Diffusion and perfusion MRI of the lung and mediastinum

With ongoing technical improvements such as multichannel MRI, systems with powerful gradients as well as the development of innovative pulse sequence techniques implementing parallel imaging, MRI has now entered the stage of a radiation-free alternative to computed tomography (CT) for chest imaging in clinical practice. Whereas in the past MRI of the lung was focused on morphological aspects, current MRI techniques also enable functional imaging of the lung allowing for a comprehensive assessment of lung disease in a single MRI exam.Perfusion imaging can be used for the visualization of regional pulmonary perfusion in patients with different lung diseases such as lung cancer, chronic obstructive lung disease, pulmonary embolism or for the prediction of postoperative lung function in lung cancer patients. Over the past years diffusion-weighted MR imaging (DW-MRI) of the thorax has become feasible with a significant reduction of the acquisition time, thus minimizing artifacts from respiratory and cardiac motion. In chest imaging, DW-MRI has been mainly suggested for the characterization of lung cancer, lymph nodes and pulmonary metastases.In this review article recent MR perfusion and diffusion techniques of the lung and mediastinum as well as their clinical applications are reviewed.     

State-of-the-art MR Imaging for Thoracic Diseases

Since thoracic MR imaging was first used in a clinical setting, it has been suggested that MR imaging has limited clinical utility for thoracic diseases, especially lung diseases, in comparison with x-ray CT and positron emission tomography (PET)/CT. However, in many countries and states and for specific indications, MR imaging has recently become practicable. In addition, recently developed pulmonary MR imaging with ultra-short TE (UTE) and zero TE (ZTE) has enhanced the utility of MR imaging for thoracic diseases in routine clinical practice. Furthermore, MR imaging has been introduced as being capable of assessing pulmonary function. It should be borne in mind, however, that these applications have so far been academically and clinically used only for healthy volunteers, but not for patients with various pulmonary diseases in Japan or other countries. In 2020, the Fleischner Society published a new report, which provides consensus expert opinions regarding appropriate clinical indications of pulmonary MR imaging for not only oncologic but also pulmonary diseases. This review article presents a brief history of MR imaging for thoracic diseases regarding its technical aspects and major clinical indications in Japan 1) in terms of what is currently available, 2) promising but requiring further validation or evaluation, and 3) developments warranting research investigations in preclinical or patient studies. State-of-the-art MR imaging can non-invasively visualize lung structural and functional abnormalities without ionizing radiation and thus provide an alternative to CT. MR imaging is considered as a tool for providing unique information. Moreover, prospective, randomized, and multi-center trials should be conducted to directly compare MR imaging with conventional methods to determine whether the former has equal or superior clinical relevance. The results of these trials together with continued improvements are expected to update or modify recommendations for the use of MRI in near future.     

Radiodiagnostik der Lunge

Radiological cross-sectional imaging modalities, particularly computed tomography (CT) have become the mainstays for diagnosing lung disease in recent years. These enable morphological visualization of pathological processes with the greatest possible spatial resolution. Modern technical developments and complementary strategies have led to new applications and new functional assessments which need to be reviewed together with state-of-the-art techniques in nuclear imaging. The diagnosis of pulmonary embolism using spiral CT angiography and magnetic resonance (MR) angiography certainly belongs in this category. CT has become the an alternative modality of first choice, and it is also challenging pulmonary angiography as the gold standard. Direct visualization of patent pulmonary arteries and thromboembolic material is complemented by that of effects on the pulmonary parenchyma and right heart function; it also provides perfusion studies and MR-based flow measurement to assess hemodynamic compromise. Ventilation studies have long been a domain of nuclear imaging, and new techniques for the direct visualization of ventilation are emerging from recent developments in the field of MR imaging, for example, using hyperpolarized inert gases. New functional parameters of ventilation can be derived from these studies. For the diagnosis of metabolically active disease, such as tumor and pneumonia, CT offers very high sensitivity, for example, in screening for intrapulmonary nodules using low-dose CT and in the early detection of pulmonary infiltrates in high-risk patients. Especially for characterizing pulmonary nodules there is a need to combine nuclear medicine techniques, such as in positron-emission tomography.     

Magnetic resonance imaging of the adrenal gland]

Adrenal imaging was performed using magnetic resonance (MR) was in 100 patients who had no clinical or biochemical evidence of adrenal abnormality and in 19 patients with 24 adrenal lesions (adenoma in 5, hyperplasia in 2, metastasis in 5, (lung cancer in 1, hepatoma in 4) adrenal cancer in 1, pheochromocytoma in 3, neuroblastoma in 3). Normal adrenal glands showed intermediate intensity between muscle and liver, and were detected in over 90% of cases on T1-weighted images (T1-weighted SE, inversion recovery). Adenomas and hyperplasias had the same intensity as normal glands. Medullary masses showed extreme hyperintensity on T2-weighted images and could be differentiated from cortical masses. Neuroblastomas were detected as hyperintense tumors with intratumoral hemorrhage and necrosis on T2-weighted MR images. Metastatic adrenal tumors from lung cancer were hyperintense on T2-weighted images, while metastasis from hepatoma showed low intensity on the same pulse sequence. In diagnosing adrenal metastasis, we must compare and contrast the tumor intensity and structure with those of the primary lesions. MR is considered a useful modality in characterizing adrenal tissue.     

Optimal Imaging Protocols for Lung Cancer Staging: CT, PET, MR Imaging, and the Role of Imaging

Chest radiography, the most commonly performed imaging technique for the detection of lung disease, is limited in accurately detecting early lung cancer. The main imaging modality for the staging of lung cancer is computed tomography (CT), supplemented by positron emission tomography (PET), usually as a hybrid technique in conjunction with CT (PET/CT). Magnetic resonance (MR) imaging is a useful diagnostic tool for specific indications and has the advantage of not using ionizing radiation. This article discusses the optimal imaging protocols for lung cancer staging using CT, PET (PET/CT), and MR imaging, and the role of imaging in patient management.     

Role of 99mTc-octreotide acetate scintigraphy in suspected lung cancer compared with 18F-FDG dual-head coincidence imaging.

The aim of this study was to evaluate the clinical value of tomographic (99m)Tc-octreotide acetate (hereafter, (99m)Tc-octreotide) scintigraphy in the detection of patients with suspected lung cancer in comparison with that of (18)F-FDG dual-head coincidence imaging (DHC). METHODS: Forty-four consecutive patients with suspected pulmonary neoplasms underwent tomographic (99m)Tc-octreotide scintigraphy and (18)F-FDG coincidence imaging using the same gantry. The region of interest was drawn on the entire primary lesion. The tumor-to-normal tissue tracer values for both (99m)Tc-octreotide and (18)F-FDG were determined using region of interests and expressed as T/N(r) and T/N(m), respectively. Final diagnosis was confirmed by histopathologic analysis or clinical follow-up. RESULTS: Thirty-one of the 44 patients had lung cancer-6 with small cell lung cancer (SCLC) and 25 with non-small cell lung cancer (NSCLC). Thirteen of the 44 patients had benign lung lesions. The sensitivity, specificity, positive predictive value, and negative predictive value of (99m)Tc-octreotide were 100%, 75.7%, 90.1%, and 100%, respectively, and of (18)F-FDG DHC were 100%, 46.1%, 83.8%, and 100%, respectively. In the 31 patients with malignant tumors, all 38 abnormal lymph nodes in 20 patients showed abnormal high focal uptake of (18)F-FDG; only 7 patients with 10 regional lymph adenopathies showed moderate uptake of (99m)Tc-octreotide. Thirteen patients with 39 distant sites of abnormal uptake visualized (imaging stage IV) with (99m)Tc-octreotide included 2 patients with brain metastases, 6 patients with pleural invasion and multiple bone metastasis, 2 patients with contralateral internal lung metastasis and pleural invasion, and 3 patients with only multiple bone metastasis. The final diagnosis was confirmed by histopathology or clinical follow-up. CONCLUSION: The sensitivity of (99m)Tc-octreotide for the detection of lung cancer at the primary lesion was comparable with that of (18)F-FDG coincidence imaging. Tomographic (99m)Tc-octreotide scintigraphy had lower sensitivity for the detection of hilar and mediastinal lymph node metastasis compared with that of (18)F-FDG coincidence PET, but it had high sensitivity for the detection of remote metastatic lesions. However, because of the small population, further investigation is necessary.     

Lung morphology: fast MR imaging assessment with a volumetric interpolated breath-hold technique: initial experience with patients

PURPOSE: To prospectively evaluate the clinical feasibility of magnetic resonance (MR) imaging of the lungs with fast volumetric interpolated three-dimensional (3D) gradient-recalled-echo (GRE) sequences and to compare this examination with standard computed tomography (CT) in patients with lung abnormalities. MATERIALS AND METHODS: Twenty-five patients with different lung abnormalities were examined with 3D GRE MR imaging. The small pulmonary nodules in seven, TNM stage of large intrapulmonary tumors in eight, and benign bronchial disease in five patients were evaluated. MR imaging-based diagnoses were compared with diagnoses made at CT and at discharge from the hospital. Contingency tables and the McNemar test were used to evaluate the significance of differences between MR imaging- and CT-based diagnoses. RESULTS: The MR imaging- and CT-based diagnoses were identical in 24 of 25 patients. In the remaining patient, clinical findings confirmed the accuracy of the MR imaging finding of pleural empyema. Ten of 15 solid pulmonary nodules smaller than 10 mm in diameter were detected at MR imaging (P >.1). Tumor stages at MR imaging and CT were identical, but lymph node stages at the two examinations differed in two of eight patients owing to overestimation of lymph node size at MR imaging (P >.2). In the five patients with bronchiectasis, MR imaging depicted 26 of 33 affected lung segments; differences between MR imaging and CT findings of bronchial dilatation (P >.05) and bronchial wall thickening (P >.2) were not significant. Peribronchial fibrosis was overestimated at MR imaging owing to image artifacts (P <.05). CONCLUSION: Study results confirmed the feasibility of fast breath-hold 3D GRE MR imaging of the lung.     

Pulmonary vein and left atrial invasion by lung cancer: assessment by breath-hold gadolinium-enhanced three-dimensional MR angiography

PURPOSE: The purpose of this work was to evaluate the ability of breath-hold gadolinium-enhanced three-dimensional (3D) MR angiography to assess the invasion of the pulmonary vein and the left atrium by lung cancer. METHOD: Gadolinium-enhanced 3D MR angiography was performed in 20 consecutive patients with lung cancer. RESULTS: At two sites with left atrial invasion shown by MR angiography, associated partial resection of the left atrium was performed. At five sites with invasion of the proximal pulmonary vein within 1.5 cm from the left atrium on MR, partial resection of the left atrium was performed at one site, and the pulmonary vein was resected at the intrapericardial portion at three sites. At two sites with invasion of the proximal pulmonary vein 1.5 cm more distal to the left atrium, the pulmonary vein was resected at the extrapericardial portion. CONCLUSION: Breath-hold gadolinium-enhanced 3D MR angiography is suitable for assessing invasion of the pulmonary vein and the left atrium by lung cancer.     

Positron emission tomography: brain tumors and lung cancer

F-18 fluorodeoxyglucose positron emission tomography is a uniquely powerful diagnostic tool that noninvasively provides information that is critical to appropriate clinical management of patients with non-small cell lung cancer. Not only does the functional information provided by PET complement and clarify the anatomic information supplied by CT and MR imaging, but the superior sensitivity and negative predictive value of PET allow for improved accuracy in diagnosis, prognosis, staging, and monitoring the effects of treatment. With better information at their disposal, clinicians and patients are able to make better-informed decisions, contributing to more appropriate and more cost-effective medical care. Truly, FDG-PET has earned its place as the new standard of care in imaging non-small cell lung cancer.     

Oxygen-enhanced MR ventilation imaging of the lung: preliminary clinical experience in 25 subjects.

OBJECTIVE: The purpose of this study was to show the feasibility of oxygen-enhanced MR ventilation imaging in a clinical setting with correlation to standard pulmonary function tests, high-resolution CT, and (81m)Kr ventilation scintigraphy. SUBJECTS AND METHODS: Seven healthy volunteers, 10 lung cancer patients, and eight lung cancer patients with pulmonary emphysema were studied. A respiratory synchronized inversion-recovery single-shot turbo-spin-echo sequence (TE, 16; inversion time, 720 msec; interecho spacing, 4 msec) was used for data acquisition. The following paradigm of oxygen inhalation was used: 21% oxygen (room air), 100% oxygen, 21% oxygen. MR imaging data including maximum mean relative enhancement ratio and mean slope of relative enhancement were correlated with forced expiratory volume in 1 sec, diffusing lung capacity, high-resolution CT emphysema score, and mean distribution ratio of (81m)Kr ventilation scintigraphy. RESULTS: Oxygen-enhanced MR ventilation images were obtained in all subjects. Maximum mean relative enhancement ratio and mean slope of relative enhancement of lung cancer patients were significantly decreased compared with those of the healthy volunteers (p < 0.0001, p < 0.0001). The mean slope of relative enhancement in lung cancer patients with pulmonary emphysema was significantly lower than that of lung cancer patients without pulmonary emphysema (p < 0.0001). Maximum mean relative enhancement ratio (r(2) = 0.81) was excellently correlated with diffusing lung capacity. Mean slope of relative enhancement (r(2) = 0.74) was strongly correlated with forced expiratory volume in 1 sec. Maximum mean relative enhancement had good correlation with the high-resolution CT emphysema score (r(2) = 0.38). The maximum mean relative enhancement had a strong correlation with the distribution ratio (r(2) = 0.77). CONCLUSION: Oxygen-enhanced MR ventilation imaging in human subjects showed regional changes in ventilation, thus reflecting regional lung function.     

Imaging prostate cancer: a multidisciplinary perspective

The major goal for prostate cancer imaging in the next decade is more accurate disease characterization through the synthesis of anatomic, functional, and molecular imaging information. No consensus exists regarding the use of imaging for evaluating primary prostate cancers. Ultrasonography is mainly used for biopsy guidance and brachytherapy seed placement. Endorectal magnetic resonance (MR) imaging is helpful for evaluating local tumor extent, and MR spectroscopic imaging can improve this evaluation while providing information about tumor aggressiveness. MR imaging with superparamagnetic nanoparticles has high sensitivity and specificity in depicting lymph node metastases, but guidelines have not yet been developed for its use, which remains restricted to the research setting. Computed tomography (CT) is reserved for the evaluation of advanced disease. The use of combined positron emission tomography/CT is limited in the assessment of primary disease but is gaining acceptance in prostate cancer treatment follow-up. Evidence-based guidelines for the use of imaging in assessing the risk of distant spread of prostate cancer are available. Radionuclide bone scanning and CT supplement clinical and biochemical evaluation (prostate-specific antigen [PSA], prostatic acid phosphate) for suspected metastasis to bones and lymph nodes. Guidelines for the use of bone scanning (in patients with PSA level > 10 ng/mL) and CT (in patients with PSA level > 20 ng/mL) have been published and are in clinical use. Nevertheless, changes in practice patterns have been slow. This review presents a multidisciplinary perspective on the optimal role of modern imaging in prostate cancer detection, staging, treatment planning, and follow-up.     

Imaging of diffuse lung diseases. Past, present, and future

For many years the plain chest radiograph was the only imaging modality used in the assessment of patients who had diffuse lung disease. Presently, high resolution computed tomography (CT) and lung scintigraphy play a major role in the assessment of these patients. Use of magnetic resonance (MR) imaging in the assessment of the lung parenchyma has been limited by poor signal-to-noise ratio and physiologic motion. Recent improvements in technique, however, have allowed assessment of patients with diffuse lung disease. It is likely that MR imaging will play an increasing role in the assessment of these patients in the near future.     

Invasion of laryngeal cartilage by cancer: comparison of CT and MR imaging

Forty-two patients with laryngeal carcinomas were examined with computed tomography (CT) and magnetic resonance (MR) imaging. The accuracy of both CT and MR imaging in the depiction of cartilage invasion was evaluated in 16 patients by comparing findings at CT and MR with pathologic findings. Calcified cartilage that has been invaded by cancer is frequently seen on CT scans as having an intact contour. Tumor approaching nonossified cartilage may simulate cartilage invasion. On T1-weighted MR images, invaded marrow of ossified cartilage is of intermediate signal intensity, allowing it to be differentiated from normal bone marrow. On proton-density images, tumor is of increased signal intensity, which allows it to be differentiated from nonossified cartilage. In our experience, the specificities of CT and MR imaging were approximately equal (91% and 88%, respectively), but CT had a considerably lower sensitivity than MR (46% vs. 89%). Gross movement artifacts, which resulted in nondiagnostic images, occurred in 16% of the MR examinations. MR imaging is recommended as the modality of choice in the diagnosis of cartilage invasion.     

Skeletal muscle metastases: a three-part study of a not-so-rare entity

Objective

Our purposes were to explore the epidemiology of metastases to skeletal muscle and their detection on fused positron emission tomography and computed tomography.

Materials and methods

We evaluated the epidemiology of skeletal muscle metastases in the literature and among cases from our hospital and studied the prevalence and appearance of skeletal muscle metastases among 433 patients undergoing fused positron emission tomography and computed tomography for non-small-cell lung cancer.

Results

We found 264 cases of skeletal muscle metastases in 151 articles. Mean age was 57.8?years with 67% men. At our hospital we studied 70 cases. Mean patient age was 55.7?years with 63% men. The most common source was lung cancer, and the most common site of involvement was the muscles of the trunk. Among our lung cancer patients undergoing fused positron emission tomography and computed tomography, we found 7 (1.6%) with skeletal muscle metastases. In only one of these seven patients was the metastasis first discovered by another imaging modality. In one patient discovery of the metastasis at fused positron emission tomography and computed tomography changed management.

Conclusion

Skeletal muscle metastases are not rare. They may be more apparent at fused positron emission tomography and computed tomography than at other staging examinations, particularly contrast-enhanced CT scanning. Radiologists need to be alert to their presence when interpreting staging examinations in cancer patients.     

MR imaging of solitary pulmonary lesion: emphasis on tuberculomas and comparison with tumors

The aim of this study was to determine whether solitary pulmonary tuberculoma and malignant tumor can be differentiated on the basis of magnetic resonance (MR) signal intensity. Twenty-eight patients with solitary pulmonary lesions were prospectively studied with MR imaging: T1-weighted, enhanced T1-weighted, proton density-weighted, and T2-weighted spin echo images were obtained. The confirmation methods used were computed tomography (CT)-guided biopsy in seven patients with lung cancer and four patients with tuberculosis; surgery in ten patients with lung cancer and five patients with tuberculosis; and laboratory data in two patients with tuberculosis. Morphologic features and MR signal intensity were examined in detail. As the test for detection of tuberculoma, signal difference on T2-weighted images was carefully analyzed. The signal intensity ratio of the nodule to thoracic muscle signal intensity was measured. The signal intensities obtained from the lung cancers and tuberculomas were variable on pre-and post-enhanced T1-weighted images and proton density-weighted images. Masses were hypointense in 2 of 17 patients with lung cancer and in 9 of 11 patients with tuberculoma on T2-weighted images (sensitivity 82%, specificity 89%, accuracy 87%). The mean signal intensity ratios of the tuberculomas to muscle were significantly lower than those of malignant tumors on T1-weighted, enhanced T1-weighted, proton density-weighted, and T2-weighted images (P < 0.0001). After gadolinium-DTPA enhancement, 2 malignant tumors and 7 tuberculomas showed a marginal rim enhancement pattern, whereas 15 malignant tumors and 2 tuberculomas revealed a diffuse enhancement. The results of MR imaging were consistent with those of CT in 84% of the patients. MR imaging is a helpful adjunctive method in terms of differentiating a tuberculoma from a malignant tumor.     

Contrast-enhanced MRI of the lung

The lung has long been neglected by MR imaging. This is due to unique intrinsic difficulties: (1) signal loss due to cardiac pulsation and respiration; (2) susceptibility artifacts caused by multiple air-tissue interfaces; (3) low proton density. There are many MR strategies to overcome these problems. They consist of breath-hold imaging, respiratory and cardiac gating procedures, use of short repetition and echo times, increase of the relaxivity of existing spins by administration of intravenous contrast agents, and enrichment of spin density by hyperpolarized noble gases or oxygen. Improvements in scanner performance and frequent use of contrast media have increased the interest in MR imaging and MR angiography of the lung. They can be used on a routine basis for the following indications: characterization of pulmonary nodules, staging of bronchogenic carcinoma, in particular assessment of chest wall invasion; evaluation of inflammatory activity in interstitial lung disease; acute pulmonary embolism, chronic thromboembolic pulmonary hypertension, vascular involvement in malignant disease; vascular abnormalities. Future perspectives include perfusion imaging using extracellular or intravascular (blood pool) contrast agents and ventilation imaging using inhalation of hyperpolarized noble gases, of paramagnetic oxygen or of aerosolized contrast agents. These techniques represent new approaches to functional lung imaging. The combination of visualization of morphology and functional assessment of ventilation and perfusion is unequalled by any other technique.     

Imaging of the pulmonary hilum: a prospective comparative study in patients with lung cancer

Using magnetic resonance imaging (MRI), dynamic computed tomography (CT), and 55 degrees posterior oblique tomography, the authors prospectively evaluated the pulmonary hilum in 35 patients with lung cancer; 19 of these patients had surgical excision of ipsilateral hilar lymph nodes and formed the study group. Their results showed no significant differences between the three imaging methods in overall accuracy of hilar evaluation. Both MRI and dynamic CT were highly sensitive but relatively nonspecific for diagnosing hilar metastasis, whereas oblique tomography had fair sensitivity and specificity. The low specificity of MRI and dynamic CT was due to detection of mildly enlarged (10-16 mm) benign hilar nodes, which were present in five (26%) of 19 patients. The calculated magnetic relaxation times, T1 and T2, were not useful in distinguishing between benign and malignant enlarged hilar nodes. The authors conclude that accurate staging of the pulmonary hilum in patients with lung cancer is not currently possible using MRI, CT, or oblique tomography.     

Gadolinium-enhanced MR imaging, T2-weighted MR imaging, and transurethral ultrasonography

PURPOSE: To assess the value and problems of dynamic gadolinium-enhanced MR imaging, T2-weighted MR imaging, and transurethral ultrasonography(TUUS) in staging of urinary bladder cancer. MATERIALS AND METHODS: Dynamic gadolinium-enhanced MR imaging and FSE T2-weighted MR imaging of 64 patients with urinary bladder cancer who subsequently had surgery were retrospectively reviewed and compared with TUUS findings. RESULTS: Specificity for muscular invasion was 90.5% with TUUS, significantly better than with dynamic MR imaging (64.9%) (p < 0.05). The rates of overestimation of superficial cancer(pT1) with dynamic MRI and T2-weighted MR imaging were 35.1%(13/37) and 24.3%(9/37), respectively. The staging accuracy of invasive cancer(pT2 or over) was 85.2% with dynamic MR imaging, which was better than the rate of 75.0% achieved with T2-weighted MR imaging. CONCLUSION: Although TUUS was a better modality for diagnosing superficial cancer(pT1), dynamic MR imaging was found to be better for diagnosing invasive(pT2 or over) cancer.     

Oxygen-enhanced magnetic resonance ventilation imaging of lung

The oxygen-enhanced magnetic resonance (MR) ventilation imaging is a new technique, and the full extent of its physiological significance has not been elucidated. This review article includes background on (1) respiratory physiology; (2) mechanism and optimization of oxygen-enhanced MR imaging technique; (3) recent applications in animal and human models; and (4) merits and demerits of the technique in comparison with hyperpolarized noble gas MR ventilation imaging. Application of oxygen-enhanced MR ventilation imaging to patients with pulmonary diseases has been very limited. However, we believe that further basic studies, as well as clinical applications of this new technique will define the real significance of oxygen-enhanced MR ventilation imaging in the future of pulmonary functional imaging and its usefulness for diagnostic radiology.     

Non-small-cell lung cancer: practice patterns of extrathoracic imaging

RATIONALE AND OBJECTIVES: The purpose of this study was to identify practice patterns of extrathoracic imaging in patients newly diagnosed with non-small-cell lung, cancer. MATERIALS AND METHODS: The authors retrospectively reviewed the charts of 125 patients (71 men, 54 women; mean age, 67 years) from five hospitals (25 patients each) with newly diagnosed non-small-cell lung cancer. Charts were reviewed for cancer cell type, evidence of metastatic disease, and performance and results of extrathoracic imaging, including computed tomography (CT) and magnetic resonance (MR) imaging of the brain, bone scanning, and abdominal CT. RESULTS: Of 125 patients, 77 (62%) underwent extrathoracic imaging. These patients included 64 (64%) of 100 patients with clinical symptoms or laboratory signs of metastatic disease and 13 (52%) of 25 patients with no such indications. Extrathoracic imaging did not differ according to cancer cell type: It was performed for 30 (60%) of 50 patients with squamous cell carcinoma, 26 (60%) of 43 patients with adenocarcinoma, and 16 (73%) of 22 patients with non-small-cell lung cancer that was not further characterized. Brain CT or MR imaging bone scanning, or abdominal CT were performed in only 48%, 39%, and 30% of patients, respectively. Brain CT or MR images or bone scans revealed metastatic disease in seven of 20 and nine of 22 patients with clinical symptoms or laboratory signs of disease, respectively. These examinations revealed disease in four of 40 and two of 27 patients without such symptoms or signs, respectively (P < .05). No significant differences emerged among the practice patterns at the five participating hospitals. CONCLUSION: No consensus was found on performance of extrathoracic imaging in patients with newly diagnosed non-small-cell lung cancer.