Seong Hoon Choi

Useful Ct Findings for Predicting the Progression of Aortic Intramural Hematoma to Overt Aortic Dissection

Purpose The purpose of this work was to assess useful CT findings for predicting the progression of aortic intramural hematoma to aortic dissection. Method We analyzed the CT findings of 29 patients with aortic intramural hematoma with regard to the following: involved site, maximum thickness of hematoma, presence or absence of compression of true lumen, and pericardial and pleural effusion. CT findings were compared with those of the patients who progressed to aortic dissection (Group I) and those who did not (Group II). Each CT finding was evaluated with independent t test and Mann-Whitney U test (p < 0.05). Results Seven of 8 cases of Type A aortic intramural hematoma and 3 of 21 cases of Type B aortic intramural hematoma progressed to aortic dissection. The type of aortic intramural hematoma, maximum thickness of hematoma, compression of true lumen, and pericardial or pleural effusion were significantly different in Groups I and II. Conclusion Type A aortic intramural hematoma, maximum thickness of hematoma, compression of true lumen, and pericardial or pleural effusion are the useful CT findings for predicting the progression of aortic intramural hematoma to aortic dissection.

Diagnostic performance of on-site CT-derived fractional flow reserve versus CT perfusion

Aims To compare the diagnostic accuracy of on-site computed tomography (CT)-derived fractional flow reserve (FFR) and stress CT myocardial perfusion (CTP) in patients with coronary artery disease. Methods and results Using a prospective CTP registry, 72 patients with invasive FFR were enrolled. CT-derived FFR was computed on-site using rest-phase CTP data. The diagnostic accuracies of coronary CT angiography (CCTA), CT-derived FFR, and stress CTP were evaluated using an area under the receiver-operating characteristic curve (AUC) with invasive FFR as a reference standard. Logistic regression and the net reclassification index (NRI) were used to evaluate incremental differences in CT-derived FFR or CTP compared with CCTA alone. The per-vessel prevalence of haemodynamically significant stenosis (FFR ≤ 0.80) was 39% (54/138). Per-vessel sensitivity and specificity were 94 and 66% for CCTA, 87 and 77% for CT-derived FFR, and 79 and 91% for CTP, respectively. There was no significant difference in the AUC values of CT-derived FFR and CTP (P = 0.845). The diagnostic performance of CCTA (AUC = 0.856) was improved by combining it with CT-derived FFR (AUC = 0.919, P = 0.004, NRI = 1.01) or CTP (AUC = 0.913, P = 0.004, NRI = 0.66). CT-derived FFR values had a moderate correlation with invasive FFR (r = 0.671, P < 0.001). Conclusion On-site CT-derived FFR combined with CCTA provides an incremental diagnostic improvement over CCTA alone in identifying haemodynamically significant stenosis defined by invasive FFR, with a diagnostic accuracy comparable with CTP.

Subcutaneous panniculitis-like T-cell lymphoma: US and CT findings in three patients

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare disorder. We examined two females and one male with multiple soft-tissue masses in the abdominal wall. One of these three patients also had soft-tissue masses in the right thigh and right buttock. The histologic diagnosis was revealed as SPTCL in all three cases. The ultrasound (US) findings in two of these cases were diffuse, ill-defined hyperechoic areas with a linear vascular signal. The findings of the abdominal and pelvic computed tomography (CT) scanning with contrast enhancement were multiple enhancing nodules with an infiltrative pattern of peripheral subcutaneous fat layer in all three cases. We report US and CT findings of SPTCL in these three patients.

Imaging features of benign solid testicular and paratesticular lesions.

ObjectiveThe presence of an intratesticular solid lesion is usually highly suspicious for malignancy. Conversely, most extratesticular solid lesions including paratesticular lesions are benign. The characteristic imaging features of malignant solid testicular lesions are well known, but various unusual causes and imaging features of benign solid testicular lesions can be particularly misleading. Therefore, a careful assessment of solid testicular and paratesticular lesions is warranted. The purpose of this article is to present the clinical and imaging features of the spectrum of benign solid testicular and paratesticular lesions.MethodsWe demonstrate a variety of benign solid testicular and paratesticular lesions and correlate them with pathologic results.ResultsSpecific the clinical and imaging features of the spectrum of benign solid testicular and paratesticular lesions have been described.ConclusionsFamiliarity with the clinical setting and imaging features of benign solid testicular and paratesticular lesions should facilitate prompt, accurate diagnosis and treatment.

Evaluation by Contrast-Enhanced MR Imaging of the Lateral Border Zone in Reperfused Myocardial Infarction in a Cat Model

Objective To identify and evaluate the lateral border zone by comparing the size and distribution of the abnormal signal area demonstrated by MR imaging with the infarct area revealed by pathological examination in a reperfused myocardial infarction cat model. Materials and Methods In eight cats, the left anterior descending coronary artery was occluded for 90 minutes, and this was followed by 90 minutes of reperfusion. ECG-triggered breath-hold turbo spin-echo T2-weighted MR images were initially obtained along the short axis of the heart before the administration of contrast media. After the injection of Gadomer-17 and Gadophrin-2, contrast-enhanced T1-weighted MR images were obtained for three hours. The size of the abnormal signal area seen on each image was compared with that of the infarct area after TTC staining. To assess ultrastructural changes in the myocardium at the infarct area, lateral border zone and normal myocardium, electron microscopic examination was performed. Results The high signal area seen on T2-weighted images and the enhanced area seen on Gadomer-17-enhanced T1WI were larger than the enhanced area on Gadophrin-2-enhanced T1WI and the infarct area revealed by TTC staining; the difference was expressed as a percentage of the size of the total left ventricle mass (T2= 39.2%; Gadomer-17 =37.25% vs Gadophrin-2 = 29.6%; TTC staining = 28.2%; p < 0.05). The ultrastructural changes seen at the lateral border zone were compatible with reversible myocardial damage. Conclusion In a reperfused myocardial infarction cat model, the presence and size of the lateral border zone can be determined by means of Gadomer-17- and Gadophrin-2-enhanced MR imaging.

Intermittent Sonographic Guidance in Air Enemas for Reduction of Childhood Intussusception

Objective. The purpose of this study was to prospectively assess the value of intermittent sonographic guidance in nonsurgical air reduction of childhood intussusception. Methods. The study group included 86 consecutive childhood intussusceptions confirmed on sonography for which we designed an air enema. With intermittent sonographic guidance of our own method, air was gradually injected to the initial intracolonic pressure of 60 mm Hg, which we attempted for 30 seconds on the initial attempt. If the air enema reduction attempts were not successful at a given pressure setting, we repeated the technique at each pressure setting upgraded by increments of 20 mm Hg up to 120 mm Hg. Surgery was performed when even repeated reduction attempts at the maximum intracolonic pressure of 120 mm Hg were unsuccessful. We calculated the successful reduction rate for the intussusceptions at each pressure setting. Results. The overall success rate of sonographically guided air enema reductions was 95% (82/86). The success rates of air enema reductions at 60, 80, 100, and 120 mm Hg showed progressive increases of 53% (42/86), 67% (58/86), 78% (67/86), and 95% (82/86), respectively, with no immediate recurrence and no gross perforation. Conclusions. The use of intermittent sonographic guidance in air enemas is thought to help safely increase successful reductions of childhood intussusception even with sufficient air enema attempts.

Classification of persistent primitive trigeminal artery (PPTA): a reconsideration based on MRA.

Background Persistent primitive trigeminal artery (PPTA) is the most common permanent carotid-basilar anastomosis. Magnetic resonance angiography (MRA) has become the primary non-invasive imaging technique for evaluation of cerebral vascular anatomy and can provide detailed 3D imaging of intracranial vessels. Purpose To evaluate the usefulness of MRA for the detection of PPTA and to re-classify its variations based on the embryologic types of PcomA and its relationship with the basilar artery and its branches. Material and Methods Of the total 7329 patients who underwent MRA at our institution from March 2008 through November 2010, we retrospectively analyzed the MRAs of 24 patients with a PPTA. Special attention was given to defining the relationship of the PPTA and the basilar artery with PcomA and to determine the site of origin, size, and course of the PPTA. The PPTA classification included five types based on their anatomic relationship to the neighboring arteries. Clinical features and associated vascular anomalies are also described. Results Twenty-four (17 women and seven men, 34 ∼ 81 years of age, mean age 59.67 years) of the 7329 patients had a PPTA (0.33 %). Eleven cases (45.8%) were classified as type 1, three (12.5%) as type 2, five (20.8%) as type 3, one (4.2%) as type 4, and four (16.7%) as type 5b. Fifteen PPTAs (62.5%) were located on the left side and nine were located (37.5%) on the right side. The basilar artery proximal to the insertion of the PPTA showed severe to moderate hypoplasia in 13 cases (54%). Nine intracranial artery aneurysms were detected in seven (29%) of the 24 study patients. Conclusion This study revealed five types of PPTA and necessitates an adjustment of the previous classification of PPTA on the basis of our MRA examinations. A PPTA should be considered by both the clinician and the radiologist who interpret MR angiography.

Abnormal Motion of the Interventricular Septum after Coronary Artery Bypass Graft Surgery: Comprehensive Evaluation with MR Imaging

Objective To define the mechanism associated with abnormal septal motion (ASM) after coronary artery bypass graft surgery (CABG) using comprehensive MR imaging techniques. Materials and Methods Eighteen patients (mean age, 58 ± 12 years; 15 males) were studied with comprehensive MR imaging using rest/stress perfusion, rest cine, and delayed enhancement (DE)-MR techniques before and after CABG. Myocardial tagging was also performed following CABG. Septal wall motion was compared in the ASM and non-ASM groups. Preoperative and postoperative results with regard to septal wall motion in the ASM group were also compared. We then analyzed circumferential strain after CABG in both the septal and lateral walls in the ASM group. Results All patients had normal septal wall motion and perfusion without evidence of non-viable myocardium prior to surgery. Postoperatively, ASM at rest and/or stress state was documented in 10 patients (56%). However, all of these had normal rest/stress perfusion and DE findings at the septum. Septal wall motion after CABG in the ASM group was significantly lower than that in the non-ASM group (2.1±5.3 mm vs. 14.9±4.7 mm in the non-ASM group; p < 0.001). In the ASM group, the degree of septal wall motion showed a significant decrease after CABG (preoperative vs. postoperative = 15.8±4.5 mm vs. 2.1±5.3 mm; p = 0.007). In the ASM group after CABG, circumferential shortening of the septum was even larger than that of the lateral wall (-20.89±5.41 vs. -15.41±3.7, p < 0.05) Conclusion Abnormal septal motion might not be caused by ischemic insult. We suggest that ASM might occur due to an increase in anterior cardiac mobility after incision of the pericardium.

High Pallidal T1 Signal is Rarely Observed in Obstructive Jaundice, but is Frequently Observed in Liver Cirrhosis

High Pallidal T1 Signal is Rarely Observed in Obstructive Jaundice, but is Frequently Observed in Liver Cirrhosis: Sung‐Jo Bang, et al. Department of Internal Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, South Korea—Although high signal intensities in the globus pallidus are frequently observed in T1‐weighted magnetic resonance images (MRI) of patients with liver cirrhosis, it is unclear whether these increases are due to portal‐systemic shunt or obstruction of biliary excretion. We therefore studied pallidal signals in 18 cancer patients with bile duct obstruction and marked jaundice (>10 mg/dl). Patients who had fever, leukocytosis or liver cirrhosis were excluded to ensure that jaundice was due to bile duct obstruction. All patients showed a dilated intrahepatic duct on computed tomography (CT) scan. A high pallidal signal was observed in one of 18 biliary obstructive patients whereas high signals were highly prevalent in liver cirrhosis. A portal‐systemic shunt rather than an obstruction of biliary excretion may be responsible for the increased blood manganese concentrations and pallidal T1 signals in chronic liver diseases.

Multi-Slice Spiral CT of Living-Related Liver Transplantation in Children: Pictorial Essay

In pediatric living-related liver transplantation, preoperative evaluation of the recipient is important for surgical planning, while the accurate diagnosis of postoperative complications is essential for graft salvage. Multiplanar and three-dimensional imaging using multi-slice spiral CT can be used for preoperative vascular imaging, as well as for evaluating postoperative complications. In this essay, we describe the usefulness of multi-slice CT, combined with a variety of different reconstruction techniques, for the preoperative evaluation of transplant recipients. In addition, we demonstrate the multi-slice CT findings of postoperative complications, including vascular stenosis or thrombosis, bile duct leak or stricture, and extrahepatic fluid collection.