Advanced viz aids coronary stent fracture detection
The use of advanced visualization software enables the utilization of coronary CT angiography (CCTA) to accurately depict stent fractures in patients that are not clearly depicted by conventional angiography, according to a study published in the December issue of Radiology.
“Stent fracture (SF) has been suggested as one of the leading risk factors of thrombosis and in-stent restenosis (ISR) in patients who have intracoronary drug-eluting stent implants,” wrote the authors of the retrospective study conducted at the University Ilsanpaik Hospital in Gyunggi-do, South Korea.
The team identified 371 patients with stent implants from a consecutive group of 3,631 patients who underwent CCTA at the facility over the course of 14 months in 2005-2006. They identified the stent type in 488 of the devices but not in 57 of them. However, the scientists reported that none of the 57 unidentified stent types fractured.
The researchers identified 24 stent types and noted that 341 of the 488 devices were drug-eluting stents: 169 Cypher (Cordis), 144 Taxus (Boston Scientific) and 28 Endeavor (Medtronic). All patients were imaged on a 64-slice CT system (Aquilion 64, Toshiba Medical Systems).
One to three of each patient’s data sets with the fewest motion artifacts were downloaded onto a 3D workstation (Rapida, Infinitt) for reformation of two 0.5- and 5.0-mm-thick orthogonal curved multiplanar reconstruction images and a varying number of 1-mm-thick perpendicular images, according to the researchers. All images were retrospectively interpreted by two radiologists experienced in cardiac CT.
Utilization of the advanced visualization software enabled the radiologists to detect stent fractures in 3.8 percent of the patients, which is higher than the prevalence of 1.9 percent to 2.6 percent cited in other recent reports. Of note, the researchers stated that fractures were found in 5 percent of the drug-eluting stents.
“Six of 18 fractured stents in five patients were missed on conventional coronary angiograms at the initial readings; four of these fractured stents were found at retrospective review and two were confirmed at fluoroscopy,” the authors noted.
As a result of their work, the scientists believe that 64-slice CCTA can be used a primary tool for the detection of coronary stent fracture.
“Since the prevalence of coronary heart disease and the use of drug-eluting stents are increasing worldwide, radiologists and cardiologists who interpret coronary CT angiograms obtained in patients with a history of stent implantation should be aware of the findings that suggest fracture,” the authors advised.
“Stent fracture (SF) has been suggested as one of the leading risk factors of thrombosis and in-stent restenosis (ISR) in patients who have intracoronary drug-eluting stent implants,” wrote the authors of the retrospective study conducted at the University Ilsanpaik Hospital in Gyunggi-do, South Korea.
The team identified 371 patients with stent implants from a consecutive group of 3,631 patients who underwent CCTA at the facility over the course of 14 months in 2005-2006. They identified the stent type in 488 of the devices but not in 57 of them. However, the scientists reported that none of the 57 unidentified stent types fractured.
The researchers identified 24 stent types and noted that 341 of the 488 devices were drug-eluting stents: 169 Cypher (Cordis), 144 Taxus (Boston Scientific) and 28 Endeavor (Medtronic). All patients were imaged on a 64-slice CT system (Aquilion 64, Toshiba Medical Systems).
One to three of each patient’s data sets with the fewest motion artifacts were downloaded onto a 3D workstation (Rapida, Infinitt) for reformation of two 0.5- and 5.0-mm-thick orthogonal curved multiplanar reconstruction images and a varying number of 1-mm-thick perpendicular images, according to the researchers. All images were retrospectively interpreted by two radiologists experienced in cardiac CT.
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| Images obtained in 77-year-old man with six fractures in two stents but no significant ISR in the RCA. Curved 0.5-mm-thick (A) and 5.0-mm-thick (B) MPRs obtained at coronary CT angiography along the long axis of the RCA depict three fractures (arrows) each in two overlapping Cypher stents (Stent A: 3.5 x 33 mm, Stent B: 3 x 33 mm). The most proximal fracture is buckled (*) at the inner curve of the angled segment. A short overlap is seen as higher attenuation of one cell strut length (dotted lines). A third Cypher stent can be seen in the distal RCA. Image and caption courtesy of the Radiological Society of North America. |
“Six of 18 fractured stents in five patients were missed on conventional coronary angiograms at the initial readings; four of these fractured stents were found at retrospective review and two were confirmed at fluoroscopy,” the authors noted.
As a result of their work, the scientists believe that 64-slice CCTA can be used a primary tool for the detection of coronary stent fracture.
“Since the prevalence of coronary heart disease and the use of drug-eluting stents are increasing worldwide, radiologists and cardiologists who interpret coronary CT angiograms obtained in patients with a history of stent implantation should be aware of the findings that suggest fracture,” the authors advised.