Sharyn MacDonald

Functional impairment in emphysema: contribution of airway abnormalities and distribution of parenchymal disease.

OBJECTIVE The aim of this study was to identify ancillary morphologic features on high-resolution CT that modify airflow obstruction and gas transfer levels in individuals with emphysema. MATERIALS AND METHODS The extent of emphysema on high-resolution CT was quantified by density masking in 101 patients. CT scans were evaluated for airway abnormalities (bronchial wall thickness, extent of bronchiectasis, bronchial dilatation, and evidence of small airways disease) and disease heterogeneity (uniformity, core-rind distribution, craniocaudal distribution, and lung texture). Stepwise regression analysis was used to determine CT features that influenced forced expiratory volume in 1 sec (FEV1) and the single-breath diffusing capacity for carbon monoxide (Dlco) for a given extent of emphysema. RESULTS The extent of emphysema using automated estimation was 28.4% +/- 12.3% (mean +/- SD). On univariate analysis the extent of emphysema correlated strongly with FEV1 (R = -0.63, p < 0.0005) and Dlco (R = -0.63, p < 0.0005) levels. Stepwise regression analysis revealed that bronchial wall thickness and the extent of emphysema were the strongest independent determinants of FEV1 (model R2 = 0.49; p = 0.002 and < 0.001, respectively); the extent of bronchiectasis and degree of bronchial dilation did not separately influence FEV1 levels. The only morphologic features linked to Dlco levels on multivariate analysis were increasingly extensive emphysema and a higher proportion of emphysema in the core region (model R2 = 0.45; p < 0.001 and 0.002, respectively). CONCLUSION The important additional CT abnormalities in individuals with emphysema that influence FEV1 and Dlco levels irrespective of disease extent are bronchial wall thickness and core-rind heterogeneity, respectively. These observations have implications for the accurate functional assessment of patients considered for lung volume reduction surgery.

Perifissural Nodules Seen at CT Screening for Lung Cancer

PURPOSE To describe and characterize the potential for malignancy of noncalcified lung nodules adjacent to fissures that are often found in current or former heavy smokers who undergo computed tomography (CT) for lung cancer screening. MATERIALS AND METHODS Institutional review board approval and informed consent were obtained. Baseline and follow-up thin-section multidetector CT scans obtained in 146 consecutive subjects at high risk for lung cancer (age range, 50-75 years; > 30 pack-year smoking history) were retrospectively reviewed. Noncalcified nodules (NCNs) were categorized according to location (parenchymal, perifissural), shape, septal connection, manually measured diameter, diameter change, and lung cancer outcome at 7(1/2) years. RESULTS Retrospective review of images from 146 baseline and 311 follow-up CT examinations revealed 837 NCNs in 128 subjects. Of those 837 nodules, 234 (28%), in 98 subjects, were adjacent to a fissure and thus classified as perifissural nodules (PFNs). Multiple (range, 2-14) PFNs were seen in 47 subjects. Most PFNs were triangular (102/234, 44%) or oval (98/234, 42%), were located inferior to the carina (196/234, 84%), and had a septal connection (171/234, 73%). The mean maximal length was 3.2 mm (range, 1-13 mm). During 2-year follow-up in 71 subjects, seven of 159 PFNs increased in size on one scan but were then stable. The authors searched a lung cancer registry 7(1/2) years after study entry and found 10 lung cancers in 139 of 146 study subjects who underwent complete follow-up; none of these cancers had originated from a PFN. CONCLUSION PFNs are frequently seen on screening CT scans obtained in high-risk subjects. Although PFNs may show increased size at follow-up CT, the authors in this study found none that had developed into lung cancer; this suggests that the malignancy potential of PFNs is low. (c) RSNA, 2010.

Lung Cancer Screening Using Multi-Slice Thin-Section Computed Tomography and Autofluorescence Bronchoscopy

Background: Thoracic computed tomography (CT) for lung cancer screening is sensitive for the detection of early peripheral lung cancer but is not sensitive for detecting central preinvasive and microinvasive cancer. Our hypothesis is that the use of a two-step strategy, using a sputum biomarker, may increase the detection rate of lung cancer by identifying individuals at highest risk. Methods: We completed a pilot study of 561 volunteer current or former smokers 50 years of age or older, with a smoking history of more than or equal to 30 pack years. All subjects received induced sputum examination and low-dose thoracic CT scan and were offered autofluorescence bronchoscopy. Results: CT detected 2408 pulmonary nodules, 80% of which were less than or equal to 4 mm in diameter. During 2-year follow-up, 95% of these nodules were stable or resolved, with only 4% showing growth at any time. A total of 28 cancers were detected in 22 subjects: 21 by CT scan and seven by autofluorescence bronchoscopy. Overall, 0.9% nodules were malignant, but growth on more than or equal to two CT scans increased the malignancy rate to 75%. The mean diameter of malignant nodules on detection was 12.8 mm (range, 3 to 36.4 mm). However, 18% of malignant nodules were less than or equal to 4 mm in diameter when first seen. Conclusions: Multi-detector row CT scanners found multiple small nodules in most subjects screened, but most were stable over the 2-year follow-up. Persistent interval growth increases the probability of malignancy from less than 1% to 75%. One quarter of detected cancers were CT occult and only seen with autofluorescence bronchoscopy. Prescreening using a sputum biomarker improved the detection rate of lung cancer from 3 to 5%.

The use of visual search for knowledge gathering in image decision support

This paper presents a new method of knowledge gathering for decision support in image understanding based on information extracted from the dynamics of saccadic eye movements. The framework involves the construction of a generic image feature extraction library, from which the feature extractors that are most relevant to the visual assessment by domain experts are determined automatically through factor analysis. The dynamics of the visual search are analyzed by using the Markov model for providing training information to novices on how and where to look for image features. The validity of the framework has been evaluated in a clinical scenario whereby the pulmonary vascular distribution on Computed Tomography images was assessed by experienced radiologists as a potential indicator of heart failure. The performance of the system has been demonstrated by training four novices to follow the visual assessment behavior of two experienced observers. In all cases, the accuracy of the students improved from near random decision making (33%) to accuracies ranging from 50% to 68%.

Staging of non-small cell lung cancer: imaging of intrathoracic disease

This article reviews the contribution of diagnostic imaging to the intrathoracic staging of non-small cell lung cancer. The principle features of the current staging system are discussed along with the relative roles of the various imaging modalities in the evaluation of the primary tumour and metastatic disease. The emerging role of positron emission tomography with fluorodeoxyglucose (FDG-PET) as a clinically useful, potentially cost effective, complementary imaging technique is also reviewed.

Measuring and managing radiologist workload: Application of lean and constraint theories and production planning principles to planning radiology services in a major tertiary hospital

We describe how techniques traditionally used in the manufacturing industry (lean management, the theory of constraints and production planning) can be applied to planning radiology services to reduce the impact of constraints such as limited radiologist hours, and to subsequently reduce delays in accessing imaging and in report turnaround.

Cardiac sarcoidosis: the Christchurch experience.

To present an overview of the diagnosis, treatment and outcomes of patients with cardiac sarcoidosis managed in Christchurch Hospital, New Zealand.

Measuring and managing radiologist workload: a method for quantifying radiologist activities and calculating the full-time equivalents required to operate a service.

Accurate and transparent measurement and monitoring of radiologist workload is highly desirable for management of daily workflow in a radiology department, and for informing decisions on department staffing needs. It offers the potential for benchmarking between departments and assessing future national workforce and training requirements. We describe a technique for quantifying, with minimum subjectivity, all the work carried out by radiologists in a tertiary department.

Measuring and managing radiologist workload: Measuring radiologist reporting times using data from a Radiology Information System

Historically, there has been no objective method of measuring the time required for radiologists to produce reports during normal work. We have created a technique for semi‐automated measurement of radiologist reporting time, and through it produced a robust set of absolute time requirements and relative value units for consultant reporting of diagnostic examinations in our hospital.

Pulmonary haemorrhage in a 13-year-old girl: An unusual presentation of systemic lupus erythematosus

A 13-year-old girl presented with a 2-month history of pallor, lethargy, cough with bloody sputum and shortness of breath. On specific questioning, she had an intermittent fever. There was no joint pain, alopecia, mouth ulcers, rashes or Raynaud’s. At the time of admission, she was on no regular medications. There was no family history of rheumatological disease. The patient immigrated from Korea 1 year ago. Systematic enquiry revealed an episode of anaemia at the age of 3–4 years for which no cause was found. She was treated with iron for 2 years. She suffered several episodes of cough and haemoptysis in the previous 4 years, and on each occasion was diagnosed as pneumonia. On one occasion, the patient had required ventilation for 3 weeks. During this admission, she was treated with antibiotics. She went on to make a full recovery. Initial investigations revealed haemoglobin 65 g/L, platelets 244 ¥ 10/L and white cell count 5 ¥ 10/L. Erythrocyte sedimentation rate (ESR) 65 mm/h and C-reactive protein <3. Renal and liver function tests were normal apart from a raised bilirubin 59 mmol/L (<21). Haemaglobinopathy screen, a-globin gene deletion studies and glucose-6-phosphate dehydrogenase screen were all negative. The direct Coombs test antiimmunoglobin G was weakly positive and haptoglobins were low (<0.07). Anti-nuclear antibody (ANA) was positive (>1:1280) with positive Ro antibodies. Double-stranded DNA, anti-neutrophil cytoplasmic antibodies and anti-glomerular basement membrane antibodies were negative. Rheumatoid factor was positive at 113 IU/mL (<30). C3 and C4 were low; C3 0.75 g/L (normal 0.9–1.8), C4 < 0.05 g/L (normal 0.1–0.4). Immunoglobin M anti-cardiolipin antibodies were weakly positive at 31 (<20) and lupus anticoagulant was negative. There was a polyclonal increase in immunoglobin G. Mycoplasma, hepatitis B, C and HIV serology were all negative. Urine sediment was normal. Chest X-ray (CXR) demonstrated diffuse airspace opacity and high-resolution computed tomography of the chest showed moderately extensive bilateral ground glass opacification throughout all zones of both lungs with relative sparing of the extreme lung bases consistent with diffuse alveolar haemorrhage (Fig. 1). Lung function tests were restrictive with the forced expiratory volume in the first second/forced vital capacity ratio of 84% and a forced vital capacity of 2.52 L (74% predicted). This was confirmed with measurement of her total lung capacity 3.47 L (78%) and her diffusing capacity of the lung for carbon monoxide (DLCO) corrected for haemoglobin of 14.5 (61% predicted). Blood gas on room air revealed a pH 7.38, PaO2 59 mmHg, PaCO2 38 mmHg, bicarbonate 28 mmol/L. An open lung biopsy was performed; specimens were negative for mycobacterium tuberculosis, legionella and fungi. Histology revealed diffuse alveolar haemorrhage with haemosiderin-laden macrophages. There was no evidence of vasculitis, capillaritis or granulomatous inflammation (Fig. 1). A diagnosis of systemic lupus erythematosus (SLE) was made. She was transfused two units of red blood cells and commenced prednisone 60 mg/day. The patient improved on prednisone with resolution of the dyspnoea, cessation of haemoptysis and improvement in the CXR findings. The haemoglobin increased, although not to normal, and the ESR rapidly decreased. C3 and C4 levels returned to normal. She remained anaemic despite oral iron supplementation and further investigations revealed a low alkaline phosphatase (37 U/L (50–350)). She was subsequently found to be zinc deficient (plasma zinc 8.5 mmol/L (10–17)). The prednisone was successfully reduced to 10 mg daily. However, on further reduction of the prednisone, she developed shortness of breath accompanied by deterioration in CXR appearances. This was associated with a small rise in ESR from 7 mm/h to 16 mm/h, although C3 and C4 remained normal. The prednisone was increased to 20 mg daily with resolution of the symptoms and radiographic improvement. Azathioprine was introduced as a steroid-sparing agent. The patient has remained well.