of 76.6% and 76.5%, respectively. There was no correlation between the texture features and the ADC value or tumor tissue cellularity. CONCLUSIONS DLBCL and FL can be differentiated by means of texture analysis on T1-weighted MRI postcontrast enhancement. These results could serve as a basis for the use of the texture features on conventional MRI as adjunct to clinical examination to distinguish DLBCL from FL.
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Savio S, Hakulinen U, Ryymin P, Hagman S, Dastidar P, Soimakallio S, Elovaara I, Eskola H. Hemispheric asymmetry measured by texture analysis and diffusion tensor imaging in two multiple sclerosis subtypes. Acta Radiol 2015; 56:844-51. [PMID: 25024438 DOI: 10.1177/0284185114539323] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 05/13/2014] [Indexed: 11/15/2022]
Abstract
BACKGROUND This paper addresses two subtypes of multiple sclerosis (MS), primary progressive multiple sclerosis (PPMS) and relapsing-remitting multiple sclerosis (RRMS). The separation of PPMS and RRMS is challenging in certain cases. PURPOSE To quantitatively determine MS subtypes using texture analysis (TA) and diffusion tensor imaging (DTI). MATERIAL AND METHODS T1-weighted (T1W) magnetic resonance imaging (MRI) and DTI of the left and right brain hemispheres of 17 patients with PPMS and 19 patients with RRMS were studied. Areas of the caudate nucleus and thalamus were investigated as normal appearing gray matter (NAGM), and areas of the cerebral peduncle and centrum semiovale were investigated as normal appearing white matter (NAWM). The described locations were symmetrical and were accurately marked. TA was performed on the T1W images, and the fractional anisotropy and apparent diffusion coefficient were determined from the DTI data. RESULTS Hemispherical differences were found with both TA and DTI. Several texture and diffusion tensor parameter values calculated for the left and right hemispheres of the patients showed statistically significant differences. The patients with RRMS had greater significant differences (P < 0.01) in the thalamus between the hemispheres than did the patients with PPMS. The TA classification accuracy of the PPMS and RRMS subtypes was above 80%. CONCLUSION TA can be helpful when distinguishing between PPMS and RRMS, while DTI appears to reveal the hemispherical asymmetry of RRMS patients.
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Affiliation(s)
- Sami Savio
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Ullamari Hakulinen
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Pertti Ryymin
- Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Sanna Hagman
- Neuroimmunology Unit, Medical School, University of Tampere, Tampere, Finland
| | - Prasun Dastidar
- Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Seppo Soimakallio
- Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Irina Elovaara
- Neuroimmunology Unit, Medical School, University of Tampere, Tampere, Finland
- Department of Neurology, Tampere University Hospital, Tampere, Finland
| | - Hannu Eskola
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Department of Radiology, Tampere University Hospital, Tampere, Finland
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Kolasa M, Hakulinen U, Helminen M, Hagman S, Raunio M, Rossi M, Brander A, Dastidar P, Elovaara I. Longitudinal assessment of clinically isolated syndrome with diffusion tensor imaging and volumetric MRI. Clin Imaging 2015; 39:207-12. [DOI: 10.1016/j.clinimag.2014.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 09/28/2014] [Accepted: 10/20/2014] [Indexed: 11/16/2022]
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Wäljas M, Iverson GL, Lange RT, Hakulinen U, Dastidar P, Huhtala H, Liimatainen S, Hartikainen K, Öhman J. A prospective biopsychosocial study of the persistent post-concussion symptoms following mild traumatic brain injury. J Neurotrauma 2015; 32:534-47. [PMID: 25363626 DOI: 10.1089/neu.2014.3339] [Citation(s) in RCA: 160] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This study examined multiple biopsychosocial factors relating to post-concussion symptom (PCS) reporting in patients with mild traumatic brain injuries (mTBI), including structural (computed tomography and magnetic resonance imaging [MRI]) and microstructural neuroimaging (diffusion tensor imaging [DTI]). Patients with mTBIs completed several questionnaires and cognitive testing at approximately one month (n=126) and one year (n=103) post-injury. At approximately three weeks post-injury, DTI was undertaken using a Siemens 3T scanner in a subgroup (n=71). Measures of fractional anisotropy were calculated for 16 regions of interest (ROIs) and measures of apparent diffusion coefficient were calculated for 10 ROIs. Patients were compared with healthy control subjects. Using International Classification of Diseases, Tenth Revision (ICD-10) PCS criteria and mild or greater symptom reporting, 59% of the mTBI sample met criteria at one month and 38% met criteria at one year. However, 31% of the healthy control sample also met criteria for the syndrome-illustrating a high false-positive rate. Significant predictors of ICD-10 PCS at one month were pre-injury mental health problems and the presence of extra-cranial bodily injuries. Being symptomatic at one month was a significant predictor of being symptomatic at one year, and depression was significantly related to PCS at both one month and one year. Intracranial abnormalities visible on MRI were present in 12.1% of this sample, and multifocal areas of unusual white matter as measured by DTI were present in 50.7% (compared with 12.4% of controls). Structural MRI abnormalities and microstructural white matter findings were not significantly associated with greater post-concussion symptom reporting. The personal experience and reporting of post-concussion symptoms is likely individualized, representing the cumulative effect of multiple variables, such as genetics, mental health history, current life stress, medical problems, chronic pain, depression, personality factors, and other psychosocial and environmental factors. The extent to which damage to the structure of the brain contributes to the persistence of post-concussion symptoms remains unclear.
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Affiliation(s)
- Minna Wäljas
- 1 Department of Neurosciences and Rehabilitation, Tampere University Hospital , Tampere, Finland
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10
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Hagman S, Kolasa M, Basnyat P, Helminen M, Kähönen M, Dastidar P, Lehtimäki T, Elovaara I. Analysis of apoptosis-related genes in patients with clinically isolated syndrome and their association with conversion to multiple sclerosis. J Neuroimmunol 2015; 280:43-8. [PMID: 25773154 DOI: 10.1016/j.jneuroim.2015.02.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 02/16/2015] [Accepted: 02/23/2015] [Indexed: 01/08/2023]
Abstract
To analyse whether the expression of apoptotic transcripts is associated with the conversion from clinically isolated syndrome (CIS) to multiple sclerosis (MS). Eleven candidate transcripts belonging to the death receptor pathway, BCL-2, the inflammasome complex and NF-ΚB family were studied in the nonconverting and converting CIS patients during the four-year follow-up period. Conversion to MS was associated with marked variability in the expression of proapoptotic genes that were linked to TGF-B1 gene levels. The predominant expression of proapoptotic genes in patients with CIS suggests an increased potential to undergo apoptosis with the goal of terminating immune responses and regulating immune system homeostasis.
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Affiliation(s)
- Sanna Hagman
- Neuroimmunology Unit, Medical School, University of Tampere and Tampere University Hospital, Tampere, Finland.
| | - Marcin Kolasa
- Neuroimmunology Unit, Medical School, University of Tampere and Tampere University Hospital, Tampere, Finland
| | - Pabitra Basnyat
- Neuroimmunology Unit, Medical School, University of Tampere and Tampere University Hospital, Tampere, Finland
| | - Mika Helminen
- Science Centre, Pirkanmaa Hospital District and School of Health Sciences, University of Tampere, Finland
| | - Mika Kähönen
- Department of Clinical Physiology, Tampere University Hospital and University of Tampere Medical School, Finland
| | - Prasun Dastidar
- Medical Imaging Centre, Department of Diagnostic Radiology, Tampere University Hospital, Tampere, Finland
| | - Terho Lehtimäki
- Department of Clinical Chemistry, Fimlab Laboratories and School of Medicine University of Tampere, Tampere, Finland
| | - Irina Elovaara
- Neuroimmunology Unit, Medical School, University of Tampere and Tampere University Hospital, Tampere, Finland; Department of Neurology, Tampere University Hospital, Tampere, Finland
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Nenonen M, Hakulinen U, Brander A, Ohman J, Dastidar P, Luoto TM. Possible confounding factors on cerebral diffusion tensor imaging measurements. Acta Radiol Open 2015; 4:2047981614546795. [PMID: 25793107 PMCID: PMC4364398 DOI: 10.1177/2047981614546795] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 07/15/2014] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Diffusion tensor imaging (DTI) is prone to numerous systemic confounding factors that should be acknowledged to avoid false conclusions. PURPOSE To investigate the possible effects of age, gender, smoking, alcohol consumption, and education on cerebral DTI parameters in a generally healthy homogenous sample with no neurological or psychiatric diseases. MATERIAL AND METHODS Forty (n = 40) subjects (mean age, 40.3 years; SD, 12.3) underwent brain DTI with 3 T magnetic resonance imaging (MRI). At enrolment, all the subjects were interviewed with respect to general health, education, history of smoking, and alcohol consumption. Studied DTI parameters included: (i) fractional anisotropy (FA); and (ii) apparent diffusion coefficient (ADC). Region-of-interest (ROI)-based measurements were estimated at 13 anatomical locations bilaterally on the axial images, except for the corpus callosum in which the ROIs were placed on the sagittal images. Circular ROI measurements were mainly used. Freehand ROI method was used with the forceps minor, uncinate fasciculus, and thalamus. Intra-observer variability and repeatability were assessed. RESULTS The most consistent finding was that aging decreased FA values in the frontal brain regions. Regarding the other confounding factors, the results were discontinuous and no concrete conclusions could be drawn from these findings. In general, intra-observer repeatability of the DTI measurement was considered relatively good. CONCLUSION Age should be noted as considerable confounding factors in ROI-based DTI analysis. More research on the effects of gender, smoking, alcohol consumption, and education is needed.
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Affiliation(s)
- Miina Nenonen
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
| | - Ullamari Hakulinen
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
| | - Antti Brander
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
| | - Juha Ohman
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
| | - Prasun Dastidar
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
| | - Teemu M Luoto
- Department of Neurosciences and Rehabilitation, Tampere University Hospital Tampere, Finland
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Hannula M, Narra N, Onnela N, Dastidar P, Hyttinen J. A multi-tissue segmentation of the human head for detailed computational models. Annu Int Conf IEEE Eng Med Biol Soc 2015; 2014:2484-7. [PMID: 25570494 DOI: 10.1109/embc.2014.6944126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This paper describes the creation of an anatomically detailed high resolution model of the human head based on the Visible Human Female data from the National Library of Medicine archives. Automatic and semi-automatic segmentation algorithms were applied over the 3 image volumes – CT, MRI and anatomical cryo-sections of the cadaver – to label a total of 23 tissues. The results were combined to create a labeled volume of the head with voxel dimensions of 0.33×0.33×0.33 mm. The individual label matrices and their corresponding surface meshes are made available to be used freely. The detailed blood vessel network and ocular tissues will be of interest in computational modelling and simulation studies.
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Sikiö M, Holli-Helenius KK, Harrison LCV, Ryymin P, Ruottinen H, Saunamäki T, Eskola HJ, Elovaara I, Dastidar P. MR image texture in Parkinson's disease: a longitudinal study. Acta Radiol 2015; 56:97-104. [PMID: 24413223 DOI: 10.1177/0284185113519775] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND Few of the structural changes caused by Parkinson's disease (PD) are visible in magnetic resonance imaging (MRI) with visual inspection but there is a need for a method capable of observing the changes beyond the human eye. Texture analysis offers a technique that enables the quantification of the image gray-level patterns. PURPOSE To investigate the value of quantitative image texture analysis method in diagnosis and follow-up of PD patients. MATERIAL AND METHODS Twenty-six PD patients underwent MRI at baseline and after 2 years of follow-up. Four co-occurrence matrix-based texture parameters, describing the image homogeneity and complexity, were calculated within clinically interesting areas of the brain. In addition, correlations with clinical characteristics (Unified Parkinson's Disease Ranking Scales I-III and Mini-Mental State Examination score) along with a comparison to healthy controls were evaluated. RESULTS Patients at baseline and healthy volunteers differed in their brain MR image textures mostly in the areas of substantia nigra pars compacta, dentate nucleus, and basilar pons. During the 2-year follow-up of the patients, textural differences appeared mainly in thalamus and corona radiata. Texture parameters in all the above mentioned areas were also found to be significantly related to clinical scores describing the severity of PD. CONCLUSION Texture analysis offers a quantitative method for detecting structural changes in brain MR images. However, the protocol and repeatability of the method must be enhanced before possible clinical use.
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Affiliation(s)
- Minna Sikiö
- Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
| | - Kirsi K Holli-Helenius
- Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland
| | - Lara CV Harrison
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Department of Anaesthesia, Tampere University Hospital, Tampere, Finland
| | - Pertti Ryymin
- Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland
| | - Hanna Ruottinen
- Tampere Medical School, University of Tampere, Tampere, Finland
- Department of Neurology and Rehabilitation, Tampere University Hospital, Tampere, Finland
| | - Tiia Saunamäki
- Department of Neurology and Rehabilitation, Tampere University Hospital, Tampere, Finland
| | - Hannu J Eskola
- Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
| | - Irina Elovaara
- Tampere Medical School, University of Tampere, Tampere, Finland
- Department of Neurology and Rehabilitation, Tampere University Hospital, Tampere, Finland
| | - Prasun Dastidar
- Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland
- Tampere Medical School, University of Tampere, Tampere, Finland
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14
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Sikiö M, Kölhi P, Ryymin P, Eskola HJ, Dastidar P. MRI Texture Analysis and Diffusion Tensor Imaging in Chronic Right Hemisphere Ischemic Stroke. J Neuroimaging 2014; 25:614-9. [PMID: 25482992 DOI: 10.1111/jon.12185] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 07/30/2014] [Accepted: 08/16/2014] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Diffusion tensor imaging (DTI) is shown to reveal changes caused by cerebral infarction. The aim of this study is to reveal those changes also in the conventional magnetic resonance (MR) images using a quantitative image analysis method, texture analysis (TA). METHODS Thirty patients who had suffered their first ever infarction located on the right hemisphere underwent DTI and conventional MRI studies in the chronic phase. DTI parameters fractional anisotropy and mean diffusivity, as well as four second-order texture parameters were calculated. Interhemispheric differences and correlations between DTI and TA parameters were evaluated. RESULTS Our DTI findings supported earlier studies as fractional anisotropy values were lowered and mean diffusivity values elevated in the lesion site, and ipsilateral cerebral peduncle, thalamus, and centrum semiovale compared to the unaffected side. Textural homogeneity parameters showed lower and complexity parameters higher values in the lesion site and ipsilateral centrum semiovale compared to the contralateral hemisphere. Correlation between the two methods was found in ipsilateral mesencephalon. CONCLUSIONS In addition to DTI method, TA could assist in revealing the changes caused by infarction, also outside the lesion site. Damaged areas were found more heterogeneous and random in texture compared to unaffected sites.
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Affiliation(s)
- Minna Sikiö
- Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland.,Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
| | - Paula Kölhi
- Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland.,Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
| | - Pertti Ryymin
- Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland
| | - Hannu J Eskola
- Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland.,Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
| | - Prasun Dastidar
- Department of Radiology, Medical Imaging Center and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland.,Medical School, University of Tampere, Tampere, Finland
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15
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Hagman S, Basnyat P, Kolasa M, Helminen M, Dastidar P, Elovaara I. The expressions of apoptotic-related genes in patients with the clinically isolated syndrome: A follow-up study. J Neuroimmunol 2014. [DOI: 10.1016/j.jneuroim.2014.08.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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16
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Koivisto J, Wolff J, Järnstedt J, Dastidar P, Kortesniemi M. Assessment of the effective dose in supine, prone, and oblique positions in the maxillofacial region using a novel combined extremity and maxillofacial cone beam computed tomography scanner. Oral Surg Oral Med Oral Pathol Oral Radiol 2014; 118:355-62. [DOI: 10.1016/j.oooo.2014.05.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 04/14/2014] [Accepted: 05/21/2014] [Indexed: 11/27/2022]
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17
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Wu X, Pertovaara H, Korkola P, Vornanen M, Järvenpää R, Dastidar P, Eskola H, Kellokumpu-Lehtinen PL. Early interim PET/CT predicts post-treatment response in diffuse large B-cell lymphoma. Acta Oncol 2014; 53:1093-9. [PMID: 24960581 DOI: 10.3109/0284186x.2014.927074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND (18)F-FDG-PET/CT has been widely used in the staging of malignant lymphomas, and accepted as a tool for response assessment. Among PET parameters, the most frequently studied is maximal standardized uptake value (SUVmax). Metabolic tumor burden (MTB) is a parameter in which both metabolic tumor volume (MTV) and tumor activity are integrated. Here, we analyzed the prognostic value of SUVmax, SUVsum (sum of the SUVmax), whole-body MTV (MTVwb) and MTBwb from baseline and interim PET/CT in patients with diffuse large B-cell lymphoma (DLBCL). MATERIAL AND METHODS Twenty-nine patients with histologically proven DLBCL were imaged by PET/CT before treatment (Exam I), and one week after the first dose of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy (Exam II). Biopsy specimens were examined by an expert hematopathologist, the Ki-67 proliferation index (PI) was estimated for each biopsy site from the MIB-1 stained sections. The response evaluation was performed after chemotherapy completion (6-8 cycles). RESULTS All patients had one or more visualized lymphomatous lesions on (18)F-FDG-PET/CT. The SUVmax of the whole-body (BmSUVmax) was higher than the SUVmax at biopsy site (BxSUVmax) (mean: 20.1 vs. 17.3, p < 0.01). The PI correlated with the BxSUVmax (p < 0.05). One week after chemotherapy, SUVmax, SUVsum, MTVwb, and MTBwb decreased significantly (p < 0.01, respectively), SUVsum, MTVwb and MTBwb at Exam II correlated with chemotherapy response at treatment completion (p < 0.05, respectively). CONCLUSION SUVmax is more accurate to detect tumor aggressiveness than biopsy in DLBCL, since BmSUVmax represents the most aggressive tumor of the patient. Interim PET/CT as early as one week after R-CHOP therapy predicts response. Thus, it could be used as a tool for guidance of risk stratification in DLBCL.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Antibodies, Monoclonal, Murine-Derived/administration & dosage
- Antineoplastic Combined Chemotherapy Protocols/administration & dosage
- Antineoplastic Combined Chemotherapy Protocols/therapeutic use
- Cyclophosphamide/administration & dosage
- Doxorubicin/administration & dosage
- Female
- Fluorodeoxyglucose F18
- Humans
- Lymphoma, Large B-Cell, Diffuse/diagnostic imaging
- Lymphoma, Large B-Cell, Diffuse/drug therapy
- Lymphoma, Large B-Cell, Diffuse/metabolism
- Lymphoma, Large B-Cell, Diffuse/pathology
- Magnetic Resonance Imaging/methods
- Male
- Middle Aged
- Positron-Emission Tomography/methods
- Prednisone/administration & dosage
- Radiopharmaceuticals
- Rituximab
- Tomography, X-Ray Computed/methods
- Vincristine/administration & dosage
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Affiliation(s)
- Xingchen Wu
- Department of Oncology, Tampere University Hospital , Tampere , Finland
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18
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Oksala N, Jaroma M, Pienimäki JP, Kuorilehto T, Vänttinen T, Lehtomäki A, Suominen VP, Dastidar P, Mäkinen K, Erkinjuntti T, Salenius JP. Preoperative white matter lesions are independent predictors of long-term survival after internal carotid endarterectomy. Cerebrovasc Dis Extra 2014; 4:122-31. [PMID: 25076957 PMCID: PMC4093648 DOI: 10.1159/000363128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 04/23/2014] [Indexed: 11/19/2022] Open
Abstract
Background Cerebral white matter lesions (WMLs) predict long-term survival of conservatively treated acute stroke patients with etiology other than carotid stenosis. In carotid endarterectomy patients, WMLs are associated with severe carotid stenosis and unstable plaques, with the risk of perioperative complications and with increased 30-day perioperative risk of death. However, no data exist on their effect on postoperative long-term survival, a factor important when considering the net benefit from carotid endarterectomy. Whether this effect is independent of classical risk factors and indications for surgery is not known either. We hypothesized that WMLs could be evaluated from preoperative routine computed tomography (CT) scans and are predictors of postoperative survival, independent of classical cardiovascular risk factors, indication category and degree of carotid stenosis. Methods A total of 353 of 481 (73.4%) consecutive patients subjected to carotid endarterectomy due to different indications, i.e. asymptomatic stenosis (n = 28, 7.9%), amaurosis fugax (n = 52, 14.7%), transient ischemic attack (n = 135, 38.2%) or ischemic stroke (n = 138, 39.1%), from prospective vascular registries during the years 2001-2010 with digital preoperative CT scans, were included in the study. WMLs were rated by a radiologist (Wahlund criteria) in a blinded fashion. Internal carotid artery (ICA) stenoses were angiographically graded (<50, 50-69, 70-99 and 100%). Odds ratios (ORs) and hazard ratios (HRs) are reported (ORs and HRs ≤1 indicate a beneficial effect). The median follow-up time was 67 months (interquartile range 45.5, range 0-129 months). Spearman's rho was used to estimate intraobserver agreement. Binary logistic regression was performed to analyze the association of risk factors with WMLs. Cox regression proportional hazards analysis was used to study the effect of different factors on survival. Results WML severity could be assessed with a substantial intraobserver agreement (Spearman's rho 0.843, p < 0.0001). Only age (OR 1.10, 95% CI 1.06-1.15; p < 0.0001 per year), degree of ipsilateral ICA stenosis (OR 2.22, 95% CI 1.08-4.55; p < 0.05 per stenosis grade) and indication category (OR 1.63, 95% CI 1.19-2.24; p < 0.01 per category) remained independently associated with WMLs. Age (HR 1.04, 95% CI 1.01-1.08; p < 0.05 per year), diabetes (HR 1.59, 95% CI 1.01-2.49; p < 0.05), peripheral arterial disease (HR 2.47, 95% CI 1.46-4.15; p < 0.01), degree of ipsilateral ICA stenosis (HR 2.56, 95% CI 1.12-5.87; p < 0.05 per stenosis grade) and WMLs (HR 3.83, 95% CI 1.17-12.5; p < 0.05) remained independently associated with increased long-term mortality. Conclusions WMLs in a preoperative CT scan provide a substantially reliable estimate of postoperative long-term survival of carotid endarterectomy patients independent of currently used criteria, i.e. cardiovascular risk factors, indication category and degree of ipsilateral ICA stenosis.
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Affiliation(s)
- Niku Oksala
- Department of Vascular Surgery, Tampere University Hospital and Medical School, Surgery, University of Tampere, Tampere, Finland
| | - Marianne Jaroma
- Heart Center, Department of Vascular Surgery, Kuopio University Hospital, Kuopio, Finland
| | | | - Tommi Kuorilehto
- Department of Vascular Surgery, Tampere University Hospital and Medical School, Surgery, University of Tampere, Tampere, Finland
| | - Teemu Vänttinen
- Department of Vascular Surgery, Tampere University Hospital and Medical School, Surgery, University of Tampere, Tampere, Finland
| | - Antti Lehtomäki
- Department of Vascular Surgery, Tampere University Hospital and Medical School, Surgery, University of Tampere, Tampere, Finland
| | - Veli-Pekka Suominen
- Department of Vascular Surgery, Tampere University Hospital and Medical School, Surgery, University of Tampere, Tampere, Finland
| | - Prasun Dastidar
- Regional Imaging Unit, Tampere University Hospital, Tampere, Finland
| | - Kimmo Mäkinen
- Heart Center, Department of Vascular Surgery, Kuopio University Hospital, Kuopio, Finland
| | - Timo Erkinjuntti
- Department of Neurology, Helsinki University Central Hospital, Helsinki, Finland ; Department of Neurological Sciences, University of Helsinki, Helsinki, Finland
| | - Juha-Pekka Salenius
- Department of Vascular Surgery, Tampere University Hospital and Medical School, Surgery, University of Tampere, Tampere, Finland
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19
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Nketiah G, Savio S, Dastidar P, Nikander R, Eskola H, Sievänen H. Detection of exercise load-associated differences in hip muscles by texture analysis. Scand J Med Sci Sports 2014; 25:428-34. [PMID: 24840507 DOI: 10.1111/sms.12247] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2014] [Indexed: 12/15/2022]
Abstract
We examined whether specific physical exercise loading is associated with texture parameters from hip muscles scanned with magnetic resonance imaging (MRI). Ninety-one female athletes representing five distinct exercise-loading groups (high-impact, odd-impact, low-impact, nonimpact and high-magnitude) and 20 nonathletic female controls underwent MRI of the hip. Texture parameters were computed from the MRI images of four hip muscles (gluteus maximus, gluteus medius, iliopsoas and obturator internus). Differences in muscle texture between the athlete groups and the controls were evaluated using Mann-Whitney U-test. Significant (P < 0.05) textural differences were found between the high-impact (triple and high jumpers) and the control group in gluteus medius, iliopsoas and obturator internus muscles. Texture of the gluteus maximus, gluteus medius and obturator internus muscles differed significantly between the odd impact (soccer and squash players) and the control group. Textures of all studied muscles differed significantly between the low impact (endurance runners) and the controls. Only the gluteus medius muscle differed significantly between the nonimpact (swimmers) and the controls. No significant difference in muscle texture was found between the high-magnitude (powerlifters) and the control group. In conclusion, MRI texture analysis provides a quantitative method capable of detecting textural differences in hip muscles that are associated with specific types of long-term exercise loadings.
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Affiliation(s)
- G Nketiah
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
| | - S Savio
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland.,Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - P Dastidar
- Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - R Nikander
- Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland.,GeroCenter Foundation for Aging Research and Development, Jyväskylä, Finland.,Jyväskylä Central Hospital, Jyväskylä, Finland
| | - H Eskola
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
| | - H Sievänen
- The UKK Institute for Health Promotion Research, Tampere, Finland
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20
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Brander A, Koskinen E, Luoto TM, Hakulinen U, Helminen M, Savilahti S, Ryymin P, Dastidar P, Öhman J. Diffusion tensor imaging of the cervical spinal cord in healthy adult population: normative values and measurement reproducibility at 3T MRI. Acta Radiol 2014; 55:478-85. [PMID: 23969263 DOI: 10.1177/0284185113499752] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Compared to diffusion tensor imaging (DTI) of the brain, there is a paucity of reports addressing the applicability of DTI in the evaluation of the spinal cord. Most normative data of cervical spinal cord DTI consist of relatively small and arbitrarily collected populations. Comprehensive normative data are necessary for clinical decision-making. PURPOSE To establish normal values for cervical spinal cord DTI metrics with region of interest (ROI)- and fiber tractography (FT)-based measurements and to assess the reproducibility of both measurement methods. MATERIAL AND METHODS Forty healthy adults underwent cervical spinal cord 3T MRI. Sagittal and axial conventional T2 sequences and DTI in the axial plane were performed. Whole cord fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were determined at different cervical levels from C2 to C7 using the ROI method. DTI metrics (FA, axial, and radial diffusivities based on eigenvalues λ1, λ2, and λ3, and ADC) of the lateral and posterior funicles were measured at C3 level. FA and ADC of the whole cord and the lateral and posterior funicles were also measured using quantitative tractography. Intra- and inter-observer variation of the measurement methods were assessed. RESULTS Whole cord FA values decreased and ADC values increased in the rostral to caudal direction from C2 to C7. Between the individual white matter funicles no statistically significant difference for FA or ADC values was found. Both axial diffusivity and radial diffusivity of both lateral funicles differed significantly from those of the posterior funicle. Neither gender nor age correlated with any of the DTI metrics. Intra-observer variation of the measurements for whole cord FA and ADC showed almost perfect agreement with both ROI and tractography-based measurements. There was more variation in measurements of individual columns. Inter-observer agreement varied from moderate to strong for whole cord FA and ADC. CONCLUSION Both ROI- and FT-based measurements are applicable methods yielding reproducible results for cervical spinal cord DTI metrics. Normative values for both measurement methods are presented.
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Affiliation(s)
- Antti Brander
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Eerika Koskinen
- Department of Neurosciences and Rehabilitation, Tampere University Hospital, Tampere, Finland
| | - Teemu M Luoto
- Department of Neurosciences and Rehabilitation, Tampere University Hospital, Tampere, Finland
| | - Ullamari Hakulinen
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Mika Helminen
- School of Health Sciences, University of Tampere, Tampere, Finland and Science Center, Pirkanmaa Hospital District, Tampere, Finland
| | - Sirpa Savilahti
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Pertti Ryymin
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Prasun Dastidar
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Tampere, Finland
| | - Juha Öhman
- Department of Neurosciences and Rehabilitation, Tampere University Hospital, Tampere, Finland
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21
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Kölhi P, Järnstedt J, Sikiö M, Viik J, Dastidar P, Peltomäki T, Eskola H. A texture analysis method for MR images of airway dilator muscles: a feasibility study. Dentomaxillofac Radiol 2014; 43:20130403. [PMID: 24773626 DOI: 10.1259/dmfr.20130403] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVES Airway dilator muscles play an important role in the analysis of breathing-related symptoms, such as obstructive sleep apnoea. Texture analysis (TA) provides a new non-invasive method for analysing airway dilator muscles. In this study, we propose a TA methodology for airway dilator muscles and prove the robustness of this method. METHODS 15 orthognathic surgery patients underwent 3-T MRI. Computerized TA was performed on 20 regions of interest (ROIs) in the patients' airway dilator muscles. 53 texture parameters were calculated for all ROIs. The robustness of the TA method was analysed by altering the locations, sizes and shapes of the ROIs. RESULTS Our study shows that there is significant difference in TA results as the size or shape of ROI changes. The change of location of the ROI inside the studied muscle does not affect the TA results. CONCLUSIONS The TA method is valid for airway dilator muscles. We propose a methodology in which the number of co-occurrence parameters is reduced by using mean values from four different directions (0°, 45°, 90° and 135°) with pixel spacing of 1 pixel.
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Affiliation(s)
- P Kölhi
- 1 Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
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22
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Wäljas M, Lange RT, Hakulinen U, Huhtala H, Dastidar P, Hartikainen K, Öhman J, Iverson GL. Biopsychosocial Outcome after Uncomplicated Mild Traumatic Brain Injury. J Neurotrauma 2014; 31:108-24. [DOI: 10.1089/neu.2013.2941] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Minna Wäljas
- Department of Neurosciences and Rehabilitation, Tampere University Hospital, Tampere, Finland
- University of Tampere Medical School, Tampere, Finland
| | - Rael T. Lange
- University of British Columbia, Vancouver, Canada
- Defense and Veterans Brain Injury Center, North Bethesda, Maryland
- Walter Reed National Military Medical Center, Bethesda, Maryland
| | - Ullamari Hakulinen
- Department of Radiology, Medical Imaging Centre and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
| | - Heini Huhtala
- School of Health Sciences, University of Tampere, Tampere, Finland
| | - Prasun Dastidar
- University of Tampere Medical School, Tampere, Finland
- Department of Radiology, Medical Imaging Centre and Hospital Pharmacy, Tampere University Hospital, Tampere, Finland
| | - Kaisa Hartikainen
- Behavioral Neurology Research Unit, Pirkanmaa Hospital District, Tampere, Finland
| | - Juha Öhman
- Department of Neurosciences and Rehabilitation, Tampere University Hospital, Tampere, Finland
- University of Tampere Medical School, Tampere, Finland
| | - Grant L. Iverson
- Department of Physical Medicine and Rehabilitation, Harvard Medical School; Red Sox Foundation and Massachusetts General Hospital Home Base Program, Boston, Massachusetts
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23
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Sikiö M, Harrison LCV, Nikander R, Ryymin P, Dastidar P, Eskola HJ, Sievänen H. Influence of exercise loading on magnetic resonance image texture of thigh soft tissues. Clin Physiol Funct Imaging 2013; 34:370-6. [DOI: 10.1111/cpf.12107] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 10/30/2013] [Indexed: 12/19/2022]
Affiliation(s)
- Minna Sikiö
- Department of Radiology; Medical Imaging Center and Hospital Pharmacy; Tampere University Hospital; Tampere Finland
- Department of Electronics and Communications Engineering; Tampere University of Technology; Tampere Finland
| | - Lara C. V. Harrison
- Department of Electronics and Communications Engineering; Tampere University of Technology; Tampere Finland
- Department of Anaesthesia; Tampere University Hospital; Tampere Finland
| | - Riku Nikander
- Department of Health Sciences; University of Jyväskylä; Tampere Finland
- GeroCenter Foundation for Aging Research and Development; Jyväskylä Finland
- Jyväskylä Central Hospital; Jyväskylä Finland
| | - Pertti Ryymin
- Department of Radiology; Medical Imaging Center and Hospital Pharmacy; Tampere University Hospital; Tampere Finland
| | - Prasun Dastidar
- Department of Radiology; Medical Imaging Center and Hospital Pharmacy; Tampere University Hospital; Tampere Finland
- Tampere Medical School; University of Tampere; Tampere Finland
| | - Hannu J. Eskola
- Department of Radiology; Medical Imaging Center and Hospital Pharmacy; Tampere University Hospital; Tampere Finland
- Department of Electronics and Communications Engineering; Tampere University of Technology; Tampere Finland
| | - Harri Sievänen
- Bone Research Group; UKK Intstitute for Health Promotion Research; Tampere Finland
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24
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Wu X, Nerisho S, Dastidar P, Ryymin P, Järvenpää R, Pertovaara H, Eskola H, Kellokumpu-Lehtinen PL. Comparison of different MRI sequences in lesion detection and early response evaluation of diffuse large B-cell lymphoma--a whole-body MRI and diffusion-weighted imaging study. NMR Biomed 2013; 26:1186-94. [PMID: 23483722 DOI: 10.1002/nbm.2933] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 01/28/2013] [Accepted: 01/28/2013] [Indexed: 05/22/2023]
Abstract
To compare different MRI sequences for the detection of lesions and the evaluation of response to chemotherapy in patients with diffuse large B-cell lymphoma (DLBCL), 18 patients with histology-confirmed DLBCL underwent 3-T MRI scanning prior to and 1 week after chemotherapy. The MRI sequences included T1-weighted pre- and post-contrast, T2 -weighted with and without fat suppression, and a single-shot echo-planar diffusion-weighted imaging (DWI) with two b values (0 and 800 s/mm(2)). Conventional MRI sequence comparisons were performed using the contrast ratio between tumor and normal vertebral body instead of signal intensity. The apparent diffusion coefficient (ADC) of the tumor was measured directly on the parametric ADC map. The tumor volume was used as a reference for the evaluation of chemotherapy response. The mean tumor volume was 374 mL at baseline, and decreased by 65% 1 week after chemotherapy (p < 0.01). The T2 -weighted image with fat suppression showed a significantly higher contrast ratio compared with images from all other conventional MRI sequences, both before and after treatment (p < 0.01, respectively). The contrast ratio of the T2 -weighted image with fat suppression decreased significantly (p < 0.01), and that of the T1 -weighted pre-contrast image increased significantly (p < 0.01), after treatment. However, there was no correlation between the change in contrast ratio and tumor volume. The mean ADC value was 0.68 × 10(-3) mm(2)/s at baseline; it increased by 89% after chemotherapy (p < 0.001), and the change in ADC value correlated with the change in tumor volume (r = 0.66, p < 0.01). The baseline ADC value also correlated inversely with the percentage change in ADC after treatment (r = -0.62, p < 0.01). In conclusion, this study indicates that T2-weighted imaging with fat suppression is the best conventional sequence for the detection of lesions and evaluation of the efficacy of chemotherapy in DLBCL. DWI with ADC mapping is an imaging modality with both diagnostic and prognostic value that could complement conventional MRI.
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Affiliation(s)
- Xingchen Wu
- Department of Oncology, Tampere University Hospital, Tampere, Finland.
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Rossi M, Ruottinen H, Soimakallio S, Elovaara I, Dastidar P. Clinical MRI for iron detection in Parkinson's disease. Clin Imaging 2013; 37:631-6. [DOI: 10.1016/j.clinimag.2013.02.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 01/03/2013] [Accepted: 02/07/2013] [Indexed: 01/12/2023]
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Sillanpää N, Saarinen JT, Rusanen H, Elovaara I, Dastidar P, Soimakallio S. Location of the clot and outcome of perfusion defects in acute anterior circulation stroke treated with intravenous thrombolysis. AJNR Am J Neuroradiol 2013; 34:100-6. [PMID: 22723067 DOI: 10.3174/ajnr.a3149] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND PURPOSE The location of the clot is a major determinant of ischemic stroke outcome. We studied the impact of the location (ICA, proximal M1 segment of the MCA, distal M1 segment, and M2 segment and more distally) of the clot on the CT perfusion parametric maps, the mismatch ratio, the amount of salvaged brain tissue, and the imaging and clinical outcomes in a retrospective acute (<3 hours) stroke cohort treated with intravenous thrombolysis. MATERIALS AND METHODS We reviewed 105 patients who underwent admission multimodal CT that revealed an occluded vessel on CTA. CT perfusion was successfully performed in 58 patients (55%). Differences among the parameters in different vessel positions were studied with the ANCOVA by using onset-to-imaging time as a covariate followed by pair-wise testing. RESULTS There were no significant differences in potential confounding variables among the groups. A clot proximal to the M2 segment produced a significantly larger defect on the MTT map. A clot in the ICA resulted in a significantly larger CBV lesion compared with the distal M1 segment, the M2 segment, and the M3 segment. In general, a more proximal thrombus created a larger CBV defect. The fraction of penumbra that was salvaged at 24 hours was higher in the more distal vessel positions. CONCLUSIONS Admission CBV defects are larger in proximal vessel occlusions. More of the penumbra can be salvaged if the occlusion is located distally. This effect seems to reach a plateau in the distal M1 segment of the MCA.
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Affiliation(s)
- N Sillanpää
- Medical Imaging Center, Tampere University Hospital, Tampere, Finland.
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Wu X, Pertovaara H, Dastidar P, Vornanen M, Paavolainen L, Marjomäki V, Järvenpää R, Eskola H, Kellokumpu-Lehtinen PL. ADC measurements in diffuse large B-cell lymphoma and follicular lymphoma: a DWI and cellularity study. Eur J Radiol 2012; 82:e158-64. [PMID: 23254159 DOI: 10.1016/j.ejrad.2012.11.021] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 11/06/2012] [Accepted: 11/13/2012] [Indexed: 01/18/2023]
Abstract
PURPOSE Diffusion-weighted magnetic resonance imaging (DW-MRI) allows quantifying the random motion of water molecules in tissue by means of apparent diffusion coefficient (ADC) measurements. The aim of the study was to determine whether ADC measurements allow discrimination of diffuse large B-cell lymphoma (DLBCL) from follicular lymphoma (FL), and to examine the relationship between cellularity and ADC value of the tumor using DWI. MATERIALS AND METHODS Thirty-two patients with histologically proven non-Hodgkin lymphoma (21 with DLBCL and 11 with FL, 17 males and 15 females, mean age 62±13 years) underwent conventional MRI and DWI examination before treatment. The ADC values of DLBCL were compared to those of FL. The ADC value of the tumor was also correlated with the tumor tissue cellularity. RESULTS The mean ADC value of DLBCL was not significantly different from that of FL (0.70±0.16×10(-3)mm(2)/s vs. 0.76±0.12×10(-3)mm(2)/s, P=0.21). The cellularity of DLBCL was significantly lower than that of FL (2991±351 cells/view vs. 4412±767 cells/view, P<0.001). There was no correlation between the ADC value and the tissue cellularity of the tumor in patients with DLBCL and FL. CONCLUSION ADC measurements could not differentiate between DLBCL and FL, and there was no correlation between the ADC value and cellularity of the tumor in patients with DLBCL and FL.
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Affiliation(s)
- Xingchen Wu
- Department of Oncology, Tampere University Hospital, Tampere, Finland.
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Hakulinen U, Brander A, Ryymin P, Öhman J, Soimakallio S, Helminen M, Dastidar P, Eskola H. Repeatability and variation of region-of-interest methods using quantitative diffusion tensor MR imaging of the brain. BMC Med Imaging 2012. [PMID: 23057584 DOI: 10.1186/1471-2342-12-30.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Diffusion tensor imaging (DTI) is increasingly used in various diseases as a clinical tool for assessing the integrity of the brain's white matter. Reduced fractional anisotropy (FA) and an increased apparent diffusion coefficient (ADC) are nonspecific findings in most pathological processes affecting the brain's parenchyma. At present, there is no gold standard for validating diffusion measures, which are dependent on the scanning protocols, methods of the softwares and observers. Therefore, the normal variation and repeatability effects on commonly-derived measures should be carefully examined. METHODS Thirty healthy volunteers (mean age 37.8 years, SD 11.4) underwent DTI of the brain with 3T MRI. Region-of-interest (ROI) -based measurements were calculated at eleven anatomical locations in the pyramidal tracts, corpus callosum and frontobasal area. Two ROI-based methods, the circular method (CM) and the freehand method (FM), were compared. Both methods were also compared by performing measurements on a DTI phantom. The intra- and inter-observer variability (coefficient of variation, or CV%) and repeatability (intra-class correlation coefficient, or ICC) were assessed for FA and ADC values obtained using both ROI methods. RESULTS The mean FA values for all of the regions were 0.663 with the CM and 0.621 with the FM. For both methods, the FA was highest in the splenium of the corpus callosum. The mean ADC value was 0.727 ×10-3 mm2/s with the CM and 0.747 ×10-3 mm2/s with the FM, and both methods found the ADC to be lowest in the corona radiata. The CV percentages of the derived measures were < 13% with the CM and < 10% with the FM. In most of the regions, the ICCs were excellent or moderate for both methods. With the CM, the highest ICC for FA was in the posterior limb of the internal capsule (0.90), and with the FM, it was in the corona radiata (0.86). For ADC, the highest ICC was found in the genu of the corpus callosum (0.93) with the CM and in the uncinate fasciculus (0.92) with FM. CONCLUSIONS With both ROI-based methods variability was low and repeatability was moderate. The circular method gave higher repeatability, but variation was slightly lower using the freehand method. The circular method can be recommended for the posterior limb of the internal capsule and splenium of the corpus callosum, and the freehand method for the corona radiata.
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Affiliation(s)
- Ullamari Hakulinen
- Department of Radiology, Medical Imaging Center of Pirkanmaa Hospital District, Teiskontie 35 PL 2000, 33521, Tampere, Finland.
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Hakulinen U, Brander A, Ryymin P, Öhman J, Soimakallio S, Helminen M, Dastidar P, Eskola H. Repeatability and variation of region-of-interest methods using quantitative diffusion tensor MR imaging of the brain. BMC Med Imaging 2012; 12:30. [PMID: 23057584 PMCID: PMC3533516 DOI: 10.1186/1471-2342-12-30] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 10/02/2012] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Diffusion tensor imaging (DTI) is increasingly used in various diseases as a clinical tool for assessing the integrity of the brain's white matter. Reduced fractional anisotropy (FA) and an increased apparent diffusion coefficient (ADC) are nonspecific findings in most pathological processes affecting the brain's parenchyma. At present, there is no gold standard for validating diffusion measures, which are dependent on the scanning protocols, methods of the softwares and observers. Therefore, the normal variation and repeatability effects on commonly-derived measures should be carefully examined. METHODS Thirty healthy volunteers (mean age 37.8 years, SD 11.4) underwent DTI of the brain with 3T MRI. Region-of-interest (ROI) -based measurements were calculated at eleven anatomical locations in the pyramidal tracts, corpus callosum and frontobasal area. Two ROI-based methods, the circular method (CM) and the freehand method (FM), were compared. Both methods were also compared by performing measurements on a DTI phantom. The intra- and inter-observer variability (coefficient of variation, or CV%) and repeatability (intra-class correlation coefficient, or ICC) were assessed for FA and ADC values obtained using both ROI methods. RESULTS The mean FA values for all of the regions were 0.663 with the CM and 0.621 with the FM. For both methods, the FA was highest in the splenium of the corpus callosum. The mean ADC value was 0.727 ×10-3 mm2/s with the CM and 0.747 ×10-3 mm2/s with the FM, and both methods found the ADC to be lowest in the corona radiata. The CV percentages of the derived measures were < 13% with the CM and < 10% with the FM. In most of the regions, the ICCs were excellent or moderate for both methods. With the CM, the highest ICC for FA was in the posterior limb of the internal capsule (0.90), and with the FM, it was in the corona radiata (0.86). For ADC, the highest ICC was found in the genu of the corpus callosum (0.93) with the CM and in the uncinate fasciculus (0.92) with FM. CONCLUSIONS With both ROI-based methods variability was low and repeatability was moderate. The circular method gave higher repeatability, but variation was slightly lower using the freehand method. The circular method can be recommended for the posterior limb of the internal capsule and splenium of the corpus callosum, and the freehand method for the corona radiata.
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Affiliation(s)
- Ullamari Hakulinen
- Department of Radiology, Medical Imaging Center of Pirkanmaa Hospital District, Teiskontie 35 PL 2000, 33521, Tampere, Finland.
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Wäljas M, Iverson GL, Hartikainen KM, Liimatainen S, Dastidar P, Soimakallio S, Jehkonen M, Öhman J. Reliability, validity and clinical usefulness of the BNI fatigue scale in mild traumatic brain injury. Brain Inj 2012; 26:972-8. [DOI: 10.3109/02699052.2012.660511] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Joro R, Dastidar P, Iivonen V, Ylänen H, Soimakallio S. NADINE: new approaches to detecting breast cancer by sequential μm-wavelength imaging with the aid of novel frequency analysis techniques. J Med Eng Technol 2012; 36:251-60. [PMID: 22512737 DOI: 10.3109/03091902.2012.674173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The study focuses on 12 breasts of six breast cancer patients sequential µm-wavelength imaging, taken by two different 3-5 μm wavelength area indium antimony (InSb) photovoltaic cameras. The aim of the study was to compare the functionality of area and pixel-based frequency analyses. Comparisons between these frequency analysis methods were made according to their relevancy to mammographic findings. Another objective of the study was to find reliable imaging conditions by specifying the border conditions for the patient stabilizing imaging bed and managing the imaging situation. According to the results, the match of pixel based frequency analysis to the mammography findings is better than using area frequency analysis. The results also indicate that when the optical axis of the camera in relation to the surface of the breast to be imaged grows to more than 40°, the emissivity changes dramatically and at that point reliable results will not be obtained. Consequently the analysis of the imagined breast requires more images to be fused into one analysis image to cover the whole breast.
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Affiliation(s)
- R Joro
- Department of Biomedical Engineering, Tampere University of Technology and BioMediTech, Tampere, Finland.
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Saarinen JT, Sillanpää N, Rusanen H, Hakomäki J, Huhtala H, Lähteelä A, Dastidar P, Soimakallio S, Elovaara I. The mid-M1 segment of the middle cerebral artery is a cutoff clot location for good outcome in intravenous thrombolysis. Eur J Neurol 2012; 19:1121-7. [PMID: 22416757 DOI: 10.1111/j.1468-1331.2012.03689.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND AND PURPOSE We studied the impact of the location of the thrombus (internal carotid artery, proximal M1 segment, distal M1 segment, M2 segment, and M3 segment of the middle cerebral artery) in predicting the clinical outcome of patients treated with intravenous thrombolytic therapy (<3 h) in a retrospective cohort. METHODS Anterior circulation thrombus was detected with computed tomography angiography in 105 patients. Baseline clinical and radiological information was collected and entered into logistic regression analysis to predict favorable clinical outcome (3-month modified Rankin Scale from 0 to 2 was a primary outcome measure). RESULTS Three months after stroke, there was a significant increase in mortality (32% vs. 3%, P < 0.001) and functional dependency (82% vs. 29%, P < 0.001) in patients with internal carotid artery or proximal M1 segment of the middle cerebral artery thrombus compared to a more distal occlusion. In the regression analysis, after adjusting for National Institutes of Health Stroke Scale, age, sex, and onset-to-treatment time, the clot location was an independent predictor of good clinical outcome (P = 0.001) and exhibited dose-response type behavior when moving from a proximal vessel position to a more distal one. When the location was dichotomized, a cutoff between the proximal and the distal M1 segments best differentiated between good and poor clinical outcome (OR = 16.0, 95% CI 3.9-66.2). CONCLUSIONS The outcome of acute internal carotid artery or proximal M1 segment of the middle cerebral artery occlusion is generally poor even if treated with intravenous thrombolysis. Alternative revascularization strategies should be considered. Vascular imaging at the admission is required to guide this decision.
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Affiliation(s)
- J T Saarinen
- Department of Neurology, Tampere University Hospital, Tampere, Finland.
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Sillanpaa N, Rusanen H, Saarinen JT, Dastidar P, Soimakallio S. Comparison of 64-row and 16-row multidetector CT in the perfusion CT evaluation of acute ischemic stroke patients receiving intravenous thrombolytic therapy. Neuroradiology 2012; 54:957-63. [DOI: 10.1007/s00234-012-1015-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Accepted: 01/26/2012] [Indexed: 11/30/2022]
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Kettunen JE, Nurmi M, Koivisto AM, Dastidar P, Jehkonen M. The presence of visual neglect after thrombolytic treatment in patients with right hemisphere stroke. ScientificWorldJournal 2012; 2012:434120. [PMID: 22454606 PMCID: PMC3289869 DOI: 10.1100/2012/434120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 12/13/2011] [Indexed: 11/17/2022] Open
Abstract
Visual neglect (VN) is a common consequence of right hemisphere (RH) stroke. The aims of this study were to explore the presence of VN after RH stroke in the patients with (T+) or without (T−) thrombolytic treatment, and to determine whether thrombolysis is a predictor of VN. The study group consisted of 77 RH infarct patients. VN was evaluated with six conventional subtests of the Behavioural Inattention Test (BIT). Stroke severity was assessed using the National Institute of Health Stroke Scale (NIHSS). In the neuropsychological examination, 22% of all RH stroke patients had VN. VN was present in 15% of the patients in the T+ group and in 28% of the patients in the T− group, but the difference was not statistically significant. Despite that, patients in the T− group had a higher risk of VN than patients in the T+ group. Our results suggest that thrombolysis independently predicted absence of VN.
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Affiliation(s)
- J E Kettunen
- Deparment of Neurology and Rehabilitation, Tampere University Hospital, P. O. Box 2000, Tampere FIN-33521, Finland
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Kettunen JE, Nurmi M, Dastidar P, Jehkonen M. Recovery From Visual Neglect After Right Hemisphere Stroke: Does Starting Point in Cancellation Tasks Change After 6 Months? Clin Neuropsychol 2012; 26:305-20. [DOI: 10.1080/13854046.2011.648213] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Rajala T, Savio S, Penttinen J, Dastidar P, Kähönen M, Eskola H, Miettunen R, Turjanmaa V, Järvenpää R. Development of a research dedicated archival system (TARAS) in a university hospital. J Digit Imaging 2012; 24:864-73. [PMID: 21042830 DOI: 10.1007/s10278-010-9350-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Recent healthcare policies have influenced the manner in which patient data is handled in research projects, and the regulations concerning protected health information have become significantly tighter. Thus, new procedures are needed to facilitate research while protecting the confidentiality of patient data and ensuring the integrity of clinical work in the expanding environment of electronic files and databases. We have addressed this problem in a university hospital setting by developing the Tampere Research Archival System (TARAS), an extensive data warehouse for research purposes. This dynamic system includes numerous integrated and pseudonymized imaging studies and clinical data. In a pilot study on asthma patients, we tested and improved the functionality of the data archival system. TARAS is feasible to use in retrieving, analyzing, and processing both image and non-image data. In this paper, we present a detailed workflow of the implementation process of the data warehouse, paying special attention to administrative, ethical, practical, and data security concerns. The establishment of TARAS will enhance and accelerate research practice at Tampere University Hospital, while also improving the safety of patient information as well as the prospects for national and international research collaboration. We hope that much can be learned from our experience of planning, designing, and implementing a research data warehouse combining imaging studies and medical records in a university hospital.
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Affiliation(s)
- Tiina Rajala
- Medical Imaging Centre, Tampere University Hospital and University of Tampere, PL 2000, 33521 Tampere, Finland.
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Myller J, Dastidar P, Torkkeli T, Rautiainen M, Toppila-Salmi S. Computed tomography findings after endoscopic sinus surgery with preserving or enlarging maxillary sinus ostium surgery. Rhinology 2012; 49:438-44. [PMID: 21991569 DOI: 10.4193/rhino10.111] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Endoscopic sinus surgery (ESS) is the main surgical approach in the treatment of chronic rhinosinusitis (CRS) after failure of medical treatment. ESS is based on the theory that obstruction of the maxillary sinus ostium is mainly behind the pathogenesis of CRS. Controversy remains concerning the enlargement of the natural maxillary sinus ostium. The aim of this study was to compare computed tomography (CT) findings after preservation or enlargement of the maxillary sinus ostium. Thirty patients with non-polypous CRS underwent randomized endoscopic sinus surgery with uncinectomy on one side and additional middle meatal antrostomy on the other side. Lund-Mackay (LM) scores and the ostium diameters were analysed from CT scans taken preoperatively and nine months postoperatively, and were used for comparison of the two operative techniques. In addition, the correlation between CT findings and subjective outcomes was studied. Comparison of the preoperative and postoperative CT scans revealed that significant reduction of LM score was achieved on both sides, regardless of the type of procedure performed. The postoperative area of the ostium remained significantly larger on the antrostomy side compared to the uncinectomy side. A large maxillary sinus ostium size seems to associate with lower postoperative LM score, but does not seem to provide superior symptom relief.
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Affiliation(s)
- J Myller
- Department of Otorhinolaryngology, University of Tampere, Tampere, Finland.
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Iverson GL, Hakulinen U, Wäljas M, Dastidar P, Lange RT, Soimakallio S, Öhman J. To exclude or not to exclude: white matter hyperintensities in diffusion tensor imaging research. Brain Inj 2012; 25:1325-32. [PMID: 22077537 DOI: 10.3109/02699052.2011.608409] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE A practical methodological issue for diffusion tensor imaging (DTI) researchers is determining what to do about incidental findings, such as white matter hyperintensities (WMHI). The purpose of this study was to compare healthy control subjects with or without WMHIs on whole brain DTI. METHOD Participants were 30 subjects (age = 37.7, SD = 11.3, Range = 18-60; 70% female) who had no known developmental, general medical, neurological or psychiatric condition that could have had an adverse affect on brain morphology. RESULTS MRI (3 Tesla) revealed, at minimum, a WMHI in eight subjects (26.7%). Fractional anisotropy (FA) was calculated for 19 regions of interest (ROI). Frequency distributions of FA scores for the 19 ROIs were calculated. The 10th percentile for each ROI was selected as a cut-off score. Having four or more low FA scores occurred in 16.7%. More subjects with incidental findings met criterion for low FA scores (37.5%), compared to 9.1% of subjects with no findings. When subjects with minor WMHIs were retained and only those with multiple incidental findings were excluded, 8.3% of the retained subjects met criterion for low FA scores compared to 50.0% of the excluded subjects. CONCLUSIONS The decision to include or exclude subjects who have incidental findings can influence the results of a study.
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Affiliation(s)
- Grant L Iverson
- British Columbia Mental Health & Addiction Services, Vancouver, BC, Canada.
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Kuusisto H, Wu X, Dastidar P, Luukkaala T, Elovaara I. Volumetric MRI assessment of brain and spinal cord in Finnish twins discordant for multiple sclerosis. Medicina (Kaunas) 2012; 48:437-441. [PMID: 23168917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND AND OBJECTIVE Brain size, white matter hyperintensity, and the development of brain atrophy are known to be highly heritable. The decrease of brain volume starts from the very onset of multiple sclerosis and is 10-fold compared with normal aging. The aim of this study was to assess whether the brain and spinal cord volumes and the volume of white matter lesions differed between twins with multiple sclerosis and their asymptomatic co-twins. MATERIAL AND METHODS A co-twin control method was used to evaluate whether the brain and spinal cord volumes differ between twins with multiple sclerosis and their co-twins. Nineteen twin pairs were studied neurologically, and the volumes of T1, T2, FLAIR, and gadolinium-enhanced lesions and those of the brain and the spinal cord were obtained by magnetic resonance imaging. RESULTS Significant differences in the brain (P=0.064) or spinal cord (P=0.648) volumes were not detected. Four of the 7 monozygotic and 5 of the 12 dizygotic co-twins had focal brain white matter lesions, but none fulfilled the magnetic resonance imaging criteria of Barkhof. Spinal cord lesions were not seen in any of the co-twins. CONCLUSIONS The absence of a significant difference in the brain or spinal cord volume between the twins with multiple sclerosis and their co-twins supports the recent observation of brain size and the development of brain atrophy being highly heritable.
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Affiliation(s)
- Hanna Kuusisto
- Department of Neurology and Rehabilitation, Tampere University Hospital, Finland.
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Losoi H, Kettunen JE, Laihosalo M, Ruuskanen EI, Dastidar P, Koivisto AM, Jehkonen M. Predictors of functional outcome after right hemisphere stroke in patients with or without thrombolytic treatment. Neurocase 2012; 18:377-85. [PMID: 22145931 DOI: 10.1080/13554794.2011.608369] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
The purpose of this study was to assess the predictors of functional outcome after right hemisphere stroke at 6-month follow up in patients with or without thrombolytic treatment. Thrombolysis did not predict functional outcome in instrumental activities of daily living (IADL). Lower acute phase basic activities of daily living (ADL) measured by the Barthel Index was a statistically significant predictor of IADL when adjusted for age and education (p = .015) and had borderline significance (p = .076) as a predictor of functional outcome when adjusted for severity of stroke at admission. When stroke severity was taken into account also higher age became a statistically significant (p = .039) predictor of functional outcome. The acute phase neuropsychological symptoms predicted the functional outcome in unadjusted analyses but when adjusted for age, education, and severity of stroke no independent association was found.
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Affiliation(s)
- H Losoi
- Department of Neurosciences and Rehabilitation, Tampere University Hospital, PO Box 2000, FI-33521 Tampere, Finland.
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Kettunen JE, Laihosalo M, Ollikainen J, Dastidar P, Nurmi L, Koivisto AM, Jehkonen M. Rightward bias in right hemisphere infarct patients with or without thrombolytic treatment and in healthy controls. Neurocase 2012; 18:359-65. [PMID: 21958419 DOI: 10.1080/13554794.2011.608367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Right hemisphere (RH) infarct patients have a tendency to begin visual scanning from the right side of a given stimulus. Our aim was to find out whether RH patients with (T+) or without (T-) thrombolytic treatment and healthy controls differ in their starting points in three cancellation tasks. Our sample comprised of 77 patients and 62 controls. Thirty-four patients received thrombolysis. Rightward orientation bias was more evident in the T- group than in the T+ group. The T+ group showed a robust tendency to start all cancellation tasks more often on the right side than the controls. Regardless of whether they had visual neglect, patients in the T+ group showed still defective rightward orienting, possibly indicating residual attentional problems. The analyses of starting points in visual cancellation tasks provide additional information on residual symptoms of attention difficulties after stroke.
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Affiliation(s)
- J E Kettunen
- 1Department of Neurology and Rehabilitation, Tampere University Hospital, Tampere, Finland.
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Wu X, Kellokumpu-Lehtinen PL, Pertovaara H, Korkola P, Soimakallio S, Eskola H, Dastidar P. Diffusion-weighted MRI in early chemotherapy response evaluation of patients with diffuse large B-cell lymphoma--a pilot study: comparison with 2-deoxy-2-fluoro- D-glucose-positron emission tomography/computed tomography. NMR Biomed 2011; 24:1181-90. [PMID: 21387451 DOI: 10.1002/nbm.1689] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 12/03/2010] [Accepted: 01/11/2011] [Indexed: 05/22/2023]
Abstract
To determine the feasibility of diffusion-weighted MRI (DWI) in the evaluation of the early chemotherapeutic response in patients with aggressive non-Hodgkin's lymphoma (NHL), eight patients with histologically proven diffuse large B-cell lymphoma were imaged by MRI, including DWI, and positron emission tomography/computed tomography (PET/CT) before treatment (E1), and after 1 week (E2) and two cycles (E3) of chemotherapy. In all patients, whole-body screening using T(1) - and T(2) -weighted images in the coronal plane was performed. To quantitatively evaluate the chemotherapeutic response, axial images including DWI were acquired. Apparent diffusion coefficient (ADC) maps were reconstructed, and the ADC value of the tumor was measured. In addition, the tumor volume was estimated on axial T(2) -weighted images. The maximum standardized uptake value (SUV(max) ) and active tumor volume were measured on fused PET/CT images. Lymphomas showed high signal intensity on DW images and low signal intensity on ADC maps, except for necrotic foci. The mean pre-therapy ADC was 0.71 × 10(-3) mm(2) /s; it increased by 77% at E2 (p < 0.05) and 24% more at E3 (insignificant); the total increase was 106% (p < 0.05). The mean tumor volume by MRI was 276 mL at baseline; it decreased by 58% at E2 (p < 0.05) and 65% more at E3 (p < 0.05), giving a total decrease of 84% (p < 0.05). All the imaged pre-therapy tumors were strongly positive on PET/CT, with a mean SUV(max) of 20. The SUV(max) decreased by 60% at E2 (p < 0.05) and 59% more at E3 (p < 0.05), giving a total decrease of 83% (p < 0.05). The active tumor burden decreased by 66% at E2 (p < 0.05). At baseline, both central and peripheral tumor ADC values correlated inversely with SUV(max) (p < 0.05), and also correlated inversely with active tumor burden on PET/CT and with tumor volume on MRI at E2 (p < 0.05). In conclusion, the results of DWI in combination with whole-body MRI were comparable with those of integrated PET/CT.
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Affiliation(s)
- Xingchen Wu
- Department of Oncology, Tampere University Hospital, Teiskontie 35, Tampere, Finland.
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Rossi M, Korkola P, Pertovaara H, Järvenpää R, Dastidar P, Wu X, Soimakallio S, Eskola H, Kellokumpu-Lehtinen PL. PET imaging in a longitudinal non-Hodgkin's lymphoma study: association with tumor volume. Acta Radiol 2011; 52:995-1002. [PMID: 21948597 DOI: 10.1258/ar.2011.110099] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Computed tomography (CT) is generally used in the evaluation of the treatment response of non-Hodgkin's lymphoma (NHL) patients. Instead of morphological images, positron emission tomography (PET) shows metabolic information that is connected to tumor activity, cell proliferation rate, and, thus, prognosis. PURPOSE To determine the prognostic value of PET for tumor volume reduction measured by CT and magnetic resonance imaging (MRI) along with clinical characteristics in NHL patients. MATERIAL AND METHODS We imaged 21 B-cell type NHL patients using whole-body 18F-FDG-PET at the onset and the completion of treatment and at six-month follow-up. The maximum standardized uptake value (SUV(max)) was calculated. Morphological tumor volume calculations were assessed using both MRI and CT. Additionally, patients underwent thorough clinical examination including several laboratory tests. RESULTS A high SUV(max) was able to predict significant tumor volume reduction at the beginning of treatment, but the relation to pure tumor volume was poor. CONCLUSION The SUV(max) values derived from FDG-PET seemed to correlate with volume changes but not with their absolute values or laboratory tests. Unlike MRI and CT, FDG-PET showed the disappearance of active tumors after treatment.
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Affiliation(s)
- Maija Rossi
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Tampere
| | - Pasi Korkola
- Medical Imaging Centre, Department of Nuclear Medicine, Tampere University Hospital, Tampere
| | | | - Ritva Järvenpää
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Tampere
| | - Prasun Dastidar
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Tampere
- Tampere Medical School, Tampere
| | - Xingchen Wu
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Tampere
- Department of Oncology, Tampere University Hospital, Tampere
| | - Seppo Soimakallio
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Tampere
- Tampere Medical School, Tampere
| | - Hannu Eskola
- Medical Imaging Centre, Department of Radiology, Tampere University Hospital, Tampere
- Department of Biomedical Engineering, Tampere University of Technology, Tampere, Finland
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Sikiö M, Holli KK, Harrison LC, Ruottinen H, Rossi M, Helminen MT, Ryymin P, Paalavuo R, Soimakallio S, Eskola HJ, Elovaara I, Dastidar P. Parkinson's disease: interhemispheric textural differences in MR images. Acad Radiol 2011; 18:1217-24. [PMID: 21784670 DOI: 10.1016/j.acra.2011.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 06/17/2011] [Accepted: 06/21/2011] [Indexed: 01/18/2023]
Abstract
RATIONALE AND OBJECTIVES Early-stage diagnosis of Parkinson's disease (PD) is essential in making decisions related to treatment and prognosis. However, there is no specific diagnostic test for the diagnosis of PD. The aim of this study was to evaluate the role of texture analysis (TA) of magnetic resonance images in detecting subtle changes between the hemispheres in various brain structures in patients with early symptoms of parkinsonism. In addition, functional TA parameters for detecting textural changes are presented. MATERIALS AND METHODS Fifty-one patients with symptoms of PD and 20 healthy controls were imaged using a 3-T magnetic resonance device. Co-occurrence matrix-based TA was applied to detect changes in textures between the hemispheres in the following clinically interesting areas: dentate nucleus, basilar pons, substantia nigra, globus pallidus, thalamus, putamen, caudate nucleus, corona radiata, and centrum semiovale. The TA results were statistically evaluated using the Mann-Whitney U test. RESULTS The results showed interhemispheric textural differences among the patients, especially in the area of basilar pons and midbrain. Concentrating on this clinically interesting area, the four most discriminant parameters were defined: co-occurrence matrix correlation, contrast, difference variance, and sum variance. With these parameters, differences were also detected in the dentate nucleus, globus pallidus, and corona radiata. CONCLUSIONS On the basis of this study, interhemispheric differences in the magnetic resonance images of patients with PD can be identified by the means of co-occurrence matrix-based TA. The detected areas correlate with the current pathophysiologic and neuroanatomic knowledge of PD.
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Harrison LCV, Nikander R, Sikiö M, Luukkaala T, Helminen MT, Ryymin P, Soimakallio S, Eskola HJ, Dastidar P, Sievänen H. MRI texture analysis of femoral neck: Detection of exercise load-associated differences in trabecular bone. J Magn Reson Imaging 2011; 34:1359-66. [PMID: 21954096 DOI: 10.1002/jmri.22751] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2010] [Accepted: 07/19/2011] [Indexed: 12/23/2022] Open
Abstract
PURPOSE To assess the ability of co-occurrence matrix-based texture parameters to detect exercise load-associated differences in MRI texture at the femoral neck cross-section. MATERIALS AND METHODS A total of 91 top-level female athletes representing five differently loading sports and 20 referents participated in this cross-sectional study. Axial T1-weighted FLASH and T2*-weighted MEDIC sequence images of the proximal femur were obtained with a 1.5T MRI. The femoral neck trabecular bone at the level of the insertion of articular capsule was divided manually into regions of interest representing four anatomical sectors (anterior, posterior, superior, and inferior). Selected co-occurrence matrix-based texture parameters were used to evaluate differences in apparent trabecular structure between the exercise loading groups and anatomical sectors of the femoral neck. RESULTS Significant differences in the trabecular bone texture, particularly at the superior femoral neck, were observed between athletes representing odd-impact (soccer and squash) and high-magnitude exercise loading (power-lifting) groups and the nonathletic reference group. CONCLUSION MRI texture analysis provides a quantitative method for detecting and classifying apparent structural differences in trabecular bone that are associated with specific exercise loading.
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Affiliation(s)
- Lara C V Harrison
- Tampere University Medical School, Tampere, Finland; Department of Biomedical Engineering, Tampere University of Technology, Tampere, Finland; Medical Imaging Centre, Tampere University Hospital, Tampere, Finland.
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Sillanpaa N, Saarinen JT, Rusanen H, Hakomaki J, Lahteela A, Numminen H, Elovaara I, Dastidar P, Soimakallio S. The clot burden score, the Boston Acute Stroke Imaging Scale, the cerebral blood volume ASPECTS, and two novel imaging parameters in the prediction of clinical outcome of ischemic stroke patients receiving intravenous thrombolytic therapy. Neuroradiology 2011; 54:663-72. [PMID: 21904832 DOI: 10.1007/s00234-011-0954-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 08/29/2011] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Recently two classification methods based on the location and the extent of thrombosis detected with CT angiography have been introduced: the Boston Acute Stroke Imaging Scale (BASIS) and the clot burden score (CBS). We studied the performance of BASIS and CBS in predicting good clinical outcome (mRS ≤ 2 at 90 days) in an acute (< 3 h) stroke cohort treated with intravenous thrombolytic therapy. METHODS Eighty-three consecutive patients who underwent multimodal CT were analyzed. Binary logistic regression model was used to assess how BASIS, CBS, and cerebral blood volume (CBV) ASPECTS predict favorable clinical outcome. Diagnostic sensitivities and specificities were calculated and compared. RESULTS Patients with low CBS and CBV ASPECTS scores and major strokes according to BASIS had significantly higher admission NIHSS scores, larger perfusion defects, and more often poor clinical outcome. In logistic regression analysis, CBV ASPECTS, CBS and BASIS were significantly associated with the clinical outcome. The performance of BASIS improved when patients with thrombosis of the M2 segment of the middle cerebral artery were classified as having minor stroke (M1-BASIS). In the anterior circulation, the sum of CBS and CBV ASPECTS (CBSV) proved to be the most robust predictor of favorable outcome. CBV ASPECTS and CBS had high sensitivity but moderate to poor specificity while BASIS was only moderately sensitive and specific. CONCLUSION CBS, BASIS, and CBV ASPECTS are statistically robust and sensitive but unspecific predictors of good clinical outcome. Two new derived imaging parameters, CBSV and M1-BASIS, share these properties and may have increased prognostic value.
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Affiliation(s)
- Niko Sillanpaa
- Medical Imaging Center, Tampere University Hospital, PL 2000, 33521 Tampere, Finland.
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Banerjee S, Dastidar P. A series of rarely observed all helical three-dimensional coordination polymers derived from various chiral amino acids: effect of amino acid side chain and their unique ability of separating cations and anions. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311090490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Sahoo P, Kumar DK, Raghavan SR, Dastidar P. The crystal engineering approach to design the pheromone releasing LMWG. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311094220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Hagman S, Raunio M, Rossi M, Dastidar P, Elovaara I. Disease-associated inflammatory biomarker profiles in blood in different subtypes of multiple sclerosis: Prospective clinical and MRI follow-up study. J Neuroimmunol 2011; 234:141-7. [DOI: 10.1016/j.jneuroim.2011.02.009] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 01/03/2011] [Accepted: 02/15/2011] [Indexed: 12/29/2022]
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Sillanpaa N, Saarinen JT, Rusanen H, Hakomaki J, Lahteela A, Numminen H, Elovaara I, Dastidar P, Soimakallio S. CT Perfusion ASPECTS in the Evaluation of Acute Ischemic Stroke: Thrombolytic Therapy Perspective. Cerebrovasc Dis Extra 2011; 1:6-16. [PMID: 22566978 PMCID: PMC3343752 DOI: 10.1159/000324324] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Background and Purpose Advances in the management of acute ischemic stroke and medical imaging are creating pressure to replace the rigid one-third middle cerebral artery (MCA) and non-contrast-enhanced CT (NCCT) Alberta Stroke Program Early CT Score (ASPECTS) thresholds used for the selection of patients eligible for intravenous thrombolytic therapy. The identification of potentially salvageable ischemic brain tissue lies at the core of this issue. In this study, the role of CT perfusion ASPECTS in the detection of reversible ischemia was analyzed. Materials and Methods We retrospectively reviewed the clinical and imaging data of 92 consecutive patients who received intravenous thrombolytic therapy for acute (duration <3 h) ischemic stroke. Most of the patients underwent admission multimodal CT, and all patients had follow-up NCCT at 24 h. ASPECTS was assigned to all modalities and correlated with clinical and imaging parameters. Receiver-operating characteristic curve analysis was performed to determine optimal thresholds for different parameters to predict clinical outcome. Results A perfusion defect could be detected in 50% of the patients. ASPECTS correlated inversely with the clinical outcome in the following order: follow-up NCCT > cerebral blood volume (CBV) > mean transit time (MTT) > admission NCCT. The follow-up NCCT and the CBV displayed a statistically significant difference from the admission NCCT, while the MTT did not reach statistical significance. The threshold that best differentiated between good and bad clinical outcome on admission was CBV ASPECTS ≥7. In patients with CT perfusion ASPECTS mismatch, MTT and CBV ASPECTS essentially provided the lower and upper limits for the follow-up NCCT ASPECTS, thus defining the spectrum of possible outcomes. Furthermore, CT perfusion ASPECTS mismatch strongly correlated (r = 0.83) with the mismatch between the tissue at risk and the final infarct, i.e. the amount of salvaged tissue. This finding suggests that the CT perfusion ASPECTS mismatch adequately identifies the amount of potentially salvageable ischemic brain tissue. Conclusions Parameters derived from the use of CT perfusion ASPECTS can detect reversible ischemia and are correlated with clinical outcome.
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Affiliation(s)
- Niko Sillanpaa
- Medical Imaging Center, Tampere University Hospital, Tampere, Finland
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