OBJECTIVE: To develop an algorithm to measure the dimensions of an airway oriented obliquely on a volumetric CT, as well as assess the effect of the imaging parameters on the correct measurement of the airway dimension. MATERIALS AND METHODS: An airway phantom with 11 poly-acryl tubes of various lumen diameters and wall thicknesses was scanned using a 16-MDCT (multidetector CT) at various tilt angles (0, 30, 45, and 60degree). The CT images were reconstructed at various reconstruction kernels and thicknesses. The axis of each airway was determined using the 3D thinning algorithm, with images perpendicular to the axis being reconstructed. The luminal radius and wall thickness was measured by the full-width-half-maximum method. The influence of the CT parameters (the size of the airways, obliquity on the radius and wall thickness) was assessed by comparing the actual dimension of each tube with the estimated values. RESULTS: The 3D thinning algorithm correctly determined the axis of the oblique airway in all tubes (mean error: 0.91 +/- 0.82degree). A sharper reconstruction kernel, thicker image thickness and larger tilt angle of the airway axis resulted in a significant decrease of the measured wall thickness and an increase of the measured luminal radius. Use of a standard kernel and a 0.75-mm slice thickness resulted in the most accurate measurement of airway dimension, which was independent of obliquity. CONCLUSION: The airway obliquity and imaging parameters have a strong influence on the accuracy of the airway wall measurement. For the accurate measurement of airway thickness, the CT images should be reconstructed with a standard kernel and a 0.75 mm slice thickness.
Algorithms ; Cone-Beam Computed Tomography/*methods ; Imaging, Three-Dimensional ; Phantoms, Imaging ; Respiratory System/*anatomy & histology

OBJECTIVE: To assess the influence of variable factors such as the size of the airway and the CT imaging parameters such as the reconstruction kernel, field-of-view (FOV), and slice thickness on the automatic measurement of airway dimension. MATERIALS AND METHODS: An airway phantom was fabricated that contained eleven poly-acryl tubes of various lumen diameters and wall thicknesses. The measured density of the poly-acryl wall was 150 HU, and the measured density of the airspace filled with polyurethane foam was -900 HU. CT images were obtained using a 16-MDCT (multidetector CT) scanner and were reconstructed with various reconstruction kernels, thicknesses and FOV. The luminal radius and wall thickness were measured using in-house software based on the full-width-half-maximum method. The measured values as determined by CT and the actual dimensions of the tubes were compared. RESULTS: Measurements were most accurate on images reconstructed with use of a standard kernel (mean error: -0.03 +/- 0.21 mm for wall thickness and -0.12 +/- 0.11 mm for the luminal radius). There was no significant difference in accuracy among images with the use of variable slice thicknesses or a variable FOV. Below a 1-mm threshold, the measurement failed to represent the change of the real dimensions. CONCLUSION: Measurement accuracy was strongly influenced by the specific reconstruction kernel utilized. For accurate measurement, standardization of the imaging protocol and selection of the appropriate anatomic level are essential.
Cone-Beam Computed Tomography/*methods ; Feasibility Studies ; Phantoms, Imaging ; Respiratory System/*anatomy & histology

A benign metastasizing leiomyoma is a rare condition that affects women with a history of uterine leiomyoma, usually after a myomectomy or hysterectomy. Typical radiographic findings include well-circumscribed solitary or multiple pulmonary nodules ranging from a few millimeters to several centimeters in diameter and scattered among the normal interstitium. We report a case of a benign metastasizing leiomyoma that manifested with multiple cavitary nodules in a 46-year-old woman with no previous history of a myomectomy or hysterectomy.
Female ; Humans ; Hysterectomy ; Leiomyoma* ; Lung ; Middle Aged ; Multiple Pulmonary Nodules ; Neoplasm Metastasis ; Uterus

OBJECTIVE: We wanted to compare the transaxial source images with the optimized three plane, thin-slab maximum intensity projection (MIP) images from electrocardiographic (ECG)-gated cardiac CT for their ability to detect hemodynamically significant stenosis (HSS), and we did this by means of performing a receiver operating characteristic (ROC) analysis. MATERIALS AND METHODS: Twenty-eight patients with a heart rate less than 66 beats per minute and who were undergoing both retrospective ECG-gated cardiac CT and conventional coronary angiography were included in this study. The contrast-enhanced CT scans were obtained with a collimation of 16x0.75-mm and a rotation time of 420 msec. The transaxial images were reconstructed at the mid-diastolic phase with a 1-mm slice thickness and a 0.5-mm increment. Using the transaxial images, the slab MIP images were created with a 4-mm thickness and a 2-mm increment, and they covered the entire heart in the horizontal long axis (4 chamber view), in the vertical long axis (2 chamber view) and in the short axis. The transaxial images and MIP images were independently evaluated for their ability to detect HSS. Conventional coronary angiograms of the same study group served as the standard of reference. Four radiologists were requested to rank each image with using a five-point scale (1 = definitely negative, 2 = probably negative, 3 = indeterminate, 4 = probably positive, and 5 = definitely positive) for the presence of HSS; the data were then interpreted using ROC analysis. RESULTS: There was no statistical difference in the area under the ROC curve between transaxial images and MIP images for the detection of HSS (0.8375 and 0.8708, respectively; p > 0.05). The mean reading time for the transaxial source images and the MIP images was 116 and 126.5 minutes, respectively. CONCLUSION: The diagnostic performance of the MIP images for detecting HSS of the coronary arteries is acceptable and this technique's ability to detect HSS is comparable to that of the transaxial source images.
Tomography, X-Ray Computed/*methods ; Retrospective Studies ; ROC Curve ; Middle Aged ; Male ; *Image Interpretation, Computer-Assisted ; Humans ; Heart Rate ; Female ; Electrocardiography ; Coronary Stenosis/*radiography ; Coronary Angiography ; Aged ; Adult

The purpose of this study is to demonstrate whether the signal intensity (SI) of myocardial infarction (MI) on contrast enhanced (CE)-cine MRI is useful for differentiating recently infarcted myocardium from chronic scar. This study included 24 patients with acute MI (36-84 years, mean age: 57) and 19 patients with chronic MI (44-80 years, mean age: 64). The diagnosis of acute MI was based on the presence of typical symptoms, i.e. elevation of the cardiac enzymes and the absence of any remote infarction history. The diagnosis of chronic MI was based on a history of MI or coronary artery disease of more than one month duration and on the absence of any recent MI within the previous six months. Retrospectively, the ECG-gated breath-hold cine imaging was performed in the short axis plane using a segmented, balanced, turbo-field, echo-pulse sequence two minutes after the administration of Gd-DTPA at a dose of 0.2 mmol/kg body weight. Delayed contrast-enhanced MRI (DCE MRI) in the same plane was performed 10 to 15 minutes after contrast administration, and this was served as the gold standard of reference. The SI of the infarcted myocardium on the CE-cine MRI was compared with that of the normal myocardium on the same image. The area of abnormal SI on the CE-cine MRI was compared with the area of hyperenhancement on the DCE MRI. The area of high SI on the CE-cine MRI was detected in 23 of 24 patients with acute MI (10 with homogenous high SI, 13 high SI with subendocardial low SI, and one with iso SI). The area of high SI on the CE-cine MRI was larger than that seen on the DCE MRI (p < 0.05). In contrast, the areas of chronic MI were seen as iso-SI with thin subendocardial low SI on the CE-cine MR in all the chronic MI patients. The presence of high SI on both the CE-cine MRI and the DCE MRI is more sensitive (95.8%) for determining the age of a MI than the presence of myocardial thinning (66.7%). This study showed the different SI patterns between recently infarcted myocardium and chronic scar on the CE-cine MRI. CE-cine MRI is thought to be quite useful for determining the age of myocardial infarction, in addition to its utility for assessing myocardial contractility.
Signal Processing, Computer-Assisted ; Retrospective Studies ; Myocardium/*pathology ; Myocardial Infarction/*diagnosis ; Middle Aged ; Male ; *Magnetic Resonance Imaging, Cine ; Magnetic Resonance Imaging/methods ; Humans ; Female ; Contrast Media ; Cicatrix/*diagnosis ; Aged, 80 and over ; Aged ; Adult

OBJECTIVE: We wanted to describe the retrospective CT features of subtle pleural metastasis without large effusion that would suggest inoperable lung cancer. MATERIALS AND METHODS: We enrolled 14 patients who had open thoracotomy attempted for lung cancer, but they were proven to be inoperable due to pleural metastasis. Our study also included 20 control patients who were proven as having no pleural metastasis. We retrospectively evaluated the nodularity and thickening of the pleura and the associated pleural effusion on the preoperative chest CT scans. We reviewed the histologic cancer types, the size, shape and location of the lung cancer and the associated mediastinal lymphadenopathy. RESULTS: Subtle pleural nodularity or focal thickening was noted in seven patients (50%) having pleural metastasis and also in three patients (15%) of control group who were without pleural metastasis. More than one of the pleural changes such as subtle pleural nodularity, focal thickening or effusion was identified in eight (57%) patients having pleural metastasis and also in three patients (15%) of the control group, and these findings were significantly less frequent in the control group patients than for the patients with pleural metastasis (p = 0.02). The histologic types of primary lung cancer in patients with pleural metastasis revealed as adenocarcinoma in 10 patients (71%) and squamous cell carcinoma in four patients (29%). The location, size and shape of the primary lung cancer and the associated mediastinal lymphadenopathy showed no significant correlation with pleural metastasis. CONCLUSION: If any subtle pleural nodularity or thickening is found on preoperative chest CT scans of patients with lung cancer, the possibility of pleural metastasis should be considered.
Adenocarcinoma/radiography/secondary ; Adult ; Aged ; Carcinoma, Squamous Cell/radiography/secondary ; Female ; Humans ; Lung Neoplasms/*pathology ; Male ; Middle Aged ; Pleural Effusion, Malignant/pathology ; Pleural Neoplasms/*radiography/*secondary ; Preoperative Care ; Retrospective Studies ; *Tomography, X-Ray Computed

We report the CT findings of diffuse esophageal spasm (DES) in a patient with dysphagia. Although an uncommon condition, DES should be included in the differential diagnosis if relatively long and symmetric segmental esophageal wall thickening and an epiphrenic esophageal diverticulum are noted at CT.
Deglutition Disorders ; Diagnosis, Differential ; Diverticulum, Esophageal ; Esophageal Spasm, Diffuse* ; Humans

OBJECTIVE: To compare observer performance using liquid-crystal display (LCD) and cathode-ray tube (CRT) monitors in the interpretation of soft-copy chest radiographs for the detection of small solitary pulmonary nodules. MATERIALS AND METHODS: By reviewing our Medical Center's radiologic information system, the eight radiologists participating in this study (three board-certified and five resident) retrospectively collected 40 chest radiographs showing a solitary noncalcified pulmonary nodule approximately 1 cm in diameter, and 40 normal chest radiographs. All were obtained using a storage-phosphor system, and CT scans of the same patients served as the gold standard for the presence of a pulmonary nodule. Digital images were displayed on both high-resolution LCD and CRT monitors. The readers were requested to rank each image using a five point scale (1 = definitely negative, 3 = equivocal or indeterminate, 5 = definitely positive), and the data were interpreted using receiver operating characteristic (ROC) analysis. RESULTS: The mean area under the ROC curve was 0.8901+/-0.0259 for the LCD session, and 0.8716+/-0.0266 for the CRT session (p > 0.05). The reading time for the LCD session was not significantly different from that for the CRT session (37.12 and 41.46 minutes, respectively; p = 0.889). CONCLUSION: For detecting small solitary pulmonary nodules, an LCD monitor and a CRT monitor are comparable.

PURPOSE: To know what is the meaning of non-diagnostic results of fine needle aspiration biopsy (FNAB) and whether repeated aspiration is needed or not in those situations. MATERIALS AND METHODS: We reviewed 1845 patients who underwent FNAB from 1997 to 2001. Non-diagnostic results of the first FNAB were divided into four groups: insufficient number of cells, inflammatory cells, necrotic debris and atypical cells. We analyzed final diagnosis of 531 patients who had non-diagnostic results from the first FNAB. Among them, 207 lesions were re-biopsied because of clinical and radiologic suspicion of malignancy. The diagnostic yield of repeated FNAB was analyzed and compared with the results of the first FNAB. RESULTS: Among 255 cases with "inflammatory cells only" results, 120 cases were confirmed benignancy on follow-up. Twenty nine of 50 atypical cells (58%) were malignant on follow-up. One hundred one of 207 repeated FNAB resulted in the non-diagnostic reports, and 106 of 207 repeated FNAB were diagnosed as specific diagnosis. Among thirty lesions showing atypical cells on the repeated FNAB, 22 (73%) were identified as malignant neoplasms. CONCLUSION: When the specimen of FNAB shows atypical cells, the possibility of malignancy is very high. When the results of FNAB is non-diagnostic in the cases with clinical and radiological suspicion of malignancy, repeated FNAB procedures should be seriously considered and will be helpful for accurate specific diagnosis.
Biopsy* ; Biopsy, Fine-Needle* ; Diagnosis ; Follow-Up Studies ; Humans

PURPOSE: To determine the specific high-resolution CT features of sarcoidosis in which the observed pattern is predominantly pseudoalveolar. MATERIALS AND METHODS: We retrospectively reviewed the HRCT findings in 15 cases in which chest radiography demonstrated pseudoalveolar consolidation. In all 15, sarcoidosis was pathologically proven. The distribution and characterization of the following CT features was meticulously scrutinized: distribution and characterization of pseudoalveolar lesions, air-bronchograms, micronodules, thickening of bronchovascular bundles and interlobular septa, lung distortion, ground-glass opacities and combined hilar and mediastinal lymphadenopathy. Follow-up CT scans were available in three cases after corticosteroid administration. RESULTS: Between one and 12 (mean, 5.6) pseudoalveolar lesions appeared as dense homogeneous or inhomogeneous opacities 1-4.5 cm in diameter and with an irregular margin located either at the lung periphery adjacent to the pleural surface or along the bronchovascular bundles, with mainly bilateral distribution (n=14, 93%). An air-bronchogram was observed in ten cases. Micronodules were observed at the periphery of the lesion or surrounding lung, which along with a thickened bronchovascular bundle was a consistent feature in all cases. Additional CT features included hilar and mediastinal lymphadenopathy (n=14, 93%), thickened interlobular septa (n=12, 80%), and ground-glass opacity (n=10, 67%). Lung distortion was noted in only one case (7%). After steroid administration pseudoalveolar lesions decreased in number and size in all three cases in which follow-up CT was available. CONCLUSION: The consistent HRCT features of pseudoalveolar sarcoidosis are bilateral multifocal dense homogenous or inhomogenous opacity and an irregular margin located either at the lung periphery adjacent to the pleural surface or along the bronchovascular bundles. Micronodules are present at the periphery of the lesion or surrounding lung. The features are reversible at steroid administration.
Follow-Up Studies ; Lung ; Lymphatic Diseases ; Radiography ; Retrospective Studies ; Sarcoidosis* ; Thorax ; Tomography, X-Ray Computed