Satinder Singh

Evaluation of Reader Variability in the Interpretation of Follow-up CT Scans at Lung Cancer Screening

PURPOSE To measure reader agreement in determining whether lung nodules detected at baseline screening computed tomography (CT) had changed at subsequent screening examinations and to evaluate the variability in recommendations for further follow-up. MATERIALS AND METHODS All subjects were enrolled in the National Lung Screening Trial (NLST), and each participant consented to the use of their de-identified images for research purposes. The authors randomly selected 100 cases of nodules measuring at least 4.0 mm at 1-year screening CT that were considered by the original screening CT reader to be present on baseline CT scans; nodules considered by the original reader to have changed were oversampled. Selected images from each case showing the entire nodule at both examinations were preloaded on a picture archiving and communication system workstation. Nine radiologists served as readers, and they evaluated whether the nodule was present at baseline and recorded the bidimensional measurements and nodule characteristics at each examination, presence or absence of change, results of screening CT, and follow-up recommendations (high-level follow-up, low-level follow-up, no follow-up). RESULTS On the basis of reviews during case selection, five nodules seen at follow-up were judged not to have been present at baseline; for 19 of the remaining 95 cases, at least one reader judged the nodule not to have been present at baseline. For the 76 nodules that were unanimously considered to have been present at baseline, 21%-47% (mean ± standard deviation, 30% ± 9) were judged to have grown. The κ values were similar for growth (κ = 0.55) and a positive screening result (κ = 0.51) and were lower for a change in margins and attenuation (κ = 0.27-0.31). The κ value in the recommendation of high- versus low-level follow-up was high (κ = 0.66). CONCLUSION Reader agreement on nodule growth and screening result was moderate to substantial. Agreement on follow-up recommendations was lower.

Acrokeratosis paraneoplastica (Bazex syndrome): Report of a case associated with small cell lung carcinoma and review of the literature

Acrokeratosis paraneoplastic (Bazex syndrome) is a rare, but distinctive paraneoplastic dermatosis characterized by erythematosquamous lesions located at the acral sites and is most commonly associated with carcinomas of the upper aerodigestive tract. We report a 58-year-old female with a history of a pigmented rash on her extremities, thick keratotic plaques on her hands, and brittle nails. Chest imaging revealed a right upper lobe mass that was proven to be small cell lung carcinoma. While Bazex syndrome has been described in the dermatology literature, it is also important for the radiologist to be aware of this entity and its common presentations.

Automated multidetector computed tomography evaluation of subacutely infarcted myocardium

BACKGROUND Delayed enhanced (DE) multidetector computed tomography (MDCT) can identify acute and chronic myocardial infarct. To our knowledge, automated techniques for infarct quantification on DE-MDCT have not been used. OBJECTIVE We evaluated an automated signal intensity (SI) threshold method for quantification of subacute myocardial infarct and identified and quantified microvascular obstruction (MO) in subacute infarct. METHODS DE-MDCT imaging was performed on 5 pigs 6-7 days after mid left anterior descending artery occlusion-reperfusion. DE-MDCT images were compared with triphenyl tetrazolium chloride (TTC) staining for infarct quantification and with hematoxylin and eosin (H&E) staining for MO quantification. Pixels with SI more than the mean SI of a remote normal myocardial region (SI(remote)) plus 2 times the standard deviation (SI(remote) + 2 SD) value were considered infarct pixels. The ratio of infarct to total area of a given slice, the percentage of infarct area per slice (PIS), was calculated. MO as a percentage of total infarct area was also calculated. RESULTS The average density values on DE-MDCT (5 minutes after contrast injection) were remote normal myocardium of 93 +/- 19 Hounsfield units (HU), infarct myocardium of 159 +/- 40 HU, blood of 140 +/- 26 HU, and MO of 85 +/- 30 HU. PIS(MDCT) showed substantial agreement with PIS(TTC) (y = 1.003x + 4.12; R = 0.90, P < 0.05). A relation was also shown between MO determined by MDCT compared with H&E staining (y = 0.74x + 3.4). CONCLUSIONS We show the feasibility of using a semiautomated SI threshold technique for quantification of subacute myocardial infarct. We also show the persistent MO in subacute myocardial infarct on DE-MDCT images.

Identification of Tricuspid Valve Vegetation by Computed Tomography Scan

We report a patient with disseminated sepsis in whom a large vegetation involving the tricuspid valve was seen on a routine nongated computed tomography (CT) study emphasizing the potential role of CT scan in endocarditis.

Large-field intravascular ultrasound for annular sizing and predicting paravalvular regurgitation during TAVR: comparisons with multidetector computed tomography and transoesophageal echocardiography

Aims The use of contrast media with multidetector computed tomography (MDCT) may induce acute kidney injury in patients with renal failure undergoing transcatheter aortic valve replacement (TAVR). We investigated the role of large-field intravascular ultrasound (IVUS) vs. MDCT and two-dimensional transoesophageal echocardiography (2D-TEE) for annular sizing and predicting paravalvular regurgitation (PVR) during TAVR. Methods and Results The aortic annulus was measured by large-field IVUS and 2D-TEE, and compared with MDCT in 50 patients undergoing TAVR. The IVUS and MDCT annular areas and diameters were not significantly different (446 ± 87 mm2 and 23.8 ± 84 mm vs. 466 ± 84 mm2 and 24 ± 2.1 mm, respectively; P > 0.05). IVUS and MDCT mean annular diameters were significantly greater than TEE diameter (23.8 ± 2.4 and 24 ± 2.1 vs. 22 ± 0.65 mm, respectively; P < 0.01). PVR ≥ Mild occurred in 13 patients (26%); 5 patients required post-dilation and 2 patients a second valve. Receiver operating characteristic analyses showed that transcatheter heart valve (THV) area - IVUS or MDCT areas equally predicted of ≥ mild PVR (areas under the curve [AUC] 0.79 and 0.81, respectively; P < 0.001), and were greater than THV diameter-TEE diameter (AUC 0.79 and 0.81 vs. 0.56, respectively; P < 0.05). Conclusions The aortic annular measurements and predicting PVR by large field IVUS were not significantly different from those of MDCT, but were greater than those of TEE. Large filed IVUS can be reliably used in lieu of MDCT for annular sizing in patients with aortic stenosis and renal failure or suboptimal MDCT images.

Incremental value of live/real time three‐dimensional transesophageal echocardiography over the two‐dimensional technique in the assessment of aortic atherosclerotic thrombi and ulcers

We present two cases in whom live/real time three‐dimensional transesophageal echocardiography (3DTEE) provided incremental value in the assessment of atherosclerotic disease in the aorta. In one patient, it identified additional atherosclerotic ulcers as well as thrombi within them which were missed by two‐dimensional (2D) TEE. In both cases, the size of the large mobile atherosclerotic plaque was underestimated by 2DTEE as compared with 3DTEE. Furthermore, 3DTEE provided volume quantification of the thrombi and ulcers which is not possible by 2DTEE. The echocardiographic findings of atherosclerotic plaques were confirmed by computed tomography in one patient and by surgery in the other.

First-in-Man Large-Field Intravascular Ultrasound-Guided Transcatheter Aortic Valve Replacement

A 93-year-old female was admitted with dyspnea and chest pain. Transthoracic echocardiography revealed a severe aortic valve stenosis with the aortic valve peak and mean gradients of 134and 73 mmHg, respectively. Cardiac catheterization showed a critical stenosis of the proximal left anterior descending coronary artery. After stenting, she developed pulmonary edema and her serum creatinine rose to 2.5 mg/dL. Because of renal failure, multidetector computed tomography (MDCT) could not be performed to size the aortic annulus. Thus balloon aortic valvoluplasty (BAV) was performed. She was readmitted with pulmonary edema 3 weeks later and her serum creatinine rose to 2.8 mg/dL. Repeat echocardiography showed that the aortic valve peak and mean gradients of 73and 43 mmHg, respectively. She was referred for transcatheter aortic valve replacement (TAVR); however, because of a high-risk of contrast-induced acute kidney injury (AKI) after MDCT, TAVR was performed guided by large-field intravascular ultrasound (IVUS). The diameters of iliac and femoral arteries measured with an Atlantis® PV peripheral IVUS catheter (8 Fr/15MHz, Boston Scientific, Natick, MA, USA) were > 6 mm. We used longitudinal IVUS view (Figure 1B) to define the junction between the left ventricular outflow tract (LVOT) and the aortic cusps (white arrow) as a pulsatile oval-shaped structure (Figure 1A), which is the aortic annulus at the level of hinge points (Figure 1B). The aortic annulus diameters and area at this level were 17 × 24 mm and 343 mm, respectively (Figure 1A).

Pulmonary endarterectomy for pulmonary hypertension from septic emboli.

Pulmonary endarterectomy (PEA) can significantly increase long-term survival in patients with chronic thromboembolic pulmonary hypertension; however, the role of PEA for chronic thromboembolic pulmonary hypertension due to pulmonary valve endocarditis is controversial. A critically ill 61-year-old man with intractable right ventricular heart failure was found to have chronic thromboembolic pulmonary hypertension due to Streptococcus bovis pulmonary valve endocarditis and underwent successful pulmonary valve replacement and PEA. The successful outcome in this case suggests that PEA should be considered in patients with this condition.

Progressive lung calcification after orthotopic heart transplant

Focal, asymmetrical pulmonary airspace opacities in post-transplant setting are commonly from infection, hemorrhage, edema or infarction. Rarely, stable or mildly progressive dense pulmonary opacities are due to pulmonary calcifications. In the majority of cases, these are asymptomatic and warrant no further intervention.

Combined intracardiac and epicardial device closure of a large left ventricular pseudoaneurysm

An 81-year-old man with a history of coronary artery bypass grafting presented with left ventricular anterolateral free wall rupture with formation of a large left ventricular pseudoaneurysm. He was referred to us for catheter-based repair as he …