Suzanne L. Aquino

Pulmonary artery sarcomas: a review of clinical and radiologic features.

Primary pulmonary artery sarcomas are rare tumors that are frequently misdiagnosed as chronic pulmonary emboli. We present classic imaging findings and review data from 136 previously reported sarcomas. We believe that the imaging findings can be quite specific, especially when the disease is advanced. Despite a recent increase in antemortem diagnosis, the prognosis remains poor. Surgery prolongs survival time and is potentially curative. Experience with adjuvant chemotherapy and radiotherapy is limited.

Significance of incidental thyroid lesions detected on CT: correlation among CT, sonography, and pathology.

OBJECTIVE The purpose of our study was to determine the prevalence of malignancy in incidental abnormalities of the thyroid gland detected on CT and to determine the relative accuracy of characterizing these abnormalities on CT as compared with sonography and pathology. MATERIALS AND METHODS We searched our departments computerized clinical database for all thoracic and cervical CT scans in which a new abnormality was incidentally identified in the thyroid gland from 1998-2001. Two hundred thirty patients with abnormal findings in the gland on CT subsequently underwent thyroid sonography, and 118 of the 230 patients underwent a diagnostic biopsy or resection. CT and sonographic images were directly reviewed to identify imaging features of each thyroid abnormality, including the location, size, appearance, and presence or absence of calcifications. Associations were evaluated using Fishers exact test of significance and the Students t test. The overall rate of malignant and potentially malignant lesions among these incidental abnormalities of the thyroid gland was calculated. RESULTS CT findings matched the sonographic characterization in 122 patients (53.0%), correctly identified the dominant nodule but missed multinodularity in 69 (30.0%) patients, and underestimated the number of nodules in 24 (10.4%) patients. CT overestimated the number of nodules in 5 (2.2%) patients and was false-positive for lesions in 10 patients (4.3%). Ninety-one patients with a single or dominant nodule on CT had pathologic correlation: 7 nodules were malignant, 17 showed malignant potential, and 67 were benign. Of 27 patients with multinodular or enlarged thyroid glands on CT and histopathologic correlation, 2 lesions were malignant and 25 benign. The presence of punctate calcifications on CT significantly correlated to the presence of microcalcifications on sonography (p < 0.02). Benign nodules were significantly smaller (mean, 2.16 +/- 1.01 cm; range, 0.6-4.5 cm) than malignant and potentially malignant nodules (mean, 2.79 +/- 0.99 cm; range, 0.7-4.6 cm) (p = 0.01). Patients 35 years or younger who had a thyroid lesion on CT were more likely to have malignancy (p < 0.01). Overall, among incidentally detected lesions of the thyroid gland, there was at least a 3.9% rate of malignancy (95% CI: 1.8-7.3%) and 7.4% rate of malignant potential (95% CI: 4.4-11.6%). CONCLUSION There is at least an 11.3% prevalence of malignant or potentially malignant lesions among incidental thyroid abnormalities detected on CT. Patients 35 years or younger who have incidental abnormalities have a significantly greater rate of malignancy. No CT feature reliably distinguishes benign from malignant lesions in the thyroid gland. CT underestimates the number of nodules relative to sonography, which suggests that sonography is a useful adjunctive test after the incidental detection of a thyroid abnormality on CT.

Acquired tracheomalacia: detection by expiratory CT scan.

Purpose The purpose of this work was to determine whether cross-sectional area and coronal and sagittal diameter measurements of the trachea between inspiration and end-expiration on CT are significantly different between patients with acquired tracheomalacia and those without this condition. Method Inspiratory and end-expiratory CT scans of the trachea of 23 normal patients and 10 patients with acquired tracheomalacia were analyzed. Percent changes in cross-sectional area, coronal, and sagittal diameters were calculated. Results For patients with tracheomalacia, mean percent changes in the upper and middle trachea between inspiration and expiration were 49 and 44%; mean changes in the coronal and sagittal diameters in the upper and middle tracheal were 4 and 10% and 39 and 54%, respectively. Control group mean percent changes in the upper and middle tracheal area were 12 and 14%, respectively, and mean changes in the coronal and sagittal diameters in the upper and middle trachea were 4 and 4% and 11 and 13%, respectively. Significant differences were calculated for changes in cross-sectional area and sagittal diameter between groups (p < 10−5). Based on receiver operator curve analysis, a >18% change in the upper trachea and 28% change in the midtrachea between inspiration and expiration were observed; the probability of tracheomalacia was 89–100%. The probability of tracheomalacia was >89%, especially if the change in sagittal diameter was >28%. Conclusion By measuring changes in tracheal cross-sectional area and sagittal diameters between inspiratory and end-expiratory CT, a significant difference can be identified between normal patients and those with acquired tracheomalacia.

Imaging Features of Sarcoidosis on MDCT, FDG PET, and PET/CT

OBJECTIVE The objectives of this article are to discuss the epidemiology and natural history of sarcoidosis; to review the classic imaging features of sarcoidosis on radiography, CT, and 67Ga nuclear medicine scans; and to present clinical examples of sarcoidosis as seen on PET and PET/CT in the chest, abdomen and pelvis, and bones. CONCLUSION The imaging features of sarcoidosis are diverse and can be seen on a variety of imaging techniques. It is important for radiologists and nuclear medicine physicians to recognize the common imaging features and patterns of sarcoidosis in order to raise the possibility in the appropriate clinical setting.

Improved radiologic staging of lung cancer with 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography and computed tomography Registration

Purpose To determine if volumetric nonlinear registration or registration of thoracic computed tomography (CT) and 2-[18F]-fluoro-2-deoxy-d-glucose–positron emission tomography (FDG–PET) datasets changes the detection of mediastinal and hilar nodal disease in patients undergoing staging for lung cancer and if it has any impact on radiologic lung cancer staging. Method Computer-based image registration was performed on 45 clinical thoracic helical CT and FDG–PET scans of patients with lung cancer who were staged by mediastinoscopy and/or thoracotomy. Thoracic CT, FDG–PET, and registration datasets were each interpreted by 2 readers for the presence of metastatic nodal disease and were staged independently of each other. Results were compared with surgical pathologic findings. Results One hundred and thirty lymph node stations in the mediastinum and hila were evaluated each on CT, PET, and registration datasets. Sensitivity, specificity, positive predictive value, and negative predictive value, respectively, for detecting metastatic nodal disease for CT were 74%, 78%, 55%, 88%; for PET with CT side by side, 59% to 76%, 77% to 89%, 48% to 68%, and 84% to 91%; and for CT–PET registration, 71% to 76%, 89% to 96%, 70% to 86%, and 90% to 91%. Registration images were significantly more sensitive in detecting nodal disease over PET for 1 reader (P = 0.0156) and were more specific than PET (P = 0.0107 and 0.0017) in identifying the absence of mediastinal disease for both readers. Registration was significantly more accurate for staging when compared with PET for both readers (P = 0.002 and 0.035). Conclusion Registration of CT and FDG–PET datasets significantly improved the specificity of detecting metastatic disease. In addition, registration improved the radiologic staging of lung cancer patients when compared with CT or FDG–PET alone.

Radiologic determination of intravascular volume status using portable, digital chest radiography: a prospective investigation in 100 patients.

ObjectiveTo answer the following questions: Can the digital chest roentgenogram (CXR) be used to differentiate patients’ volume status? Do clinical data alter radiologists’ accuracy in interpreting the digital CXR? DesignProspective cohort study. SettingNine adult intensive care units of a tertiary care medical center. PatientsOne hundred thirty-five consecutive patients with pulmonary artery catheters, of whom 35 were excluded because of unacceptable pulmonary artery occlusion pressure (PAOP) tracings. MethodsEach patient had a portable, anteroposterior, supine digital CXR. Clinicians evaluated volume status and then measured hemodynamic data within 1 hr of the CXR. Digital CXRs were independently interpreted on two separate occasions (with and without clinical information) by three experienced chest radiologists, and these interpretations were compared with hemodynamic data. ResultsOf the 100 patients, 39 had PAOP >18 mm Hg, whereas 61 had PAOP <18 mm Hg. Radiologists’ accuracy in differentiating volume status increased with incorporation of clinical data (56% without vs. 65% with clinical data, p = .009). Using objective receiver operating characteristic–derived cutoffs of 70 mm for vascular pedicle width and 0.55 for cardiothoracic ratio, radiologists’ accuracy in differentiating PAOP >18 mm Hg from PAOP <18 mm Hg was 70%. The intrareader and the inter-reader correlation coefficients were very high. The likelihood ratio of the CXR in determining volume status using the objective vascular pedicle width and cardiothoracic ratio measures was 3.1 (95% confidence interval, 1.9–6.0), significantly higher than subjective CXR interpretations with and without clinical data (p < .001). ConclusionsDifferentiating intravascular volume status with portable, supine, digital CXRs may be improved by using objective cutoffs of vascular pedicle width >70 mm and cardiothoracic ratio >0.55 or by incorporating clinical data.

Does Initial Staging or Tumor Histology Better Identify Asymptomatic Brain Metastases in Patients with Non–small Cell Lung Cancer?

Background: To determine whether the distribution, staging features, or tumor histology of non–small cell lung cancer (NSCLC) distinguishes neurologically symptomatic from asymptomatic patients initially diagnosed with lung cancer, and to determine whether these factors may predict the presence of brain metastasis. Methods: We performed a retrospective review of 809 patients with NSCLC and brain metastases who were treated in our institution between January 1996 and March 2003. Patients who had brain metastasis on initial staging were included. Thoracic computed tomographic scans were reviewed for lung tumor features and staging. Neurological computed tomographic or magnetic resonance image scans were assessed for distribution of brain metastases. Medical records were reviewed for comprehensive staging, tumor histology, and neurological symptoms. Fishers exact test was used to determine any differences among tumor histology, staging, and imaging features among patients with or without neurological symptoms. Results: Of the 809 patients, 181 had brain metastasis at initial staging. Among these 181 patients, 120 (66%) presented with neurological symptoms (group 1); 61 (34%) patients were asymptomatic (group 2). Patients with adenocarcinoma and large-cell carcinoma had greater odds of brain metastases than patients with squamous cell carcinoma (p = 0.001). There were 106 (58.6%) patients with adenocarcinoma, 32 (17.7%) with large cell carcinoma, and 18 (9.9%) with squamous cell carcinoma. In both groups, most lung cancers were in the right lung with upper lobe dominance. No significant difference in tumor histology or T stage was found between groups, although group 2 was more likely to have a higher N stage. Of the 181 patients with brain metastasis, 60 (33.1%) had N0 disease, 51 (28.2%) had T1 disease, and 23 (19.2%) had no other metastasis. There was no correlation between number/distribution of brain metastases and tumor histology, although patients with disease in the cerebellum or temporal lobes had a greater likelihood of neurological symptoms (odds ratio 3.7). Conclusion: There was no significant difference in tumor histology, staging, or distribution between symptomatic or asymptomatic patients with NSCLC with brain metastases. The odds of brain metastases were greater in those with adenocarcinoma or large-cell carcinoma.

Optimal CT breathing protocol for combined thoracic PET/CT

OBJECTIVE The objective of this study was to determine the optimal breathing protocol for combined PET/CT scans of the thorax. SUBJECTS AND METHODS Eighty combined PET/CT scans were obtained in 64 patients (30 women, 34 men; mean age, 57 years; range, 19-86 years). The 80 PET/CT scans consisted of five group of patients (16 PET/CT scans per group) who underwent whole-body combined 18F-FDG PET/CT with different CT breathing protocols: expiration, mid suspended breath-hold, quiet breathing, small breath in, and regular breath in. The quality of alignment was analyzed at the diaphragm, aortic arch, heart, thoracic spine, and lung apices using a scale of ratings from 1 (very poor) to 5 (excellent). The Kruskal-Wallis test was used to compare alignment between breathing protocols for each anatomic reference point. RESULTS Alignment of the PET and CT data sets was excellent with three breathing protocols: expiration, mid suspended breath-hold, and quiet breathing, with no statistical differences. Significant misalignment occurred at the diaphragm (p < 0.0001) and heart (p < 0.0001) with the small breath-in and regular breath-in techniques. CONCLUSION Excellent image fusion of combined PET/CT data sets in the thorax, especially at the diaphragm and heart, can be achieved with expiration, mid suspended breath-hold, or quiet breathing. Quiet breathing is recommended for optimal patient comfort during acquisition of attenuation-correction CT data sets.

Herpes simplex virus 1 pneumonia : Patterns on CT scans and conventional chest radiographs

PURPOSE The goal of our study was to describe the herpes simplex virus type 1 (HSV 1) pneumonia patterns on CT scans and chest radiographs. METHOD We retrospectively reviewed clinical records and chest radiographs of 24 patients with HSV 1 pneumonia and 10 with pneumonia from combined HSV and mixed flora infection. We also reviewed CT scans available for eight patients with HSV pneumonia and four with mixed pneumonia. RESULTS CT scans of eight patients with HSV pneumonia demonstrated multifocal segmental and subsegmental ground-glass opacities (n = 8), additional focal areas of consolidation (n = 6), scattered distribution (n = 6), and pleural effusions (n = 7). Chest radiographs (23 patients) showed patchy segmental and subsegmental ground-glass opacities and consolidation (n = 23), scattered distribution (n = 20), and pleural effusions (n = 12). Radiographic patterns for isolated HSV pneumonia and mixed flora pneumonia were not significantly different. CONCLUSION With a growing population of at-risk immunosuppressed patients, it is important to recognize CT and chest radiography patterns consistent with, although nonspecific for, HSV 1 pneumonia.

Association of lung perfusion disparity and mortality in patients with cystic fibrosis awaiting lung transplantation.

BACKGROUND The risk of death for patients with end-stage cystic fibrosis awaiting lung transplantation remains high and most patients succumb to respiratory failure. This study was conducted to evaluate the usefulness of ventilation-perfusion scintillation scans, obtained during the pre-transplant period, to identify patterns that predict prognosis while on the waiting list. These patterns were compared with other pulmonary physiologic markers of ventilation and perfusion obtained from pulmonary function and cardiopulmonary exercise tests. METHODS From November 1990 to January 1999, 46 patients with cystic fibrosis were listed for bilateral lung transplantation. Fourteen (30.4%) died while waiting for a transplant (Group 1), whereas 32 were transplanted successfully or remain alive and waiting (Group 2). Mean arterial blood gas values, Brasfield radiograph scores, cardiopulmonary exercise data and the degree of scintillation scan abnormalities between lungs were compared for each group. RESULTS Mean survival for Group 1 was 10.2 +/- 1.7 months, and for Group 2 was 23.5 +/- 3.0 months (p < 0.001). The right upper lung zone was the most severely affected segment. The Cox proportional hazards model revealed an increased perfusion disparity and resting hypercapnia as the main predictors of death while on the transplant list. The Kaplan-Meier analysis indicated greater survival for the groups with <30% disparity between lungs on the pre-transplant scintillation scans. CONCLUSIONS The results suggest that severe, unilateral perfusion abnormalities seen on scintillation scans in patients with cystic fibrosis are associated with an increased risk of dying while on the lung transplant waiting list and may be helpful in identifying patients who should be considered for early or living-donor transplantation.