scholarly journals Computed Tomography Perfusion, Magnetic Resonance Imaging, and Histopathological Findings After Laparoscopic Renal Cryoablation: An In Vivo Pig Model

2016 ◽  
Vol 16 (4) ◽  
pp. 406-413 ◽  
Author(s):  
Tommy Kjærgaard Nielsen ◽  
Øyvind Østraat ◽  
Ole Graumann ◽  
Bodil Ginnerup Pedersen ◽  
Gratien Andersen ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Central Zone ◽  
Peripheral Zone ◽  
Scar Tissue ◽  
Resonance Imaging ◽  
Computed Tomography Perfusion ◽  
Laparoscopic Assisted

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.

scholarly journals Diagnostic accuracy of whole-brain computed tomography perfusion for detection of ischemic stroke in patients with mild neurological symptoms

2018 ◽  
Vol 31 (5) ◽  
pp. 464-472 ◽  
Author(s):  
Robert A Frank ◽  
Santanu Chakraborty ◽  
Trevor McGrath ◽  
Alexander Mungham ◽  
James Ross ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Whole Brain ◽  
Computed Tomography Perfusion ◽  
Brain Computed Tomography ◽  
Diffusion Weighted ◽  
Weighted Magnetic Resonance Imaging

Mild and minor acute neurological symptoms may lead to diagnostic uncertainty, resulting in a heterogeneous group of patients with true ischemic events and stroke mimics with a potential for poor outcomes. More than half of ischemic stroke patients present as minor strokes (National Institutes of Health Stroke Scale score <6). Whole-brain computed tomography perfusion can be used as a diagnostic test for minor stroke, offering a potential method of reducing diagnostic uncertainty in these patients. We hypothesize that whole-brain computed tomography perfusion imaging features could accurately predict infarction in patients with minor neurological deficits. This retrospective chart review enrolled consecutive patients suspected of acute ischemic stroke with a National Institutes of Health Stroke Scale score <6, who underwent whole-brain computed tomography perfusion and follow-up diffusion-weighted magnetic resonance imaging at our institution. Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios were calculated for whole-brain computed tomography perfusion, using follow-up diffusion-weighted magnetic resonance imaging as a reference standard. A total of 524 patients (mean age: 67 years; range: 17–96 years; 56% men) met the inclusion criteria. Patients were excluded for non-diagnostic ( n = 25) or missing maps ( n = 8) scans, non-ischemic findings ( n = 7), and lack of follow-up magnetic resonance imaging ( n = 336). The final analysis included 148 patients who underwent diffusion-weighted magnetic resonance imaging. Whole-brain computed tomography perfusion has a sensitivity of 0.57 (95% CI: 0.45–0.69) and a specificity of 0.82 (95% CI: 0.71–0.90). The positive and negative predictive values and positive and negative likelihood ratios were 75%, 67%, 3.09, and 0.53, respectively. Our analysis suggests that although whole-brain computed tomography perfusion may offer some value as an adjunctive test for improving confidence in offering stroke treatment, it is not sufficiently sensitive or specific to accurately predict cerebral infarcts in patients with minor neurological symptoms.

Cardiac Computed Tomography and Magnetic Resonance Imaging of the Tricuspid Valve: Preprocedural Planning and Postprocedural Follow-up

2022 ◽  
Vol 11 (1) ◽  
pp. 27-40
Author(s):  
Bernardo B.C. Lopes ◽  
Go Hashimoto ◽  
Vinayak N. Bapat ◽  
Paul Sorajja ◽  
Markus D. Scherer ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Tricuspid Valve ◽  
Cardiac Computed Tomography ◽  
Resonance Imaging

scholarly journals Magnetic resonance imaging and computed tomography in assessing cardiac veins and scar tissue

EP Europace ◽  
2008 ◽  
Vol 10 (Supplement 3) ◽  
pp. iii110-iii113 ◽  
Author(s):  
N. R. Van de Veire ◽  
J. D. Schuijf ◽  
G. B. Bleeker ◽  
M. J. Schalij ◽  
J. J. Bax
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Scar Tissue ◽  
Resonance Imaging ◽  
Cardiac Veins

scholarly journals Comparison of Computed Tomography Perfusion and Magnetic Resonance Imaging Perfusion-Diffusion Mismatch in Ischemic Stroke

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 ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Ischemic Stroke ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Computed Tomography Perfusion ◽  
Magnetic Resonance Imaging Perfusion

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 ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Dynamic Computed Tomography ◽  
Resonance Imaging ◽  
Computed Tomography Perfusion

scholarly journals Cardiac Magnetic Resonance Imaging used for Evaluation of Adipose-Derived Stromal Cell Therapy in Patients with Chronic Ischemic Heart Disease

2019 ◽  
Vol 28 (12) ◽  
pp. 1700-1708
Author(s):  
Abbas Ali Qayyum ◽  
Anders Bruun Mathiasen ◽  
Naja Dam Mygind ◽  
Niels Groove Vejlstrup ◽  
Jens Kastrup
Keyword(s):  
Magnetic Resonance Imaging ◽  
Heart Disease ◽  
Placebo Group ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Myocardial Perfusion ◽  
Stromal Cell ◽  
Scar Tissue ◽  
Resonance Imaging

Adipose-derived stromal cell (ASC) therapy is currently investigated as a new treatment option for patients with ischemic heart disease (IHD). The aim of this study was to evaluate the effect of ASC therapy in patients with chronic IHD measuring myocardial perfusion and cardiac function using cardiac magnetic resonance imaging (CMRI). Patients were included in MyStromalCell trial, a phase II, randomized, double-blinded, placebo-controlled study investigated the effect of ASCs in patients with chronic IHD with preserved left ventricular ejection fraction (LVEF). In total, 41 of 60 patients underwent cine, late enhancement, rest and stress imaging with CMRI. There was a non-significant difference between stress and rest values in maximal signal intensity, a measure of myocardial perfusion, from baseline to follow-up comparing placebo with ASC group (–52.52 ± 88.61 and 3.05 ± 63.17, p = 0.061, respectively). LVEF, myocardial mass, stroke volume, left ventricle end-diastolic volume and end-systolic volume changed non-significantly (–0.5 ± 4.7%, –3.5 ± 13.1 g, –0.7 ± 8.6 mL, 1.9 ± 25.1 mL and 2.6 ± 16.5 mL, respectively) in the placebo group and in the ASC group (0.7 ± 8.6%, 0.9 ± 10.8 g, –0.3 ± 26.1 mL, –3.0 ± 31.5 mL and –2.7 ± 20.4 mL, respectively) from baseline to 6 months follow-up. The amount of scar tissue was unchanged in the placebo group by 0.0 ± 1.6 g, p = 1.0 and in the ASC group with –0.3 ± 2.3 g, p = 0.540. There was no difference between the groups. There was a non-significant trend toward increased myocardial perfusion but no significant changes in functional parameters or amount of scar tissue in patients treated with ASCs compared with patients allocated into the placebo group.

scholarly journals Diagnosis of a tympanic paraganglioma with CT perfusion imaging: a technical note and case description

2017 ◽  
Vol 31 (3) ◽  
pp. 324-327
Author(s):  
Christoph J Maurer ◽  
Antje Aschendorff ◽  
Horst Urbach
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Carotid Artery ◽  
Perfusion Imaging ◽  
Sigmoid Sinus ◽  
Resonance Imaging ◽  
Computed Tomography Perfusion ◽  
Computed Tomography Perfusion Imaging

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.

Altered Brain Computed Tomography Perfusion in Patients With Fluctuating Lacunar Syndrome and Normal Magnetic Resonance Imaging

2016 ◽  
Vol 73 (3) ◽  
pp. 348 ◽  
Author(s):  
Salvatore Rudilosso ◽  
Xabier Urra ◽  
Oscar Chirife ◽  
Ángel Chamorro
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Computed Tomography Perfusion ◽  
Brain Computed Tomography ◽  
Lacunar Syndrome
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