scholarly journals Safety of regadenoson with theophylline reversal during dynamic computed tomography perfusion and magnetic resonance imaging in patients with CAD

2020 ◽  
Author(s):  
Anna Oleksiak ◽  
Mariusz Kruk ◽  
Mateusz Śpiewak ◽  
Barbara Miłosz-Wieczorek ◽  
Magdalena Marczak ◽  
...  
2016 ◽  
Vol 16 (4) ◽  
pp. 406-413 ◽  
Author(s):  
Tommy Kjærgaard Nielsen ◽  
Øyvind Østraat ◽  
Ole Graumann ◽  
Bodil Ginnerup Pedersen ◽  
Gratien Andersen ◽  
...  

The present study investigates how computed tomography perfusion scans and magnetic resonance imaging correlates with the histopathological alterations in renal tissue after cryoablation. A total of 15 pigs were subjected to laparoscopic-assisted cryoablation on both kidneys. After intervention, each animal was randomized to a postoperative follow-up period of 1, 2, or 4 weeks, after which computed tomography perfusion and magnetic resonance imaging scans were performed. Immediately after imaging, open bilateral nephrectomy was performed allowing for histopathological examination of the cryolesions. On computed tomography perfusion and magnetic resonance imaging examinations, rim enhancement was observed in the transition zone of the cryolesion 1week after laparoscopic-assisted cryoablation. This rim enhancement was found to subside after 2 and 4 weeks of follow-up, which was consistent with the microscopic examinations revealing of fibrotic scar tissue formation in the peripheral zone of the cryolesion. On T2 magnetic resonance imaging sequences, a thin hypointense rim surrounded the cryolesion, separating it from the adjacent renal parenchyma. Microscopic examinations revealed hemorrhage and later hemosiderin located in the peripheral zone. No nodular or diffuse contrast enhancement was found in the central zone of the cryolesions at any follow-up stage on neither computed tomography perfusion nor magnetic resonance imaging. On microscopic examinations, the central zone was found to consist of coagulative necrosis 1 week after laparoscopic-assisted cryoablation, which was partially replaced by fibrotic scar tissue 4 weeks following laparoscopic-assisted cryoablation. Both computed tomography perfusion and magnetic resonance imaging found the renal collecting system to be involved at all 3 stages of follow-up, but on microscopic examination, the urothelium was found to be intact in all cases. In conclusion, cryoablation effectively destroyed renal parenchyma, leaving the urothelium intact. Both computed tomography perfusion and magnetic resonance imaging reflect the microscopic findings but with some differences, especially regarding the peripheral zone. Magnetic resonance imaging seems an attractive modality for early postoperative follow-up.


Stroke ◽  
2012 ◽  
Vol 43 (10) ◽  
pp. 2648-2653 ◽  
Author(s):  
Bruce C.V. Campbell ◽  
Søren Christensen ◽  
Christopher R. Levi ◽  
Patricia M. Desmond ◽  
Geoffrey A. Donnan ◽  
...  

2017 ◽  
Vol 31 (3) ◽  
pp. 324-327
Author(s):  
Christoph J Maurer ◽  
Antje Aschendorff ◽  
Horst Urbach

Paragangliomas can be diagnosed accurately using magnetic resonance imaging and dynamic four-dimensional magnetic resonance angiography. Four-dimensional imaging uses the highly vascularised structure of these tumours, which results in a homogenous capillary blush and usually, due to the arteriovenous shunting, in an early draining vein. By these features the tumour can be differentiated from other neoplasms. The authors describe a case of a paraganglioma localised in the middle ear of an elderly patient. Magnetic resonance contraindications led to preoperative diagnostics with high resolution computed tomography of the temporal bone and additionally computed tomography perfusion imaging instead of magnetic resonance imaging with four-dimensional magnetic resonance angiography. Using the computed tomography perfusion dataset, regions of interest were placed in the carotid artery, the sigmoid sinus and the tympanic mass. In the computer-assisted analysis the tumour showed late arterial enhancement and delayed wash-out compared to the enhancement curves of the carotid artery and the sigmoid sinus. This corresponded to the highly vascularised nature of a paraganglioma. On postoperative follow-up imaging computed tomography perfusion showed almost no enhancement of a small residual tympanic mass, which was then considered to be granulation tissue. In conclusion, in the case of magnetic resonance contraindications the preoperative diagnosis of tympanic paraganglioma can be made using computed tomography imaging criteria alone. Computed tomography perfusion imaging may be helpful in these cases to detect residual or recurrent tumour.


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