Design and evaluation of learning strategies for a group of radiographers in radiostereometric analysis (RSA)

IntroductionThe purpose of this study was to design and evaluate a radiostereometric analysis (RSA) program aimed at radiographers in order to increase their cognitive and practical skills, thereby increasing image quality and minimizing exposure repetition.Methods and materialsTwenty radiographers were randomized into two identically sized study groups. Training consisted of a theoretical and practical workshop using a phantom. Tests were performed to compare the effect of training to nontraining, and the effect of time duration on the maintenance of RSA skills. The effect of training was measured by a written test and three defined parameters influencing image quality.ResultsGroup A reduced significantly (p < 0.001) by 31.3 mm (21–31%) the distance between the centrum of the prosthesis (CP) and the centrum of the calibration field (CCF) and increased the number of beads (NB) visible by 3.6 (out of 18). A further significant reduction of 5.1 mm (p = 0.023), 1.0 bead more (p < 0.001) and a 2.1 (p = 0.022) point better rotation of the prosthesis (RP) was registered two months later. Group B was tested twice without training and no significant improvement was registered. One month after training group B had experienced overall significant improvement on a par with group A.ConclusionIt is realistic to implement an RSA X-ray training program where radiographers significantly improve their theoretical and practical skills in centering the CP closer to the CCF, NB and RP. A duration of up to two months after training does not influence the quality of participants' performance.     

A pilot study to determine the effect of radiographer training on radiostereometric analysis imaging technique

IntroductionProducing x-ray images for radiostereometric analysis (RSA) is a demanding technique. Suboptimal examinations result in a high percentage of exposure repetition. The aim of this pilot study was to use an experiential training approach to sharpen the skills of radiographers in acquiring images of an optimal quality.MethodsA controlled trial using action research strategy was used. The study entailed a two phased approach. Radiographers were purposefully recruited and trained to perform the required investigations. Each phase included 12 examinations of a total knee arthroplasty phantom followed by 10 patient examinations. The quality of all x-ray images performed during the two phases was characterized by measuring the number of visible beads, the center position of the prosthesis (CP) compared to the center of calibration field (CCF). The number of re-exposures used to obtain a usable image during patient examinations was also recorded.ResultsThe radiographers undergoing the training resulted in a significant improvement in the quality of images produced and visualization of the beads. That is, the ability to move the CP on average 36.1 mm closer to the CCF (p < 0.001), the number of visible beads increased by 3.1 (p < 0.001) and radiographers needed 2.1–2.9 exposures less to obtain RSA images of sufficient qualities during patient examinations in phase 2 (p < 0.001).ConclusionThis study illustrates the value of experiential method of teaching and learning with minimal compromise on patient safety but a significant contribution in terms of establishing quality of RSA images.     

Comparison of Percutaneous Transhepatic Variceal Embolization (PTVE) Followed by Partial Splenic Embolization versus PTVE Alone for the Treatment of Acute Esophagogastric Variceal Massive Hemorrhage

PurposeTo compare the efficacy of percutaneous transhepatic variceal embolization (PTVE) followed by partial splenic embolization (PSE) with that of PTVE alone for the treatment of acute massive hemorrhage of esophagogastric varices in patients with cirrhosis unable to undergo alternative procedures.Materials and MethodsSixty-five patients with acute variceal massive hemorrhage were retrospectively studied, including 31 who underwent PTVE/PSE and 34 who underwent PTVE and refused PSE. Recurrent bleeding rate, survival rate, postoperative complications, number of days of hospitalization after PTVE, and outcome were evaluated. Peripheral blood cell counts and hemoglobin levels before and at 1 week and 6, 12, and 24 months after intervention were analyzed.ResultsCumulative recurrent bleeding rates at 6, 12, and 24 months after intervention in the PTVE/PSE group were 3.2%, 6.7%, and 13.3%, compared with 20.6%, 36.7%, and 53.6%, respectively, in the PTVE group; the difference at each time point was statistically significant (all P < .01). There were more cases of ascites and portal hypertensive gastropathy after PTVE than after PTVE/PSE (P < .05). Survival rates at 6, 12, and 24 months in the PTVE/PSE group were 100%, 96.8%, and 96.8%, compared with 94.1%, 88.2%, and 82.4%, respectively, in the PTVE group. There were significant differences in peripheral blood cell counts and hemoglobin levels between the PTVE/PSE and PTVE groups at all observed time points (all P < .01).ConclusionsPTVE/PSE not only has long-term efficacy in alleviating hypersplenism, but decreases recurrent bleeding and maintains hepatic reserve in patients with cirrhosis and esophagogastric variceal massive hemorrhage unable to undergo other procedures.     

High-pitch versus sequential mode for coronary calcium in individuals with a high heart rate: Potential for dose reduction

BackgroundTo determine the impact of high-pitch spiral acquisition on radiation dose and cardiovascular disease (CVD) risk stratification by coronary artery calcium (CAC) assessment with computed tomography in individuals with a high heart rate.MethodsOf the ROBINSCA trial, 1990 participants with regular rhythm and heart rates >65 beats per minute (bpm) were included. As reference, 390 participants with regular heart rates ≤65 bpm were used. All participants underwent prospectively electrocardiographically(ECG)-triggered imaging of the coronary arteries using dual source CT at 120 kVp, 80 ref mAs using both high-pitch spiral mode and sequential mode. Radiation dose, Agatston score, number of positive scores, as well as median absolute difference of the Agatston score were determined and participants were stratified into CVD risk categories.ResultsA similar percentage of participants with low heart rates and high heart rates had a positive CAC score in data sets acquired in high-pitch spiral (low heart rate: 57.7%, high heart rate: 55.8%) and sequential mode (58.0%, 54.7%, p = n.s.). The median absolute difference in Agatston scores between acquisition modes was 14.2% and 9.2%, for the high and low heart rate groups, respectively. Excellent agreement for risk categorization between the two data acquisition modes was found for the high (κ = 0.927) and low (κ = 0.946) heart rate groups. Radiation dose was 48% lower for high-pitch spiral versus sequential acquisitions.ConclusionRadiation dose for the quantification of coronary calcium can be reduced by 48% when using the high-pitch spiral acquisition mode compared to the sequential mode in participants with a regular high heart rate. CVD risk stratification agreement between the two modes of data acquisition is excellent.     

Short-Term Rebleeding Rates for Isolated Gastric Varices Managed by Transjugular Intrahepatic Portosystemic Shunt versus Balloon-Occluded Retrograde Transvenous Obliteration

PurposeTo assess the short-term rebleeding rate associated with the use of a transjugular intrahepatic portosystemic shunt (TIPS) compared with balloon-occluded retrograde transvenous obliteration (BRTO) for management of gastric varices (GV).Materials and MethodsA single-center retrospective comparison of 50 patients with bleeding from GV treated with a TIPS or BRTO was performed. Of 50 patients, 27 (17 men and 10 women; median age, 55 y; range, 31–79 y) received a TIPS with covered stents, and 23 (12 men and 11 women; median age, 52 y; range, 23–83 y) underwent a BRTO procedure with a foam sclerosant. All study subjects had clinical and endoscopic evidence of isolated bleeding GV and were hemodynamically stable at the time of the procedure. Clinical and endoscopic follow-up was performed. Kaplan-Meier analysis was used to evaluate rebleeding rates from the GV.ResultsThe technical success rate was 100% in the TIPS group and 91% in the BRTO group (P = .21). Major complications occurred in 4% of the patients receiving TIPS and 9% of patients the undergoing BRTO (P = .344). Encephalopathy was reported in 4 of 27 (15%) patients in the TIPS group and in none of the patients in the BRTO group (0%; P = .12). At 12 months, the incidence of rebleeding from a GV source was 11% in the TIPS group and 0% in the BRTO group (P = .25).ConclusionsBRTO appears to be equivalent to TIPS in the short-term for management of bleeding GV. Further comparative studies are warranted to determine optimal management strategies in individual patients.     

Fluoroscopic versus Laparoscopic Implantation of Peritoneal Dialysis Catheters: A Retrospective Cohort Study

PurposeA previous clinical trial showed that radiologic insertion of first peritoneal dialysis (PD) catheters by modified Seldinger technique is noninferior to laparoscopic surgery in patients at low risk in a clinical trial setting. The present cohort study was performed to confirm clinical effectiveness of radiologic insertion in everyday practice, including insertion in patients with expanded eligibility criteria and by fellows in training.Materials and MethodsBetween 2004 and 2009, 286 PD catheters were inserted in 249 patients, 133 with fluoroscopic guidance in the radiology department and 153 by laparoscopic surgery. Survival analyses were performed with the primary outcome of complication-free catheter survival and secondary outcomes of overall catheter survival and patient survival. Outcomes were assessed at last follow-up, as long as 365 days after PD catheter insertion.ResultsIn the radiologic group, unadjusted 365-day complication-free catheter, overall catheter, and patient survival rates were 22.6%, 81.2%, and 82.7%, respectively, compared with 22.9% (P = .52), 76.5% (P = .4), and 92.8% (P = .01), respectively, in the laparoscopic group. Frequencies of individual complications were similar between groups. Adjusting for patient age, comorbidity, and previous PD catheter, the hazard ratio (HR) for catheter complications by radiologic versus laparoscopic insertion is 0.90 (95% confidence interval [CI], 0.62–1.31); the HR for overall catheter survival is 1.25 (95% CI, 0.59–2.65); and that for death is 2.47 (95% CI, 0.84–7.3).ConclusionsRadiologic PD catheter insertion is a clinically effective alternative to laparoscopic surgery, although there was poorer long-term survival with radiologic catheter placement, possibly because of preferential selection of radiologic insertion for more frail patients.     

Endovascular Procedures versus Intravenous Thrombolysis in Stroke with Tandem Occlusion of the Anterior Circulation

PurposeStroke with tandem occlusion within the anterior circulation presents a lower probability of recanalization and good clinical outcome after intravenous (IV) thrombolysis than stroke with single occlusion. The present study describes the impact of endovascular procedures (EPs) compared with IV thrombolysis alone on recanalization and clinical outcome.Materials and MethodsThirty patients with symptom onset less than 4.5 hours and tandem occlusion within the anterior circulation were analyzed retrospectively. Recanalization was assessed per Thrombolysis In Cerebral Infarction (TICI) classification on computed tomography, magnetic resonance imaging, or digital subtraction angiography within 24 hours. Infarct size was detected on follow-up imaging as a dichotomized variable, ie, more than one third of the territory of the middle cerebral artery. Clinical outcomes were major neurologic improvement, independent outcome (90-d modified Rankin Scale [mRS] score), symptomatic intracerebral hemorrhage (sICH; per European Cooperative Acute Stroke Study criteria), and death within 7 days.ResultsPatients treated with EPs (n = 14) were significantly younger and had a history of arterial hypertension more frequently than patients treated with IV thrombolysis alone (n = 16). Recanalization (ie, TICI score 2b/3; EP, 64%; IV, 19%; P = .01), major neurologic improvement (EP, 64%; IV, 19%; P = .01), and independent outcome (mRS score ≤ 2; EP, 54% IV, 13%; P = .02) occurred more often in the EP group, whereas infarct sizes greater than one third of the MCA territory (EP, 43%; IV, 81%; P = .03) were observed less often. Rates of sICH (P = .12) and death within 7 days (P = .74) did not differ significantly.ConclusionsHigher recanalization rate, smaller infarct volume, and better clinical outcome in the EP group should encourage researchers to include this subgroup of patients in prospective randomized trials comparing IV thrombolysis versus EP in stroke.     

Prospective,Randomized Study of Coil Embolization versus Surefire Infusion System during Yttrium-90 Radioembolization with Resin Microspheres

PurposeTo compare standard coil embolization versus the use of an antireflux microcatheter (ARM) in patients undergoing planning angiography before selective internal radiation therapy (SIRT).Materials and MethodsA prospective, single-center trial was performed in which 30 patients were randomly assigned to undergo SIRT with coil embolization or the use of an ARM. The coil group underwent detachable coil embolization of nontarget vessels, and the ARM group underwent infusion of macroaggregated albumin with use of an ARM system, without coil embolization. Single-photon emission computed tomography (CT)/CT was then performed to assess for nontarget distribution. The primary endpoint was fluoroscopy time during planning angiography. Secondary endpoints included deployment time, total procedure time, radiation dose–area product, contrast agent used, and adverse events. Endpoints were evaluated during planning angiography and SIRT.ResultsOver a 9-month period, 30 consecutive patients were randomized at a 1:1 ratio between coil embolization and ARM groups. Technical success rates were 100% in both groups. Mean fluoroscopy time was significantly reduced in the ARM group versus the coil embolization group (1.8 min [range, 0.4–4.9 min] vs 6.0 min [range, 1.9–15.7 min]; P = .002). The planning procedure time (P < .001), deployment time (P < .001), dose–area product (P = .04), and amount of contrast agent used (P < .001) were also significantly less in the ARM group than in the coil embolization group. No nontarget distribution was detected in either group. There was no difference between groups in dose delivered on the day of SIRT (P = .71). There were no major or minor adverse events at 30 days.ConclusionsThe use of an ARM during planning angiography can significantly reduce fluoroscopy time, procedure time, and radiation dose.     

Dynamic CT angiography for the diagnosis of patients with thoracic outlet syndrome: Correlation with patient symptoms

IntroductionVasculo-nervous structures serving the upper limbs may be compressed as they pass through three areas: the inter-scalene triangle (IST), the costo-clavicular space (CCS) and the retropectoralis minor space (RMS). The diagnosis of thoracic outlet syndrome (TOS) is essentially clinical, but requires imaging to specify the site of compression, its grade and the existence of predisposing anatomical factors, in order to guide the treatment and eliminate the main differential diagnoses.Material and methodsImages from 141 patients who underwent dynamic CT angiography of the thoracic outlets from June 2008 to January 2015 were analyzed retrospectively. Patients had unilateral or bilateral vascular, neurological, mixed or atypical symptoms. We studied the degree of stenosis of the subclavian artery with the following grading system: 1 (0-<25%), 2 (25-<50%), 3 (50-<75%), 4 (75-100%). The site of stenosis and the presence of underlying anatomical predisposing factors were also taken in account.ResultsA total of 221 thoracic outlets were analyzed. Symptoms were neurological, mixed, vascular and atypical in 30%, 28%, 13% and 12%, respectively. Among patients with bilateral acquisitions, 38 outlets were asymptomatic; 40% of symptomatic outlets and only 5% of asymptomatic ones had grade 3 or 4 stenosis. 63% of the stenosis were in the CCS and 37% in the IST; 21% had a predisposing anatomical factor most often a costo-clavicular anomaly, associated with significant stenosis in 50% of cases.ConclusionVascular stenosis of more than 50% on dynamic CT angiography is strongly associated with TOS. Predisposing factors were present in 21% of cases, causing significant vascular stenosis in half, underscoring the need for functional evaluation.     

Coils versus Gelatin Particles with or without Intraarterial Antibiotics for Partial Splenic Embolization: A Comparative Evaluation

PurposeTo compare the efficacy, complications, and inflammatory levels in partial splenic embolization (PSE) with coils or gelatin sponge (GS) particles with or without intraarterial antibiotic agents.Materials and MethodsForty-four patients with hypersplenism treated by PSE were assessed. GS particles were used in 31 patients, and coils were used in 13 patients. In 17 of the 31 patients who received GS, GS suspended in antibiotic solution was injected via the splenic artery. In the other 14 patients, antibiotic agents were not used. In all 13 coil group patients, an antibiotic solution was intraarterially injected before embolization. Platelet counts were compared between the GS and coil groups. Complications and serum C-reactive protein (CRP) levels were compared among the three groups.ResultsThere were no significant differences in platelet counts and platelet increased ratios at 6 months (10.0 × 10⁴/µL and 193% in the GS group vs 9.0 × 10⁴/µL and 221% in the coil group), and no significant differences in frequencies of complications. However, one splenic abscess occurred in a patient treated with GS without antibiotics, resulting in death. The mean serum CRP level in the GS with antibiotic group at 2 weeks was significantly lower than in the other two groups.ConclusionsThe efficacy of PSE is similar with the use of coils versus GS particles. Prophylactic intraarterial antibiotic treatment could be useful in preventing inflammatory reactions after PSE.     

Histopathologic Comparison of Monopolar versus No-Touch Multipolar Radiofrequency Ablation to Treat Hepatocellular Carcinoma within Milan Criteria

PurposeTo compare histopathologically the completeness of radiofrequency (RF) ablation to treat hepatocellular carcinoma (HCC) with monopolar or multipolar technique.Materials and MethodsThirty-five consecutive patients (mean age, 59 y) with cirrhosis and HCC (n = 59) within Milan criteria received RF ablation and subsequently underwent liver transplantation (LT) for tumor progression or liver failure. Data were extracted retrospectively from a prospective database. Thirty nodules were treated with a monopolar device with internally cooled (n = 17) or perfused (n = 13) electrodes, and 29 were treated with a multipolar technique with internally cooled electrodes based on the “no-touch” concept. This consisted of inserting two or three straight electrodes around the nodule to avoid intratumor puncture to the greatest extent possible. Effectiveness of the three devices was compared by histopathologic examination of explants. Fisher exact and χ² tests and multivariate logistic regression analysis were performed.ResultsMean sizes of nodules ablated (25, 22, and 21.6 mm) and median times from ablation to LT (11, 7.5, and 8.4 months) for patients treated with the monopolar internally cooled electrode device (MoICD), monopolar perfused electrode device (MoPED), and multipolar internally cooled electrode device (MuICD), respectively, were similar (P = .8 and P = .9, respectively). Pathologic examination showed complete necrosis for eight of 17 and six of 13 nodules treated with the MoICD and MoPED, respectively, versus 26 of 29 treated with the MuICD (P = .0019). In multivariate analysis, RF technique remained the predictive factor for complete necrosis (P = .005).ConclusionsAblation of small HCCs with multipolar RF ablation based on the no-touch concept improves the rate of complete necrosis during pathologic examination compared with monopolar techniques.     

US-Guided Placement and Tip Position Confirmation for Lower-Extremity Central Venous Access in Neonates and Infants with Comparison versus Conventional Insertion

PurposeTo describe experience with the use of ultrasound (US)–guided placement and tip position confirmation for direct saphenous and single-incision tunneled femoral noncuffed central venous catheters (CVCs) placed in neonates and infants at the bedside.Materials and MethodsA retrospective review of the interventional radiology (IR) database and electronic medical records was performed for 68 neonates and infants who received a CVC at the bedside and for 70 age- and weight-matched patients with CVCs placed in the IR suite between 2007 and 2012. Technical success, complications, and outcomes of CVCs placed at the bedside were compared with those in an age- and weight-matched sample of children with CVCs placed in the IR suite.ResultsA total of 150 primary insertions were performed, with a technical success rate of 100%. Total catheter lives for CVCs placed at the bedside and in the IR suite were 2,030 catheter-days (mean, 27.1 d) and 2,043 catheter-days (mean, 27.2 d), respectively. No significant difference was appreciated between intraprocedural complications, mechanical complications (bedside, 1.53 per 100 catheter-days; IR, 1.76 per 100 catheter-days), or infectious complications (bedside, 0.39 per 100 catheter-days; IR, 0.34 per 100 catheter-days) between groups.ConclusionsUS-guided placement and tip position confirmation of lower-extremity CVCs at bedside for critically ill neonates and infants is a safe and feasible method for central venous access, with similar complications and catheter outcomes in comparison with CVCs placed by using fluoroscopic guidance in the IR suite.     

Hypertrophic Cardiomyopathy (HCM): New insights into Coronary artery remodelling and ischemia from FFRCT

IntroductionAngina, myocardial ischemia, and coronary artery physiology in hypertrophic cardiomyopathy (HCM) are poorly understood. However, coronary computed tomography angiography (CCTA) with fractional flow reserve from CT (FFRCT) analysis offers a non-invasive method for evaluation of coronary artery volume to myocardial mass ratio (V/M) that may provide insight into such mechanisms. Thus, we sought to investigate changes in V/M in HCM.MethodsA retrospective analysis was performed on 37 HCM patients and 37 controls matched for age, sex, and cardiovascular risk factors; CCTA-derived coronary artery lumen volume (V) and myocardial mass (M) were used to determine V/M. FFR_CT values were calculated for the left anterior descending (LAD), left circumflex (LCx) and right coronary (RCA) arteries as well as the 3-vessel cumulative FFR_CT values.ResultsHCM patients had significantly increased myocardial mass (176 ± 84 vs. 119 ± 27 g, p < 0.0001) and total coronary artery luminal volume (4112 ± 1139 vs. 3290 ± 924 mm³, p < 0.0001) that resulted from increases in segmented luminal volumes of both the left and right coronary artery systems. However, HCM patients had significantly decreased V/M (23.8 ± 5.9 vs. 26.5 ± 5.3 mm³/g; p = 0.026) which was further decreased when restricting V/M analysis to those HCM patients with septal hypertrophy (22.4 mm³/g, p = 0.01) that was mild-moderately predictive of HCM (AUC = 0.68). HCM patients also showed significantly lower nadir FFR_CT values in the LCx (0.87 ± 0.06 vs. 0.91 ± 0.06, p = 0.02), and cumulative 3-vessel FFR_CT values (2.58 ± 0.18 vs. 2.63 ± 0.14, p = 0.006).ConclusionsHCM patients demonstrate significantly greater coronary volume. Despite this, HCM patients suffer from decreased V/M. Further prospective studies evaluating the relationship between V/M, angina, and heart failure in HCM are needed.     

Rationale and design of advantage (additional diagnostic value of CT perfusion over coronary CT angiography in stented patients with suspected in-stent restenosis or coronary artery disease progression) prospective study

BackgroundRecent studies demonstrated a significant improvement in the diagnostic performance of coronary CT angiography (CCTA) for the evaluation of in-stent restenosis (ISR). However, coronary stent assessment is still challenging, especially because of beam-hardening artifacts due to metallic stent struts and high atherosclerotic burden of non-stented segments. Adenosine-stress myocardial perfusion assessed by CT (CTP) recently demonstrated to be a feasible and accurate tool for evaluating the functional significance of coronary stenoses in patients with suspected coronary artery disease (CAD). Yet, scarce data are available on the performance of CTP in patients with previous stent implantation.Aim of the studyWe aim to assess the diagnostic performance of CCTA alone, CTP alone and CCTA plus CTP performed with a new scanner generation using quantitative invasive coronary angiography (ICA) and invasive fractional flow reserve (FFR) as standard of reference.MethodsWe will enroll 300 consecutive patients with previous stent implantation, referred for non-emergent and clinically indicated invasive coronary angiography (ICA) due to suspected ISR or progression of CAD in native coronary segments. All patients will be subjected to stress myocardial CTP and a rest CCTA. The first 150 subjects will undergo static CTP scan, while the following 150 patients will undergo dynamic CTP scan. Measurement of invasive FFR will be performed during ICA when clinically indicated.ResultsThe primary study end points will be: 1) assessment of the diagnostic performance (diagnostic rate, sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy) of CCTA, CTP, combined CCTA-CTP and concordant CCTA-CTP vs. ICA as standard of reference in a territory-based and patient-based analysis; 2) assessment of sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CCTA, CTP, combined CCTA-CTP and concordant CCTA-CTP vs. invasive FFR as standard of reference in a territory-based analysis.ConclusionsThe ADVANTAGE study aims to provide an answer to the intriguing question whether the combined anatomical and functional assessment with CCTA plus CTP may have higher diagnostic performance as compared to CCTA alone in identifying stented patients with significant ISR or CAD progression.     

Randomized Clinical Trial of Cutting Balloon Angioplasty versus High-Pressure Balloon Angioplasty in Hemodialysis Arteriovenous Fistula Stenoses Resistant to Conventional Balloon Angioplasty

PurposeTo compare the efficacy and safety of cutting balloon angioplasty (CBA) versus high-pressure balloon angioplasty (HPBA) for the treatment of hemodialysis autogenous fistula stenoses resistant to conventional percutaneous transluminal angioplasty (PTA).Materials and MethodsIn a prospective, randomized clinical trial involving patients with dysfunctional, stenotic hemodialysis arteriovenous fistulas (AVFs), patients were randomized to receive CBA or HPBA if conventional PTA had suboptimal results (ie, residual stenosis > 30%). A total of 516 patients consented to participate in the study from October 2008 to September 2011, 85% of whom (n = 439) had technically successful conventional PTA. The remaining 71 patients (mean age, 60 y; 49 men) with suboptimal PTA results were eventually randomized: 36 to the CBA arm and 35 to the HPBA arm. Primary and secondary target lesion patencies were determined by Kaplan–Meier analysis.ResultsClinical success rates were 100% in both arms. Primary target lesion patency rates at 6 months were 66.4% and 39.9% for CBA and HPBA, respectively (P = .01). Secondary target lesion patency rates at 6 months were 96.5% for CBA and 80.0% for HPBA (P = .03). There was a single major complication of venous perforation following CBA. The 30-day mortality rate was 1.4%, with one non–procedure-related death in the HPBA group.ConclusionsPrimary and secondary target lesion patency rates of CBA were statistically superior to those of HPBA following suboptimal conventional PTA. For AVF stenoses resistant to conventional PTA, CBA may be a better second-line treatment given its superior patency rates.     

Reproducibility of ultrasound-derived muscle thickness and echo-intensity for the entire quadriceps femoris muscle

IntroductionMuscle thickness (MT) and muscle echo-intensity (EI) allow the study of skeletal muscle adaptive changes with ultrasound. This study investigates the intra- and inter-session reliability and agreement of MT and EI measurements for each of the four heads of the quadriceps femoris in transverse and longitudinal scans, using two sizes for the region of interest (ROI); EI measurements only.MethodsThree B-mode images from two views were acquired from each head of quadriceps femoris from twenty participants (10 females) in two sessions, 7 days apart. EI was measured using a large and a small ROI. Reliability was examined with the mixed two-way intra-class correlation coefficient (ICC), the standard error of mean (SEM) and the smallest detectable change (SDC). Bland–Altman's plots were used to study agreement.ResultsHigh to very high inter-session ICC values were found for MT for all muscle heads, particularly for measurements from transverse scans. For EI measurement, ICC values ranged from low to high, with higher ICC values seen with the largest ROI. SDC values ranged between 0.19 and 0.53 cm for MT and between 3.73 and 18.56 arbitrary units (a.u.) for two ROIs. Good agreement existed between MT measurements made in both scans. A small bias and larger 95% limits of agreement were seen for EI measurements collected with the two ROI sizes.ConclusionUltrasound measures of MT and EI show moderate to very high reliability. The reliability and agreement of MT and EI measurements are improved in transverse scans and with larger ROIs.     

Muscle thickness and echo-intensity changes of the quadriceps femoris muscle during a strength training program

IntroductionUltrasound (US) has an important role in musculoskeletal (MSK) evaluation, allowing the study of muscle morphology and function. Muscle thickness (MT) and muscle echo-intensity (EI) are two important parameters that may quantify muscle structural adaptations to a variety of stimuli. The aim was to explore the potential of quantitative US imaging for assessing the adaptations and responses of the muscle tissue to increased contractile activity using B-mode US. This study was centred on the quadriceps femoris muscle contractile activity on MT and EI.Methods and materialsTwenty-eight young male adults participated in the study, divided in a control group and two training groups performing concentric or eccentric strength training, respectively. The effect of a 15-week strength program was studied on MT and EI in several regions of the heads of the quadriceps femoris using B-mode US. All images acquisitions and measurements were done by the same experience sonographer.ResultsStrength training resulted in an increase of MT at all muscles and sites (p < 0.05), except the VM. Strength training failed in changing EI in most of the quadriceps femoris, except in the VI and some regions of the VL. No statistically significant differences were observed in our quantitative US parameters between concentric and eccentric training (p > 0.05).ConclusionThese results emphasise the value of MT as a quantifiable muscle US method for evaluating muscle adaptation to exercise training. However, the inconsistency of the EI values indicates that more studies are needed to develop it as an accurate diagnostic tool.     

The problem of police-related cardiac arrest

The term “positional asphyxia” was originally used to describe the situation in which the upper airways becomes compromised by sharp angulation of the head or neck, or where the chest wall is splinted and the diaphragm is prevented from moving because of an unusual position of the body. The term was redefined in the early 1980s to describe sudden death during physical restraint of an individual who is in a prone position. A large percent of reported victims were overweight males. Most were in early middle age and manifesting psychotic behavior at the time of death. Most were reported to have unremarkable autopsies, save for the finding, in many cases, of cocaine or methamphetamine (more recently synthetic cannabinoids and cathinones as well). As no cause of death was apparent (other than non-specific signs such as pulmonary edema), it became common practice to attribute death to force exerted on the decedent's back. When experimental studies with human volunteers disproved this notion, the term “restraint asphyxia” was substituted for positional asphyxia, but with nearly the exact same meaning. No experimental study has ever determined the actual amount of force necessary to cause asphyxia by force applied to the back (although the range of required static force is known), nor the duration for which it must be applied.This review discusses the epidemiology and the evidence for and against the theory of “restraint/positional” asphyxia. It also considers alternative theories of causation, including the findings of studies suggesting that cardiac channelopathies/cardiomyopathies may explain many cases of ARD.     

Magnetic resonance imaging of a transient splenial lesion of the corpus callosum resolved within a week

The transient splenial lesion (TSL) of the corpus callosum (CC) is an uncommon radiologic finding incidentally detected on Magnetic Resonance Imaging (MRI).It was first observed in epileptic patients and ever since it has been described in varied neurologic conditions but its etiology is still little known. Slow disappearance of signal abnormalities in the CC mainly occurs after some weeks or months and then TSL carries a good prognosis making unnecessary invasive therapies and procedures. We report a case of an isolated TSL of CC in a patient suffering from psychotic and hormonal disorders, which spontaneously resolved within only one week.     

Vacuum-Assisted Thrombectomy Device (AngioVac) in the Management of Symptomatic Iliocaval Thrombosis

Three patients with complete iliocaval thrombosis causing symptomatic leg swelling failed initial treatment with standard pharmacomechanical techniques. The occluded segments of the inferior vena cava and iliac veins were subsequently treated with the AngioVac Cannula (AngioDynamics, Latham, New York) and extracorporeal venous bypass circuit. In each patient, symptoms improved after treatment. This report discusses potential benefits and ancillary techniques of using the AngioVac device for iliocaval venous thrombosis.