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- Granberg, T, et al.
(författare)
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Clinical Feasibility of Synthetic MRI in Multiple Sclerosis : A Diagnostic and Volumetric Validation Study.
- 2016
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Ingår i: American Journal of Neuroradiology. - 0195-6108 .- 1936-959X. ; 37:6, s. 1023-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Quantitative MR imaging techniques are gaining interest as methods of reducing acquisition times while additionally providing robust measurements. This study aimed to implement a synthetic MR imaging method on a new scanner type and to compare its diagnostic accuracy and volumetry with conventional MR imaging in patients with MS and controls.MATERIALS AND METHODS: Twenty patients with MS and 20 healthy controls were enrolled after ethics approval and written informed consent. Synthetic MR imaging was implemented on a Siemens 3T scanner. Comparable conventional and synthetic proton-density-, T1-, and T2-weighted, and FLAIR images were acquired. Diagnostic accuracy, lesion detection, and artifacts were assessed by blinded neuroradiologic evaluation, and contrast-to-noise ratios, by manual tracing. Volumetry was performed with synthetic MR imaging, FreeSurfer, FMRIB Software Library, and Statistical Parametric Mapping. Repeatability was quantified by using the coefficient of variance.RESULTS: Synthetic proton-density-, T1-, and T2-weighted images were of sufficient or good quality and were acquired in 7% less time than with conventional MR imaging. Synthetic FLAIR images were degraded by artifacts. Lesion counts and volumes were higher in synthetic MR imaging due to differences in the contrast of dirty-appearing WM but did not affect the radiologic diagnostic classification or lesion topography (P = .50-.77). Synthetic MR imaging provided segmentations with the shortest processing time (16 seconds) and the lowest repeatability error for brain volume (0.14%), intracranial volume (0.12%), brain parenchymal fraction (0.14%), and GM fraction (0.56%).CONCLUSIONS: Synthetic MR imaging can be an alternative to conventional MR imaging for generating diagnostic proton-density-, T1-, and T2-weighted images in patients with MS and controls while additionally delivering fast and robust volumetric measurements suitable for MS studies.
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- Liberg, B., et al.
(författare)
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The neural correlates of self-paced finger tapping in bipolar depression with motor retardation
- 2013
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Ingår i: Acta Neuropsychiatrica. - : Cambridge University Press (CUP). - 0924-2708 .- 1601-5215. ; 25:1, s. 43-51
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Motor retardation is a characteristic feature of bipolar depression, and is also a core feature of Parkinson's disease. Within the framework of the functional deafferentiation theory in Parkinson's disease, we hypothesised that motor retardation in bipolar depression is mediated by disrupted subcortical activation, leading to decreased activation of cortical motor areas during finger tapping. Methods: We used functional magnetic resonance imaging to investigate neural activity during self-paced finger tapping to elucidate whether brain regions that mediate preparation, control and execution of movement are activated differently in subjects with bipolar depression (n = 9) compared to healthy controls (n = 12). Results: An uncorrected whole-brain analysis revealed significant group differences in dorsolateral and ventromedial prefrontal cortex. Corrected analyses showed non-significant differences in patients compared to controls: decreased and less widespread activation of the left putamen and left pallidum; increased activity in the left thalamus and supplementary motor area; decreased activation in the left lateral pre- and primary motor cortices; absence of activation in the pre-supplementary motor area; activation of the bilateral rostral cingulate motor area. Conclusion: Both movement preparation and execution may be affected in motor retardation, and the activity in the whole left-side motor circuit is altered during self-initiated motor performance in bipolar depression.
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- Ouellette, R., et al.
(författare)
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Validation of Rapid Magnetic Resonance Myelin Imaging in Multiple Sclerosis
- 2020
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Ingår i: Annals of Neurology. - : Wiley. - 0364-5134 .- 1531-8249. ; 87:5, s. 710-724
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Magnetic resonance imaging (MRI) is essential for multiple sclerosis diagnostics but is conventionally not specific to demyelination. Myelin imaging is often hampered by long scanning times, complex postprocessing, or lack of clinical approval. This study aimed to assess the specificity, robustness, and clinical value of Rapid Estimation of Myelin for Diagnostic Imaging, a new myelin imaging technique based on time-efficient simultaneous T1/T2 relaxometry and proton density mapping in multiple sclerosis. Methods: Rapid myelin imaging was applied using 3T MRI ex vivo in 3 multiple sclerosis brain samples and in vivo in a prospective cohort of 71 multiple sclerosis patients and 21 age/sex-matched healthy controls, with scan–rescan repeatability in a subcohort. Disability in patients was assessed by the Expanded Disability Status Scale and the Symbol Digit Modalities Test at baseline and 2-year follow-up. Results: Rapid myelin imaging correlated with myelin-related stains (proteolipid protein immunostaining and Luxol fast blue) and demonstrated good precision. Multiple sclerosis patients had, relative to controls, lower normalized whole-brain and normal-appearing white matter myelin fractions, which correlated with baseline cognitive and physical disability. Longitudinally, these myelin fractions correlated with follow-up physical disability, even with correction for baseline disability. Interpretation: Rapid Estimation of Myelin for Diagnostic Imaging provides robust myelin quantification that detects diffuse demyelination in normal-appearing tissue in multiple sclerosis, which is associated with both cognitive and clinical disability. Because the technique is fast, with automatic postprocessing and US Food and Drug Administration/CE clinical approval, it can be a clinically feasible biomarker that may be suitable to monitor myelin dynamics and evaluate treatments aiming at remyelination.
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- Bergendal, G., et al.
(författare)
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Callosal atrophy in multiple sclerosis is related to cognitive speed
- 2013
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Ingår i: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 19:7, s. 969-969
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Tidskriftsartikel (refereegranskat)abstract
- Bergendal G, Martola J, Stawiarz L, Kristoffersen-Wiberg M, Fredrikson S, Almkvist O. Callosal atrophy in multiple sclerosis is related to cognitive speed. Acta Neurol Scand: 2013: 127: 281-289. (C) 2012 John Wiley & Sons A/S. Background Long-term changes regarding corpus callosum area (CCA) and information processing speed in cognitive and sensory-motor tasks have rarely been studied in multiple sclerosis (MS). Objective and methods Information processing speed in cognitive (Symbol Digit Modalities Test, SDMT), sensory (visual and auditory reaction time) and motor (finger-tapping speed, FT; right and left hand) tasks as well as auditory inter-hemispheric transfer (verbal dichotic listening, VDL) was related to CCA, measured by MRI at baseline and at follow-up after nine years in 22 patients with MS. Possible confounding by demographic (age, gender and education), clinical (symptom onset, duration, severity of disease) and relative brain volume (RBV) as well as T2 lesion load was taken into account. Results The smaller the CCA at baseline, the slower was SDMT performance at baseline. In a similar way, CCA at follow-up was associated with poor SDMT result at follow-up. Furthermore, the higher the annual rate of change in CCA, the poorer was performance in VDL on the left ear and the more pronounced was the right ear advantage. A positive relationship between performance in VDL right ear and annual rate of change in RBV was also seen. Sensory-motor tests were not significantly associated with CCA. T2 lesion load at baseline was associated with FT performance at baseline. Demographic, clinical and radiological (RBV and T2 lesion load) characteristics did not confound the significant relation between CCA and SDMT. Conclusions CCA unlike RBV and T2 lesion load was associated with SDMT, which indicated a marked cognitive rather than perceptual-motor component.
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- Gardin, A, et al.
(författare)
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Magnetic resonance signal, rather than tendon volume, correlates to pain and functional impairment in chronic Achilles tendinopathy
- 2006
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 47:7, s. 718-724
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To depict abnormal tendon matrix composition using magnetic resonance imaging (MRI) in chronic Achilles tendinopathy, and correlate intratendinous signal alterations to pain and functional impairment. Material and Methods: MRI of the Achilles tendon was performed on 25 patients with chronic Achilles tendinopathy (median age 50, range 37–71 years). All patients suffered from pain in the mid-portion of the Achilles tendon. Intratendinous signal was calculated from five different sagittal sequences, using a computerized 3D seed-growing technique. Pain and functional impairment were evaluated using a questionnaire completed by patients. Results: Severity of pain and functional impairment correlated to increased mean intratendinous signal in the painful tendon in all MR sequences ( P<0.05, median r = 0.38, range 0.28–0.43 for pain; P<0.05, median r = 0.48, range 0.29–0.49 for functional impairment). However, tendon volume did not correlate to pain or functional impairment ( P>0.05). Difference in mean intratendinous signal between symptomatic and contralateral asymptomatic tendons was highly significant in all sequences ( P<0.05) except on T2-weighted images ( P = 0.6). Conclusion: Severity of pain and disability correlated to increased MR signal rather than to tendon volume in patients with unilateral mid-portion chronic Achilles tendinopathy.
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- Granberg, T, et al.
(författare)
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Corpus callosum atrophy is strongly associated with cognitive impairment in multiple sclerosis: Results of a 17-year longitudinal study
- 2015
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Ingår i: Multiple sclerosis (Houndmills, Basingstoke, England). - : SAGE Publications. - 1477-0970 .- 1352-4585. ; 21:9, s. 1151-1158
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Tidskriftsartikel (refereegranskat)abstract
- Cognitive impairment is common in multiple sclerosis (MS) and may be subtle. The corpus callosum is essential for connectivity-demanding cognitive tasks and is significantly affected in MS, therefore it may serve as a marker for cognitive function. Objective: The objective of this paper is to longitudinally study the normalized corpus callosum area (nCCA) as a marker of cognitive function and disability in MS. Methods: Thirty-seven MS patients were followed from 1996 with follow-ups in 2004 and 2013. A healthy matched control group was recruited. The Expanded Disability Status Scale (EDSS) and Symbol Digit Modalities Test (SDMT) were assessed. The nCCA was measured on T2-weighted images. Volumetry was performed with FreeSurfer. Results: Disease duration spanned five decades (1.6–46 years). Annual corpus callosal atrophy rate decreased with disease duration. nCCA was strongly correlated with SDMT ( r = 0.793, p < 0.001) and moderately correlated with EDSS ( r = −0.545, p < 0.001) after adjusting for disease duration, age and sex. The correlations of brain parenchymal fraction, white matter fraction, gray matter fraction and normalized lesion volume were less strong. Conclusions: The nCCA correlates well with physical and cognitive disability in time perspectives close to two decades, outperforming volumetric measurements. The nCCA is fast and could be feasible for clinical implementation where it may help identify patients in need of neuropsychological evaluation.
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| 28. |
- Granberg, T, et al.
(författare)
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Radiologically isolated syndrome--incidental magnetic resonance imaging findings suggestive of multiple sclerosis, a systematic review
- 2013
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Ingår i: Multiple sclerosis (Houndmills, Basingstoke, England). - : SAGE Publications. - 1477-0970 .- 1352-4585. ; 19:3, s. 271-280
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Tidskriftsartikel (refereegranskat)abstract
- With increasing availability of magnetic resonance imaging (MRI), there is also an increase in incidental abnormal findings. MRI findings suggestive of multiple sclerosis in persons without typical multiple sclerosis symptoms and with normal neurological findings are defined as radiologically isolated syndrome (RIS). Half of the persons with RIS have their initial MRI because of headache, and some have a subclinical cognitive impairment similar to that seen in multiple sclerosis. Radiological measurements also show a similarity between RIS and multiple sclerosis. Approximately two-thirds of persons with RIS show radiological progression and one-third develop neurological symptoms during mean follow-up times of up to five years. Cervical cord lesions are important predictors of clinical conversion. Management has to be individualised, but initiation of disease modifying therapy is controversial and not recommended outside of clinical trials since its effects have not been studied in RIS. Future studies should try to establish the prevalence and long-term prognosis of RIS, its impact on quality of life, and define the role of disease modifying therapy in RIS.
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| 29. |
- Movin, T, et al.
(författare)
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Intratendinous alterations as imaged by ultrasound and contrast medium-enhanced magnetic resonance in chronic achillodynia
- 1998
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Ingår i: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 19:5, s. 311-317
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: We performed a comparative study of ultrasonography and gadolinium imaging contrast-enhanced T1-weighted magnetic resonance to evaluate tendon pathology in chronic Achilles tendon disorder. Another main issue was to evaluate the structural basis as defined by histopathology from hypoechoic compared with normoechic areas within the same tendon. Materials and Methods: Twenty patients (16 male, 4 females, median age 40 years) with chronic achillodynia participated in the study. Clinical examination revealed swelling and tenderness localized to the midportion of the Achilles tendon. Contrast medium-enhanced magnetic resonance imaging (CME-MRI) was performed in all patients. Ultrasonography-guided core biopsies were taken from regions with a clear widening of the tendon and a pathologic low-echo signal as well as from normoechoic areas. The specimens were analyzed with a standardized protocol giving a total tendon score (0–24), and a stereologic method for quantification of glycosaminoglycan (GAG)-rich areas. Results: The volume of the intratendinous abnormality was larger in 13 of 20 when imaged by CME-MR ( P < 0.05), whereas the shape and enlargement of the tendon per se were similarly imaged by ultrasound (US) and CME-MR. Tendon pathology as imaged by US was graded as severe from hypoechoic regions and moderate from normoechoic regions. The corresponding quantification of GAGs was 0.36 compared with 0.17, respectively ( P < 0.001). Conclusion: CME-MR imaging revealed greater sensitivity in demonstrating intratendinous pathology than the ultrasound; this was documented by the larger size of the corresponding lesion and the fact that the pathology was occurring in areas that were considered normal by ultrasonography. US hypoechoic areas showed a markedly abnormal tendon structure including an increased amount of GAG-rich areas. However, moderate pathology was also found in the neighboring normoechogenous areas within the same tendon, indicating a more generalized disorder than depicted by echogenic properties.
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| 30. |
- Movin, T, et al.
(författare)
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MR imaging in chronic Achilles tendon disorder
- 1998
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 39:2, s. 126-132
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: the primary objective was to compare 4 imaging sequences (T1-weighted, T2-weighted, proton density, and T1-weighted with gadolinium contrast agent enhancement) with regard to intratendinous signal abnormality in patients with achillodynia. the secondary objective was to relate the images to the clinical symptoms and histopathological findings Material and Methods: Twenty patients (16 men, 4 women, median age 40 years) with chronic achillodynia participated in the study. the symptoms prohibited activity and clinical examination revealed swelling and tenderness 1.5–6 cm proximal to the Achilles tendon insertion. of the 20 patients: 5 had bilateral achillodynia, 4 had had previous contralateral Achilles tendon disorder, and 11 had never had symptoms in the contralateral tendon region. These 11 tendons served as controls for comparison MR imaging was performed on a superconductive 1.5 T unit. Both Achilles tendons were examined (n=40) at the same time, and multiple sagittal and transversal images were obtained. the corresponding sections on these images were visually graded according to both extension and level of MR signal intensity. Tissue was obtained for microscopic examination from the most symptomatic side in all patients (n=20) Results: T1-weighted images following gadolinium contrast medium enhancement proved to be the best method by which to visualize intratendinous signal abnormality. This sequence revealed signal abnormality in 24/25 symptomatic tendons and in 1/11 control tendons ( p>0.001). Histopathological examination showed an increased noncollagenous extracellular matrix and altered fiber structure in the lesions corresponding to the contrast-enhanced areas Conclusion: Gadolinium enhancement improved the imaging of intratendinous signal abnormality on T1-weighted images. There was a high level of extracellular glycosaminoglycans, which are highly-fixed negatively-charged macromolecules with extreme water-retaining capacity and which may have contributed to the enhancement by the gadolinium contrast agent
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| 31. |
- Shalabi, A, et al.
(författare)
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Dynamic contrast-enhanced mr imaging and histopathology in chronic achilles tendinosis. A longitudinal MR study of 15 patients
- 2002
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 43:2, s. 198-206
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate the value of dynamic contrast-enhanced MR imaging (DEMRI) and its correlation to symptoms and histopathology in chronic Achilles tendinosis. Material and Methods: Fifteen patients with severe symptoms underwent DEMRI preoperatively and 2 years postoperatively. US-guided core biopsies of tendinosis tissue were obtained preoperatively and the specimens were analyzed using a semiquantitative protocol. DEMRI was evaluated by calculating the area under curve (AUC) of signal alteration and the static MR by a semiquantitative grading scale. A questionnaire and clinical examination evaluated the clinical outcome. Results: Early contrast enhancement (first 72 s) was seen in DEMRI at tendon lesions of the symptomatic Achilles tendons with a significant difference to asymptomatic contralateral tendon that revealed no or mild enhancement. Increased severity of tendon pathology (including fiber structure abnormality, increased vascularity, rounding of nuclei and increased amount of glycosaminoglycans) was correlated to both dynamic and static signal enhancement. Two years following surgical treatment, the signal alterations showed regression of early contrast enhancement (AUC decreased from 9 preoperatively to 2 postoperatively). The clinical outcome was as follows: 8 patients excellent, 4 good, 2 fair and 1 poor. Conclusion: Patients with chronic painful achillodynia showed an early contrast-agent enhancement corresponding to the tendon lesion. Increased enhancement correlated to increased severity of tendon histopathology and patient symptoms. Two years after surgical treatment the contrast-agent enhancement decreased.
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| 33. |
- Shalabi, A, et al.
(författare)
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MR evaluation of chronic Achilles tendinosis. A longitudinal study of 15 patients preoperatively and two years postoperatively
- 2001
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 42:3, s. 269-276
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate surgically treated patients with chronic Achilles tendinosis by MR. Material and Methods: Gd-contrast-enhanced (CME) T1-, precontrast T1-, PD- and T2-weighted images were obtained preoperatively and 2 years following surgical treatment on 15 middle-aged patients with severe symptoms of chronic Achilles tendinosis. MR evaluation included the depiction of intratendinous signal alterations and their volume, and also measurement of tendon diameter. A questionnaire and clinical examination evaluated the clinical outcome. Results: The most sensitive sequence to depict an intratendinous lesion was the CME T1-WI. There was marked regress of the estimated volume of the intratendinous signal alteration from a median of 1.2 cm3 preoperatively to 0.0 cm3 postoperatively on CME T1-WI. CME T1-WI showed a regress in intratendinous signal abnormality from 13 out of 15 patients preoperatively to 4 of 15 patients 2 years postoperatively. The a.p. dimension was 9 mm at both MR occasions. The clinical outcome was excellent in 8, good in 5, fair in 1 and poor in 1 patient. Conclusion: Surgical treatment of chronic Achilles tendinosis and its healing resulted in a decrease or elimination of the intratendinous signal alteration correlating to an improved clinical outcome 2 years postoperatively.
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| 36. |
- Szabo, BK, et al.
(författare)
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Dynamic MR imaging as a predictor of prognosis in breast cancer
- 2006
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Ingår i: SPECTROSCOPY-AN INTERNATIONAL JOURNAL. - : Hindawi Limited. - 0712-4813. ; 20:1, s. 19-28
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Forskningsöversikt (övrigt vetenskapligt/konstnärligt)abstract
- Contrast-enhanced MR imaging (CE-MRI) has become a widely accepted complementary method for diagnosing breast cancer. It has been suggested for evaluating patients with breast implants, patients at risk of tumour multifocality or recurrence, search for occult primary cancer in presence of axillary metastasis and monitoring the effect of preoperative chemotherapy. The clinical usefulness of MR imaging in patients with increased genetic risk of breast cancer is still under investigation. There is scientific evidence to support the hypothesis that CE-MRI may carry the prognostic significance of angiogenesis, and one of the future indications of this method can be the prognostic evaluation of breast cancer patients by the functional mapping of the angiogenic activity of tumours. On the basis of the promising results of recent reports, further large-scale studies are needed to evaluate the impact of MR parameters on long term overall survival of patients with breast cancer.
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