Kyung Mo Yeon

Renal Artery Evaluation: Comparison of Spiral CT Angiography to Intra-arterial DSA

PURPOSE To assess the role of spiral computed tomographic angiography (CTA) in renal artery evaluation. MATERIALS AND METHODS The authors prospectively performed both CTA and intraarterial digital subtraction angiography (IA-DSA) in 50 consecutive patients (24 males and 26 females) who ranged between 9 and 77 years old (mean, 39.3 years), in whom renovascular hypertension was suspected (n = 32) or who were potential renal donors (n = 18). The major scan parameters of CTA were 3-mm collimation, 4-5-mm/sec table speed, and 2-mm reconstruction interval. Both CTA and IA-DSA images were blindly interpreted by two radiologists with respect to the number of accessory renal arteries and the location and severity of renal artery stenosis. RESULTS CTA demonstrated 27 of 28 accessory renal arteries (detection rate = 96%). For the detection of stenoses greater than 50% (37 of 127 renal arteries, at 40 sites), the sensitivity and specificity of CTA were 90% and 97%, respectively. For the detection of stenoses greater than 50% in the main renal arteries (32 of 99 main renal arteries, at 32 sites), the sensitivity and specificity of CTA were 100% and 97%, respectively. CONCLUSION CTA is a reliable and accurate screening modality for the evaluation of renal arteries in patients with suspected renovascular hypertension and in potential renal donors.

Lung cancer in patients with idiopathic pulmonary fibrosis: CT findings.

PURPOSE The frequency of lung cancer in patients with idiopathic pulmonary fibrosis (IPF) is higher than that of general population. To evaluate CT findings of lung cancer associated with IPF, we analyzed 32 patients with lung cancer associated with IPF. METHOD We analyzed retrospectively 32 patients with histologically confirmed lung cancer out of 244 consecutive cases diagnosed as IPF by either CT and clinical findings (n = 220) or histologically (n = 24). The patients were 40-85 years old (mean 66 years, M/F = 31/1). Scanning techniques were conventional CT in 24 patients, high-resolution CT (HRCT) in 2 patients, and both conventional CT and HRCT in 6 patients. We analyzed the CT patterns, locations, and histologic types of lung cancer. RESULTS The frequency of lung cancer in patients with IPF was 13.1% (32/244). In 17 of 32 patients, the CT findings of lung cancer were ill defined lesions mimicking air-space consolidation. Lung cancer was located mainly in the lower lobes (21/32) and peripheral portion (21/32). Histologically, squamous cell carcinoma was the most common type (18/32). CONCLUSION Typical CT findings of lung cancer were ill defined consolidation-like masses at the peripheral portion where the most advanced fibrosis was located.

High resolution CT findings of miliary tuberculosis

PURPOSE The purpose of this study was to analyze high resolution CT (HRCT) findings of miliary tuberculosis and to assess the clinical utility of HRCT in the management of patients with miliary tuberculosis. METHOD We reviewed retrospectively HRCT scans of 25 patients with histopathologically (n = 16) and/or microbiologically (n = 9) proven miliary tuberculosis. RESULTS HRCT scans showed miliary nodules in 24 patients, which varied in size from 1 to 5 mm, with either sharply (n = 21) or poorly (n = 3) defined margins. The nodules had diffuse random distribution throughout both lungs and within the secondary pulmonary lobules. In 23 patients, areas of ground-glass opacities (GGOs) were observed with variable extent and distribution. The patients who had dyspnea showed large areas of GGOs, and two patients with impending adult respiratory distress syndrome revealed extensive GGOs. Both intralobular reticulation and interlobular septal thickening were seen in 10 patients. CONCLUSION Miliary nodules and GGOs are the predominant HRCT findings in patients with miliary tuberculosis, and HRCT scans are helpful in the early diagnosis and proper management of patients with miliary tuberculosis.

Pulmonary Tuberculosis in Infants: Radiographic and CT Findings

OBJECTIVE As complications of tuberculosis are frequent in infancy, correct diagnosis of tuberculosis in infants is important. The purposes of this study are to summarize radiographic and CT findings of pulmonary tuberculosis in infants and to determine the radiologic features frequently seen in infants with this disease. CONCLUSION Frequent radiologic findings of pulmonary tuberculosis in infants are mediastinal or hilar lymphadenopathy with central necrosis and air-space consolidations, especially masslike consolidations with low-attenuation areas or cavities within the consolidation. Disseminated pulmonary nodules and airway complications are also frequently detected in this age group. CT is a useful diagnostic technique in infants with tuberculosis because it can show parenchymal lesions and tuberculous lymphadenopathy better than chest radiography. CT scans can also be helpful when chest radiographs are inconclusive or complications of tuberculosis are suspected.

AN EXPERIMENTAL STUDY OF EMBOLIC EFFECT ACCORDING TO INFUSION RATE AND CONCENTRATION OF SUSPENSION IN TRANSARTERIAL PARTICULATE EMBOLIZATION

RATIONALE AND OBJECTIVES The authors evaluate the embolic effect according to infusion rate and concentration of particulate suspension, focusing on arterial occlusion level. METHODS The renal arteries of 14 rabbits were embolized with 150 to 250 microns polyvinyl alcohol (PVA) particles, divided into four groups according to two different infusion rates (1 mg/second and 0.1 mg/second) and two different concentrations of suspension (10 mg/mL and 2.5 mg/mL). Arteriograms obtained immediately and a week after embolization were assessed for occlusion level. For the nephrograms obtained a week after embolization, the opacifying areas were graded from 0 to 4. Median coronal sections of each kidney specimen were investigated for the presence of peripheral infarct grossly and for the presence of PVA particles in the small artery microscopically. RESULTS Arteriograms showed various occlusion levels. Using a 0 to 4 grading system, the opacifying area of the nephrogram obtained 1 week after embolization was noted to be smaller in the low infusion rate group (P < 0.05). In gross and microscopic pathologic examination, the number of cases with peripheral infarct or PVA particles in the small artery (< 300 microns) was greater in the group with the low infusion rate and low concentration (P < 0.05). CONCLUSIONS In transarterial particulate embolization, slower infusion of more diluted suspension provides for a more distal arterial occlusion.

Inflammatory Myofibroblastic Tumors of the Abdomen as Mimickers of Malignancy: Imaging Features in Nine Children

OBJECTIVE The purpose of this study was to evaluate retrospectively the CT and sonographic features in nine children with pathologically proven inflammatory myofibroblastic tumors of the abdomen. CONCLUSION Although inflammatory myofibroblastic tumors occur in various sites and the imaging characteristics are variable, tumors showed different imaging patterns that were dependent on the site at which the tumor had originated.

Mediastinal Castleman Disease: Ct Findings

Objective Our objective was to characterize the CT findings of mediastinal Castleman disease. Materials and Methods We reviewed the CT findings of mediastinal Castleman disease in 10 patients. Results In nine cases of hyaline-vascular type Castleman disease, lymph nodes were 2–7 cm in diameter and located in the hilum in six patients, superior mediastinum in two patients, and posterior mediastinum in one patient. On CT the tumors were well-demarcated round masses showing dense homogeneous enhancement after contrast medium injection. Dynamic CT in one case showed gradual centripetal enhancement of the mass. In one case of hyaline-vascular type Castleman disease, lumpy and irregular calcifications were noted in the center of the mass. In the one case of plasma cell type Castleman disease, multiple small homogeneously enhancing nodes were found in the mediastinal and supraclavicular area. Conclusion CT findings may suggest the preoperative diagnosis of mediastinal Castleman disease.

Congenital intrahepatic portohepatic venous shunt: treatment with coil embolisation.

Abstract Congenital abnormalities of the portal venous system are rare. There are few radiological descriptions of intrahepatic portosystemic venous shunt detected in the perinatal period. We report a congenital portosystemic shunt that was detected by US and treated with coil embolisation in the neonatal period.

Tuberculous Stenosis of the Left Main Bronchus: Results of Treatment with Balloons and Metallic Stents☆

PURPOSE To assess the results of treatment with balloon dilation and metallic Z stents in patients with tuberculous stenosis of the left main bronchus. MATERIALS AND METHODS Nineteen patients with tuberculous stenosis of the left main bronchus were treated with balloon (n = 15) and self-expanding metallic Z stents (n = 4). Respiratory status and pulmonary function tests were followed up for 2-90 months. RESULTS In the balloon group, improvements in dyspnea occurred in 73% (11 of 15 patients) immediately, 73% after 1 month, 73% after 6 months, 64% after 1 year, 64% after 3 years, and 42% after 6 years (Kaplan-Meier method). Improvement of pulmonary function (FEV1 or FVC) was achieved in 62% (eight of 13) after 1 year. In the stent group, immediate improvements of dyspnea or pulmonary function occurred in all patients. However, fracture of the stents occurred in two patients, at 4 and 18 months, respectively. Occlusion of the lumen of the stent by granulation tissue occurred in another at 18 months. CONCLUSION Balloon dilation can be an effective method for the treatment of tuberculous stenosis of the main bronchus. Metallic Z stents should be used cautiously because of their problems of mechanical durability and overgrowth of granulation tissue.

Childhood moyamoya disease: quantitative evaluation of perfusion MR imaging--correlation with clinical outcome after revascularization surgery.

PURPOSE To evaluate whether perfusion magnetic resonance (MR) imaging can depict hemodynamic status after revascularization surgery and whether changes at perfusion MR imaging after revascularization surgery correspond with clinical outcome in moyamoya disease. MATERIALS AND METHODS An institutional review board approved this retrospective study; informed consent was waived. Pre- and postoperative perfusion MR imaging data in 67 children with moyamoya disease (mean age, 7.2 years; range, 2-13 years) were included. Regional time to peak (rTTP) and regional cerebral blood volume (rCBV) were calculated by adjusting cerebral time to peak (TTP) and cerebral blood volume (CBV) values by using cerebellar reference values. For quantitative regional analysis, pixel values were divided into five categories (>0, >2, >4, >6, and >8 seconds), and percentages of pixels in rTTP meeting these time conditions were calculated. Changes in the values after revascularization were calculated. Postoperative clinical outcomes were categorized as follows: 1 indicated excellent; 2, good; 3, fair; and 4, poor. Pre- and postoperative perfusion parameters were compared by using a paired t test; relationships between perfusion parameters and clinical outcomes were investigated by using one-way analysis of variance, with a significance level of .05. RESULTS rTTP, rCBV, and percentage of pixels of rTTP decreased significantly after revascularization surgery. Pre- and postoperative rTTP were significantly different for the clinical outcome categories. Change in rTTP and change in percentage of pixels of rTTP (>0 seconds to >6 seconds) were significantly different for the clinical outcome categories. CONCLUSION TTP and CBV perfusion maps can depict hemodynamic status after revascularization surgery in moyamoya disease. Furthermore, changes in TTP perfusion maps after revascularization surgery correspond with clinical outcome in patients with moyamoya disease.