Acute pulmonary complications in patients with hematologic malignancies.

Various acute pulmonary complications may occur in patients with hematologic malignancies because they are in an immunocompromised state due to systemic disease or to chemotherapy or hematopoietic stem cell transplantation. Pulmonary complications may arise from other treatment regimens, as well, or from direct pulmonary involvement in the malignant disease process. The differential diagnosis of pulmonary opacities in patients with hematologic malignancies is broad and includes both infectious and noninfectious causes. Pulmonary hemorrhage, edema, leukostasis, and pneumonia are well-known and common acute pulmonary complications. Less common complications are now encountered with increasing frequency because of the increasing complexity of therapeutic regimens for hematologic malignancies, which may include various drugs that are in clinical trials or were recently released to market. These once uncommon acute pulmonary complications include retinoic acid syndrome, tyrosine kinase inhibitor-induced pulmonary complications, engraftment syndrome, and hemophagocytic lymphohistiocytosis. It is often difficult to differentiate between these entities. However, the clinical setting and radiologic imaging findings may provide clues for interpreting imaging findings of abnormal pulmonary opacity in patients with a hematologic malignancy. Pulmonary hemorrhage is characterized by a sudden onset of symptoms and rapid progression of pulmonary imaging abnormalities and usually occurs in patients with impaired coagulation or a predisposition to bleed. Pulmonary edema should be considered when typical findings of hydrostatic pulmonary edema are seen. Pulmonary leukostasis develops in patients with hyperleukocytosis and leads to symptoms such as a cough, fever, and dyspnea. Various types of pneumonia may develop, depending on the degree and duration of immunosuppression in the patient. Retinoic acid syndrome, tyrosine kinase inhibitor-induced pulmonary complications, and engraftment syndrome occur after specific treatments, so a detailed medical history including recent or current treatments may be helpful for diagnosis. Accurate differentiation of these entities allows their appropriate management, with resultant decreases in morbidity and mortality.

Complications of pneumoconiosis: radiologic overview.

A wide spectrum of pulmonary complications occurs in patients with pneumoconiosis. Those complications include chronic obstructive pulmonary disease, hemoptysis, pneumothorax, pleural disease, tuberculosis, autoimmune disease, anthracofibrosis, chronic interstitial pneumonia, and malignancy. Generally, imaging workup starts with plain chest radiography. However, sometimes, plain radiography has limited role in the diagnosis of pulmonary complications of pneumoconiosis because of overlapping pneumoconiotic infiltration. Computed tomography (CT), ultrasonography (US), and magnetic resonance imaging (MRI) are potentially helpful for the detection of pulmonary complications in patients with pneumoconiosis. CT, with its excellent contrast resolution, is more sensitive and specific method than plain radiograph in the evaluation of pulmonary abnormalities. CT is useful in detecting lung parenchymal abnormalities caused by infection, anthracofibrosis, and chronic interstitial pneumonia. Also, CT is valuable in distinguishing localized pneumothorax from bullae and aiding the identification of multiloculated effusions. US can be used in detection of complicated pleural effusions and guidance of the thoracentesis procedure. MRI is useful for differentiating between progressive massive fibrosis and lung cancer. Radiologists need to be familiar with the radiologic and clinical manifestations of, as well as diagnostic approaches to, complications associated with pneumoconiosis. Knowledge of the various imaging features of pulmonary complications of pneumoconiosis can enhance early diagnosis and improve the chance to cure.

Bronchiectasis in active tuberculosis.

BACKGROUND: Bronchiectasis in tuberculosis (TB) is usually considered chronic traction bronchiectasis associated with healed scars. However, bronchiectasis can occasionally be seen in active TB. PURPOSE: To evaluate prevalence, appearance, and changes of bronchiectasis associated with active TB on computed tomography (CT). MATERIAL AND METHODS: A total of 391 patients with active TB who had undergone CT scans at the time of diagnosis were included in the study. Active TB was diagnosed when the sputum or the sample obtained by bronchoalveolar lavage tested positive using an acid-fast bacillus (AFB) smear test, polymerase chain reaction (PCR) test, or an AFB culture. The CT scans were reviewed focusing on bronchiectasis within consolidations or nodules. Cases with bronchiectasis beyond the consolidation or nodules were excluded from the study to exclude pre-existing traction bronchiectasis. The prevalence and appearance (cylindrical, varicose, cystic, and presence of focal erosion) of bronchiectasis and its time-dependent changes were analyzed. In addition, the presence of the feeding bronchus sign was checked. Here, the feeding bronchus sign was defined as a CT finding where the cavity communicates with the dilated airway. RESULTS: In 100 (25%) of the 391 patients, bronchiectasis was present within consolidations or nodules on CT. The shape of the bronchiectasis was cylindrical in all patients and focal erosions were revealed in 75 patients (75%). Nine patients had both cylindrical and varicose forms of the bronchiectasis. The feeding bronchus sign was observed in 42 patients (42%). Follow-up CT was performed on 19 of 100 patients. The bronchiectasis had progressed in 11 patients (58%), improved in four patients (21%), remained unchanged in one patient (5%), and could not be determined in the remaining three patients (16%). In nine patients, CT images prior to diagnosis were available, and in all these cases, bronchiectasis was newly developed. CONCLUSION: Bronchiectasis can be seen within active inflammation in one-fourth of active TB on CT. In association with active inflammation, bronchiectasis is mostly cylindrical with focal erosions, occasionally accompanied by the feeding bronchus sign.

Multidetector row computed tomography quantification of bronchiolitis obliterans syndrome after hematopoietic stem cell transplantation: a pilot study.

PURPOSE: To evaluate multidetector row computed tomographic indexes to quantify bronchiolitis obliterans syndrome (BOS) after hematopoietic stem cell transplantation by correlation with pulmonary function tests (PFT). MATERIALS AND METHODS: Eighteen patients with BOS after hematopoietic stem cell transplantation and 18 age-matched healthy volunteers were included. They underwent multidetector row computed tomography including inspiration and expiration scans. The patients also underwent PFTs. Mean lung density (MLD), relative areas (RAs) of lung with attenuation coefficients below specific thresholds, and 9 percentiles of the distribution of attenuation coefficients were computed. These parameters and PFT results were correlated. RESULTS: Mean MLD on inspiration (MLDin), MLD on expiration (MLDex), and the difference between the 2 (ΔMLD) were -858.5 HU, -788.6 HU, and 69.9, respectively, for the patients and -815.9 HU, -691.8 HU, and 124.1, respectively, for the volunteers. These parameters showed significant differences between the 2 groups (P<0.001) and strongly correlated with patients' residual forced expiratory volume in 1 second (FEV1) (r=0.71, 0.92, and 0.85, P≤0.001, respectively). RA with attenuation coefficients <-800 HU (RA800e) and the 80th percentile (80the) on expiration correlated most highly with the patients' residual FEV1 (r=-0.94, P<0.001). CONCLUSIONS: RA with attenuation coefficients <-800 HU (RA800e) and the 80th percentile (80the) on expiration are valid indexes of the patients' residual FEV1 in BOS.

CT evaluation of vocal cord paralysis due to thoracic diseases: a 10-year retrospective study.

PURPOSE: To discuss computed tomography (CT) evaluation of the etiology of vocal cord paralysis (VCP) due to thoracic diseases. MATERIALS AND METHODS: From records from the past 10 years at our hospital, we retrospectively reviewed 115 cases of VCP that were evaluated with CT. Of these 115 cases, 36 patients (23 M, 13 F) had VCP due to a condition within the thoracic cavity. From these cases, we collected the following information: sex, age distribution, side of paralysis, symptom onset date, date of diagnosis, imaging, and primary disease. The etiology of VCP was determined using both historical information and diagnostic imaging. Imaging procedures included chest radiograph, CT of neck or chest, and esophagography or esophagoscopy. RESULTS: Thirty-three of the 36 patients with thoracic disease had unilateral VCP (21 left, 12 right). Of the primary thoracic diseases, malignancy was the most common (19, 52.8%), with 18 of the 19 malignancies presenting with unilateral VCP. The detected malignant tumors in the chest consisted of thirteen lung cancers, three esophageal cancers, two metastatic tumors, and one mediastinal tumor. We also found other underlying etiologies of VCP, including one aortic arch aneurysm, five iatrogenic, six tuberculosis, one neurofibromatosis, three benign nodes, and one lung collapse. A chest radiograph failed to detect eight of the 19 primary malignancies detected on the CT. Nine patients with lung cancer developed VCP between follow-ups and four of them were diagnosed with a progression of malignancy upon CT evaluation of VCP. CONCLUSION: CT is helpful for the early detection of primary malignancy or progression of malignancy between follow-ups. Moreover, it can reveal various non-malignant causes of VCP.

Malignant solitary fibrous tumor of the pleura: computed tomography-pathological correlation and comparison with computed tomography of benign solitary fibrous tumor of the pleura.

PURPOSE: The aim of this study was to determine the computed tomography (CT)-pathological correlation of malignant solitary fibrous tumors of the pleura (MSFP) and to compare these findings with CT findings of benign solitary fibrous tumors of the pleura (BSFTP). MATERIALS AND METHODS: We retrospectively identified the clinical, CT, and pathological findings in seven cases of MSFP. There was a CT-pathological correlation for the MSFPs. Additionally, 12 cases of BSFTP from case files were compared with the clinical and CT features of the MSFPs. RESULTS: On CT, the MSFP appeared as a heterogeneously enhancing mass >10 cm (100%). Pleural metastasis (57.1%) and lung metastasis (14.3%) were associated. In the CT-pathological correlation, the enhancing area was mixed cellular and collagenous tissue with hypercellularity, mitosis, and pleomorphism. Hemorrhage, necrosis, cystic, or myxoid degeneration produced areas of intratumoral low attenuation. MSFPs showed a higher incidence of intratumoral low-attenuation areas (P = 0.034) and pleural metastasis (P = 0.009); and on CT, MSFPs tended to be larger than BSFTPs (P = 0.076). CONCLUSION: MSFPs showed a >10 cm pleural mass with low-attenuation regions on CT, which corresponded to hemorrhage, necrosis, cystic, or myxoid degeneration. MSFPs had a higher incidence of intratumoral low-attenuation areas and pleural metastasis, and on CT they tended to be larger than BSFTPs.

Consolidations in nodular bronchiectatic Mycobacterium avium complex lung disease: Mycobacterium avium complex or other infection?

PURPOSE: The objective of this study is to define the clinical implications of consolidations in nodular bronchiectatic type Mycobacterium avium complex (NBMAC) infection. MATERIALS AND METHODS: A total of 69 patients (M : F = 17 : 52; mean age, 64 years; age range, 41-85 years) with MAC isolated in the sputum culture and nodular bronchiectasis on the initial and follow-up CT scans were included. We retrospectively reviewed the incidence of consolidation and analyzed its clinical course by using radiographic changes with or without anti-MAC drug therapy. RESULTS: In 44 of the 69 cases (64%), focal consolidations were seen on the initial and follow-up CT images. In 35 of the 44 (80%) cases, consolidations completely regressed, and in 3 cases (7%), consolidations partially regressed within 2 months with only antibiotics. In 2 cases (5%), the consolidations remained stable for over 2 months without anti-MAC drug therapy. Only in 4 cases (9%) did the consolidations improve after anti-MAC drug therapy. In 11 of the 38 cases (29%) with responsiveness to antibiotics, non-mycobacterial micro-organisms were identified in sputum, including pseudomonas, hemophilus, staphylococcus, and others. CONCLUSION: In NB-MAC, consolidations are commonly present on CT. In these conditions, most of consolidations result from pneumonia other than MAC.

Early CT findings of tomotherapy-induced radiation pneumonitis after treatment of lung malignancy.

OBJECTIVE: The objective of our study was to evaluate the early CT findings of tomotherapy-induced radiation pneumonitis. MATERIALS AND METHODS: Tomotherapy was performed during the study period in 31 patients with peripheral pulmonary malignancies, 25 of whom underwent follow-up CT within the first 3 months after tomotherapy. These 25 patients, with a total of 77 target lesions, were enrolled for the analysis. We evaluated pulmonary toxicity by the Common Toxicity Criteria for Adverse Events (CTCAE) method and retrospectively analyzed the CT findings of radiation pneumonitis, focusing on the appearance (attenuation, shape, degree of fibrosis) and location (concentric vs eccentric, centrifugal vs centripetal) of radiation pneumonitis relative to the target lesions. RESULTS: Radiation pneumonitis developed around 34 target lesions (34/77, 44%) in 13 patients (13/25, 52%) during the first 3 months after tomotherapy. Five patients needed steroid therapy (CTCAE grade 2, 5/25 [20%]) and the remaining eight patients required no additional treatment (CTCAE grade 0 or 1, 20/25 [80%]). In appearance, the common CT findings were irregular shape (18/34), ground-glass attenuation (19/34), and no or minimal fibrosis (33/34). The location of the radiation pneumonitis was eccentric (22/34) and centrifugal (19/34) relative to the target lesions. CONCLUSION: Radiation pneumonitis commonly developed with minimal clinical findings within 3 months after tomotherapy. The CT findings were nonspecific: focal, irregular-shaped ground-glass opacities with minimal fibrosis. However, the location of the radiation pneumonitis tended not to correspond to the planned target volume and had a centrifugal distribution. In addition, the immediate area around the target tended to be spared.

Pulmonary tuberculosis after hematopoietic stem cell transplantation: radiologic findings.

AIM: To determine the radiologic features of pulmonary tuberculosis in hematopoietic stem cell transplant (HSCT) recipients. MATERIALS AND METHODS: Between January 1996 and December 2005, 10 patients with pulmonary tuberculosis were analyzed. Chest radiographs were available in all of these patients and chest computed tomography (CT) scans were available in 7 patients. We retrospectively analyzed each patient's chest radiographic and CT findings. RESULTS: On chest radiography (n=10), the most common abnormalities were air-space consolidation (100%) and nodules (80%). Parenchymal lesions appeared mixed with other findings (80%). The most common mixed pattern was nodules with consolidations (80%). Parenchymal lesions were multilobar (80%), patchy (70%), or bilateral (80%). Evidence of a zonal predominance was not seen. On chest CT scans (n=7), the most common parenchymal lesions were consolidation (100%), nodules (71%), tree-in-bud appearance (43%), and ground-glass opacity (43%). Parenchymal lesions seen on CT scans also appeared mixed (86%) and multilobar in distribution (100%). Significant zonal predominance was not noted on CT scans. Cavity was noted in 14% of the study patients and lymphadenopathy was noted in 71% of these patients on CT scans. CONCLUSIONS: The radiologic features of pulmonary tuberculosis in HSCT recipients were nodules or air-space consolidation. Most of the abnormalities were mixed with other findings and had multilobar distribution, however, a lobar predilection was not seen. Awareness of radiologic findings of pulmonary tuberculosis in HSCT recipients may help the diagnosis of pulmonary tuberculosis.

Benign tumors of the tracheobronchial tree: CT-pathologic correlation.

OBJECTIVE: The purpose of this essay is to illustrate the CT findings of variable benign tumors of the tracheobronchial tree and to correlate the CT and pathologic findings in 17 patients. CONCLUSION: The tracheal tumors were eccentric, well-defined, polypoid masses in all cases. The endobronchial tumors were masses confined within the bronchus in all cases, and atelectasis or pneumonia of the distal parenchyma was frequently associated. Of the six hamartomas, one was a fatty mass, and two were nodules with calcification. The others were soft-tissue-density nodules. The lipomas manifested as fat density on CT scans in both cases. The other benign tumors were low-attenuating, soft-tissue-density masses without characteristic findings on CT scans.

Thoracic manifestations of breast cancer and its therapy.

Breast cancer is the second most common cause of cancer-related death in women. In most patients, imaging demonstrates thoracic changes resulting from either treatment, complications of treatment, or tumor recurrence or metastasis. The postsurgical imaging appearance of the chest wall depends on the surgical method used (radical mastectomy, modified radical mastectomy, breast-conserving surgery, breast reconstruction). The most common surgery-related complication is seroma. Radiation therapy frequently causes radiation pneumonitis, which occurs approximately 4-12 weeks after the completion of therapy and is characteristically limited to the field of irradiation. Chemotherapy-related complications include cardiotoxicity, pneumonitis, and infection. Ultrasonography and computed tomography are more sensitive than physical examination for detecting local and regional recurrence. The thorax is a common site of metastasis, which may affect the lymph nodes, bone, lung, pleura, or heart and pericardium. Bone metastasis is usually evaluated with bone scintigraphy and may cause spinal cord compression, a serious complication that requires early diagnosis. Intrapulmonary metastasis may manifest as single or multiple pulmonary nodules, airspace pattern metastasis, lymphangitic metastasis, or endobronchial metastasis. Pleural metastasis usually manifests as pleural effusion, with or without a pleural mass. Familiarity with the spectrum of radiologic findings in breast cancer patients allows accurate image interpretation and correct diagnosis.

Airway obstruction in rheumatoid arthritis: CT manifestations, correlated with pulmonary function testing.

In the present study, the signs of airflow obstruction on inspiratory and expiratory CT scans in 45 patients with rheumatoid arthritis were investigated. Radiologic findings were evaluated and correlated with the clinical data, which included rheumatoid factors and pulmonary function tests results. A lung biopsy was performed in five patients. The pattern of CT findings was as follows: infiltrative (n=15), obstructive (n=12), mixed (infiltrative and obstructive; n=10), other complicating diseases (n=7), and normal (n=1). The rheumatologic factor between patients with bronchial wall thickenings and patients without thickenings was significantly different (p=0.009). The forced expiratory flow rate between 25% and 75% of the vital capacity (FEF(25-75%)) was significantly more reduced in patients with interlobular septal thickenings than in patients without these thickenings. The patients with mosaic attenuation had significantly lower mean values of FEF(25-75% ) (p=0.001) and a lower peak expiratory flow (p=0.003) than patients without mosaic attenuation. On expiratory scans, the mean air-trapping score was 21%. These air-trapping scores were found to be well correlated with FEV1/FVC (r=0.230, p=0.0452), and FEF25-75% (r=-0.63, p= 0.05). It is widely known that a relatively higher percentage of mosaic attenuation with air-trapping and a good correlation between these and functional values contribute to the detection of early airway obstruction in patients with rheumatoid arthritis, and even in patients with infiltrative lung disease only.

Bronchiolitis obliterans after allogenic bone marrow transplantation: HRCT findings.

OBJECTIVE: To evaluate the high resolution computed tomography (HRCT) findings of bronchiolitis obliterans (BO) after bone marrow transplantation (BMT). MATERIALS AND METHODS: During the past three years, 11 patients were diagnosed as having BO after BMT when they developed irreversible air flow obstruction, with an FEV(1) value of less than 80% of the baseline value, without any clinical evidence of infection. All 11 patients underwent HRCT, of whom eight also underwent follow-up HRCT. The HRCT images were assessed retrospectively for the presence of decreased lung attenuation, segmental or subsegmental bronchial dilatation, diminution of peripheral vascularity, centrilobular nodules, and branching linear structure on the inspiratory images. The lobar distribution of the decreased lung attenuation and bronchial dilatation was also examined. The presence of air trapping was investigated on the expiratory images. The interval changes of the HRCT findings were evaluated in those patients who had followup images. RESULTS: Abnormal HRCT findings were present in all cases; the most common abnormalities were decreased lung attenuation (n=11), subsegmental bronchial dilatation (n=6), diminution of peripheral vascularity (n=6), centrilobular nodules or branching linear structure (n=3), and segmental bronchial dilatation (n=3). Expiratory air trapping was noted in all patients. The decreased lung attenuation and bronchial dilatations were more frequent or extensive in the lower lobes. Interval changes were found in all patients with follow-up HRCT: increased extent of decreased lung attenuation (n=7); newly developed or progressed bronchial dilatation (n=4); and increased lung volume (n=3). CONCLUSION: HRCT scans are abnormal in patients with BO, with the most commonly observed finding being areas of decreased lung attenuation. While the HRCT findings are not specific, it is believed that their common features can assist in the diagnosis of BO in BMT recipients.

Pregnancy- and lactation-associated breast cancer: mammographic and sonographic findings.

OBJECTIVE: To evaluate the mammographic and sonographic findings of pregnancy-associated breast cancer. METHODS: A total of 22 consecutive patients with breast cancer pathologically diagnosed during pregnancy (n = 10) or lactation (n = 12) were included in this study. The ages of the patients ranged from 26 to 49 years. Both mammography and sonography were performed on 12 patients; sonography only was performed on 7 patients; and mammography only was performed on 3 patients. Mammographic and sonographic findings were evaluated retrospectively. RESULTS: Mammography revealed positive findings in 13 (86.7%) of 15 patients, even though all 15 patients had dense breasts. Mammographic findings included masses (n = 5), masses with calcifications (n = 2), calcifications with axillary lymphadenopathy (n = 2), a mass with axillary lymphadenopathy (n = 1), calcifications alone (n = 1), asymmetric density alone (n = 1), and diffuse skin and trabecular thickening alone (n = 1). Sonographic findings were positive and showed masses for all 19 patients (100%). The common sonographic findings of masses were irregular shapes (n = 15), irregular margins (n = 16), parallel orientation (n = 11), complex echo patterns (n = 14, including marked cystic [anechoic] components [n = 4]), and posterior acoustic enhancement (n = 12). Surrounding tissue effects could be seen in 5 patients, including ductal changes (n = 2), Cooper ligament thickening (n = 1), edema (n = 3), and skin thickening (n = 3). Calcifications within or outside a mass (n = 7) and axillary lymphadenopathy (n = 8) were also detected. CONCLUSIONS: Although a mass could not be discernible by mammography because of increased radiodensity during pregnancy or lactation, calcification, asymmetric density, axillary lymphadenopathy, and skin and trabecular thickening were helpful for diagnosis of pregnancy-associated breast cancer. Sonographic findings of a solid mass with posterior acoustic enhancement and a marked cystic component were somewhat different from the appearance of breast cancer in nonpregnant women, possibly because of the physiologic changes of pregnancy and lactation.

New subtraction algorithms for evaluation of lesions on dynamic contrast-enhanced MR mammography.

We report new subtraction algorithms for the detection of lesions in dynamic contrast-enhanced MR mammography(CE MRM). Twenty-five patients with suspicious breast lesions underwent dynamic CE MRM using 3D fast low-angle shot. After the acquisition of the T1-weighted scout images, dynamic images were acquired six times after the bolus injection of contrast media. Serial subtractions, step-by-step subtractions, and reverse subtractions, were performed. Two radiologists attempted to differentiate benign from malignant lesion in consensus. The sensitivity, specificity, and accuracy of the method leading to the differentiation of malignant tumor from benign lesions were 85.7, 100, and 96%, respectively. Subtraction images allowed for better visualization of the enhancement as well as its temporal pattern than visual inspection of dynamic images alone. Our findings suggest that the new subtraction algorithm is adequate for screening malignant breast lesions and can potentially replace the time-intensity profile analysis on user-selected regions of interest.

Radiologic localization of esophageal level: comparison with distance from incisor at endoscopy.

RATIONALE AND OBJECTIVES: The esophageal level on radiography was compared with that at endoscopy by establishing a relationship between the radiologic landmarks, i.e., the vertebral level and the distance from the carina, and the distance from the incisor at endoscopy. METHODS: Three hundred ninety spot films in 65 patients who underwent endoscopic retrograde cholangiopancreatography were analyzed. Six spot films were obtained for each patient, wherein the distances of the endoscopic tip were located at 20, 25, 30, 35, 40, and 45 cm from the incisors. On each radiogram, the vertebral level scores were measured as 1 to 12, for the location of the endoscopic tip at the levels of T1 through T12, respectively. When the endoscopic tip was located at the lower half of the vertebral body, 0.5 point was added to the vertebral level score and when the tip was noted at the upper half of it, no additional score was given. The distance between the endoscopic tip and the carina was also measured. Correlations of the distance of the endoscopic tip from the incisors on endoscopy with the vertebral body levels and the distance from the carina on radiography, accounting for patient height, were analyzed by multiple linear regression and equations were extracted. RESULTS: Equation 1 for the vertebral level score (VL) for a given distance of endoscopic tip from incisor (DI) at a given patient height (H) was VL = 0.432DI - 0.048H + 0.099 (r2 = 0.968). Equation 2 for the distance from the carina (DC) for a given DI at a given H was DC = 0.957DI - 0.137H - 5.841 (r2 = 0.983). Two tables denoting radiologic VLs and DCs for given endoscopic DIs and patients' heights were generated using these equations. CONCLUSIONS: Regressed equations and tables will enable radiologists to better localize the esophageal lesions that are seen at endoscopy, and vice versa.

Radiologic features of all-trans-retinoic acid syndrome.

OBJECTIVE: The treatment of acute promyelocytic leukemia with all-trans-retinoic acid (ATRA) sometimes results in a syndrome characterized by fever, respiratory distress, weight gain, pleural and pericardial effusion, and pulmonary infiltrates. We report the radiologic features of ATRA syndrome. MATERIALS AND METHODS: During the past 5 years, 69 patients with acute promyelocytic leukemia were treated with ATRA. Of this group, 15 patients developed ATRA syndrome. Serial chest radiographs of the 15 patients with ATRA syndrome were evaluated retrospectively for the presence of pleural effusion, pulmonary nodules, consolidation, ground-glass opacity, septal lines, increased pulmonary blood volume, peribronchial cuffing, and air bronchogram. Also, we measured the cardiothoracic ratio and the vascular pedicle width. RESULTS: Chest radiographs showed increased cardiothoracic ratio in 13 of the 15 patients, increased vascular pedicle width in 13, increased pulmonary blood volume in 13, septal lines in nine, peribronchial cuffing in nine, ground-glass opacity in nine, consolidation in seven, and nodules in seven. Pleural effusion was noted in 11 of the 15 patients, and air bronchogram was noted in five of the 15 patients. Pulmonary hemorrhage developed in three patients who were being treated with ATRA; they showed bilateral, diffuse, poorly defined nodules and ground-glass opacity on radiography. CONCLUSION: Most patients with ATRA syndrome have abnormal findings on chest radiographs, and the abnormalities are similar to those of pulmonary edema.