Lung volume reduction surgery: comparison of preoperative radiologic features and clinical outcome.

PURPOSE: To examine the relationship between preoperative radiologic findings and clinical outcome after lung volume reduction surgery. MATERIALS AND METHODS: In 50 consecutive patients, preoperative chest radiographs and computed tomographic (CT) scans were scored by four radiologists for features related to the severity and distribution of emphysema and compared with clinical improvement in forced expiratory volume in 1 second (FEV1), arterial partial pressure of oxygen, and exercise tolerance 6 months after surgery. RESULTS: In the 47 surviving patients, follow-up data showed greater postoperative improvement in function in patients with a global pattern of predominantly upper-lobe emphysema (P < .05) and in patients with a more heterogeneous distribution of emphysema, compressed lung, and a larger percentage of normal and mildly emphysematous lung (P < .05 for improvement in FEV1). Radiographic scores for individual features were more strongly correlated with outcome than CT scores. The combination of upper-lobe severity and percentage of normal and mildly emphysematous lung at CT were the strongest predictors of improvement in FEV1 (r2 = .49). The three patients who died were older (P = .05) and had more severe, diffuse emphysema compared with other patients. CONCLUSION: Imaging studies may help predict the degree of improvement and therefore should be considered an integral part of an objective patient selection process. Radiography alone may be adequate for initial screening.

Depiction of pulmonary emboli with spiral CT: optimization of display window settings in a porcine model.

PURPOSE: To determine optimal spiral computed tomographic (CT) image display for depiction of pulmonary emboli (PE). MATERIALS AND METHODS: Autologous PE detected in 10 pigs with contrast material-enhanced spiral CT were displayed with six display window settings (standard mediastinal window and five modified windows referenced to attenuation values in pulmonary artery [PA] branches). The thrombus gray level and gray level contrast and separability of PE versus those of the local PA branch were computed for each window setting; results were compared with repeated measured analysis of variance. RESULTS: Of 114 PE detected pathologically, 28 were visible with spiral CT. Two of the 28 PE were not detectable with standard mediastinal windows. Statistically significantly improved gray level contrast and separability were noted with modified windows referenced to the second-order PA branch and the local PA branch than with the standard mediastinal and other modified window settings (P < .05). However, thrombus gray level was statistically significantly higher with the standard mediastinal window (P < .05). CONCLUSION: PE are best depicted as filling defects when displayed with a modified window referenced to the right or left main PA attenuation. Standard mediastinal windows are useful for identifying vessels that are occluded completely with PE.

Pseudomass due to atelectasis in patients with severe bullous emphysema.

OBJECTIVE: This study describes the atypical presentation of atelectasis as a pseudomass in patients with severe bullous emphysema. MATERIALS AND METHODS: The radiologic studies and clinical records of 11 patients with severe bullous emphysema and mass-like opacities representing atelectatic lung were reviewed. The diagnosis was proven by surgery in nine patients and by follow-up imaging in two patients. RESULTS: Pseudomasses were found primarily in the upper lobes and the right middle lobe (n = 10). Common features included an oblong, lenticular, or triangular shape (n = 8); a sharp interface with aerated lung (n = 9); hyperexpansion of the hemithorax containing the pseudomass (n = 8); a central location abutting the mediastinum (n = 8); and adjacent emphysema (n = 11). CT revealed subsegmental atelectasis in other lobes adjacent to the bullous lung in six patients. In three patients, the pseudomasses were associated with persistent distention of large bullae following spontaneous pneumothoraces. Reexpansion of pseudomasses occurred in seven of the eight patients who underwent resection of bullous lung. CONCLUSION: These pseudomasses most likely result from compression of the lung by adjacent large bullae. The diagnosis should be suspected when central, sharply marginated, mass-like opacities that are oblong, lenticular, or triangular are bordered by severe bullous emphysema.

Bronchial dehiscence after lung transplantation: correlation of CT findings with clinical outcome.

PURPOSE: To determine whether computed tomography (CT) can help predict which patients will require surgical or bronchoscopic intervention during healing of bronchial anastomotic dehiscence after lung transplantation. MATERIALS AND METHODS: The authors followed up 25 bronchoscopically proved dehiscent anastomoses through healing in 19 patients who underwent lung transplantation. CT findings were correlated with bronchoscopic results and clinical outcome. RESULTS: A bronchial defect and extraluminal air were initially present at CT in all 25 dehiscent anastomoses. Of 12 bronchial defects less than or equal to 4 mm, only one required intervention during healing (P < .05). Of 12 bronchial defects greater than 4 mm, six required intervention during healing. Eight of nine dehiscences with a tiny or small amount of extraluminal air healed with conservative treatment. Of 16 dehiscences associated with a moderate to large amount of extraluminal air, nine were treated conservatively and six required therapeutic intervention. Three healing anastomoses required bronchial stent placement. One patient died in the perioperative period. CONCLUSION: In patients with small dehiscences ( < 4mm) and patients with a tiny or small amount of extraluminal air, the anastomosis tends to heal without sequela. When patients have larger amounts of extraluminal air or larger ( > 4mm) dehiscences at presentation, CT cannot help predict which patients will require intervention.

Imaging evaluation of obstructive atelectasis.

Segmental or lobar atelectasis is a common radiographic finding in patients with bronchial obstruction. Although in many cases the presence and cause of atelectasis can be ascertained from the plain chest radiograph, computed tomography (CT) often provides valuable additional information, particularly with regard to the precise location and extent of the obstructing process. CT also can be used to differentiate between benign and malignant causes of obstructive atelectasis. After administration of intravenous contrast material, CT may distinguish a proximal obstructing tumor from collapsed lung or adjacent mediastinal structures. In some patients, magnetic resonance imaging (MRI) can provide comparable and/or complementary information. In this article, we review the major applications of CT and MRI, as well as the capabilities and limitations of both techniques, in the evaluation of patients with obstructive atelectasis.

Lung transplant edema: chest radiography after lung transplantation--the first 10 days.

PURPOSE: To determine the imaging spectrum and clinical correlates of lung transplant edema within the first 10 days after lung transplantation. MATERIALS AND METHODS: The study group consisted of 105 consecutive lung transplant recipients. Lung infiltrates on chest radiographs were scored and characterized. Findings that satisfied the accepted description of reperfusion edema were identified. Lung ischemia times and the clinical or biopsy diagnosis of acute rejection were correlated with radiographic findings. RESULTS: Lung infiltrates compatible with reperfusion edema were seen in 97% of transplanted lungs without a demonstrable correlation with lung ischemia times. Lung scores between groups of patients treated and not treated for acute rejection were not statistically significantly different. CONCLUSION: The spectrum of findings attributable to lung transplantation or reperfusion edema is variable and diminishes the use of chest radiography as an early postoperative modality for monitoring acute rejection.

Bronchial dehiscence in lung transplantation: CT evaluation.

PURPOSE: To determine the signs of bronchial dehiscence on computed tomographic (CT) scans in a select subset of lung transplant recipients. MATERIALS AND METHODS: In 23 patients who underwent single or bilateral sequential lung transplantations, CT scans were obtained for suspected or known diagnosis of bronchial dehiscence. Dehiscence was identified at bronchoscopy in 17 of the 23 patients. In four patients, the dehiscence was bilateral, resulting in 21 anastomotic dehiscences. RESULTS: CT allowed identification of a bronchial defect in 100% of the bronchoscopically proved dehiscences but only one (5%) of the 18 bronchoscopically proved intact anastomoses. CT also demonstrated extraluminal air in 100% of the bronchoscopically proved dehiscences. Only a very small amount of extraluminal air (without associated bronchial defect) was identified on CT scans in the early postoperative period in four additional patients with bronchoscopically proved intact anastomoses. CONCLUSION: CT is an easily performed and well-tolerated technique that has a high degree of sensitivity and specificity for depicting bronchial dehiscence.

Aortic dissection: effect of prospective chest radiographic diagnosis on delay to definitive diagnosis.

PURPOSE: To determine the effect of the interpretation of plain chest radiographs on the time to definitive diagnosis of aortic dissection. MATERIALS AND METHODS: The authors evaluated chest radiographs from 75 patients in whom chest radiography was performed before aortic dissection was diagnosed. The radiographs and available comparison images were retrospectively reviewed to identify cases in which aortic dissection should have been suggested before the diagnosis was made. RESULTS: Radiographic reports suggested that only 19 patients (25%) had an aortic dissection or thoracic aortic aneurysm or needed additional imaging of the aorta. No statistically significant correlation existed between interpretation of the chest radiographs and delay to diagnosis, type of dissection, availability of previously obtained images, or presence of characteristic clinical symptoms. Retrospective analysis showed that the chest radiographs of 36 patients (48%) contained sufficient findings to suggest the diagnosis. In five patients, failure to prospectively suggest dissection was associated with a delay to diagnosis of more than 24 hours. CONCLUSION: Although prospective interpretation of the chest radiograph shortened the delay to definitive diagnosis for only a limited number of patients, retrospective analysis suggests that the delay can be shortened for additional patients.

Chest radiography in patients with early stage prostatic carcinoma. Effect on treatment planning and cost analysis.

STUDY OBJECTIVE: An evaluation of the impact of routine preoperative chest radiographs was retrospectively undertaken in a pilot group of 292 patients with prostatic carcinoma who were part of a prospective study of prostate specific antigen screening for prostate carcinoma. DESIGN: Retrospective. SETTING: Hospital-based outpatients. PATIENTS AND PARTICIPANTS: A cost-effectiveness model was used to assess the value of routine chest radiography in this patient population. Chest radiography findings were categorized into four groups based on follow-up and impact. MEASUREMENTS AND RESULTS: Forty-three patients (15 percent) had a total of 45 positive findings on their chest radiographs. No patient had intrathoracic metastases from prostatic carcinoma. Only two patients (both with unsuspected second neoplasms) had findings that impacted on their treatment and one avoided retropubic radical prostatectomy. Total cost was $2,000 (based on Medicare reimbursement), or $14,000 (based on physician and hospital charges). CONCLUSION: Although benefit is small in terms of number of patients affected, clinical impact, in the two patients with significant findings, was great. Although cost-effectiveness cannot be confirmed on the basis of this series, further evaluation of its utility for this application should be undertaken.

Three-dimensional radiation treatment planning study for patients with carcinoma of the lung.

PURPOSE: Several reports in the literature suggest that local-regional control and possibly survival could be improved for inoperable nonsmall cell lung cancer if the radiation dose to the target volume could be increased. Higher doses, however, bring with them the potential for increased side effects and complications of normal tissues. Three-dimensional treatment planning has shown significant potential for improving radiation treatment planning in several sites, both for tumor coverage and for sparing of normal tissue from high doses of radiation and, thus, has the potential of developing radiation therapy techniques that result in uncomplicated local-regional control of lung cancer. We have studied the feasibility of large-scale implementation of true three-dimensional technologies in the treatment of patients with cancers of the thorax. METHODS AND MATERIALS: CT scans were performed on 10 patients with inoperable nonsmall cell lung cancer to obtain full volumetric image data, and therapy was planned on our three-dimensional radiotherapy treatment planning system. Target volumes were determined using the new ICRU nomenclature--Gross Tumor Volume, Clinical Target Volume, and Planning Target Volume. Plans were performed according to our standard treatment policies based on traditional two-dimensional radiotherapy treatment planning methodologies and replanned using noncoplanar three-dimensional beam techniques. The results were quantitatively compared using dose-volume histograms, dose-surface displays, and dose statistics. RESULTS: Target volume delineation remains a difficult problem for lung cancer. Defining Gross Tumor Volume and Clinical Target Volume may depend on window and level settings of the three-dimensional radiotherapy treatment planning system, suggesting that target volume delineation on hard copy film is inadequate. Our study shows that better tumor coverage is possible with three-dimensional plans. Dose to critical structures (e.g., the heart) could often be reduced (or at least remain acceptable) using noncoplanar beams even with dose escalation to 75 to 80 Gy for the planning volume surrounding the Gross Target Volume. CONCLUSION: Commonly used beam arrangements for treatment of lung cancer appear to be inadequate to safely deliver tumor doses of higher than 70 Gy. Although conventional treatment techniques may be adequate for tumor coverage, they are inadequate for sparing of normal tissues when the prescription dose is escalated. The ability to use noncoplanar fields for such patients is a major advantage of three-dimensional planning. This capability led to better tumor coverage and reduced dose to critical normal tissues. However, this advantage was achieved at the expense of a greater time commitment by the treatment planning staff (particularly the radiation oncologist) and a greater complexity of treatment delivery. In summary, three-dimensional radiotherapy treatment planning appears to provide the radiation oncologist with the necessary tools to increase tumor dose, which may lead to increased local-regional control in patients with lung cancer while maintaining normal tissue doses at acceptable tolerance levels.

New techniques in chest radiography.

Advances in film-screen radiography (e.g., InSight) and beam equalization radiography (e.g., AMBER) have improved the quality of standard chest radiographs. Despite the improved visibility of the mediastinum and retrocardiac and retrodiaphragmatic lung with AMBER, it is debatable whether this advantage outweighs its disadvantages, especially the increased cost of the unit and decreased reliability. The benefits of storage phosphor systems have largely been in the area of bedside radiography, where consistent image quality over a wide range of exposures and image processing compensate for the lower spatial resolution. More routine application of this technology to standard chest radiography is likely, especially as image processing techniques improve and digital units become more cost effective. Storage phosphor digital imaging may be the most appropriate technique for entry of images into a picture archiving and communication system in which images stored in image management systems can be displayed on high-resolution monitors in local or distant sites. Such systems have the potential of improving patient care by providing more rapid access to radiographic images, especially if the image is accompanied by an immediate report. Because of the significant expense of a picture archiving and communication system, their introduction is likely to be gradual, via networks in specific areas such as between intensive care units and radiology departments.

CT screening for comorbid disease in patients with prostatic carcinoma: is it cost-effective?

OBJECTIVE: The role of imaging in patients with newly diagnosed prostatic carcinoma is controversial. Currently, 35% of patients with prostatic carcinoma undergo CT at the time of diagnosis, despite reports of the lack of efficacy of CT in staging the disease. We sought to evaluate the cost-effectiveness of CT in detecting unrelated comorbid disease (significant disease unrelated to prostatic carcinoma) that might affect decisions on treatment in this population of patients. MATERIALS AND METHODS: We reviewed the medical records of 273 consecutive patients with newly diagnosed prostatic carcinoma who had CT of the abdomen and pelvis as part of their preoperative evaluation. Using costs based on Medicare reimbursements, we assessed the impact of the CT findings (related to comorbid disease) on overall costs and savings related to the workup and treatment of these patients. RESULTS: Sixty-six patients (24%) had findings suggestive of comorbid disease. The CT findings had near-term impact on only four patients (two in whom large abdominal aortic aneurysms were detected and two in whom second primary cancers were found), despite nearly $155,000 spent on the screening CT scans and more than $4400 spent on further evaluation of false-positive CT findings. The clinical impact varied from intervening semiurgent surgery to cancellation of prostatic surgery and institution of radiation therapy. CONCLUSION: CT is not cost-effective in screening for comorbid disease that would affect treatment in patients with newly diagnosed prostatic carcinoma.

Diagnosis of pulmonary complications associated with lung transplantation in children: value of CT vs histopathologic studies.

OBJECTIVE: The purpose of this study was to compare the CT findings with those of histopathologic studies to determine if CT can be used to differentiate between the pulmonary parenchymal complications that occur in children after lung transplantation. MATERIALS AND METHODS: Seventeen children who underwent 14 bilateral and three single lung transplantations were studied. The study population included nine girls and eight boys 2-16 years old (mean, 11 years). CT scans were examined for evidence of interlobular septal thickening, air-space consolidation, ground-glass opacities, nodules, bronchial dilatation, decreased vascularity, and pleural effusions. Thirty-one histopathologic diagnoses from 25 transbronchial biopsies were available for comparison with CT findings. The final histopathologic diagnoses were acute rejection (n = 10), chronic rejection (n = 6), infection (n = 7), nonspecific findings (n = 4), and no abnormalities (n = 4). RESULTS: No significant difference was noted in the CT findings in patients with acute rejection, chronic rejection, and infection. CONCLUSION: In this limited study of children, CT findings were not helpful in differentiating between the different parenchymal pulmonary complications associated with lung transplantation. On the basis of these preliminary findings, we recommend caution in suggesting specific diagnoses based on CT scans without histologic proof.

Pediatric lung transplantation: radiographic-histopathologic correlation.

Chest radiographic and histopathologic findings were retrospectively reviewed to determine the spectrum of findings in 16 children who underwent a total of 19 lung transplantations. Radiographs were evaluated for air-space disease, interstitial disease, Kerley B lines, pleural fluid, and cardiac size, and the interval from transplantation to the onset of complications was determined. Radiographic findings were correlated with 62 histopathologic diagnoses obtained from 51 transbronchial and open lung biopsy specimens. The final histopathologic diagnoses were acute rejection (n = 19), chronic rejection (n = 8), infection (n = 11), lymphoproliferative disorder (n = 4), and nonspecific (n = 20). The radiographic patterns of the complications were not significantly different. Seventy-nine percent (15 of 19) of episodes of acute rejection and 64% (seven of 11) of episodes of infection occurred within 5 weeks of transplantation, while 63% (five of eight) of the episodes of chronic rejection occurred after this period. Since chest radiographs are nonspecific, caution should be exercised in basing clinical decisions only on the radiographic pattern in the absence of corroborative clinical and histopathologic findings.

Chondrosarcoma of the larynx: CT features.

PURPOSE: To define the typical CT features of chondrosarcoma of the larynx. PATIENTS AND METHODS: Results of CT studies, performed on 10 patients with pathologically proved chondrosarcoma of the larynx, were retrospectively reviewed and correlated with clinical presentation. RESULTS: In all patients, the mass was detected on CT. The most frequent site of origin of the tumor was the cricoid cartilage (nine cases) followed by the thyroid cartilage (one case). Coarse or stippled calcification within the tumor was the most helpful radiologic finding and was seen in every case. In eight patients, the tumor had both an endolaryngeal and an extralaryngeal growth pattern, whereas in two patients the tumor was entirely endolaryngeal. Hoarseness, dyspnea, and dysphagia were the most common symptoms. In all patients presenting with dyspnea, the tumor exhibited endolaryngeal components. In patients presenting with hoarseness, three tumors had endolaryngeal and extralaryngeal components and two tumors were entirely endolaryngeal. CONCLUSION: Cross-sectional imaging afforded excellent evaluation of the airway as well as the extralaryngeal component of the tumor.

Omental flap in lung transplantation.

Some surgeons performing lung transplantation will wrap the bronchial anastomosis with omentum in an attempt to improve healing. The authors retrospectively reviewed the chest radiographs and computed tomographic (CT) scans of 31 patients who underwent lung transplantation with bronchial omentopexy to determine the CT appearance of the intrathoracic omentum and the frequency and type of chest radiographic manifestations created by the omental flap. The omental flap was seen at CT in all patients, was predominantly of fatlike attenuation, and contained linear areas of increased attenuation representing omental vessels. In 16 patients (52%), a total of 29 chest radiographic findings that corresponded to the omental flap were seen. There was no statistically significant correlation between the type of operative procedure and the presence of a chest radiographic correlate for the omentum. The results showed that the omental flap is a potential diagnostic pitfall on post-lung transplantation chest radiographs; when there is confusion, however, the omentum can be identified with CT because of its attenuation value and characteristic course.

CT of focal pulmonary masses in childhood.

Focal pulmonary masses in children encompass a spectrum of conditions including congenital lesions, inflammatory masses, hematomas, and benign and malignant tumors. Congenital masses include bronchial atresia, sequestration, cystic adenomatoid malformation, and pulmonary vascular anomalies. Inflammatory masses most commonly result from infection and include pulmonary abscess, granulomas, and postinflammatory pseudotumors. Blunt trauma can cause a hematoma, which decreases in size on serial radiographs. Pulmonary neoplasms may be benign such as papilloma, hamartoma, and bronchial carcinoid tumor (low-grade malignancy), or they may be malignant as in sarcoma, carcinoma, and pulmonary blastoma. Because computed tomography (CT) is the most sensitive technique in detecting and helping characterize parenchymal disease, it has become the procedure of choice for further investigation of lesions seen or suggested on plain chest radiographs. Understanding the CT appearance of these lesions can allow an accurate diagnosis and optimize management of the patient's condition.

Anatomy of the major fissure: evaluation with standard and thin-section CT.

The major fissures of the right and left lungs were studied with standard computed tomography (CT) (10-mm-thick sections) and thin-section CT (2-mm-thick sections) in 50 patients. On standard CT scans, the major fissures were seen in 90%-100% of cases at each of three selected levels. They usually appeared as hypoattenuating bands and less often as lines or hyperattenuating bands. Although in most cases the major fissure was seen as a line on thin-section CT scans, this appearance was more common in the upper portion of the left major fissure than in the upper portion of the right major fissure. A "double-fissure sign" was most frequently seen at the base of the left lung; however, the sign was also seen at higher levels, with approximately equal frequency in the right and left lungs. An incomplete major fissure was noted in the right lung in 32 cases (64%) and in the left lung in 26 cases (52%). The upper and middle portions of the left major fissure were less frequently incomplete than were the comparable portions of the right major fissure. Thin-section CT provided better delineation of the major interlobar fissures than did standard CT.