| 61. |
- Holtås, Stig, et al.
(författare)
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A ring-enhancing metastasis with central high signal on diffusion-weighted imaging and low apparent diffusion coefficients
- 2000
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 42:11, s. 824-827
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Tidskriftsartikel (refereegranskat)abstract
- Diffusion-weighted imaging (DWI) has been reported to be useful in the differential diagnosis between abscesses and cystic or necrotic tumours. However, experience is still limited and the true sensitivity and specificity remain to be determined. Our purpose is to describe a ring-enhancing metastasis of adenocarcinoma with a DWI pattern similar to that reported for abscesses. The tumour had a diameter of 1.5 cm and give signal from its centre similar to that of normal brain on T1-weighted images, whereas it was increased on T2-weighted images, and surrounded by a low signal ring, suggesting a capsule. The signal was high on DWI and the apparent diffusion coefficient (ADC) was low (0.55 x 10(-3) mm2/s). The findings were misinterpreted as representing an abscess in the early capsule-formation stage, but the signal pattern probably represented early tumour necrosis with intracellular oedema, but without liquefaction. Findings on DWI during the early capsule formation stage in abscesses and early tumour necrosis are probably similar and must be interpreted with caution.
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| 62. |
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| 63. |
- Holtås, Stig, et al.
(författare)
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MRI in acute transverse myelopathy
- 1993
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Ingår i: Neuroradiology. - 1432-1920. ; 35:3, s. 221-226
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Tidskriftsartikel (refereegranskat)abstract
- The MRI examinations of seven patients with acute transverse myelopathy (ATM) were analysed. The patients were examined 2-5 times during the course of their disease with short and long TR/TE spin-echo sequences in the sagittal projection. A previous history of autoimmune disorder and/or signs of infection at the onset of ATM were present in all cases. Cerebrospinal fluid analysis showed local synthesis of immunoglobulin in the nervous system in three cases and signs of infectious myelitis in one. During the acute phase four patients had local enlargement of the cord and all had increased signal on long TR/TE sequences. The outcome was grave in the majority of patients and there seemed to be a correlation between the degree of cord enlargement, persistence of increased signal intensity and limited recovery. Atrophy and remaining high signal intensity were noted on late MRI in patients with poor outcome. In one patient with probable anterior spinal artery occlusion, cavitation of the cord was seen.
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| 64. |
- Håkansson, Claes, et al.
(författare)
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Structural imaging findings on non-enhanced computed tomography are severely underreported in the primary care diagnostic work-up of subjective cognitive decline
- 2019
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 61:4, s. 397-404
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The purpose of this study was to investigate how structural imaging findings of medial temporal lobe atrophy (MTA), posterior cortical atrophy (PCA), global cortical atrophy (GCA), white matter changes (WMC), and Evans’ index/width of lateral ventricles (EI/WLV) are reported in the primary care diagnostic work-up of patients with subjective cognitive decline or mild cognitive impairment. Methods: We included 197 patients referred to a non-enhanced computed tomography (NECT) as part of the diagnostic work-up. We compared the frequencies of reported findings in radiology reports written by neuroradiologists and general radiologists with actual pathological findings in a second view done by a single neuroradiologist using the MTA, PCA, GCA, WMC, and EI/WLV visual rating scales. Structural findings were also compared to cognitive tests. Results: We found that MTA and PCA were clearly underreported by both neuroradiologists and general radiologists. The presence of GCA and WMC was also underreported among general radiologists. Only MTA showed a clear association with cognitive test results. Conclusions: We believe that the use of visual rating scales should be put into clinical practice to increase the yield of clinical NECT exams in the investigation of cognitive impairment. Special emphasis should be put on reporting MTA.
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| 65. |
- Jaff, Nasren, et al.
(författare)
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Transcriptomic analysis of the harvested endothelial cells in a swine model of mechanical thrombectomy
- 2018
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Ingår i: Neuroradiology. - : SPRINGER. - 0028-3940 .- 1432-1920. ; 60:7, s. 759-768
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Tidskriftsartikel (refereegranskat)abstract
- In mechanical thrombectomy (MT) for ischemic stroke, endothelial cells (ECs) from intracranial blood vessels adhere to the stent retriever device and can be harvested. However, understanding the molecular biology and the role of the endothelium in different pathological conditions remains insufficient. The purpose of the study was to characterize and analyze the molecular aspect of harvested ECs using cell culture and transcriptomic techniques in an MT swine model relevant to clinical ischemic stroke. In swine, preformed thrombi were injected into the external carotid and subclavian arteries to occlude their branches. MT was performed according to clinical routine. The stent retriever device and thrombus were treated with cell dissociation buffer. The resulting cell suspension was analyzed by immunohistochemistry and was cultured. Cultured cells were analyzed using single-cell RNA sequencing (scRNA-seq) after fluorescence-activated cell sorting (FACS). A total number of 37 samples were obtained containing CD31-positive cells. Cell culture was successful in 90% of samples, and the cells expressed multiple typical EC protein markers. Eighty-nine percent of the sorted cells yielded high-quality transcriptomes, and single-cell transcriptomes from cultured cells showed that they expressed typical endothelial gene patterns. Gene expression analysis of ECs from an occluded artery did not show distinctive clustering into subtypes. ECs harvested during MT can be cultured and analyzed using single-cell transcriptomic techniques. This analysis can be implemented in clinical practice to study the EC gene expression of comorbidities, such as hypertension, diabetes mellitus, and metabolic syndrome, in patients suffering from acute ischemic stroke.
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| 66. |
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| 67. |
- Jin, Ying, et al.
(författare)
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"Soap bubble" sign as an imaging marker for posterior fossa ependymoma Group B
- 2023
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Ingår i: Neuroradiology. - : Springer. - 0028-3940 .- 1432-1920. ; 65, s. 1707-1714
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate the predictive value of the "soap bubble" sign on molecular subtypes (Group A [PFA] and Group B [PFB]) of posterior fossa ependymomas (PF-EPNs).Methods: MRI scans of 227 PF-EPNs (internal retrospective discovery set) were evaluated by two independent neuroradiologists to assess the "soap bubble" sign, which was defined as clusters of cysts of various sizes that look like "soap bubbles" on T2-weighted images. Two independent cohorts (external validation set [n = 31] and prospective validation set [n = 27]) were collected to validate the "soap bubble" sign.Results: Across three datasets, the "soap bubble" sign was observed in 21 PFB cases (7.4% [21/285] of PF-EPNs and 12.9% [21/163] of PFB); none in PFA. Analysis of the internal retrospective discovery set demonstrated substantial interrater agreement (1st Rating: kappa = 0.71 [0.53-0.90], 2nd Rating: kappa = 0.83 [0.68-0.98]) and intrarater agreement (Rater 1: kappa = 0.73 [0.55-0.91], Rater 2: kappa = 0.74 [0.55-0.92]) for the "soap bubble" sign; all 13 cases positive for the "soap bubble" sign were PFB (p = 0.002; positive predictive value [PPV] = 100%, negative predictive value [NPV] = 44%, sensitivity = 10%, specificity = 100%). The findings from the external validation set and the prospective validation set were similar, all cases positive for the "soap bubble" sign were PFB (p < 0.001; PPV = 100%).Conclusion: The "soap bubble" sign represents a highly specific imaging marker for the PFB molecular subtype of PF-EPNs.
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| 68. |
- Johansson, Elias, et al.
(författare)
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Atherosclerotic ICA stenosis coinciding with ICA asymmetry associated with Circle of Willis variations can mimic near-occlusion
- 2020
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Ingår i: Neuroradiology. - : Springer. - 0028-3940 .- 1432-1920. ; 62, s. 101-104
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Tidskriftsartikel (refereegranskat)abstract
- Differentiating carotid near-occlusion (tight atherosclerotic stenosis causing distal artery size reduction) from conventional stenosis is the first step when grading carotid stenoses with NASCET method. The internal carotid artery (ICA) can be asymmetrically associated with Circle of Willis variations. When such ICA asymmetry coincides with stenosis, it may mimic near-occlusion. We studied ICA anatomical variant prevalence in 4042 consecutive CTA exams from all indications, 53 excluded due to carotid occlusion, 814 with any >= 50% steno-occlusive disease intra- or extracranially, 3228 without. Of the 3989 included cases, 568 (14%) had ICA asymmetry, of which 335 (59%) were from associated with Circle of Willis variations. Of 3228 patients without >= 50% stenosis or other steno-occlusive disease intra- and extracranially; 257 (8.0%) demonstrated ICA asymmetry associated with Circle of Willis variations, equally common among sexes and age unrelated and most frequently attributed to an ipsilateral A1 hypoplasia/aplasia, less often attributed to large contralateral posterior communicating artery. As ICA asymmetry associated with Circle of Willis variations are common, caution should be exercised diagnosing near-occlusion on asymmetry alone.
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| 69. |
- Johansson, Elias, et al.
(författare)
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Defining carotid near-occlusion with full collapse: a pooled analysis
- 2022
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Ingår i: Neuroradiology. - : Springer-Verlag New York. - 0028-3940 .- 1432-1920. ; 64, s. 59-67
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Create a new definition of near-occlusion with full collapse to predicting recurrent stroke.Methods: Pooled analysis of two studies. Patients with symptomatic ≥ 50% carotid stenoses were included. Outcome was preoperative recurrent ipsilateral ischemic stroke or retinal artery occlusion within 28 days of presenting event. We analyzed several artery diameters on computed tomography angiography and stenosis velocity on ultrasound.Results: A total of 430 patients with symptomatic ≥ 50% carotid stenosis were included, 27% had near-occlusion. By traditional definition, 27% with full collapse and 11% without full collapse reached the outcome (p = 0.047). Distal internal carotid artery (ICA) diameter, ICA ratio, and ICA-to-external carotid artery ratio were associated with the outcome. Best new definition of full collapse was distal ICA diameter ≤ 2.0 mm and/or ICA ratio ≤ 0.42. With this new definition, 36% with full collapse and 4% without full collapse reached the outcome (p < 0.001).Conclusions: Defining near-occlusion with full collapse as distal ICA diameter ≤ 2.0 mm and/or ICA ratio ≤ 0.42 seems to yield better prognostic discrimination than the traditional appearance-based definition. This novel definition can be used in prognostic and treatment studies of near-occlusion with full collapse.
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| 70. |
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