Faculty Bibliography

Cavities occasionally are encountered on thoracic images. Their differential diagnosis is large and includes, among others, various infections, autoimmune conditions, and primary and metastatic malignancies. We offer an algorithmic approach to their evaluation by initially excluding mimics of cavities and then broadly classifying them according to the duration of clinical symptoms and radiographic abnormalities. An acute or subacute process (< 12 weeks) suggests common bacterial and uncommon nocardial and fungal causes of pulmonary abscesses, necrotizing pneumonias, and septic emboli. A chronic process (≥ 12 weeks) suggests mycobacterial, fungal, viral, or parasitic infections; malignancy (primary lung cancer or metastases); or autoimmune disorders (rheumatoid arthritis and granulomatosis with polyangiitis). Although a number of radiographic features can suggest a diagnosis, their lack of specificity requires that imaging findings be combined with the clinical context to make a confident diagnosis.

Computed tomography pulmonary angiography (CTPA) has become the primary imaging modality for evaluating the pulmonary arteries. Although pulmonary embolism is the primary indication for CTPA, various pulmonary vascular abnormalities can be detected in adults. Knowledge of these disease entities and understanding technical pitfalls that can occur when performing CTPA are essential to enable accurate diagnosis and allow timely management. This review will cover a spectrum of acquired abnormalities including pulmonary embolism due to thrombus and foreign bodies, primary and metastatic tumor involving the pulmonary arteries, pulmonary hypertension, as well as pulmonary artery aneurysms and stenoses. Additionally, methods to overcome technical pitfalls and interventional treatment options will be addressed.

PURPOSE: An increased incidence of sarcoidosis has been demonstrated in firefighters, supporting the concern that occupational/environmental exposure may pose an etiologic risk factor. This incidence increased further after September 11, 2001 following exposure to World Trade Center (WTC) dust and gases. We review computed tomography (CT) features in this population, comparing the range of findings and physiological correlates with those typically reported in unexposed individuals with pulmonary sarcoidosis. MATERIALS AND METHODS: With CT imaging we retrospectively identified 46 patients with WTC-related sarcoidosis, between March 18, 2002 and April 5, 2014. Scans were independently reviewed by 2 dedicated thoracic radiologists and assessed for disease patterns and correlation with pulmonary functions. RESULTS: The majority (37/46; 80%) had symmetric mediastinal and hilar lymphadenopathy. Similarly, most (38/46; 83%) had perilymphatic nodules. Foci of ill-defined ground glass attenuation were present in 6 (13%). Coalescent nodularity was present in 15 (33%). Only 3 (7%) had parenchymal reticulation. A mixed pattern of lung findings was present in 21 (46%). When all forms of parenchymal disease were scored by zonal distribution, 21 (46%) had parenchymal disease predominantly involving mid and upper lungs; 11/46 (24%) had a random distribution without zonal predominance; 6/46 (13%) demonstrated atypical lower zone predominance. Whereas 15/46 (33%) had obstructive airways disease on pulmonary function tests, there were no CT findings that were predictive of obstructive airways disease. CONCLUSIONS: The majority of cases of WTC-related sarcoidosis demonstrated typical radiographic appearances of sarcoidosis, with symmetric hilar and mediastinal lymphadenopathy and mid to upper lung perilymphatic nodules; these findings were consistent with other previously reported cases of sarcoid-like granulomatous disease in association with various alternate underlying etiologies. There was no correlation between disease patterns or extent on CT and pulmonary function testing, likely at least in part due to the overall mild extent of disease in this population.

OBJECTIVES: We hypothesise that there is an association between an elevated pulmonary artery/aorta (PA/A) and World Trade Center-Lung Injury (WTC-LI). We assessed if serum vascular disease biomarkers were predictive of an elevated PA/A. DESIGN: Retrospective case-cohort analysis of thoracic CT scans of WTC-exposed firefighters who were symptomatic between 9/12/2001 and 3/10/2008. Quantification of vascular-associated biomarkers from serum collected within 200 days of exposure. SETTING: Urban tertiary care centre and occupational healthcare centre. PARTICIPANTS: Male never-smoking firefighters with accurate pre-9/11 forced expiratory volume in 1 s (FEV1) >/=75%, serum sampled /=0.92 (n=38) and PA/A<0.92(n=59) to determine serum vascular biomarkers that were predictive of this vasculopathy. OUTCOME MEASURES: The primary outcome of this study was to identify a PA/A ratio in a cohort of individuals exposed to WTC dust that was associated with WTC-LI. The secondary outcome was to identify serum biomarkers predictive of the PA/A ratio using logistic regression. RESULTS: PA/A>/=0.92 was associated with WTC-LI, OR of 4.02 (95% CI 1.21 to 13.41; p=0.023) when adjusted for exposure, body mass index and age at CT. Elevated macrophage derived chemokine and soluble endothelial selectin were predictive of PA/A>/=0.92, (OR, 95% CI 2.08, 1.05 to 4.11, p=0.036; 1.33, 1.06 to 1.68, p=0.016, respectively), while the increased total plasminogen activator inhibitor 1 was predictive of not having PA/A>/=0.92 (OR 0.88, 0.79 to 0.98; p=0.024). CONCLUSIONS: Elevated PA/A was associated with WTC-LI. Development of an elevated PA/A was predicted by biomarkers of vascular disease found in serum drawn within 6 months of WTC exposure. Increased PA/A is a potentially useful non-invasive biomarker of WTC-LI and warrants further study.

OBJECTIVE: The purpose of this study was to assess the impact of an automated program on improvement in lung nodule matching efficiency. MATERIALS AND METHODS: Four thoracic radiologists independently reviewed two serial chest CT examinations from each of 57 patients. Each radiologist performed timed manual lung nodule matching. After 6 weeks, all radiologists independently repeated the timed matching portion using an automated nodule matching program. The time required for manual and automated matching was compared. The impact of nodule size and number on matching efficiency was determined. RESULTS: An average of 325 (range, 244-413) noncalcified solid pulmonary nodules was identified. Nodule matching was significantly faster with the automated program irrespective of the interpreting radiologist (p < 0.0001 for each). The maximal time saved with automated matching was 11.4 minutes (mean, 2.3 +/- 2.0 minutes). Matching was faster in 56 of 57 cases (98.2%) for three readers and in 46 of 57 cases (80.7%) for one reader. There were no differences among readers with respect to the mean time saved per matched nodule (p > 0.5). The automated program achieved 90%, 90%, 79%, and 92% accuracy for the four readers. The improvement in efficiency for a given patient using the automated technique was proportional to the number of matched nodules (p < 0.0001) and inversely proportional to nodule size (p < 0.05). CONCLUSION: Use of the automated lung nodule matching program significantly improves diagnostic efficiency. The time saved is proportionate to the number of nodules identified and inversely proportional to nodule size. Adoption of such a program should expedite CT examination interpretation and improve report turnaround time.

AIM: To evaluate the incidence of unsuspected pulmonary embolism (PE) in an unselected population of outpatients undergoing contrast-enhanced multidetector computed tomography (MDCT) for indications other than the investigation of PE. MATERIALS AND METHODS: Outpatients undergoing CT of the chest over a 6-month period were retrospectively identified and images reviewed. Inpatients and patients undergoing unenhanced CT of the chest were excluded. Data, including referring specialty, patient age and sex, reasons for examination, level of embolism, image quality, and section thickness were recorded. Radiology reports were reviewed with respect to whether or not the embolism was noted at the time of initial reporting. RESULTS: Following exclusions 440 patients were reviewed (195 women and 245 men). PE was identified in 10 of the 440 patients, an incidence of 2.23%. One pulmonary embolus was in the main pulmonary artery, three were in lobar arteries, three in segmental arteries, and three in subsegmental arteries. Patients over the age of 60 years were more likely to have an embolism (9/300, 2.9%) compared with those under 60 years (1/140, 0.7%). Seven of the 10 positive examinations were carried out in patients who were known or later shown to have malignancy. Seven of the 10 emboli were reported at the time of initial reporting. CONCLUSION: The outpatient population has a significant incidence of unsuspected PE. PE should be actively sought when reporting examinations performed for alternative indications, particularly where cancer is a known or suspected diagnosis

OBJECTIVE: The imaging of pulmonary nodules is an evolving and dynamic field. In this review, we discuss the detection and multitechnique characterization of pulmonary nodules, emphasizing the impact of technological advances on both noninvasive and invasive evaluation and surveillance. The potential contribution of MRI, evolving imaging-guided techniques, and computer applications are also discussed. CONCLUSION: Advances in MDCT and PET and the potential contribution of fast-imaging MRI sequences and computer applications should continue to improve our evaluation of the solitary pulmonary nodule

Peutz–Jeghers syndrome is a rare condition characterised by mucocutaneous pigmentation, polyposis and an increased cancer risk at a number of gastrointestinal and extra intestinal organs. We look at the typical appearances of the gastrointestinal features on conventional barium follow-through, magnetic resonance (MR) enterography and multi-detector computed tomography (MDCT). We discuss the current recommendations for surveillance in this patient group