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1.
Acta Neurochir (Wien) ; 166(1): 137, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38485848

RESUMO

BACKGROUND: Several neurovascular procedures require temporary occlusion of cerebral arteries, leading to ischemia of unpredictable length, occasionally causing brain infarction. Experimental models of cerebral ischemia-reperfusion injury have established that platelet adhesion and coagulation play detrimental roles in reperfusion injury following transient cerebral ischemia. Therefore, in a model of cerebral ischemia-reperfusion injury (IRI), we investigated the therapeutic potential of a dual antiplatelet and anticoagulant (APAC) heparin proteoglycan mimetic which is able to bind to vascular injury sites. METHODS: Brain ischemia was induced in mice by transient occlusion of the right middle cerebral artery for 60 min. APAC, unfractionated heparin (UFH) (both at heparin equivalent doses of 0.5 mg/kg), or vehicle was intravenously administered 10 min before or 60 min after the start of ischemia. At 24 h later, mice were scored for their neurological and motor behavior, and brain damage was quantified. RESULTS: Both APAC and UFH administered before the onset of ischemia reduced brain injury. APAC and UFH pretreated mice had better neurological and motor functions (p < 0.05 and p < 0.01, respectively) and had significantly reduced cerebral infarct sizes (p < 0.01 and p < 0.001, respectively) at 24 h after transient occlusion compared with vehicle-treated mice. Importantly, no macroscopic bleeding complications were observed in either APAC- or UFH-treated animals. However, when APAC or UFH was administered 60 min after the start of ischemia, the therapeutic effect was lost, but without hemorrhaging either. CONCLUSIONS: Pretreatment with APAC or UFH was safe and effective in reducing brain injury in a model of cerebral ischemia induced by transient middle cerebral artery occlusion. Further studies on the use of APAC to limit ischemic injury during temporary occlusion in neurovascular procedures are indicated.


Assuntos
Lesões Encefálicas , Isquemia Encefálica , Traumatismo por Reperfusão , Camundongos , Animais , Anticoagulantes/farmacologia , Anticoagulantes/uso terapêutico , Infarto da Artéria Cerebral Média/tratamento farmacológico , Encéfalo/metabolismo , Heparina/farmacologia , Heparina/uso terapêutico , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Traumatismo por Reperfusão/tratamento farmacológico
2.
Ann Vasc Surg ; 104: 71-80, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37454900

RESUMO

BACKGROUND: Life-long follow-up after endovascular aneurysm repair (EVAR) is costly and burdensome to the patient. Follow-up should be stratified based on the risk of EVAR failure. Aneurysm neck is thought to be the single most important risk factor. This study investigated neck anatomy as a predictor of neck-related adverse events after EVAR. METHODS: This retrospective single-center study included consecutive patients undergoing elective EVAR for infrarenal abdominal aortic aneurysms between 2011 and 2016 (n = 222) who were followed with yearly imaging until December 2020. Hostile neck was defined as neck length ≤15 mm, width ≥28 mm, angulation ≥60°, calcification, or thrombus ≥50% of circumference or conical neck based on preoperative computed tomography angiography. Neck-related adverse event was defined as aneurysm rupture, any neck-related reintervention or type 1a endoleak during follow-up. RESULTS: Ninety (41%) patients had hostile neck and 132 (59%) had friendly neck. There were no differences in 30-day mortality (1% vs. 1%, P = 0.78), major adverse events (20% vs. 16%, P = 0.43) or reinterventions during the hospital stay (8% vs. 4%, P = 0.20) between patients with hostile and friendly neck. Estimated survival at 1 year was 89 ± 3% for hostile neck and 95 ± 2% for friendly neck patients (P < 0.01). Five-year survival estimates were 51 ± 6% and 66 ± 4%, respectively. Aneurysm-related mortality was higher after 6 years in patients with hostile neck (P < 0.01). Twenty-four patients (11%) suffered neck-related adverse events with mean time-to-event of 3.3 ± 2.8 years; there were no differences between the groups stratified by neck anatomy. Incidentally, preoperative aneurysm diameter was found to be an independent risk factor for neck-related adverse events and aneurysm-related mortality; 53 patients (24%) had aneurysm diameter ≥70 mm, which was associated with nearly 4-fold risk of neck-related complications during the follow-up. CONCLUSIONS: Friendly neck anatomy may not protect from neck-related adverse events after EVAR in the long-term. Especially patients with large aneurysms should be followed closely.

3.
BMC Med Imaging ; 19(1): 58, 2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-31349798

RESUMO

BACKGROUND: The reliable quantification of myocardial blood flow (MBF) with MRI, necessitates the correction of errors in arterial input function (AIF) caused by the T1 saturation effect. The aim of this study was to compare MBF determined by a traditional dual bolus method against a modified dual bolus approach and to evaluate both methods against PET in a porcine model of myocardial ischemia. METHODS: Local myocardial ischemia was induced in five pigs, which were subsequently examined with contrast enhanced MRI (gadoteric acid) and PET (O-15 water). In the determination of MBF, the initial high concentration AIF was corrected using the ratio of low and high contrast AIF areas, normalized according to the corresponding heart rates. MBF was determined from the MRI, during stress and at rest, using the dual bolus and the modified dual bolus methods in 24 segments of the myocardium (total of 240 segments, five pigs in stress and rest). Due to image artifacts and technical problems 53% of the segments had to be rejected from further analyses. These two estimates were later compared against respective rest and stress PET-based MBF measurements. RESULTS: Values of MBF were determined for 112/240 regions. Correlations for MBF between the modified dual bolus method and PET was rs = 0.84, and between the traditional dual bolus method and PET rs = 0.79. The intraclass correlation was very good (ICC = 0.85) between the modified dual bolus method and PET, but poor between the traditional dual bolus method and PET (ICC = 0.07). CONCLUSIONS: The modified dual bolus method showed a better agreement with PET than the traditional dual bolus method. The modified dual bolus method was found to be more reliable than the traditional dual bolus method, especially when there was variation in the heart rate. However, the difference between the MBF values estimated with either of the two MRI-based dual-bolus methods and those estimated with the gold-standard PET method were statistically significant.


Assuntos
Isquemia Miocárdica/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Algoritmos , Animais , Meios de Contraste , Modelos Animais de Doenças , Humanos , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Suínos
4.
Ann Vasc Surg ; 53: 165-170, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29886215

RESUMO

BACKGROUND: Claudication and critical limb threatening ischemia are significant causes of mortality in the elderly. The gold standard of superficial femoral artery (SFA) revascularization is thus far considered to be the femoropopliteal bypass. The aim of this study was to compare mid-term patency between drug-eluting stents (DESs) and prosthetic bypass grafts (BSX). Studies have reported comparable results for both the methods. METHODS: Forty-six patients with claudication or rest pain due to a 5-25 cm SFA occlusion were randomized between DES and BSX groups. The follow-up period was 24 months, and the primary outcome measure was overall patency. Secondary outcome measures were primary and primary assisted patency, change in ankle-brachial index (ABI), and amputation-free survival. RESULTS: Forty-one patients were eventually analyzed. Six-month secondary patency was 91% (DES) versus 83% (BSX) (P = 0.450). The corresponding numbers at 12 months in the DES and BSX groups were 74% and 80% (P = 0.750), respectively. At 24 months, the respective numbers were 56% and 71% (P = 0.830). There were no statistically significant differences in primary or assisted primary patency at 1, 6, or 12 months. CONCLUSION: There were no demonstrable differences in patency rates or clinical outcomes such as ABI or major amputations between DES and BSX. Although underpowered, the results suggest noninferiority of the DES compared with prosthetic bypass surgery. TRIAL REGISTRATION: The trial was preregistered at ClinicalTrials.org (NCT01450722).


Assuntos
Implante de Prótese Vascular/instrumentação , Prótese Vascular , Stents Farmacológicos , Procedimentos Endovasculares/instrumentação , Artéria Femoral/cirurgia , Doença Arterial Periférica/cirurgia , Artéria Poplítea/cirurgia , Grau de Desobstrução Vascular , Idoso , Idoso de 80 Anos ou mais , Amputação Cirúrgica , Implante de Prótese Vascular/efeitos adversos , Procedimentos Endovasculares/efeitos adversos , Feminino , Artéria Femoral/diagnóstico por imagem , Artéria Femoral/fisiopatologia , Finlândia , Oclusão de Enxerto Vascular/etiologia , Oclusão de Enxerto Vascular/fisiopatologia , Oclusão de Enxerto Vascular/terapia , Humanos , Salvamento de Membro , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/fisiopatologia , Artéria Poplítea/diagnóstico por imagem , Artéria Poplítea/fisiopatologia , Intervalo Livre de Progressão , Estudos Prospectivos , Desenho de Prótese , Fatores de Tempo , Resultado do Tratamento
5.
Stroke ; 48(7): 1986-1989, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28468927

RESUMO

BACKGROUND AND PURPOSE: We investigated which aneurysm-related risk factors for rupture best discriminate ruptured versus unruptured saccular intracranial aneurysms (sIAs) in subarachnoid hemorrhage patients with multiple sIAs. METHODS: We included 264 subarachnoid hemorrhage patients with a ruptured sIA and at least one additional unruptured sIA, from the Kuopio Intracranial Aneurysm database from 2003 to 2015. These patients had 268 ruptured and 445 unruptured sIAs. Angiograms of the 713 sIAs were reevaluated for multiple variables describing aneurysm shape. Multivariate generalized linear mixed models were used to calculate odds ratios with corresponding 95% confidence intervals for the independent risk factors for aneurysm rupture. RESULTS: In the multivariate analysis, only sIA size (P<0.004) and irregular shape (P<0.000) independently associated with sIA rupture. As an independent risk factor, irregular shape showed the strongest association with rupture (odds ratio 90.3; 95% confidence interval, 47.0-173.5). The sIA location, flow angles, bottleneck factor, or aspect ratio were not significantly associated with rupture. CONCLUSIONS: Irregular shape may identify the ruptured sIA better than size in patients presenting with aSAH and multiple sIAs.


Assuntos
Aneurisma Roto/diagnóstico por imagem , Aneurisma Intracraniano/diagnóstico por imagem , Hemorragia Subaracnóidea/diagnóstico por imagem , Aneurisma Roto/complicações , Aneurisma Roto/epidemiologia , Finlândia/epidemiologia , Humanos , Aneurisma Intracraniano/complicações , Aneurisma Intracraniano/epidemiologia , Fatores de Risco , Hemorragia Subaracnóidea/epidemiologia , Hemorragia Subaracnóidea/etiologia
6.
Duodecim ; 133(2): 150-8, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29205015

RESUMO

Acute mesenteric ischemia resulting from mesenteric arterial thrombosis is a life-threatening cardiovascular complication with symptoms ranging from sudden-onset abdominal pain to vague symptoms of several days' duration. Although contrast-enhanced computed tomography is an excellent diagnostic tool, detection of the disease before the development of permanent intestinal injury is still difficult. Endovascular treatment is usually successful in restoring intestinal blood flow acutely. Chronic mesenteric ischemia requires urgent detection and therapy in order to prevent irreversible intestinal ischemia.


Assuntos
Procedimentos Endovasculares , Isquemia Mesentérica/diagnóstico por imagem , Isquemia Mesentérica/cirurgia , Tomografia Computadorizada por Raios X , Doença Aguda , Humanos
7.
Duodecim ; 132(21): 1973-82, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-29190049

RESUMO

Intra-arterial thrombectomy is a highly effective mode of treatment for properly selected patients with acute cerebral ischemia. Imaging studies are essential for making a decision on the treatment of acute cerebral infarction. In imaging, a combination of unenhanced CT scan of the head and CT angiography of the carotid and cerebral arteries during one imaging procedure is recommended for all patients coming into the hospital within the time window for thrombectomy, for patients with unclear time of onset of the symptoms and for whom cerebral hemorrhage is excluded as the cause in unenhanced CT scan. This may further be complemented with CT perfusion imaging. In certain acute situations magnetic resonance imaging is also useful.


Assuntos
Angiografia Cerebral , Angiografia por Tomografia Computadorizada , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/terapia , Trombectomia , Terapia Trombolítica , Tomada de Decisões , Humanos , Imageamento por Ressonância Magnética , Planejamento de Assistência ao Paciente
8.
J Endovasc Ther ; 20(3): 257-64, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23731293

RESUMO

PURPOSE: To evaluate results of endovascular stent-graft placement for aneurysms of the descending aorta in 3 Finnish university hospitals during 1998-2010. METHODS: Among 158 consecutive patients treated with stent-graft placement for disease of the descending thoracic aorta, all 69 patients (58 men; mean age 71.7 years, range 54-90) with an aneurysm were included in the analysis. Medical records, radiological images, and national death records were collected and analyzed on an intention-to-treat basis. RESULTS: The 30-day mortality rate was 3.7% in 54 elective patients and 46.7% in 15 urgently treated acute patients. The paraparesis rate was 4.3%, and the major stroke rate was 4.3% after the operation. There were 4 aneurysm ruptures, all in the urgent group, two of whom had access failure. The other two died despite seemingly good initial results. The mean follow-up was 34.8±29 months. Two late ruptures occurred in patients who were lost to follow-up. In all, 12 type I (10 early, 2 late) and 1 late type III endoleaks were encountered in the observation period. CONCLUSION: Based on our findings, endovascular treatment of aneurysms of the descending aorta is relatively safe. To reduce the risk of postoperative complications, optimal preoperative imaging is mandatory. Postoperative regular imaging controls are indicated for early detection and prompt treatment of late type I or III endoleaks and to reduce the risk of late ruptures.


Assuntos
Aneurisma da Aorta Torácica/cirurgia , Prótese Vascular , Procedimentos Endovasculares , Stents , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
9.
Neuroradiology ; 55(10): 1221-31, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23861213

RESUMO

INTRODUCTION: Intracranial stents have theoretical advantages in the treatment of wide-necked intracranial aneurysms, but the usability of intracranial stents in the retreatment of recurrent intracranial aneurysms is relatively unknown. In this study, we aim to evaluate the safety and efficacy of stent-assisted embolization in the retreatment of recurrent or residual intracranial aneurysms. METHODS: Retrospective evaluation was carried out for 55 consecutive patients (17 men and 38 women; mean age 51.5 years), with 56 recurrent or residual intracranial aneurysms electively retreated with stent-assisted embolization. RESULTS: The technical success rate was 91% (50/55 patients). Procedural complications were encountered with six patients (11%). Angiographic and clinical follow-up data were available for 51 patients (93%), with a mean follow-up period of 28.1 months. No rebleedings were encountered during the study period. The clinical outcome was favorable in 50 patients (91%), with a Glasgow Outcome Score of 4 (N = 14) or 5 (N = 36) at the end of the study period. Poor clinical outcome correlated with very large (>2 cm) total aneurysm size (P = 0.002), large (>10 mm) recurrent aneurysm size (P = 0.011), and occurrence of periprocedural complications (P < 0.001). CONCLUSION: Stent-assisted coil embolization is beneficial for the retreatment of wide-necked recurrent or residual intracranial aneurysms, but stability and permanent occlusion of the recurrent aneurysm is unlikely if the aneurysm exceeds 2 cm in diameter, the recurrent diameter of the aneurysm exceeds 10 mm, or if mass effect is present with the recurrent aneurysm.


Assuntos
Aneurisma Roto/mortalidade , Aneurisma Roto/terapia , Embolização Terapêutica/mortalidade , Aneurisma Intracraniano/mortalidade , Aneurisma Intracraniano/terapia , Complicações Pós-Operatórias/mortalidade , Stents , Adolescente , Adulto , Idoso , Comorbidade , Feminino , Finlândia/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida , Resultado do Tratamento , Adulto Jovem
10.
Acta Radiol ; 53(7): 754-8, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22798292

RESUMO

BACKGROUND: Short proximal neck of an abdominal aortic aneurysm is associated with risk of treatment failure during abdominal aortic repair. Important side branches, such as renal arteries, cannot be covered without serious consequences. PURPOSE: To test the feasibility of preoperative fenestration of abdominal aortic stent grafts with a re-entry catheter and steerable sheath to preserve the patency of renal arteries in an animal model. MATERIAL AND METHODS: Three domestic pigs were anesthetised and a stent graft placed in the abdominal aorta, covering the renal arteries. An attempt was made to fenestrate the renal arteries through the prosthesis using the Outback re-entry catheter supported by the Channel Steerable sheath. The hole that was created was dilated and stented. The specimens were visually analyzed after sacrifice. RESULTS: In one pig, the graft material was successfully traversed and a guide wire advanced in the renal arteries. Due to insufficient guide wire support and a poor balloon profile, dilatation of the fenestration failed. In another pig, the procedure was technically successful, but a long warm ischemia time for the left kidney caused infarction. In the third experiment, the procedure had to be discontinued due to a technical failure of the Outback device. CONCLUSION: Fenestration of a stent graft with a re-entry device through a steerable sheath is technically feasible in vivo. However, without further refinement of the instrumentation, the technique cannot be recommended in elective cases of abdominal aortic repair, but if the renal arteries are covered accidentally during endovascular treatment, the technique may be a valuable salvage option if surgical revascularization is not considered as an option.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Prótese Vascular , Artéria Renal/cirurgia , Stents , Procedimentos Cirúrgicos Vasculares/métodos , Animais , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Estudos de Viabilidade , Fluoroscopia , Modelos Animais , Punções , Artéria Renal/diagnóstico por imagem , Suínos
11.
CVIR Endovasc ; 5(1): 57, 2022 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-36308646

RESUMO

PURPOSE: Aim of this technical note article is to introduce a modified, novel way to custom create a candy-plug (CP) device to endovascularly occlude false lumen. The technique is illustrated by a patient case with significant backflow to false lumen (FL). The patient had already undergone surgical repair of the ascending aorta, aortic arch and subsequent TEVAR procedure down to the ostium of the celiac trunk because of type A aortic dissection, but the descending thoracic aorta continued to dilate due to backflow to the FL from an uncovered tear at the level of the renal arteries. MATERIALS AND METHODS: We modified a Gore Excluder 36-45 mm aortic extender (W. L. Gore & Associates, Inc. Flagstaff, USA) endoprosthesis into a CP device that was subsequently positioned under local anesthesia into the FL of the distal descending thoracic aorta. RESULTS: In 1 month control the backflow to false lumen had ceased and the aorta had decreased in diameter from 69 to 66 mm, FL from 37 to 34 mm, true lumen (TL) remained the same 32 mm. CONCLUSION: We describe a modified, effective candy-plug technique to occlude retrograde false lumen filling in aortic dissection.

12.
Radiology ; 261(2): 634-42, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22012905

RESUMO

PURPOSE: To determine the clinical outcome and the success of stent application for high-grade lesions of the infrapopliteal arteries compared with treatment with percutaneous transluminal angioplasty (PTA) in critical limb ischemia (CLI). MATERIALS AND METHODS: In this ethics board-approved randomized prospective study, PTA or stent application was performed on 131 lesions in 88 patients with CLI. The primary end points were clinical improvement after endovascular treatment and limb salvage rate. Secondary end points were defined by the minimal lumen diameter (MLD) before and after the revascularization procedure, percentage of residual diameter stenosis (DS), binary restenosis rate (>50% DS and >70% DS), and incidence of target lesion revascularization at 9-month follow-up. RESULTS: At 3 months, the clinical status in the PTA group was less improved than that in the stent group (P = .008). At 9 months, there had been five minor and two major amputations in the PTA group and five major and five minor amputations in the stent group. MLD was significantly larger and the percentage of DS was significantly less in the stent group at completion angiography. At 9 months, the angiographic control showed better trends for the stent group in comparison to the PTA group despite that no significant differences were detected (MLD, 1.19 mm ± 0.92 vs 1.02 mm ± 1.02; DS, 38.68% ± 25.47 vs 43.31% ± 28.37). CONCLUSION: Infrapopliteal stent application is an effective treatment modality in CLI. The PTA and stent groups were essentially equal at 3 and 9 months except for the difference in clinical improvement in the stent group at 3 months.


Assuntos
Angioplastia/métodos , Isquemia/terapia , Perna (Membro)/irrigação sanguínea , Artéria Poplítea , Stents , Idoso , Idoso de 80 Anos ou mais , Carbono , Distribuição de Qui-Quadrado , Materiais Revestidos Biocompatíveis , Europa (Continente) , Feminino , Humanos , Salvamento de Membro , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento
13.
J Vasc Interv Radiol ; 22(1): 89-94, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21106388

RESUMO

PURPOSE: To evaluate the response of various stent grafts after needle fenestration and sequential dilation with standard percutaneous transluminal angioplasty (PTA) and cutting balloons and sealing of the fenestration with a side branch stent graft. MATERIALS AND METHODS: Five commercially available aortic stent grafts (Endurant, Gore TAG, Talent, Valiant, and Zenith) were fenestrated with a needle. The fenestrations were sequentially dilated up to 10 mm with PTA balloons or cutting balloons. The residual diameter stenosis and visual appearance of the fenestration was estimated after each dilation. The joint between the main prosthesis and a side branch stent graft, placed through the fenestration, was visually assessed. RESULTS: Stent grafts responded variably after fenestration and balloon dilation; the holes were round or oval with smooth, fringed, frayed, or torn edges. Talent and Valiant fabrics were easiest to dilate, whereas Zenith was the most resilient. Dilation with a cutting balloon led to fully open fenestrations in all stent grafts. Good apposition of the side branch stent graft to the main prosthesis was achieved unless fenestration was located in close proximity to a stent strut. CONCLUSIONS: The balloon-based technique, especially the cutting balloon, fully opened the fenestrations up to 10 mm, and the fenestrations could be successfully covered with side branch stent grafts. Various graft fabrics responded variably to balloon dilation, however, which may have significant impact on the clinical in situ fenestration of individual aortic stent grafts.


Assuntos
Angioplastia com Balão/instrumentação , Doenças da Aorta/terapia , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Stents , Teste de Materiais , Desenho de Prótese
14.
Acta Radiol ; 52(9): 1024-31, 2011 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-21969705

RESUMO

BACKGROUND: Lateral lumbar spinal canal stenosis is a common etiology of lumbar radicular symptoms. Quantitative measurements have commonly demonstrated better repeatability than visual assessments. We are not aware of any studies examining the repeatability of quantitative assessment of the lateral canal. PURPOSE: To evaluate the repeatability of visual assessments and newly developed quantitative measurements of lateral lumbar spinal canal stenosis using magnetic resonance imaging (MRI). MATERIAL AND METHODS: Twenty-eight patients with lateral lumbar spinal canal stenosis or prior spinal surgery with recurrent symptoms were imaged with MRI. A radiologist, a neurosurgeon and a spine research trainee graded visually and quantitatively subarticular (n = 188) and foraminal zones (n = 260) of the lateral spinal canal. Quantitative measurements included the minimal subarticular width and the cross-sectional area of the foramen. RESULTS: The repeatability of visual assessment at the subarticular zone and foraminal zones between raters varied from 0.45-0.59 and 0.42-0.53, respectively. Similarly, the intraclass correlation coefficients for the quantitative measurements varied from 0.67-0.71 and 0.66-0.76, respectively. The intra-rater repeatability for the visual assessments of the subarticular and foraminal zones was 0.70 and 0.62, respectively, while the corresponding intraclass correlation coefficients for quantitative measurements were 0.83 and 0.81, respectively. CONCLUSION: Inter-rater repeatability of visual assessments of lateral stenosis is moderate, whereas quantitative measurements of both subarticular width and the cross-sectional area of the foramen have substantial reproducibility and may be particularly useful for longitudinal studies and research purposes. The clinical value of these parameters requires further study.


Assuntos
Vértebras Lombares , Imageamento por Ressonância Magnética , Estenose Espinal/patologia , Adulto , Idoso , Humanos , Vértebras Lombares/patologia , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Estenose Espinal/diagnóstico
15.
PLoS One ; 16(4): e0249772, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33882098

RESUMO

PURPOSE: This single-center study compared three threshold settings for automated analysis of the ischemic core (IC) and penumbral volumes using computed tomographic perfusion, and their accuracy for predicting final infarct volume (FIV) in patients with anterior circulation acute ischemic stroke (AIS). METHODS: Fifty-two consecutive AIS patients undergoing mechanical thrombectomy (November 2015-March 2018) were included. Perfusion images were retrospectively analyzed using a single CT Neuro perfusion application (syngo.via 4.1, Siemens Healthcare GmbH). Three threshold values (S1-S3) were derived from another commercial package (RAPID; iSchema View) (S1), up-to-date syngo.via default values (S2), and adapted values for syngo.via from a reference study (S3). The results were compared with FIV determined by non-contrast CT. RESULTS: The median IC volume (mL) was 24.6 (interquartile range: 13.7-58.1) with S1 and 30.1 (20.1-53.1) with S2/S3. After removing the contralateral hemisphere from the analysis, the median IC volume decreased by 1.33(0-3.14) with S1 versus 9.13 (6.24-14.82) with S2/S3. The median penumbral volume (mL) was 74.52 (49.64-131.91), 77.86 (46.56-99.23), and 173.23 (125.86-200.64) for S1, S2, and S3, respectively. Limiting analysis to the affected hemisphere, the penumbral volume decreased by 1.6 (0.13-9.02), 19.29 (12.59-26.52), and 58.33 mL (45.53-74.84) for S1, S2, and S3, respectively. The correlation between IC and FIV was highest in patients with successful recanalization (n = 34, r = 0.784 for S1; r = 0.797 for S2/S3). CONCLUSION: Optimizing thresholds significantly improves the accuracy of estimated IC and penumbral volumes. Current recommended values produce diversified results. International guidelines based on larger multicenter studies should be established to support the standardization of volumetric analysis in clinical decision-making.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , AVC Isquêmico/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Idoso , Isquemia Encefálica/patologia , Isquemia Encefálica/cirurgia , Tomada de Decisão Clínica/métodos , Feminino , Humanos , AVC Isquêmico/patologia , AVC Isquêmico/cirurgia , Masculino , Imagem de Perfusão/métodos , Estudos Retrospectivos , Software , Trombectomia/métodos
16.
Ann Biomed Eng ; 49(2): 653-662, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32820382

RESUMO

Contrast-enhanced magnetic resonance imaging (MRI) is a promising method for estimating myocardial blood flow (MBF). However, it is often affected by noise from imaging artefacts, such as dark rim artefact obscuring relevant features. Machine learning enables extracting important features from such noisy data and is increasingly applied in areas where traditional approaches are limited. In this study, we investigate the capacity of machine learning, particularly support vector machines (SVM) and random forests (RF), for estimating MBF from tissue impulse response signal in an animal model. Domestic pigs (n = 5) were subjected to contrast enhanced first pass MRI (MRI-FP) and the impulse response at different regions of the myocardium (n = 24/pig) were evaluated at rest (n = 120) and stress (n = 96). Reference MBF was then measured using positron emission tomography (PET). Since the impulse response may include artefacts, classification models based on SVM and RF were developed to discriminate noisy signal. In addition, regression models based on SVM, RF and linear regression (for comparison) were developed for estimating MBF from the impulse response at rest and stress. The classification and regression models were trained on data from 4 pigs (n = 168) and tested on 1 pig (n = 48). Models based on SVM and RF outperformed linear regression, with higher correlation (R SVM 2 = 0.81, R RF 2 = 0.74, R linear_regression 2 = 0.60; ρSVM = 0.76, ρRF = 0.76, ρlinear_regression = 0.71) and lower error (RMSESVM = 0.67 mL/g/min, RMSERF = 0.77 mL/g/min, RMSElinear_regression = 0.96 mL/g/min) for predicting MBF from MRI impulse response signal. Classifier based on SVM was optimal for detecting impulse response signals with artefacts (accuracy = 92%). Modified dual bolus MRI signal, combined with machine learning, has potential for accurately estimating MBF at rest and stress states, even from signals with dark rim artefacts. This could provide a protocol for reliable and easy estimation of MBF, although further research is needed to clinically validate the approach.


Assuntos
Circulação Coronária , Coração/diagnóstico por imagem , Coração/fisiologia , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/fisiopatologia , Animais , Feminino , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Suínos
17.
J Magn Reson Imaging ; 31(3): 617-24, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20187204

RESUMO

PURPOSE: To investigate the relationship between magnetic resonance imaging (MRI) measures and uterus and leiomyoma size reductions after uterine artery embolization (UAE). MATERIALS AND METHODS: Fifty-two women with leiomyomas underwent selective UAEs. Uterine and dominant leiomyoma sizes were measured with preinterventional MRI and a 6-month follow-up MRI. Four MRI measures of the dominant leiomyoma were recorded: T1 time; T2 time; leiomyoma-to-skeletal muscle T2 SI-ratio; and percentage of contrast enhancement. To evaluate the predictive value of MRI measures we used Spearman rank correlation, area under the receiver operating characteristic (ROC) curve (A(z)), and values for diagnostic performance. RESULTS: Uterus and dominant leiomyoma size reductions were highly variable. Leiomyoma size reductions of >or=75% were accurately predicted with leiomyoma-to-skeletal muscle T2 SI-ratio (ROC curve A(z) = 0.930; 95% confidence interval [CI]: 0.853, 1.000). Leiomyoma size reductions >or=75% were predicted by leiomyoma-to-skeletal muscle T2 SI-ratio >or=3.5 and T1-time >or=750 msec with 100% and 86% sensitivities and 67% and 72% specificities, respectively. Uterus size reduction >or=50% were identified by dominant leiomyoma-to-skeletal muscle T2 SI-ratio >or=2.5. CONCLUSION: Uterus and dominant leiomyoma size reductions after UAE were predicted with preoperative MRI measures of the dominant leiomyoma.


Assuntos
Leiomioma/diagnóstico , Leiomioma/terapia , Imageamento por Ressonância Magnética/métodos , Embolização da Artéria Uterina/métodos , Neoplasias Uterinas/diagnóstico , Neoplasias Uterinas/terapia , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Cuidados Pré-Operatórios/métodos , Prognóstico , Resultado do Tratamento
18.
Eur Radiol ; 20(10): 2524-32, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20526776

RESUMO

OBJECTIVE: To compare uterine artery embolisation (UAE) and hysterectomy for the treatment of leiomyomas at 2-year follow-up in a prospective, randomised, single-centre study. METHODS: Fifty-seven symptomatic patients were randomised to UAE (n = 27) or hysterectomy (n = 30). Complications, recovery, reinterventions and satisfaction with treatment were recorded. Primary endpoint was improvement of symptoms. Analyses were performed by intent-to-treat and per protocol. RESULTS: Two hysterectomy patients (7%) developed major complications. Hospital discharge occurred earlier after UAE than after hysterectomy (p < 0.001). Length of sick leave was longer after hysterectomy than after UAE (p < 0.001). Twenty-two (82%) UAE patients and 28 (93%) hysterectomy patients reported overall relief of symptoms (p = 0.173). In 12/18 (67%) UAE patients menorrhagia was completely resolved or reduced. Improvement of pressure symptoms was reported significantly more by UAE patients than by hysterectomy patients (19/20 [95%] versus 18/26 [69%], respectively; p = 0.029). Five (19%) UAE patients underwent additional interventions due to worsening symptoms. Twenty-four (89%) UAE patients and 29 (97%) hysterectomy patients would have chosen treatment again (p = 0.336). CONCLUSION: UAE gave relief of symptoms (apart from menorrhagia) comparable to hysterectomy with less severe complications, but with an increased rate of secondary interventions. UAE may be the preferable treatment especially for patients with pressure symptoms.


Assuntos
Histerectomia/métodos , Leiomioma/terapia , Embolização da Artéria Uterina/métodos , Neoplasias Uterinas/terapia , Adulto , Índice de Massa Corporal , Feminino , Seguimentos , Humanos , Leiomioma/patologia , Imageamento por Ressonância Magnética/métodos , Oncologia/métodos , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Neoplasias Uterinas/patologia
19.
J Vasc Interv Radiol ; 21(2): 181-5, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20022764

RESUMO

PURPOSE: To evaluate the value of preoperative embolization of the inferior mesenteric artery (IMA) before endovascular repair of an abdominal aortic aneurysm. MATERIALS AND METHODS: From January 2000 to October 2006, 79 patients (mean age, 72.3 years; 69 men) scheduled for endovascular aneurysm repair (EVAR) were found to have a patent IMA at computed tomography. Coil embolization of the patent IMA was performed in 40 patients at Kuopio University Hospital, and their outcome was compared with that of 39 patients with a patent IMA who underwent EVAR at Oulu University Hospital without preoperative IMA embolization (control group). All patients were treated with a Zenith stent-graft. The mean follow-up time was 3.4 years +/- 1.7 (median, 3.1 years; range, 0-7.6 years). RESULTS: There were significantly fewer type II endoleaks in the IMA embolization group than in the control group (25% vs 59%, respectively; P = .002). Preoperative IMA embolization did not correlate with aneurysm size change. The overall linearized aneurysm shrinkage rate per year was 1.4 mm per year +/- 3.8 in the IMA embolization group and 1.7 mm per year +/- 2.4 in the control group (P = .72). CONCLUSIONS: Preoperative coil embolization of the IMA reduced the frequency of type II endoleaks after EVAR, but the authors failed to show any influence on late postoperative aneurysm shrinkage.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Embolização Terapêutica , Artéria Mesentérica Inferior/fisiopatologia , Falha de Prótese , Stents , Grau de Desobstrução Vascular , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/fisiopatologia , Aortografia/métodos , Implante de Prótese Vascular/efeitos adversos , Feminino , Finlândia , Humanos , Masculino , Artéria Mesentérica Inferior/diagnóstico por imagem , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento
20.
Scand Cardiovasc J ; 44(2): 125-8, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19961285

RESUMO

OBJECTIVES: The aim of this study was to retrospectively evaluate three risk scoring methods in predicting outcome after elective endovascular repair of an abdominal aortic aneurysm. DESIGN: A Zenith stent graft was employed in 205 patients during years 2001-2005. RESULTS: The 30-day postoperative mortality rate was 2.9%. Receiver operating characteristics (ROC) curve analysis showed that the Glasgow aneurysm score (GAS) (AUC: 0.843, p=0.004) and the Giles' score (AUC 0.815, p=0.009) had a rather large area under the curve in predicting 30-day mortality rate. The modified Leiden score was much less accurate (AUC: 0.594). The best cut-off value for the GAS in predicting 30-day mortality was 90 (0.6% vs. 17.9%, p<0.0001). Patients with a GAS > or = 90 had a 4-year survival rate of 56.8%, whereas it was 78.5% among those with a lower GAS (p = 0.001). The best cut-off value for the Giles' score was 11 (1.3% vs. 8.3%, p<0.0001). Patients with a Giles' score > or = 11 had a 4-year survival rate of 63.9%, whereas it was 79.0% among those with a lower score (p = 0.016). CONCLUSIONS: The GAS and Giles' risk scoring methods are good predictors of poor immediate and late outcome after EVAR.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular/efeitos adversos , Indicadores Básicos de Saúde , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/mortalidade , Prótese Vascular , Implante de Prótese Vascular/métodos , Implante de Prótese Vascular/mortalidade , Procedimentos Cirúrgicos Eletivos , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Razão de Chances , Valor Preditivo dos Testes , Desenho de Prótese , Curva ROC , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Stents , Fatores de Tempo , Resultado do Tratamento
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