Beatrice Trotman-Dickenson

Relationship between pulmonary artery diameter at computed tomography and pulmonary artery pressures at right-sided heart catheterization

Rationale and Objectives. The purpose of the study was to determine the relationship between pulmonary artery (PA) size at computed tomography (CT) and PA pressures, to develop a noninvasive CT method of PA pressure measurement, and to determine a PA diameter that can enable differentiation of normal subjects from those with ptfimonary hypertension. Methods. PA vessel diameters in 55 candidates for lung and heart-lung transplantation were measured at CT and correlated with PA pressures with both linear and stepwise multiple regression. The multiple regression equations were then tested prospectively in 35 pretransplantation patients. Results. Combined main and left main PA cross-sectional area corrected for body surface area showed the best correlation with mean PA pressure ( r = .87). The multiple regression equations helped predict mean PA pressure within 5 mm Hg in 50% of patients with chronic lung disease and in only 8% of patients with pulmonary vascular disease. Conclusion. There was a very good correlation between main and left main PA size and mean PA pressure. At present, however, CT has not demonstrated sufficient accuracy to be used clinically.

Radiology in the Intensive Care Unit (Part I)

The increasing complexity of the intensive care patient combined with the recent advances in imaging technology has generated a new perspective on intensive care radiology. The purpose of this 2-part review article is to describe the contribution of radiology to the management of these critically ill patients. The first article will discuss the impact of picture archiving and communication system (PACS) on critical care management and utility of the portable chest radiograph in the detection and evaluation of pulmonary disease with correlation to computed tomography (CT). The second article describes in more detail the increasing role of CT in diagnosis and therapeutic procedures. In particular, the implementation of CT pulmonary angiography in the evaluation of pulmonary emboli and the introduction of the new multislice detector CT scanners that allow even the most dyspneic patient to be evaluated. Pleural complications in the intensive care unit and image-guided intervention will also be discussed.

Vascular Enhancement and Image Quality of MDCT Pulmonary Angiography in 400 Cases: Comparison of Standard and Low Kilovoltage Settings

OBJECTIVE The purpose of this study was to investigate the vascular enhancement and image quality of pulmonary CT angiography performed with lower peak kilovoltage settings in a large patient sample. MATERIALS AND METHODS This retrospective study was approved by our institutional review board, which waived the requirement for informed consent. Four hundred patients believed to have a pulmonary embolism were studied. All patients underwent 16- or 64-MDCT with automatic tube current modulation. The 200 patients in the standard peak kilovoltage group (mean age, 57 years; range, 22-95 years) underwent MDCT at 130 or 120 kVp. The 200 patients in the low peak kilovoltage group (mean age, 56 years; range, 21-92 years) underwent MDCT at 110 or 100 kVp. Vascular enhancement was evaluated by measurement of the attenuation value in the main pulmonary artery and segmental and subsegmental arteries. Image noise was quantified by measurement of the SD of the attenuation value in the main pulmonary artery. One blinded radiologist assessed image quality using visual scores. Wilcoxons rank test was used to evaluate differences between the groups. RESULTS Mean vascular enhancement in the main pulmonary artery had significantly higher attenuation values in the low peak kilovoltage group (376.1 +/- 102.9 HU) than in the standard peak kilovoltage group (309.2 +/- 94.8 HU) (p < 0.0001). Mean attenuation values in all measured segmental and subsegmental arteries were significantly higher in the low peak kilovoltage group than in the standard peak kilovoltage group (p < 0.0001). Image noise in the low peak kilovoltage group was significantly higher than in the standard peak kilovoltage group (p < 0.0001). There was no significant difference in the image quality scores of the two groups (p = 0.116). CONCLUSION Lowering kilovoltage improved vascular enhancement without deterioration of image quality. The results of our study confirm previously reported preliminary findings.

The spectrum of Castleman's disease: mimics, radiologic pathologic correlation and role of imaging in patient management.

Castlemans disease (CD) is a rare benign lymphoid disorder with variable clinical course. The two principal histologic subtypes of CD are hyaline-vascular and plasma cell variants and the major clinicoradiological entities are unicentric and multicentric CD. Management of CD is tailored to clinicoradiologic subtype. In this review, we describe the CT, MR and PET/CT findings in Castlemans disease which can help suggest a diagnosis of CD as well as emphasize role of imaging in management of patients with CD.

CT manifestations of respiratory syncytial virus infection in lung transplant recipients.

PURPOSE The purpose of our study was to evaluate CT findings during respiratory syncytial virus (RSV) infection in lung transplant recipients and to identify sequelae. METHOD Thirty-nine CT scans prior to, during, and following acute infection in 10 lung transplant recipients were reviewed. Abnormalities that were new from baseline observations and occurred within 4 weeks of diagnosis were defined as acute. Chronic findings were defined as those present >4 weeks after diagnosis. RESULTS Findings in nine patients were ground-glass (seven), air-space (five), and tree-in-bud (four) opacities and acute bronchial dilatation (four) and wall thickening (four). Patients lacked pleural effusions or lymph node enlargement. Five of seven patients with follow-up exams had new air trapping (three), persistent bronchial dilatation (three), and thickening (two). Three and 2 of the 10 patients developed bronchiolitis obliterans syndrome and obliterative bronchiolitis, respectively. CONCLUSION During acute infection, patients commonly had ground-glass opacities but lacked pleural effusions and lymph node enlargement. There can be chronic sequelae after infection.

Routine Pelvic and Lower Extremity CT Venography in Patients Undergoing Pulmonary CT Angiography

OBJECTIVE The purpose of our study was to assess the utility of performing routine pelvic and lower extremity CT venography (CTV) along with pulmonary CT angiography (CTA) in all patients evaluated for pulmonary embolism. MATERIALS AND METHODS Eight hundred twenty-nine consecutive patients (281 men and 548 women) underwent CTA-CTV for pulmonary embolism. Reports were evaluated as follows: positive or negative for pulmonary embolism with or without deep venous thrombosis (DVT) or with nondiagnostic CTV. Coexisting factors of malignancy, previous venous thromboembolism (VTE), recent surgery, and cardiovascular disease comprised the high-risk group of 446 patients. The remaining 383 patients formed the low-risk group. Statistical analysis included four binary predictors (previous VTE, malignancy, cardiovascular disease, and surgery) and three binary outcome variables (pulmonary embolism, DVT, and VTE). Chi-square test and univariate and multivariate regression analyses were performed. RESULTS VTE, pulmonary embolism, and DVT occurred in 152 (18.3%), 124 (15.0%), and 61 (7.3%) of 829 patients, respectively. Between the high-risk and low-risk groups, prevalence of VTE was 114 (25.6%) of 446 and 38 (9.9%) of 383 patients, respectively (p < 0.001); prevalence of pulmonary embolism was 92 (20.6%) of 446 and 32 (8.3%) of 383 patients, respectively (p < 0.001). Isolated DVT was found in 28 (3.4%) of 829 patients. The incremental value of CTV for the entire cohort was 3.4%, 0.72% in the low-risk group (six of 829) and 2.6% (22 of 829) in the high-risk group. For outcome variable VTE, malignancy and previous VTE were statistically significant (p = 0.04 and p < 0.001, respectively); for pulmonary embolism, malignancy and previous VTE were statistically significant (p = 0.03 and p = 0.005, respectively); for DVT, only previous VTE was statistically significant (p < 0.001). CONCLUSION CTV should not be performed routinely in all patients evaluated for pulmonary embolism and may only be useful in patients with a high probability of pulmonary embolism, including those with a history of VTE and possible malignancy.

Contrast Opacification Using a Reduced Volume of Iodinated Contrast Material and Low Peak Kilovoltage in Pulmonary CT Angiography: Objective and Subjective Evaluation

OBJECTIVE The purpose of our study was to evaluate whether a reduced volume of iodinated contrast material for pulmonary CT angiography (CTA) using a low peak kilovoltage (kVp) technique yields equivalent opacification in all vessels. MATERIALS AND METHODS Four hundred fifty-two consecutive pulmonary CTA patients (265 women and 187 men; age range, 18-91 years; mean age, 56.2 years) were retrospectively evaluated. Patients were grouped into those receiving 125 mL (n = 229) and 75 mL (n = 223) of 370 mg I/mL iodinated contrast material. Low kVp was used in all patients. Hounsfield units were measured at lobar, posterobasal segment, posterobasal ramus, and medial basal subsegmental ramus in the left lower lobe. Three thoracic radiologists blinded to contrast dose independently and randomly evaluated the quality of enhancement using a 3-point scale at the same levels. The two-sample Students t test was used to compare contrast opacification between groups; Spearmans correlation and the C-statistic were used to assess objective and subjective measurements. Interreader agreement was measured using Kendalls coefficient. RESULTS Mean contrast opacification differences between 125 mL versus 75 mL were not statistically significant (p > 0.21) at the lobar, segmental, and posterior basal rami, although the mean trended (p = 0.07) toward higher opacification of the medial basal ramus among 75 mL patients. Across all four pulmonary artery segments, there was good concordance between subjective and objective measurements, significantly higher than the null value of 0.50 (p > 0.05). For subsegmental arteries, concordance between objective and subjective measures was greater for the 75 mL group (p < 0.05). There was good interreader concordance, with a concordance coefficient of 0.70 (95% CI, 0.66-0.74). CONCLUSION Both objective and subjective measures of contrast opacification support a reduction from 125 to 75 mL of contrast medium required for pulmonary CTA.

Frequency and Severity of Pulmonary Hemorrhage in Patients Undergoing Percutaneous CT-guided Transthoracic Lung Biopsy: Single-Institution Experience of 1175 Cases

PURPOSE To evaluate the frequency and severity of pulmonary hemorrhage after transthoracic needle lung biopsy (TTLB) and assess possible factors associated with pulmonary hemorrhage. MATERIALS AND METHODS This retrospective study was approved by the institutional review board. The requirement to obtain informed consent was waived. Records from 1113 patients who underwent 1175 TTLBs between January 2008 and April 2013 were retrospectively reviewed. Primary outcomes were pulmonary hemorrhage, documented hemoptysis, and bleeding complications necessitating intervention. Pulmonary hemorrhage was graded as follows: 0, none; 1, less than or equal to 2 cm around the needle; 2, more than 2 cm and sublobar; 3, at least lobar; and 4, hemothorax. Patient, technique, and lesion-related variables were evaluated as predictors of pulmonary hemorrhage. Patient-related variables included main pulmonary artery diameter (mPAD) at computed tomography (CT), pulmonary artery pressures at echocardiography and right-sided heart catheterization, medications, chronic lung disease, bleeding diathesis, and immunodeficiency. Technique- and lesion-related variables included needle gauge, number of passes, pleura-needle angle, lesion size and morphologic characteristics, and distance to pleura. Univariate analysis was performed with χ(2), Fisher exact, and Student t tests. RESULTS Pulmonary hemorrhage occurred in 483 of the 1175 TTLBs (41.1%); hemoptysis was documented in 21 of the 1175 TTLBs (1.8%). Higher-grade hemorrhage (grade 2 or higher) occurred in 201 of the 1175 TTLBs (17.1%); five of the 1175 TTLBs (0.4%) necessitated hemorrhage-related admission. Higher-grade hemorrhage was more likely to occur with female sex (P = .001), older age (P = .003), emphysema (P = .004), coaxial technique (P = .025), nonsubpleural location (P < .001), lesion size of 3 cm or smaller (P < .001), and subsolid lesions (P = .028). Enlarged mPAD at CT (≥2.95 cm) was not significantly associated with higher-grade hemorrhage (P = .430). CONCLUSION Pulmonary hemorrhage after TTLB is common but rarely requires intervention. An enlarged mPAD at CT may not be a risk factor for higher-grade hemorrhage.

HRCT findings of proximal interruption of the right pulmonary artery.

The purpose of this study is to present the characteristic HRCT findings of the lung parenchyma in patients with proximal interruption of the right main pulmonary artery. HRCT findings of proximal interruption of the right pulmonary artery demonstrated reticular opacities, septal thickening, subpleural consolidation, cystic lung changes, and pleural thickening in all 5 patients; bronchial dilation and bronchial wall thickening in 4 patients; and subpleural ground glass opacity (GGO) in 3 patients. The changes may be caused by absent pulmonary artery perfusion and development of systemic vessel collateralization.

MR Imaging of Benign and Malignant Pleural Disease

MR imaging serves as a problem-solving tool in the diagnosis of inflammatory and infectious pleural diseases and primary and secondary pleural malignancies. Knowledge of MR imaging appearance of pleural diseases, including pleural effusions and empyema, benign and malignant pleural tumors, and especially mesothelioma, helps guide treatment decisions and surgical planning.