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36 result(s) for "Padley, Simon"
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Discrepancy Between Achieved and Vendor-Predicted Ablation Zones in the Lung: Contributing Factors
PurposeSeveral factors are known to affect lung ablation zones. Questions remain as to why there are discrepancies between achieved and vendor-predicted ablation zones and what contributing factors can be modified to balance therapeutic effects with avoidance of complications. This retrospective study of lung tumour microwave ablation analyses day 1 post-treatment CT to assess the effects of lesion-specific and operator-dependent factors on ablation zones.Methods and MaterialsConsecutive patients treated at a tertiary centre from 2018 to 2021 were included. All ablations were performed using a single microwave ablation device under lung isolation. The lung tumours were categorised as primary or secondary, and their “resistance” to ablation was graded according to their locations. Intraprocedural pulmonary inflation was assessed as equal to or less than the contralateral non-isolated lung. Ablation energy was categorised as high, medium, or low. Ablation zone dimensions were measured on day 1 CT and compared to vendor reference charts. Ablations with multiple needle positions or indeterminate boundaries were excluded.ResultsA total of 47 lesions in 31 patients were analysed. Achieved long axes are longer than predicted by 5 mm or 14% (p < 0.01) without overall short axis discrepancy. Secondary tumours (p = 0.020), low-resistance location (p < 0.01), good lung inflation (p < 0.01), low (p = 0.003) and medium (p = 0.038) total energy produce lengthened long axes by 4–6 mm or 10–19%. High total energy results in shorter than predicated short axes by 6 mm or 18% (p = 0.010).ConclusionWe identified several factors affecting ablation zone dimensions which may have implications for ablation planning and the avoidance of complications.
Clinical and economic consequences of non-cardiac incidental findings detected on cardiovascular computed tomography performed prior to transcatheter aortic valve implantation (TAVI)
Transcatheter aortic valve implantation (TAVI) is an effective treatment option for patients with severe degenerative aortic valve stenosis who are high risk for conventional surgery. Computed tomography (CT) performed prior to TAVI can detect pathologies that could influence outcomes following the procedure, however the incidence, cost, and clinical impact of incidental findings has not previously been investigated. 279 patients underwent CT; 188 subsequently had TAVI and 91 were declined. Incidental findings were classified as clinically significant (requiring treatment), indeterminate (requiring further assessment), or clinically insignificant. The primary outcome measure was all-cause mortality up to 3 years. Costs incurred by additional investigations resultant to incidental findings were estimated using the UK Department of Health Payment Tariff. Incidental findings were common in both the TAVI and medical therapy cohorts (54.8 vs. 70.3 %; P  = 0.014). Subsequently, 45 extra investigations were recommended for the TAVI cohort, at an overall average cost of £32.69 per TAVI patient. In a univariate model, survival was significantly associated with the presence of a clinically significant or indeterminate finding (HR 1.61; P  = 0.021). However, on multivariate analysis outcomes after TAVI were not influenced by any category of incidental finding. Incidental findings are common on CT scans performed prior to TAVI. However, the total cost involved in investigating these findings is low, and incidental findings do not independently identify patients with poorer outcomes after TAVI. The discovery of an incidental finding on CT should not necessarily influence or delay the decision to perform TAVI.
A Golden Conundrum
A 67-year-old Kuwaiti gentleman admitted with a history of intermittent cough and exertional dyspnea was found, on examination, to be jaundiced with bilateral basal pulmonary crackles.
Implications of incidental findings from lung screening for primary care: data from a UK pilot
Regional lung cancer screening (LCS) is underway in England, involving a “lung health check” (LHC) and low-dose CT scan for those at high risk of cancer. Incidental findings from LHCs or CTs are usually referred to primary care. We describe the proportion of participants referred from the West London LCS pilot to primary care, the indications for referral, the number of general practitioner (GP) attendances and consequent changes to patient management, and provide an estimated cost-burden analysis for primary care. A small proportion (163/1542, 10.6%) of LHC attendees were referred to primary care, primarily for suspected undiagnosed chronic obstructive pulmonary disease (55/163, 33.7%) or for QRISK® (63/163, 38.7%) assessment. Ninety one of 159 (57.2%) participants consenting to follow-up attended GP appointments; costs incurred by primary care were estimated at £5.69/LHC participant. Patient management changes occurred in only 36/159 (22.6%) referred participants. LHCs result in a small increase to primary care workload provided a strict referral protocol is adhered to. Changes to patient management arising from incidental findings referrals are infrequent.
Sixty-four-slice computed tomography coronary angiography compared with myocardial perfusion scintigraphy for the diagnosis of functionally significant coronary stenoses in patients with a low to intermediate likelihood of coronary artery disease
Multislice computed tomography coronary angiography (CTA) was proposed as a method for investigating possible coronary artery disease (CAD) in patients who present with chest pain but with a low to intermediate likelihood of CAD. Sixty-four-channel CTA was compared prospectively with 99mTc-tetrofosmin myocardial perfusion scintigraphy (MPS) (as the gold standard in the detection of flow-limiting stenoses) for the detection of functionally significant CAD. Fifty-two consecutive symptomatic patients with a low to intermediate likelihood of coronary artery disease, and who were referred for MPS, also underwent CTA. The CTA datasets were analyzed by two experienced observers who were blinded to the MPS data, and coronary artery segments were reported as < 50%, 50% to 69%, 70% to 99% stenoses, or occluded. The MPS images were similarly analyzed for inducible perfusion abnormalities, and coronary territories were identified. At the patient level, agreement between CTA and MPS for CTA lesions at ≥ 50% was 87% (sensitivity, 100%; specificity, 84%; positive predictive value, 50%; negative predictive value, 100%). For CTA lesions, agreement at ≥ 70% was 96% (sensitivity, 86%; specificity, 98%; positive predictive value, 86%; negative predictive value, 98%). In patients with a low to intermediate likelihood of CAD, there is good correlation between MPS and CTA for the detection of functionally significant coronary artery stenoses when CTA detects a narrowing of ≥ 70% severity. Computed tomography coronary angiography stenoses of 70% should be used to determine functional significance, and not 50%, as is the usual practice at present.
Technical feasibility and validation of a coronary artery calcium scoring system using CT coronary angiography images
Objectives We validate a novel CT coronary angiography (CCTA) coronary calcium scoring system. Methods Calcium was quantified on CCTA images using a new patient-specific attenuation threshold: mean + 2SD of intra-coronary contrast density (HU). Using 335 patient data sets a conversion factor (CF) for predicting CACS from CCTA scores (CCTAS) was derived and validated in a separate cohort ( n  = 168). Bland–Altman analysis and weighted kappa for MESA centiles and Agatston risk groupings were calculated. Results Multivariable linear regression yielded a CF: CACS = (1.185 × CCTAS) + (0.002 × CCTAS × attenuation threshold). When applied to CCTA data sets there was excellent correlation ( r  = 0.95; p  < 0.0001) and agreement (mean difference −10.4 [95 % limits of agreement −258.9 to 238.1]) with traditional calcium scores. Agreement was better for calcium scores below 500; however, MESA percentile agreement was better for high risk patients. Risk stratification was excellent (Agatston groups k  = 0.88 and MESA centiles k  = 0.91). Eliminating the dedicated CACS scan decreased patient radiation exposure by approximately one-third. Conclusion CCTA calcium scores can accurately predict CACS using a simple, individualized, semiautomated approach reducing acquisition time and radiation exposure when evaluating patients for CAD. This method is not affected by the ROI location, imaging protocol, or tube voltage strengthening its clinical applicability. Key Points • Coronary calcium scores can be reliably determined on contrast - enhanced cardiac CT • This score can accurately risk stratify patients • Elimination of a dedicated calcium scan reduces patient radiation by a third
Comparison of 64-slice cardiac computed tomography with myocardial perfusion scintigraphy for assessment of global and regional myocardial function and infarction in patients with low to intermediate likelihood of coronary artery disease
Cardiac computed tomography (CCT) has the potential to assess both coronary anatomy and ventricular function in a single study. We examined the agreement between CCT and myocardial perfusion scintigraphy (MPS) for the assessment of global and regional ventricular function. Research CCT was performed in 52 patients with a low to intermediate likelihood of coronary artery disease referred for MPS. Left ventricular end-diastolic volume, left ventricular end-systolic volume, left ventricular ejection fraction (LVEF), and myocardial wall motion and thickening were compared between techniques. In addition, myocardial contrast attenuation on CCT was compared with radiotracer uptake on MPS. LVEF values agreed well (mean difference, 4.1%; SD, 15.13%), but CCT left ventricular end-diastolic volume was greater compared with MPS (mean difference, 46.0 mL; SD, 33.34 mL) ( P < .001). There was moderate agreement for segmental myocardial motion and thickening, with κ values of 0.57 (95% confidence interval, 0.51-0.63) and 0.47 (95% confidence interval, 0.41-0.53), respectively. Seventeen patients had hypoattenuation in at least 1 myocardial segment on CCT. Three of four patients with concomitant abnormalities of wall motion and thickening on CCT had infarction in the same territory on MPS. There was good agreement for LVEF between CCT and MPS but myocardial volumes differed, and these modalities cannot be used interchangeably. Mild abnormalities of regional function are detected more commonly by CCT than by MPS. Myocardial hypoattenuation on CCT is highly specific for myocardial infarction when associated with reduction of systolic wall thickening and regional wall motion abnormality.
Deriving coronary artery calcium scores from CT coronary angiography: a proposed algorithm for evaluating stable chest pain
We validate a method of calcium scoring on CT coronary angiography (CTCA) and propose an algorithm for the assessment of patients with stable chest pain. 503 consecutive patients undergoing coronary artery calcium score (CACS) and CTCA were included. A 0.1 cm 2 region of interest was used to determine the mean contrast density on CTCA images either in the left main stem (LM) or right coronary artery. Axial 3 mm CTCA images were scored for calcium using conventional software with a modified threshold: mean LM contrast density (HU) + 2SD. A conversion factor (CF) for predicting CACS from raw CTCA scores (rCTCAS) was determined using a multivariable regression model adjusted for model over-optimism (1,000 bootstrap samples). Accuracy of this method was determined using weighted kappa for NICE recommended CACS groupings (0, 1–400, >400) and Bland–Altman analysis for absolute score. With the CF applied: CACS = (1.183 × rCTCAS) + (0.002 × rCTCAS × threshold), there was excellent agreement between methods for absolute score (mean difference 5.44 [95 % limits of agreement −207.0 to 217.8]). The method discriminated between high (>400) and low risk (<400) calcium scores with a sensitivity and specificity of 85 and 99 %, and a PPV and NPV of 92 and 98 %, respectively, and led to a significant reduction in radiation exposure (6.9 [5.1–10.2] vs. 5.2 [6.3–8.7] mSv; p  < 0.0001). Our proposed method allows a comprehensive assessment of coronary artery pathology through the use of an individualised, semi-automated approach. If incorporated into stable chest pain guidelines the need for further functional testing or invasive angiography could be determined from CTCA alone, supporting a change to the current guidelines.
Pulmonary laceration secondary to a traumatic soccer injury: a case report and review of the literature
Pulmonary lacerations are an uncommon injury typically associated with high-impact trauma. Most cases occur as a result of high-speed road traffic collisions. Although chest wall and pleural injuries are commonly associated with sports-related thoracic trauma, pulmonary injuries are far less common. There are only a few reported cases of significant pulmonary trauma associated with sports injuries, the majority of which have described pulmonary contusions occurring as a result of thoracic injury sustained while playing high-impact contact sports such as American football. Pulmonary laceration occurring as result of soccer-related thoracic trauma has never previously been reported.