we included patients diagnosed with kd who underwent clinically indicated cardiac catheterization and coronary angiography between march 2013 and august 2014 at the children s university hospital st - justine , montreal , quebec , canada . indications for catheterization were either routine follow - up of aneurysms or new cardiac symptoms suggestive of ischemia . exclusion criteria included concurrent vascular inflammatory disease , evidence of underlying cause of hypercholesterolemia , or diseases known to induce vascular structural changes . subjects coronary artery lesion evolution was reviewed by assessing previous echocardiography examinations and coronary angiographies , and compared with oct findings . this retrospective chart review was approved by the local ethics review board . a bmw ( abbott vascular ) or a terumo ( terumo interventional systems ) coronary guidewire was advanced distally in the coronary artery following intracoronary administration of nitroglycerine titrated to patients body habitus . the dragonfly catheter ( st - jude medical , inc ) was advanced over a guiding coronary catheter ( 6 fr for adolescents and young adults , 5 fr for younger patients ) . a low - osmolality contrast agent , isovue-300 ( bracco imaging ) , was hand injected in most cases ( power injection in selected older patients ) for intracoronary blood clearance . the detection of blood clearance in the lumen triggers automatic pullback recording of the oct lens within the dragonfly catheter at a pullback speed of 20  mm / s and a frame rate of 100  frames / s.6 all coronary angiography studies were reviewed for the presence or absence of aneurysm ( with giant caa being defined as a luminal diameter > 8  mm ) , significant coronary artery stenosis ( defined as luminal narrowing exceeding 50% in diameter ) , in stent - restenosis or dissection . serial measurements of the intima and media were performed along the length of the coronary vessel by using the enabled semiautomatic calliper tool ( st - jude medical , inc ) and the intima / media ratio was then calculated . when disappearance of the media was observed , a value of 1  m was given to allow calculation of the intima / media ratio . cross - sectional frames containing artifacts or side branches comprising > 25% of the image were excluded from the analysis . for segments with persistent caa , measurements were made in sections adjacent to the caa . in segments with regressed caa , measurements were taken at previous caa sites as well as adjacent sections . the images were also qualitatively analyzed for the presence of intimal hyperplasia , loss of normal layered structures of the vessel wall ( disappearance of the tunica media ) , medial irregularities , calcifications , macrophage accumulation , white thrombi ( platelet - rich ) , red thrombi ( red blood cell  rich ) and neovascularization , according to the consensus standards for acquisition , measurement , and reporting of oct studies.5 the measurements of the intima and media were made by the cardiologist performing coronary angiography with oct imaging ( n.d . ) . qualitative oct image analysis was performed by 2 independent blinded interventional cardiologists trained in intra - coronary imaging ( r.i . safety data , including radiation dose , radiation time , amount of contrast dye and nitroglycerine used were documented . complications related to the procedure , including ischemic events , vasospasm , dissection of the coronary artery , cardiac arrhythmias , and coronary or catheter thrombosis , were reported . quantitative variables were expressed as meansd or median ( range ) , and categorical variables as frequencies or percentages . the kolmogorov comparison of affected and unaffected coronary segments was performed using student t test for continuous variables with normal distributions and the mann all analyses were performed with sigmastat v3.5 ( dundas software , germany ) . a 2-tailed p value of < 0.05 was deemed significant . we included patients diagnosed with kd who underwent clinically indicated cardiac catheterization and coronary angiography between march 2013 and august 2014 at the children s university hospital st - justine , montreal , quebec , canada . indications for catheterization were either routine follow - up of aneurysms or new cardiac symptoms suggestive of ischemia . exclusion criteria included concurrent vascular inflammatory disease , evidence of underlying cause of hypercholesterolemia , or diseases known to induce vascular structural changes . subjects coronary artery lesion evolution was reviewed by assessing previous echocardiography examinations and coronary angiographies , and compared with oct findings . a bmw ( abbott vascular ) or a terumo ( terumo interventional systems ) coronary guidewire was advanced distally in the coronary artery following intracoronary administration of nitroglycerine titrated to patients body habitus . the dragonfly catheter ( st - jude medical , inc ) was advanced over a guiding coronary catheter ( 6 fr for adolescents and young adults , 5 fr for younger patients ) . a low - osmolality contrast agent , isovue-300 ( bracco imaging ) , was hand injected in most cases ( power injection in selected older patients ) for intracoronary blood clearance . the detection of blood clearance in the lumen triggers automatic pullback recording of the oct lens within the dragonfly catheter at a pullback speed of 20  mm / s and a frame rate of 100  frames / s.6 all coronary angiography studies were reviewed for the presence or absence of aneurysm ( with giant caa being defined as a luminal diameter > 8  mm ) , significant coronary artery stenosis ( defined as luminal narrowing exceeding 50% in diameter ) , in stent - restenosis or dissection . serial measurements of the intima and media were performed along the length of the coronary vessel by using the enabled semiautomatic calliper tool ( st - jude medical , inc ) and the intima / media ratio was then calculated . when disappearance of the media was observed , a value of 1  m was given to allow calculation of the intima / media ratio . cross - sectional frames containing artifacts or side branches comprising > 25% of the image were excluded from the analysis . for segments with persistent caa , measurements were made in sections adjacent to the caa . in segments with regressed caa , measurements were taken at previous caa sites as well as adjacent sections . the images were also qualitatively analyzed for the presence of intimal hyperplasia , loss of normal layered structures of the vessel wall ( disappearance of the tunica media ) , medial irregularities , calcifications , macrophage accumulation , white thrombi ( platelet - rich ) , red thrombi ( red blood cell  rich ) and neovascularization , according to the consensus standards for acquisition , measurement , and reporting of oct studies.5 the measurements of the intima and media were made by the cardiologist performing coronary angiography with oct imaging ( n.d . ) . qualitative oct image analysis was performed by 2 independent blinded interventional cardiologists trained in intra - coronary imaging ( r.i . safety data , including radiation dose , radiation time , amount of contrast dye and nitroglycerine used were documented . complications related to the procedure , including ischemic events , vasospasm , dissection of the coronary artery , cardiac arrhythmias , and coronary or catheter thrombosis , were reported . quantitative variables were expressed as meansd or median ( range ) , and categorical variables as frequencies or percentages . the kolmogorov comparison of affected and unaffected coronary segments was performed using student t test for continuous variables with normal distributions and the mann all analyses were performed with sigmastat v3.5 ( dundas software , germany ) . a 2-tailed p value of < 0.05 was deemed significant . the study comprised 18 patients ( 10 males , 55.6% ) who underwent oct imaging 9.05.1  years after onset of kd ( table1 ) . patients were 3.42.9  years old at kd diagnosis , with a median of 5 ( range 3 to 6 ) fulfilled diagnostic criteria of kd , with 7/18 ( 38.9% ) having incomplete clinical criteria of kd . patients received intravenous immunoglobulin treatment 9.95.2  days after the onset of fever , among whom 5/18 patients ( 27.8% ) had a delayed therapy ( treatment started > 10  days after the onset of fever ) . caa were present in 14/18 ( 77.8% ) patients on follow up , with 7/14 ( 50% ) having giant caa , and 7/14 ( 50% ) having regressed aneurysmal lesions at the time of oct ( table2 ) . indications for coronary angiography were routine follow - up in order to survey caa progress ( n=14 ) and evaluation of symptoms suggestive of ischemia ( n=4 ) ; 3 patients with acute chest pain ( among those , 2 patients with abnormal technetium ( 99mtc ) sestamibi ( tc - mibi ) myocardial perfusion scintigraphy , and 1 with a history of d - transposition of the great arteries corrected in the neonatal period ) , and 1 with fatigue and dyspnea on exercise . patient characteristics at onset of kawasaki disease caa indicates coronary artery aneurysm ; ivig , intravenous immunoglobulin ; kd , kawasaki disease . detailed patient characteristics at onset of kawasaki disease caa indicates coronary artery aneurysm ; ivig , intravenous immunoglobulin ; kd , kawasaki disease . patient characteristics at the time of oct oct indicates optical coherence tomography . the estimated radiation dose of a complete examination including angiography and oct imaging was 597.0678.0  mgy , or 10.95.2  mgy / kg . importantly , the safety data represent the entire angiography procedure , not only oct imaging , including therapeutic procedures in some patients . intracoronary nitroglycerin was administered to all patients to prevent coronary artery spasm at a dose of 83.944.3  g / kg ( right coronary artery ) and 93.046.7  g / kg ( left coronary artery ) , respectively . no major complications , such as ischemic event , coronary artery dissection , or arrhythmia occurred during the procedure . one patient had a transitory uneventful right coronary artery vasospasm at the site of a regressed aneurysm where intimal hyperplasia with preserved media as well as fibrosis was observed on oct . safety data during procedure lca indicates left coronary artery ; rca , right coronary artery . includes 1  ml / kg ( up to 40  ml ) for left ventriculography . cardiac catheterization and selective coronary angiography were performed including oct of all 3 coronary vessels in 44.4% of patients , while 38.9% and 16.7% of patients underwent oct imaging of 2 or 1 coronary arteries , respectively . significant coronary artery wall changes were identified in aneurysmal sites as well as angiographically normal segments ( table5 ) . normal coronary artery wall structure was defined as a trilaminar , well - delineated pattern of the arterial wall with the intima being characterized by a highly backscattering signal - rich layer , the media by a homogeneous layer that has low backscattering , and the adventitia by highly backscattering layer ( figure 1 ) . intimal hyperplasia was the most frequent finding in our study cohort and was observed in 15 ( 83.3% ) patients ( figure 2 ) . the thickness of the intima was significantly different between diseased and normal coronary artery segments ( 390.8166.0  m versus 61.717.0  m , p<0.001 ) . eccentric intimal hyperplasia , defined as focal ( as opposed to circumferential ) intimal thickening , was observed in 52.4% of segments , while concentric intimal hyperplasia was seen in 47.6% of segments . similarly , media thickness differed significantly between aneurysmal and angiographically normal segments ( 30.256.9  m versus 61.416.7  m , p<0.001 ) . consequently , the calculated intima / media ratio was statistically different between diseased and normal segments ( 320.4236.2 versus 1.00.3 , p<0.001 ) ( table6 ) . frequency of abnormal oct findings oct indicates optical coherence tomography . quantitative analysis of oct data lad indicates left anterior descending artery ; lcx , left circumflex artery ; oct , optical coherence tomography ; rca , right coronary artery . normal coronary artery with intima ( white measure ) and media ( blue measure ) being well delineated and of normal thickness . . partial disappearance of the tunica media was found in 13/18 ( 72.2% ) patients ( figure 3 ) . calcifications , and calcified nodules were detected in 5/18 ( 27.8% ) patients ( figure 5 ) . light attenuation consistent with macrophage accumulation was found in 8/18 ( 44.4% ) of patients ( figure 6 ) . white thrombus was identified in 3/18 ( 16.7% ) patients ( figure 7 ) and neovascularization in 2/18 ( 11.1% ) patients ( figure 8) , while no red thrombus could be seen . however , pathological structural changes were observed more often in segments with persistent caa ( 18/18 , 100% ) , compared to 13/24 ( 54.2% ) for angiographically normal segments ( regressed caa , and no history of caa ) . out of 3 cases of previous stent implantation ( all of which were drug - eluting stents ) , 2 cases showed neointima proliferation measuring 80 to 160  m , while in 1 case no proliferation was detected . summary of oct imaging results caa indicates coronary artery aneurysm ; oct , optical coherence tomography . severe concentric intimal thickening ( yellow and green measures ) with loss of the normal structure of the vessel wall , disappearance of media ( red arrow ) , and nonobstructive luminal narrowing . intimal hyperplasia ( white measure ) with medial irregularities most likely due to fibrosis ( red arrow ) with diffuse medial thickening . calcified nodule ( pink measure ) , characterized by a well - demarcated border and heterogeneous , low - signal composition . intimal hyperplasia ( green measure ) with macrophage accumulation ( red arrow ) : signal - rich band , strongly light - attenuating and causing an underlying signal - poor region . white thrombus ( white and blue measures ) , characterized by a signal - rich , irregular mass protruding into the lumen with mild light attenuation ( as opposed to red thrombus ) . intimal hyperplasia ( pink measure ) with ellipsoid structures of varying size with a dark appearance suggesting microvessels , a typical picture seen in neovascularization ( red arrow ) . the study comprised 18 patients ( 10 males , 55.6% ) who underwent oct imaging 9.05.1  years after onset of kd ( table1 ) . patients were 3.42.9  years old at kd diagnosis , with a median of 5 ( range 3 to 6 ) fulfilled diagnostic criteria of kd , with 7/18 ( 38.9% ) having incomplete clinical criteria of kd . patients received intravenous immunoglobulin treatment 9.95.2  days after the onset of fever , among whom 5/18 patients ( 27.8% ) had a delayed therapy ( treatment started > 10  days after the onset of fever ) . caa were present in 14/18 ( 77.8% ) patients on follow up , with 7/14 ( 50% ) having giant caa , and 7/14 ( 50% ) having regressed aneurysmal lesions at the time of oct ( table2 ) . indications for coronary angiography were routine follow - up in order to survey caa progress ( n=14 ) and evaluation of symptoms suggestive of ischemia ( n=4 ) ; 3 patients with acute chest pain ( among those , 2 patients with abnormal technetium ( 99mtc ) sestamibi ( tc - mibi ) myocardial perfusion scintigraphy , and 1 with a history of d - transposition of the great arteries corrected in the neonatal period ) , and 1 with fatigue and dyspnea on exercise . patient characteristics at onset of kawasaki disease caa indicates coronary artery aneurysm ; ivig , intravenous immunoglobulin ; kd , kawasaki disease . detailed patient characteristics at onset of kawasaki disease caa indicates coronary artery aneurysm ; ivig , intravenous immunoglobulin ; kd , kawasaki disease . the estimated radiation dose of a complete examination including angiography and oct imaging was 597.0678.0  mgy , or 10.95.2  mgy / kg . importantly , the safety data represent the entire angiography procedure , not only oct imaging , including therapeutic procedures in some patients . intracoronary nitroglycerin was administered to all patients to prevent coronary artery spasm at a dose of 83.944.3  g / kg ( right coronary artery ) and 93.046.7  g / kg ( left coronary artery ) , respectively . no major complications , such as ischemic event , coronary artery dissection , or arrhythmia occurred during the procedure . one patient had a transitory uneventful right coronary artery vasospasm at the site of a regressed aneurysm where intimal hyperplasia with preserved media as well as fibrosis was observed on oct . safety data during procedure lca indicates left coronary artery ; rca , right coronary artery . includes 1  ml / kg ( up to 40  ml ) for left ventriculography . cardiac catheterization and selective coronary angiography were performed including oct of all 3 coronary vessels in 44.4% of patients , while 38.9% and 16.7% of patients underwent oct imaging of 2 or 1 coronary arteries , respectively . significant coronary artery wall changes were identified in aneurysmal sites as well as angiographically normal segments ( table5 ) . normal coronary artery wall structure was defined as a trilaminar , well - delineated pattern of the arterial wall with the intima being characterized by a highly backscattering signal - rich layer , the media by a homogeneous layer that has low backscattering , and the adventitia by highly backscattering layer ( figure 1 ) . intimal hyperplasia was the most frequent finding in our study cohort and was observed in 15 ( 83.3% ) patients ( figure 2 ) . the thickness of the intima was significantly different between diseased and normal coronary artery segments ( 390.8166.0  m versus 61.717.0  m , p<0.001 ) . eccentric intimal hyperplasia , defined as focal ( as opposed to circumferential ) intimal thickening , was observed in 52.4% of segments , while concentric intimal hyperplasia was seen in 47.6% of segments . similarly , media thickness differed significantly between aneurysmal and angiographically normal segments ( 30.256.9  m versus 61.416.7  m , p<0.001 ) . consequently , the calculated intima / media ratio was statistically different between diseased and normal segments ( 320.4236.2 versus 1.00.3 , p<0.001 ) ( table6 ) . quantitative analysis of oct data lad indicates left anterior descending artery ; lcx , left circumflex artery ; oct , optical coherence tomography ; rca , right coronary artery . normal coronary artery with intima ( white measure ) and media ( blue measure ) being well delineated and of normal thickness . . partial disappearance of the tunica media was found in 13/18 ( 72.2% ) patients ( figure 3 ) . calcifications , and calcified nodules were detected in 5/18 ( 27.8% ) patients ( figure 5 ) . light attenuation consistent with macrophage accumulation was found in 8/18 ( 44.4% ) of patients ( figure 6 ) . white thrombus was identified in 3/18 ( 16.7% ) patients ( figure 7 ) and neovascularization in 2/18 ( 11.1% ) patients ( figure 8) , while no red thrombus could be seen . the above findings were found in both aneurysmal and angiographically normal coronary artery segments . however , pathological structural changes were observed more often in segments with persistent caa ( 18/18 , 100% ) , compared to 13/24 ( 54.2% ) for angiographically normal segments ( regressed caa , and no history of caa ) . out of 3 cases of previous stent implantation ( all of which were drug - eluting stents ) , 2 cases showed neointima proliferation measuring 80 to 160  m , while in 1 case no proliferation was detected . summary of oct imaging results caa indicates coronary artery aneurysm ; oct , optical coherence tomography . severe concentric intimal thickening ( yellow and green measures ) with loss of the normal structure of the vessel wall , disappearance of media ( red arrow ) , and nonobstructive luminal narrowing . intimal hyperplasia ( white measure ) with medial irregularities most likely due to fibrosis ( red arrow ) with diffuse medial thickening . calcified nodule ( pink measure ) , characterized by a well - demarcated border and heterogeneous , low - signal composition . intimal hyperplasia ( green measure ) with macrophage accumulation ( red arrow ) : signal - rich band , strongly light - attenuating and causing an underlying signal - poor region . white thrombus ( white and blue measures ) , characterized by a signal - rich , irregular mass protruding into the lumen with mild light attenuation ( as opposed to red thrombus ) . intimal hyperplasia ( pink measure ) with ellipsoid structures of varying size with a dark appearance suggesting microvessels , a typical picture seen in neovascularization ( red arrow ) . our study shows significant structural changes of the arterial wall in patients with kd as assessed by oct imaging . the most frequent finding in this population was intimal hyperplasia , followed by fibrotic vessel wall changes , partial disappearance of media , macrophage accumulation , and calcifications . interestingly , these structural arterial wall changes were not only seen at aneurysmal sites , but also in coronary artery segments that appeared angiographically normal , suggesting that oct imaging may add incremental diagnostic value to conventional imaging techniques in patients with kd . the findings seen by oct imaging in the present study are consistent with histopathologic observations after kd . the acute stage is characterized by necrotizing arteritis , responsible for saccular aneurysm formation at risk of rupture or thrombosis . the subacute / chronic phase is marked by an inflammatory process associated with luminal fibroblastic proliferation , with destruction of the internal elastic lamina , external elastic lamina and media in the most severe cases . the chronic phase is marked by intraluminal stenosing caused by myofibroblast proliferation , with progressive luminal narrowing and intimal hyperplasia ( figure 9).8 coronary artery showing severe intimal hyperplasia ( yellow measure ) with resulting stenosis ( red arrow ) . the observation that striking changes , in particular intimal hyperplasia , are observed in coronary artery segments where aneurysmal dilatation had regressed on angiography are in line with 2 previous case reports.7,9 the first series included kd and post - transplant pediatric patients . it focused on feasibility and safety , describing 4 kd patients with normal concurrent angiography and 1 with mild irregularities of the proximal right coronary artery . their qualitative findings were comparable to ours , with intimal hyperplasia , absence of media , thrombosis , calcification , and neovascularization being reported.7 kakimoto et  al in 2014 described 2 adolescents with a history of kd in whom oct showed intimal hyperplasia and disruption of the media , not only on segments with caa but also on normal angiographic segments.9 oct was also used for stent positioning guidance in a patient with a severely calcified coronary plaque presenting with acute coronary syndrome and a history of kd coronary artery complications.10 our findings are of particular importance when considering that these persistent vascular wall abnormalities , which are not evident on angiography , may contribute to the increased risk of myocardial ischemia observed in young adults who suffered from kd earlier in life.1114 another important perspective is the fact that there are no current guidelines for the evaluation and treatment of adult patients who had kd . thus , identifying more precisely a population at risk may have the potential to tailor treatment and improve outcomes . furthermore , oct imaging may help to choose the proximal and distal stent landing zones during percutaneous interventions , owing to a better depiction of coronary wall abnormalities in kd patients that can not be readily appreciated on coronary angiography . of note , however , the retrospective design of our study does not allow addressing the prognostic value of our findings , which needs to be assessed by a prospective study with adequate power . furthermore , the pathophysiological relevance of our findings can not be estimated by the current study since histopathological correlates are lacking . intimal thickening or hyperplasia on oct may be the result of destruction of the internal elastic layer , proliferation of vascular smooth - muscle cells , and fibrous tissue in the intima following the inflammatory process of kd . macrophage accumulation , however , seen in 44.4% of our study population , points towards an inflammatory process and raises the question whether ( and for how long ) the inflammatory process outlasts the acute arteritis phase and the development of aneurysms in kd . notably , previous histopathology studies provided conflicting results regarding macrophage involvement in the late disease process of kd,15,16 and oct imaging may help to clarify the natural course of inflammatory coronary artery changes in kd . whether the vasculopathy observed after kd is a distinct process or accelerated atherosclerosis has been controversially discussed in the past . importantly , in line with previous histopathological studies , no typical features of atherosclerosis , such as necrotic cores or lipid pools , have been identified in patients after kd in our study.11,15,16 oct can not image through blood because it attenuates the infrared light before reaching the arterial wall , hence the need for blood clearance before acquisition of images . in the early stages of oct development , blood clearance was performed with an occlusive balloon installed proximally.6 lately , oct technology does not require coronary artery occlusion . instead , nonocclusive flush with contrast dye is detected by the lens and pullback is triggered automatically.6,17,18 while the risks of oct imaging have been well characterized in the early stages of its utilization in the adults , transient chest pain ( 47.6% of patients ) , transient ecg changes ( 45.5% of patients ) , and ventricular fibrillation were mostly associated with the coronary balloon occlusion technique for lumen clearance . other associated complications included deep guide catheter intubation ( 0.6% ) , air embolism ( 0.6% ) , and coronary artery dissection ( 0.2%).19 in the current era of oct imaging , proximal balloon occlusion is no longer in use due to procedural ischemic events.17 the nonocclusive clearance technique , applied to our series , is rarely a cause of major complications such as death , myocardial infarction , emergency revascularization , embolization , life - threatening arrhythmia , coronary dissection , prolonged and severe vessel spasm , and contrast - induced nephropathy.20 in our series , only 1 patient had a transient uneventful vasospasm , most likely owing to the fact that the oct technique ( eg , hand injection of contrast dye instead of power injection ) and material ( small catheter size ) were adapted for appropriate use in children . the presence of mural thrombi by angiography was not considered an absolute exclusion criterion for the oct procedure , and the decision to perform oct was left to the discretion of the interventional cardiologist ( n.d . ) considering the risk of distal embolization . nevertheless , at present data regarding safety measures of oct imaging in a pediatric population are lacking and will have to be provided by adequately powered studies . first , the most important limitation of this study is the absence of comparison to the  gold standard  of histopathology . second , the penetration depth of oct amounts only 0.1 to 2  mm and therefore limits the analysis of giant caa.6 third , the prognostic value of our findings and the course of caa as evaluated by oct can not be assessed by the present study due to its retrospective design and its small population . in our experience , oct proved to be safe , providing new insights in the setting of kd . these findings should be further validated in larger cohort studies , and if possible with pathologic correlation .
backgroundcoronary artery aneurysms ( caa ) are serious complications of kawasaki disease ( kd ) . 
 optical coherence tomography ( oct ) is a high - resolution intracoronary imaging modality that characterizes coronary artery wall structure . 
 the purpose of this work was to describe caa wall sequelae after kd.methods and resultskd patients scheduled for routine coronary angiography underwent oct imaging between march 2013 and august 2014 . 
 subjects clinical courses , echocardiography , and coronary angiography examinations were reviewed retrospectively . 
 oct was performed in 18 patients aged 12.45.5  years , 9.05.1  years following onset of kd . of those , 
 14 patients ( 77.7% ) had a history of caa ( 7 with giant caa and 7 with regressed caa at time of oct ) . 
 intracoronary nitroglycerin was given to all patients ( 88.445.5  g / m2 ) . 
 mean radiation dose was 10.95.2  mgy / kg . 
 one patient suffered from a transitory uneventful vasospasm at the site of a regressed caa ; otherwise no major procedural complications occurred . the most frequent abnormality observed on oct was intimal hyperplasia ( 15 patients , 83.3% ) seen at both aneurysmal sites and angiographically normal segments amounting to 390.8166.0  m for affected segments compared to 61.717  m for unaffected segments ( p<0.001 ) . 
 disappearance of the media , and presence of fibrosis , calcifications , macrophage accumulation , neovascularization , and white thrombi were seen in 72.2% , 77.8% , 27.8% , 44.4% , and 33.3% of patients.conclusionsin this study , oct proved safe and insightful in the setting of kd , with the potential to add diagnostic value in the assessment of coronary abnormalities in kd . 
 the depicted coronary structural changes correspond to histological findings previously described in kd .