The term ‘emphysema’ is generally used in a morphological sense, and therefore imaging modalities have an important role in diagnosing this disease. In particular, high resolution computed tomography (HRCT) is a reliable tool for demonstrating the pathology of emphysema, even in subtle changes within secondary pulmonary lobules. Generally, pulmonary emphysema is classified into three types related to the lobular anatomy: centrilobular emphysema, panlobular emphysema, and paraseptal emphysema. In this pictorial review, we discuss the radiological – pathological correlation in each type of pulmonary emphysema. HRCT of early centrilobular emphysema shows an evenly distributed centrilobular tiny areas of low attenuation with ill-defined borders. With enlargement of the dilated airspace, the surrounding lung parenchyma is compressed, which enables observation of a clear border between the emphysematous area and the normal lung. Because the disease progresses from the centrilobular portion, normal lung parenchyma in the perilobular portion tends to be preserved, even in a case of far-advanced pulmonary emphysema. In panlobular emphysema, HRCT shows either panlobular low attenuation or ill-defined diffuse low attenuation of the lung. Paraseptal emphysema is characterized by subpleural well-defined cystic spaces. Recent topics related to imaging of pulmonary emphysema will also be discussed, including morphometry of the airway in cases of chronic obstructive pulmonary disease, combined pulmonary fibrosis and pulmonary emphysema, and bronchogenic carcinoma associated with bullous lung disease.

Purpose: To determine the postural difference of diaphragmatic motion between the sitting and supine positions. Materials and Methods:A total of 10 healthy men were examined using a vertically open 0.5-T magnetic resonance (MR) system. A total of 40 sequential MR images were obtained in both the sitting and supine positions during two to five respiratory cycles. The diaphragmatic excursions (DEs) were measured on three diaphragmatic points of six sagittal planes for both positions. The differences in DEs between the anterior and posterior parts of the diaphragm were also determined.Results: DEs in the supine position were significantly greater than those in the sitting position at 15 of the 18 points. In five of the six sagittal planes, the difference of DE between posterior and anterior points was significantly larger in the supine position than in the sitting position. There have been several investigations on the evaluation of diaphragmatic motion using magnetic resonance imaging (MRI) since Gierada et al (1) first presented it (2-6). However, there is no study in which respiratory function was assessed using MRI in an upright position. For physiological investigation of normal respiratory mechanics, conduction of the study in the erect or sitting position would be more desirable since a large portion of human existence is spent in these positions. A vertically open MRI system makes this possible. In this article, the postural difference in diaphragmatic motion between the sitting and supine positions in healthy subjects was investigated using a vertically open MR system. Conclusion MATERALS AND METHODS SubjectsA total of 10 healthy male volunteers participated in this study. The mean age of the subjects was 30 years (range ϭ 25-43 years), mean weight was 73.9 kg (range ϭ 63-82 kg), and mean body mass index was 24.1 kg/m 2 (range ϭ 20.6 -28.3 kg/m 2 ). All subjects were nonsmokers without any pulmonary abnormalities. They were informed of the purpose of this study and details of the methods prior to giving written consent. Approval for this study was granted by our institutional review board.

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Purpose:To assess the feasibility of magnetic resonance voiding cystourethrography (MRVCUG) using MR fluoroscopy for evaluation of vesicoureteral reflux (VUR), and its use as a noninvasive alternative to standard VCUG. Materials and Methods:A total of 22 MR studies of 16 patients (five months to 41 years old) with primary VUR diagnosed by standard VCUG were evaluated. Six patients underwent MR studies and standard VCUG pre-and postoperatively. MR fluoroscopy was executed with a non-enhanced heavily T2-weighted single-shot fast spin-echo (FSE) sequence. The MR findings were correlated with those obtained by the gold standard, standard VCUG. Results:Of the 44 kidney-ureter units, 20 were refluxing on MRVCUG and 21 were refluxing on standard VCUG. There were one false-positive and two false-negative units. MRVCUG was 90% sensitive with a specificity of 96% for detecting VURs that were calculated based on kidney-ureter units. Two false-negative units were found in mild cases (grade I and II). For the units of grade III, IV, and V (highgrade reflux), MRVCUG detected all of the refluxing renal collecting systems. PRIMARY VESICOURETERAL REFLUX (VUR) is present in 25% to 40% of children with repeat cases of urinary tract infection (UTI) (1) and may cause renal scarring, particularly in patients with the severe form (2). Renal insufficiency and arterial hypertension is associated with renal damage caused by VUR and UTI in children. It is important to detect VUR before the onset of infection to prevent such complications (3). Voiding cystourethrography (VCUG) is the standard method for diagnosing VUR (4). However, its disadvantages include radiation exposure to the gonads, and urethral catheterization, which induces fear, distress, and pain in the patients and their parents (5). Radionuclide cystography is another sensitive method for detecting VUR. It can be performed with less radiation; however, the spatial resolution is unsatisfactory (6). Contrast-enhanced voiding urosonography has been shown to have high diagnostic accuracy comparable to that of VCUG (7), but both of these techniques are invasive. A variety of noninvasive methods using ultrasonography have been introduced for the diagnosis of VUR; however, these procedures are still not accurate enough or are less objective compared to conventional VCUG (8,9). The purpose of this study was to evaluate the feasibility of magnetic resonance VCUG (MRVCUG) as a noninvasive and non-radiating alternative to standard VCUG for diagnosing and managing patients with VUR. Conclusion MATERIALS AND METHODS SubjectsFrom September 2003 to January 2005, a total of 22 MRVCUG studies were performed on 16 patients (11 males and five females, 5 months to 41 years old, mean age ϭ 10.3 years) before and/or after anti-reflux surgery. Eleven patients were younger than seven years old, and six of these were between 5 and 12 months of age. Six patients underwent MRVCUG both pre-and postoperatively. Informed consent was obtained for all cases, and approval for this study was granted by the in...

MSCT was feasible for the detection of coronary artery stenosis.