PURPOSE: A common finding of carotid artery on magnetic resonance angiograms(MRAs) is a signal dropout along the posterior wall of carotid bulb due to reverse flow. The purpose of this study is to evaluate variable flow patterns on bifurcated carotid arterial phantoms using steady-state flow. MATERIALS AND METHODS: We designed phantoms of a bifurcated carotid artery with acrylic materials. Flow patterns were evaluated with axial and coronal imaging of MRA(2D-TOF, 3D-TOF), color Doppler imaging, and computational fluid dynamics (CFD) within the phantoms constructed of an automated closed-type circulatory system filled with 4% sugar solution. These findings were compared with findings obtained from normal volunteers. RESULTS: Axial 3D-TOF MRA images exhibited closer resemblance to the contour of the inner wall of phantoms when compared to coronal 2D-TOF MRA imaging. However, 2D-TOF MRA showed good contrast difference of signal intensities between forward flow area and reverse flow area. Dark zones with reduced signal intensities due to reversed flow were separated from the outer wall of the internal and external carotid arteries by a thin layer of forward flow along the wall on the source slice image of MRA. The general hemodynamics of the phantoms on MRA were identical to hemodynamics on color Doppler imaging and CFD. The results obtained with the phantoms matched the findings on normal volunteers. CONCLUSION: Although representations of bifurcated carotid arterial phantoms on axial 3D-TOF MRA were excellent if ideally desinged, the zone of reversed flow could be a significant factor in creating distorted image when the zone of reversed flow contacted directly with curved or deformed arterial wall.
Carotid Arteries ; Carotid Artery, External ; Healthy Volunteers ; Hemodynamics ; Humans ; Hydrodynamics ; Magnetic Resonance Angiography* ; Patient Dropouts

PURPOSE: It has been suggested that an ulceration or hemorrhage within an atheroma on a stenotic carotid artery is a clinically important cause of transient ischemic attack(TIA). In previous studies, due to its inherent signal loss by static or turbulent flow, magnetic resonance angiography(MRA) proved to be an unreliable methed for the evaluation of subtle changes of ulceration. To improve the detectability of the ulceration within atheroma, avascular phantom was filled with gadolinium solution of various concentrations during various MR sequences. MATERIALS AND METHODS: Several vascular phantoms made of elastic silicon mimicking an ulcerated stenotic internal carotid artery(ICA) were constructed, and gadolinium solution of different concentrations (1:1000 and 1:200 of Gd-DTPA) and distilled water were introduced into the vascular phantoms using a computerized pulsatile pump. To evaluate maximum intensity projection(MIP), multiple planar reconstruction(MPR) and source images, axial and coronal images of MRA with 2D-TOF(time of flight) and 3D-TOF were reviewed. Each image of various sequences was compared with plain X-ray films of each phantom filled with barium. RESULTS: On all MR suquences, the images of the phantom of the normal carotid bifurcation were superior to the images of ulcerated and stenotic phantoms. MPR and MIP were the optimal image for detecting and defining ulceration and stenosis. Better quality images were obtained when a higher concentration of Gd-DTPA was used and when the 3D-TOF technique instead of the 2D-TOF technique was applied. CONCLUSION: This study reveals that a combination of higher concentration gadolinium with MPR and MIP on 3D-TOF technique could be optimal for the evaluation of ulceration and/or stenosis at the bifurcation of the carotid artery.
Barium ; Carotid Arteries ; Carotid Artery, Internal* ; Constriction, Pathologic ; Gadolinium ; Gadolinium DTPA ; Hemorrhage ; Magnetic Resonance Angiography* ; Plaque, Atherosclerotic ; Silicones ; Ulcer* ; Water ; X-Ray Film

PURPOSE: The most important factor discrediting the reliability of MRAs is the overestimation of the degree of stenosis in the internal carotid artery(ICA). The purpose of this study is to evaluate the second aryhemodynamics and the cause(s) for the overestimation of the degree of variable stenotic phantoms of the carotidartery using steady-state flow on MRAs. MATERIALS AND METHODS: Using scrylic materials, normal and variable stenotic phantoms of the bifurcated carotid artery were constructed (40% and 65%). Flow patterns were evaluated with axial and coronal imaging of MRAs (2D-TOF and 3D-TOF) and DSAs of phantoms constructed from an automated closed-type circulatory system filled with 10% glucose solution. These findings were then compared with those obtained from CFD. RESULTS: 3D-TOF axial MRA of asymmetrically 40 percent stenotic phantom revealed 40 percent stenosis identical to the stenotic region of phantoms with continued poststenotic signal loss, whereas 3D-TOFzsial MRA of symmetrically 65 percent stenotic phantom showed markedly decreased signal intensity at the poststenotic segment resembling occlusion. Source image of 2D-TOF coronal MRA showed redistribution (from theinternal to external carotid artery side) of the central axis of inflow depending upon the degree of stenosis ofthe ICA ; this redistribution can be a cause of the decreased signal at the poststenotic segment, due to a reduced volume of flow through the stenotic segment. The general hemodynamics of the variable stenotic phantoms on MRA were identical to the hemodynamics on DSA and CFD. CONCLUSION: Although dephasing from turbulent flow and character of maximum intensity projection (MIP) were suggested as the main cause of the decreased poststenotic signal, our study indicated that a hemodynamically redistributed central axis of inflow and reduced flow volume through stenotic channel is one of the basic factors of the decreased signal intensity ot the poststenotic segmenton MRA.
Axis, Cervical Vertebra ; Carotid Arteries ; Carotid Artery, External ; Constriction, Pathologic* ; Glucose ; Hemodynamics*

PURPOSE: Purpose of this study was to determine if quantitative measures of CT attenuation and ADC values in combination with conventional imaging features can differentiate primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM). MATERIALS AND METHODS: Twenty-six patients with histologically-proven GBM (14 men and 12 women; median age, 50 years; age range, 22 - 73 years) and 14 patients with PCNSL (11 men and 3 women; median age, 61 years; age range, 41 - 74 years) were enrolled. Maximum CT attenuation, minimum ADC, and lesion to normal parenchyma minimum ADC ratios were measured in solid tumor regions. Conventional imaging features were evaluated for the following: ill-defined margin, homogeneous enhancement pattern, degree of necrosis, extent of tumor involvement and multiplicity. The Mann-Whitney test was used to compare maximum CT attenuation and minimum ADC values for PCNSL and GBM. Fisher's exact test was used to evaluate relationships between pathologic diagnoses and imaging features. RESULTS: The CT attenuations were similar for PCNSL and GBM (37.84 +/- 6.90 HU versus 37.00 +/- 5.54 HU, p = 0.68), but minimum ADC and minimum ADC ratio were significant lower in PCNSL than in GBM (595.01 +/- 228.28 10(-6) mm2/s versus 736.52 +/- 162.05 10(-6) mm2/s; p = 0.028, 0.87 +/- 0.26 versus 1.14 +/- 0.29; p = 0.007). PCNSL showed greater homogeneous enhancement and smaller necrotic areas than GBM (p = 0.003 and p < 0.001, respectively) and was more likely to have multiple tumors than GBM (p = 0.039). When necrotic PCNSL (n = 4) and necrotic GBM (n = 24) were compared, minimum ADC and minimum ADC ratios were also significantly lower in PCNSL, but CT attenuation were not. CONCLUSION: Although CT attenuation does not provide valuable information, minimum ADC and minimum ADC ratio and some imaging features can aid the differentiation of PCNSL and GBM.
Central Nervous System ; Diffusion ; Glioblastoma ; Humans ; Lymphoma ; Male ; Necrosis

Striae gravidarum are a common problem in postpartum women, who may experience serious emotional distress due to multiple streaks of scars on the abdomen. There is still no consensus on the treatment method for this problem. For a postpartum woman in her late 30s, who requested striae removal from the lower mid-abdomen, we developed and performed the keyhole-shaped vertical mini-abdominoplasty. This 37-year-old woman, who had given birth to two children, presented with multiple striae on the lower mid-abdomen and periumbilical area, as well as mild bulging in this area. The keyhole-shaped vertical mini-abdominoplasty, including multiple striae on the lower mid-abdomen and periumbilical skin, was designed. An area of striated lower abdominal and periumbilical skin, measuring approximately 10×15 cm2 and weighing about 450 g, was excised. Midline reinforcement of the loosened anterior rectus sheath with 3-0 Prolene sutures was done. Both lateral abdominal skin flaps were medially advanced to close the skin defects. Postoperatively, the patient had a favorable lower abdominal appearance with markedly fewer striae on the lower mid-abdomen and periumbilical area. The keyhole vertical mini-abdominoplasty can effectively correct moderate striae on the lower mid-abdomen and periumbilical area in postpartum women in their late 30s to middle age.

PURPOSE: We determine the Korean antibody titer and positive rate of tetanus by using a with qualitative test (ELISA) and a quantitative test (TQS(R)). METHODS: This study was prospective collecting study with uncontolled patients who were admitted in 21 Emergency Departments during 3 months in South Korea. We measured TQS(R) and collected the serum with a centrifuge for 5 groups, which was classified with age: 2~10 years (I), 11~20 years (II), 21~30 years (III), 31~40 years (IV), 41~60 years (V), in each hospital. The freezed serum and the protocol with TQS(R) results were taken at the Soonchunhyang University Bucheon hospital to be analyzed. RESULTS: The number of enrolled patients was 1816 (male 58%). The positive rate of TQS(R) was 835 patients (46%), and there was no relation with region or sex. In sex and age, there was a definitive decline in the group III fort males and females. The results of ELISA was showed that 62.8% (> 0.15 IU/ml) and 52.2% (> 0.2 IU/ml) had protective levels of tetanus antibody. The proportion decreased to approximately 43% and 18% among persons 40~60 years of age at each level of antibody titers. By region and population, there was no statistical relationship with TQS(R) and ELISA, but previous military service was associated with a higher prevalence of protective antibodies to tetanus (p<0.001). CONCLUSIONS: A substantial portion of adults in South Korea do not have antibody levels that are protective against tetanus. Also, the mean level of tetanus antibody titers was definitively lower than those of other developed conturies and consistently decreased with aging. Therefore, an adult formulation diphteria and tetanus toxoid every 5 or 10 years is recommended for all adults between 20 and 60 years of age after being tested with TQS(R) in South Korea.
Adult ; Aging ; Antibodies ; Emergency Service, Hospital ; Enzyme-Linked Immunosorbent Assay ; Epidemiology ; Female ; Gyeonggi-do ; Humans ; Korea ; Male ; Military Personnel ; Prevalence ; Prospective Studies ; Tetanus ; Tetanus Toxoid