A Rotatable Quality Control Phantom for Evaluating the Performance of Flat Panel Detectors in Imaging Moving Objects.

As the use of diagnostic X-ray equipment with flat panel detectors (FPDs) has increased, so has the importance of proper management of FPD systems. To ensure quality control (QC) of FPD system, an easy method for evaluating FPD imaging performance for both stationary and moving objects is required. Until now, simple rotatable QC phantoms have not been available for the easy evaluation of the performance (spatial resolution and dynamic range) of FPD in imaging moving objects. We developed a QC phantom for this purpose. It consists of three thicknesses of copper and a rotatable test pattern of piano wires of various diameters. Initial tests confirmed its stable performance. Our moving phantom is very useful for QC of FPD images of moving objects because it enables visual evaluation of image performance (spatial resolution and dynamic range) easily.

Occupational dose in interventional radiology procedures.

OBJECTIVE: Interventional radiology tends to involve long procedures (i.e., long fluoroscopic times). Therefore, radiation protection for interventional radiology staff is an important issue. This study describes the occupational radiation dose for interventional radiology staff, especially nurses, to clarify the present annual dose level for interventional radiology nurses. MATERIALS AND METHODS: We compared the annual occupational dose (effective dose and dose equivalent) among interventional radiology staff in a hospital where 6606 catheterization procedures are performed annually. The annual occupational doses of 18 physicians, seven nurses, and eight radiologic technologists were recorded using two monitoring badges, one worn over and one under their lead aprons. RESULTS: The annual mean ± SD effective dose (range) to the physicians, nurses, and radiologic technologists using two badges was 3.00 ± 1.50 (0.84-6.17), 1.34 ± 0.55 (0.70-2.20), and 0.60 ± 0.48 (0.02-1.43) mSv/y, respectively. Similarly, the annual mean ± SD dose equivalent range was 19.84 ± 12.45 (7.0-48.5), 4.73 ± 0.72 (3.9-6.2), and 1.30 ± 1.00 (0.2-2.7) mSv/y, respectively. The mean ± SD effective dose for the physicians was 1.02 ± 0.74 and 3.00 ± 1.50 mSv/y for the one- and two-badge methods, respectively (p < 0.001). Similarly, the mean ± SD effective dose for the nurses (p = 0.186) and radiologic technologists (p = 0.726) tended to be lower using the one-badge method. CONCLUSION: The annual occupational dose for interventional radiology staff was in the order physicians > nurses > radiologic technologists. The occupational dose determined using one badge under the apron was far lower than the dose obtained with two badges in both physicians and nonphysicians. To evaluate the occupational dose correctly, we recommend use of two monitoring badges to evaluate interventional radiology nurses as well as physicians.

Interatrial mechanical dyssynchrony shown by tissue doppler imaging during atrial flutter.

Although regular supraventricular tachycardia is traditionally classified on the basis of P-wave morphology, diagnostic accuracy is limited to information obtained from surface electrocardiography. Intracardiac electrophysiology is a conclusive although invasive diagnostic method. We report a case of regular supraventricular tachycardia with a heart rate of 162 bpm. M-mode echocardiography of the interatrial septum clarified both the atrial rate and the ventricular response ratio. Tissue Doppler M-mode imaging demonstrated the delay between the posterior wall motion of the left and right atrium. Although it deserves further study, transthoracic echocardiography may provide useful information in addition to electrocardiography.

Long-term results of the S.M.A.R.T. Control(TM) stent for superficial femoral artery lesions, J-SMART registry.

BACKGROUND: The use of a stent in the treatment of lesions of the superficial femoral artery (SFA) remains controversial. Although some reports have suggested that use of a nitinol stent in conjunction with aggressive medical management is effective for long SFA lesions, few long-term, large-scale studies have been done. METHODS AND RESULTS: A retrospective analysis was conducted of data from a multicenter study in which the S.M.A.R.T. Control(TM) stent was used for treatment of de novo SFA lesions. A total of 528 lesions in 432 patients were included. Mean patient age was 72.5±9.1 years; mean stent length was 15.7±8.1cm; 259 lesions (49%) were classified as C/D according to the TransAtlantic Inter-Society Consensus (TASC) II classification. Primary and secondary patency at 4 years was 66% and 87%, respectively. No cilostazol administration (41% re-stenosis group vs. 29% no-restenosis group, P<0.01), female gender (42% vs. 26%, P<0.01), younger age (70.7±9.3 years vs. 72.9±9.0 years, P<0.05), and chronic total occlusion (CTO; 72% vs. 52%, P<0.01) were independent predictors of re-stenosis. CONCLUSIONS: The S.M.A.R.T. Control(TM) stent provided good long-term durability in the treatment of SFA lesions, and no cilostazol administration, female gender, younger age and CTO were associated with re-stenosis.

Evaluation of novel X-ray protective eyewear in reducing the eye dose to interventional radiology physicians.

The new recommendation of the International Commission on Radiological Protection for occupational eye dose is an equivalent dose limit to the eye of 20 mSv year-1, averaged over a 5-year period. This recommendation is a drastic reduction from the previous limit of 150 mSv year-1. Hence, it is important to protect physicians' eyes from X-ray radiation. Particularly in interventional radiology (IVR) procedures, many physicians use protective lead (Pb) glasses to reduce their occupational exposure. This study assessed the shielding effects of novel 0.07 mm Pb glasses. The novel glasses (XR-700) have Pb-acrylic lens molded in three dimensions. We studied the novel type of 0.07 mm Pb glasses over a period of seven consecutive months. The eye dose occupational radiation exposure of seven IVR physicians was evaluated during various procedures. All IVR physicians wore eye dosimeters (DOSIRIS™) close to the left side of the left eye. To calculate the shielding effects of the glasses, this same type of eye dosimeter was worn both inside and outside of the Pb lenses. The average shielding effect of the novel glasses across the seven physicians was 61.4%. Our results suggest an improved shielding effect for IVR physicians that use these glasses. No physician complained that the new glasses were uncomfortable; therefore comfort is not a problem. The lightweight glasses were acceptable to IVR physicians, who often must perform long procedures. Thus, the novel glasses are comfortable and reasonably protective. Based on the results of this study, we recommend that IVR physicians use these novel 0.07 mm Pb glasses to reduce their exposure.

Antiplatelet therapy and stent thrombosis after sirolimus-eluting stent implantation.

BACKGROUND: The influences of antiplatelet therapy discontinuation on the risk of stent thrombosis and long-term clinical outcomes after drug-eluting stent implantation have not yet been addressed adequately. METHODS AND RESULTS: In an observational study in Japan, 2-year outcomes were assessed in 10 778 patients undergoing sirolimus-eluting stent implantation. Data on status of antiplatelet therapy during follow-up were collected prospectively. Incidences of definite stent thrombosis were 0.34% at 30 days, 0.54% at 1 year, and 0.77% at 2 years. Thienopyridine use was maintained in 97%, 62%, and 50% of patients at 30 days, 1 year, and 2 years, respectively. Patients who discontinued both thienopyridine and aspirin had a significantly higher rate of stent thrombosis than those who continued both in the intervals of 31 to 180 days, 181 to 365 days, and 366 to 548 days after stent implantation (1.76% versus 0.1%, P<0.001; 0.72% versus 0.07%, P=0.02; and 2.1% versus 0.14%, P=0.004, respectively). When discontinuation of aspirin was taken into account, patients who discontinued thienopyridine only did not have an excess of stent thrombosis in any of the time intervals studied. Adjusted rates of death or myocardial infarction at 24 months were 4.1% for patients taking thienopyridine and 4.1% for patients not taking thienopyridine (P=0.99) in the 6-month landmark analysis. CONCLUSIONS: Discontinuation of both thienopyridine and aspirin, but not discontinuation of thienopyridine therapy only, was associated with an increased risk of stent thrombosis. Landmark analysis did not suggest an apparent clinical benefit of thienopyridine use beyond 6 months after sirolimus-eluting stent implantation.

Radiation eye dose to medical staff during respiratory endoscopy under X-ray fluoroscopy.

Although the clinical value of fluoroscopically guided respiratory endoscopy (bronchoscopy) is clear, there have been very few studies on the radiation dose received by staff during fluoroscopically guided bronchoscopy. The International Commission on Radiological Protection (ICRP) is suggesting reducing the occupational lens dose limit markedly from 150 to 20 mSv/year, averaged over defined periods of five years. The purpose of this study was to clarify the current occupational eye dose of bronchoscopy staff conducting fluoroscopically guided procedures. We measured the occupational eye doses (3-mm-dose equivalent, Hp(3)) of bronchoscopy staff (physicians and nurses) over a 6-month period. The eye doses of eight physicians and three nurses were recorded using a direct eye dosimeter, the DOSIRIS. We also estimated eye doses using personal dosimeters worn at the neck. The mean ± SD radiation eye doses (DOSIRIS) to physicians and nurses were 7.68 ± 5.27 and 2.41 ± 1.94 mSv/6 months, respectively. The new lens dose limit, 20 mSv/year, may be exceeded among bronchoscopy staff, especially physicians. The eye dose of bronchoscopy staff (both physicians and nurses) was underestimated when measured using a neck dosimeter. Hence, the occupational eye dose of bronchoscopy staff should be monitored. To reduce the occupational eye dose, we recommend that staff performing fluoroscopically guided bronchoscopy wear Pb glasses. correct evaluation of the lens dose [Hp(3)] using an eye dosimeter such as the DOSIRIS is necessary for bronchoscopy staff.

Hybrid Operating Room System for the Treatment of Thoracic and Abdominal Aortic Aneurysms: Evaluation of the Radiation Dose Received by Patients.

In recent years, endovascular treatment of aortic aneurysms has attracted considerable attention as a promising alternative to traditional surgery. Hybrid operating room systems (HORSs) are increasingly being used to perform endovascular procedures. The clinical benefits of endovascular treatments using HORSs are very clear, and these procedures are increasing in number. In procedures such as thoracic endovascular aortic repair (TEVAR) and endovascular aortic repair (EVAR), wires and catheters are used to deliver and deploy the stent graft in the thoracic/abdominal aorta under fluoroscopic control, including DSA. Thus, the radiation dose to the patient is an important issue. We determined radiation dose indicators (the dose-area product (DAP) and air karma (AK) parameters) associated with endovascular treatments (EVAR and TEVAR) using a HORS. As a result, the mean ± standard deviation (SD) DAPs of TEVAR and EVAR were 323.7 ± 161.0 and 371.3 ± 186.0 Gy x cm2, respectively. The mean ± SD AKs of TEVAR and EVAR were 0.92 ± 0.44 and 1.11 ± 0.54 Gy, respectively. The mean ± SD fluoroscopy times of TEVAR and EVAR were 13.4 ± 7.1 and 23.2 ± 11.7 min, respectively. Patient radiation dose results in this study of endovascular treatments using HORSs showed no deterministic radiation effects, such as skin injuries. However, radiation exposure during TEVAR and EVAR cannot be ignored. The radiation dose should be evaluated in HORSs during endovascular treatments. Reducing/optimizing the radiation dose to the patient in HORSs is important.

Impact of Diabetes Mellitus on Critical Limb Ischemia With Below the Knee Disease: Japan Below-the-Knee Artery Treatment Subanalysis.

BACKGROUND: A strong association exists between diabetes mellitus and critical limb ischemia. METHODS AND RESULTS: We performed endovascular therapy on 1060 limbs in 884 patients with below knee lesions only. The patients were divided into diabetes (DG) and nondiabetes groups (NDG). Limb salvage was poorer in the DG (79% vs 89%, P = .0061). No significant difference was observed in mortality, amputation-free survival (AFS), and target vessel revascularization (TVR). Multivariate analysis revealed diabetes status, infection, poor activity of daily living (ADL), younger age, and procedure failure as independent predictors of major amputation in DG. In the NDG, procedure failure was the predictor, and younger age and poor ADL showed tendency of major amputation. CONCLUSIONS: Mortality, AFS, and TVR showed no significant difference between the 2 groups, but major amputation was more frequent in DG. Not only revascularization but also infection and diabetes control were very important for limb salvage in DG.

Three-dimensional relationship between the conus branch and the precordial leads confirmed by 64-multidetector-row computed tomography.

A 65-year-old man with effort angina pectoris underwent percutaneous coronary intervention of the proximal right coronary artery. The lesion was dilated with a bare-metal stent under wire protection of the conus branch (CB). However, the jailed CB was occluded. Electrocardiogram with conventional precordial leads (V(1) through V(6)) accompanied with the supplementary leads (V(1) through V(6)) positioned 1 intercostal space higher showed marked ST elevation in V(1) through V(3) that was more prominent in V(1) through V(3). The 64-multidetector-row computed tomographic coronary angiography showed recanalization of the CB located just in the center of the V(1), V(2), V(1), and V(2) electrodes.

Outcome of percutaneous intrapericardial fibrin-glue injection therapy for left ventricular free wall rupture secondary to acute myocardial infarction.

Left ventricular free wall rupture (LVFWR) is a fetal complication of acute myocardial infarction. This study was conducted to test the feasibility of percutaneous intrapericardial fibrin-glue injection therapy (PIFIT) for LVFWR after acute myocardial infarction and to assess its clinical outcome. From January 2000 to December 2004, LVFWR was confirmed by echocardiography in 22 patients. Thirteen patients showing abrupt hemodynamic collapse failed to recover from resuscitation maneuvers and died <2 hours after LVFWR. The remaining 9 patients (5 women, mean age 73 +/- 10 years) underwent PIFIT. Pericardiocentesis was performed from the subxiphoid process, and a 6Fr pigtail catheter was introduced into the pericardial space. After bloody fluid was drained from the catheter, the fibrin glue was injected into the pericardial space. There were no complications relating to pericardiocentesis and PIFIT. One patient underwent surgical repair on the day of PIFIT because of uncontrollable bleeding from pericardial drainage. In-hospital death as a result of rerupture occurred in 2 patients on days 4 and 7 after PIFIT. Echocardiography during follow-up revealed no evidence of pseudoaneurysm or left ventricular restriction. On follow-up at a median of 4.0 years (interquartile range 3.1 to 4.8), 1 noncardiac death occurred at 3.3 months. The other 5 patients were free of cardiovascular events and in New York Heart Association functional class I. In conclusion, PIFIT is a simple, effective, and less invasive technique for the management of LVFWR and thus can be an alternative to surgical repair for LVFWR after acute myocardial infarction.

Responsiveness to dobutamine stimulation in patients with left ventricular apical ballooning syndrome.

To investigate the underlying mechanisms of the left ventricular (LV) apical ballooning syndrome, we evaluated the functional responsiveness to dobutamine stimulation in patients with the syndrome. Over a 22-month period, 11 consecutive patients with the apical ballooning syndrome were referred to our institution. All 11 patients were women and 57 to 85 years of age (mean 73 +/- 10). Among them, 10 patients underwent low-dose dobutamine echocardiography within 24 hours after admission (17 +/- 8 hours). Echocardiography was repeated in the convalescent phase (48 +/- 33 days) to assess functional outcome. In the resting state, all patients showed akinetic wall motion in the midportion of the left ventricle and apical left ventricle. After low-dose dobutamine infusion, akinetic wall motion detected at rest did not show any improvement despite the hypercontractile basal LV wall. In the convalescent phase, LV dysfunction was not observed on echocardiography in all 11 patients. The LV apical ballooning syndrome has a unique feature that reversible dysfunction lacks functional amelioration during dobutamine administration. In conclusion, this finding suggests that the pathophysiologic mechanisms of the syndrome appear to be distinct from those of myocardial stunning after transient ischemia, and catecholamine-mediated cardiac toxicity may play a role in the development of the syndrome.

Occupational eye dose in interventional cardiology procedures.

It is important to measure the radiation dose [3-mm dose equivalent, Hp(3)] in the eye. This study was to determine the current occupational radiation eye dose of staff conducting interventional cardiology procedures, using a novel direct eye dosimeter. We measured the occupational eye dose [Hp(3)] in physicians and nurses in a catheterization laboratory for 6-months. The eye doses [Hp(3)] of 12 physicians (9 with Pb glasses, 3 without), and 11 nurses were recorded using a novel direct eye dosimeter, the DOSIRISTM. We placed dosimeters above and under the glasses. We also estimated the eye dose [0.07-mm dose equivalent] using a neck personal dosimeter. The eye doses among interventional staff ranked in the following order: physicians without Pb glasses > physicians with Pb glasses > nurses. The shielding effect of the glasses (0.07-mm Pb) in a clinical setting was approximately 60%. In physicians who do not wear Pb glasses, the eye dose may exceed the new regulatory limit for IR staff. We found good correlations between the neck dosimeter dose and eye dosimeter dose (inside or outside glasses, R2 = 0.93 and R2 = 0.86, respectively) in physicians. We recommend that interventional physicians use an eye dosimeter for correct evaluation of the lens dose.

Use of everolimus-eluting stent with a bioresorbable polymer coating for treatment of recurrent in-stent restenosis.

Recently, an everolimus-eluting stent utilizing a bioresorbabale PLA polymer coating to release the agent everolimus has proven safe and effective in preventing restenosis for up to six months in de novo coronary arteries. But the use of a bioresorbable polymer-coated everolimus-eluting stent for in-stent restenosis lesions has not been previously investigated. This is a case report of one-year angiographic follow-up results after the implantation of a bioresorbable PLA polymer-coated everolimus-eluting stent for the treatment of recurrent in-stent restenosis. The case involved a 63-year-old female who had repeatedly presented with recurrent in-stent restenosis in the LCX. We successfully treated this recurrent ISR lesion by using a bioresorbable PLA polymer-coated everolimus-eluting stent; the one-year follow-up angiography revealed prevention of ISR after the implantation of this device.

Uncommon presentation of drug-refractory pacemaker-mediated common atrioventricular nodal reentrant tachycardia and a simple solution by reprogramming.

An 81-year-old woman who had undergone dual chamber pacemaker implantation for sick sinus syndrome was referred to our hospital with drug-refractory common atrioventricular (AV) nodal reentrant tachycardia. Ventricular pacing (Vp) following premature atrial contraction (PAC) with a long AV interval induced ventriculoatrial (VA) conduction, which allowed the tachycardia to be initiated. The sensed AV interval was shortened to 80 ms, allowing Vp during the refractory period of VA conduction. Postventricular atrial refractory period was shortened to 180 ms to sense PACs with short coupling interval. After reprogramming, the suppression of the tachycardia by blocking VA conduction following Vp was confirmed.

A new miniature catheter with side-holes for percutaneous transradial or transbrachial coronary angiography.

The percutaneous arm approach through the radial or brachial artery for diagnostic cardiac catheterization has advantages, such as a lower incidence of access-site complications and decreased patient discomfort, particularly when smaller diameter catheters are employed. However, the pressure produced by high-flow jets of contrast material exiting from an end-hole against the vascular wall can cause coronary dissection or myocardial blushing. To avoid this type of complication, we designed and developed a new miniature (4 French) catheter with two side-holes for coronary angiography. Under conditions similar to those of a clinical situation, we obtained the relationship between the pressure produced by the jets exiting from an end-hole and the force with which the tip of the catheter was pushed against the vascular wall. The presence of the side-holes substantially decreased the pressure at forces ranging between 0 and 15 gf, and at all injection rates (2.0 3.5 ml/second), but their location did not affect the pressure. In a preliminary clinical study, the new catheters with side-holes were feasible and effective for coronary angiography through the radial artery. Furthermore, the distribution of contrast material decreased the incidence of dislodgement of the catheter from the coronary ostia and enabled good visualization of the coronary ostia and proximal branches.

Complex renal artery aneurysm: successful exclusion with balloon-expandable covered stent.

We report an incidentally noted aneurysm in the left renal artery in a 60-year-old woman. Repair was recommended due to the size of the aneurysm and the patient's history of hypertension. The aneurysm was located in a bifurcation lesion, and angulation at the site was approximately 90 degrees. We were able to successfully exclude the aneurysm, however, with a balloon-expandable covered stent. This suggests that balloon-expandable covered stents offer excellent delivery and precise deployment, even in cases where complex anatomical issues are involved.