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Whal Lee

Publications and source records attributed to Whal Lee.

14 recordsLinked to original sources
PubMed2025

Cardiac CT fractal analysis of LV noncompaction and common cardiomyopathies.

BACKGROUND: Left ventricular noncompaction (LVNC), or hypertrabeculation, is a myocardial condition that remains challenging to diagnose and differentiate from other cardiomyopathies. This study evaluated the ability of cardiac CT to differentiate between LVNC, hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), and controls using fractal analysis of LV trabeculae. METHODS: Subjects with LVNC, HCM, DCM, as well as controls, who underwent coronary CT angiography were included. LV trabecular structure was quantified using fractal analysis on a stack of 15 short-axis CT images. For each subject, maximum (FDmax) and average (FDglobal) fractal dimensions were reported. A subset of subjects also had clinically acquired cardiac MRI (CMR) exams for comparison. One-way ANOVA, Pearson correlation, and Bland-Altman analysis were used for statistical analysis. RESULTS: The study included 313 subjects (median age: 58.8 [48.1-68.0] years, 153 male) categorized into Control (89), LVNC (46), HCM (106), and DCM (72) cohorts. FDmax was significantly higher in LVNC (1.379 &#x200b;&#xb1; &#x200b;0.047) than in Control (1.305 &#x200b;&#xb1; &#x200b;0.033), HCM (1.321 &#x200b;&#xb1; &#x200b;0.040), and DCM (1.344 &#x200b;&#xb1; &#x200b;0.054) cohorts; all p &#x200b;< &#x200b;0.001. Similarly, FDglobal was significantly higher in LVNC (1.279 &#x200b;&#xb1; &#x200b;0.041) than in the other cohorts; all p &#x200b;< &#x200b;0.05. In a subset of 132 subjects with both CT and CMR exams, fractal dimensions from the two modalities were strongly correlated (r &#x200b;= &#x200b;0.63, p &#x200b;< &#x200b;0.0001), with CT-derived values being higher (1.337 &#x200b;&#xb1; &#x200b;0.049 vs. 1.262 &#x200b;&#xb1; &#x200b;0.045, p &#x200b;< &#x200b;0.0001). CONCLUSIONS: CT-derived fractal dimensions of LV trabecular structure were significantly higher in LVNC compared to control subjects, HCM, and DCM. CT-derived fractal dimensions strongly correlated with, but were higher than, those from cardiac MRI in the same subjects.

Humans↗
PubMed2007

Internal mammary arteries supplying hepatocellular carcinoma: vascular anatomy at digital subtraction angiography in 97 patients.

PURPOSE: To retrospectively evaluate the vascular anatomy of the internal mammary arteries that supply hepatocellular carcinomas (HCCs), with an emphasis on number of tumor feeders. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board; informed consent was waived. Between August 1996 and July 2005, internal mammary arteries that supply HCCs were found in 97 (2.2%) of 4438 patients (76 men, 21 women; mean age, 55 years +/- 10.5 [standard deviation]; range, 19-79 years). Computed tomographic scans and digital subtraction angiograms in these 97 patients were retrospectively reviewed in consensus by two interventional radiologists. Tumor size, number of tumor feeders, and tumor location were recorded. The t test and analysis of variance were used to correlate tumor size with number of tumor feeders, tumor feeder laterality, and transcatheter arterial chemoembolization (TACE) time. RESULTS: The following 125 tumor feeders were identified in 97 patients: phrenic branch (n = 59), musculophrenic artery (n = 40), superior epigastric artery (n = 15), anterior intercostal artery (n = 6), ensiform artery (n = 4), and pericardiacophrenic artery (n = 1). In two patients, tumors were in dorsal hepatic areas directly beneath the diaphragm. Half of the tumors located in liver segments II or III were supplied by the right internal mammary artery. In three patients, the tumor feeders from the left internal mammary artery crossed the midline. Tumor size was not statistically associated with number of tumor feeders (P = .076), tumor feeder laterality (P = .141), and TACE time (P = .729). CONCLUSION: The common tumor feeders of the internal mammary artery are the phrenic branch and the musculophrenic artery. Moreover, the internal mammary artery can supply a tumor even in the dorsal hepatic area.

Adult↗
PubMed2006

Aneurysm of the ductus arteriosus in a patient with Larsen syndrome.

Larsen syndrome is characterized by multiple congenital joint dislocations and a characteristic flattened facial appearance. The aetiology is unknown, but the syndrome is considered a probable connective tissue disorder and the cardiovascular manifestations are similar to those of Marfan syndrome. We describe an 8-year-old girl with the characteristic features of Larsen syndrome who was also affected by a saccular aneurysm of the descending aorta, just distal to the left subclavian artery. We present the radiological findings and review the literature.

Abnormalities, Multiple↗
PubMed2006

Differential effect of intracoronary infusion of mobilized peripheral blood stem cells by granulocyte colony-stimulating factor on left ventricular function and remodeling in patients with acute myocardial infarction versus old myocardial infarction: the MAGIC Cell-3-DES randomized, controlled trial.

BACKGROUND: The efficacy of intracoronary infusion of granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood stem cells (PBSCs) has not been compared between patients with acute (AMI) versus old myocardial infarction (OMI). In addition, the potential risk of restenosis associated with G-CSF-based stem cell therapy has not been evaluated in the setting of drug eluting stent (DES) implantation. METHODS AND RESULTS: We randomly allocated 96 patients with myocardial infarction who underwent coronary revascularization with DES for the culprit lesion into 4 groups. Eighty-two patients completed 6-month follow-up; AMI cell infusion (n=25), AMI control (n=25), OMI cell infusion (n=16), and OMI control group (n=16). In cell infusion groups, PBSCs were mobilized by G-CSF for 3 days and delivered to infarcted myocardium via intracoronary infusion. The AMI cell infusion group showed a significant additive improvement in left ventricular ejection fraction (LVEF) and remodeling compared with controls (change of LVEF: +5.1+/-9.1% versus -0.2+/-8.6%, P<0.05; change of end-systolic volume: -5.4+/-17.0 mL versus 6.5+/-21.9 mL, P<0.05). In OMI patients, however, there was no significant change of LVEF and ventricular remodeling in spite of significant improvement of coronary flow reserve after cell infusion. G-CSF-based cell therapy did not aggravate neointimal growth with DES implantation. CONCLUSIONS: Intracoronary infusion of mobilized PBSCs with G-CSF improves LVEF and remodeling in patients with AMI but is less definite in patients with OMI. G-CSF-based stem cell therapy with DES implantation is both feasible and safe, eliminating any potential for restenosis.

Acute Disease↗
PubMed2006

Hepatocellular carcinoma: transcatheter arterial chemoembolization of the gonadal artery.

Over the past 9 years, the authors have identified gonadal arteries supplying hepatocellular carcinoma in seven of 4,438 patients (0.16%) whom they attempted to treat by transcatheter arterial chemoembolization. All seven patients had tumors in the Couinaud segment 6 (S6) of the liver (mean size, 6.8 cm). The gonadal arteries in all seven patients showed anatomic variations, including a high origin (n = 3) and a common trunk with the adrenal artery (n = 4). The gonadal artery with anatomic variation may supply hepatocellular carcinomas located in liver S6.

Adult↗
PubMed2006

Superficial venous aneurysm: reports of 3 cases and literature review.

OBJECTIVE: The purpose of this series is to describe the ultrasonographic and computed tomographic (CT) findings of superficial venous aneurysms sometimes misdiagnosed as subcutaneous soft tissue tumors. METHODS: Two of the patients had an asymptomatic subcutaneous mass that gradually increased in size; the third patient had a superficial mass in the right antecubital fossa associated with pain and occasional edema. All of the patients were examined with ultrasonography, and 2 had CT scans. RESULTS: In all cases, ultrasound examinations showed a well-defined heterogeneous echoic lesion that was contiguous with the adjacent superficial vein and easily compressed by the probe, whereas a Doppler study indicated a venous spectral wave without pulsation. Dynamic enhanced CT showed homogeneous enhancement in the late phase, with contiguity with the adjacent vein. Only the third patient had an internal, floating, heterogeneous, echoic mass-like lesion, suggesting a chronic thrombus in the lesion on ultrasonography. This patient underwent aneurysmectomy with end-to-end anastomosis. CONCLUSIONS: Venous aneurysm should be included in the differential diagnosis of a subcutaneous mass, and an accurate understanding of the differences between superficial and deep venous aneurysms may help in diagnosis and treatment.

Aneurysm↗
PubMed2005

Role of computed tomographic angiography in the detection and comprehensive evaluation of persistent sciatic artery.

PURPOSE: To define the role of computed tomographic (CT) angiography in the evaluation of persistent sciatic artery and to identify its potential advantages as a diagnostic modality. METHODS: Between July 2002 and August 2004, 307 consecutive patients underwent CT angiography for suspected lower-extremity arterial insufficiency. All CT angiograms were retrospectively reviewed to determine the presence and laterality of persistent sciatic artery and its associated vascular abnormalities, such as aneurysm, thrombus, distal thromboembolism, and atherosclerotic change. The relationship of persistent sciatic artery with adjacent structures, such as sciatic nerve, muscle, accompanying vein, and femoral artery, as well as the presence of other anomalies, was analyzed. Clinical data regarding the presenting symptoms and hospital course were obtained from patient charts. RESULTS: Six persistent sciatic arteries, with or without occlusion, were identified in five female patients (age range, 54 to 80 years). CT angiography revealed unilateral persistent sciatic artery in four patients (left, 3; right, 1) and bilateral persistent sciatic artery in one patient. Aneurysm was present in two (mean size, 26 mm x 20 mm), thrombosis in three, and distal thromboembolism in all six persistent sciatic arteries. All persistent sciatic arteries coursed along the sciatic nerve and continued as popliteal artery. Characteristically, in all these instances, the superficial femoral arteries were hypoplastic and tapered smoothly. Anomalous popliteal venous drainage was noted in all ipsilateral limbs with persistent sciatic artery and even in contralateral limbs with normal superficial femoral artery in all but one. CONCLUSION: CT angiography enables the detection of persistent sciatic artery even in the presence of complete occlusion and is useful in the comprehensive evaluation of various complications and associated venous anomalies. It can potentially be used as the sole imaging modality for persistent sciatic artery.

Aged↗
PubMed2005

Recognizing extrahepatic collateral vessels that supply hepatocellular carcinoma to avoid complications of transcatheter arterial chemoembolization.

Extrahepatic collateral arteries commonly supply hepatocellular carcinomas if the tumors are large or peripherally located. Because development of these vessels interferes with effective control of the tumor with transcatheter arterial chemoembolization (TACE), radiologists should become familiar with the imaging findings of extrahepatic collateral vessels to detect them at an early stage. The authors observed 2104 such vessels in 860 patients over 5.5 years. The extrahepatic collateral vessels observed originated from the inferior phrenic artery, omental branch, adrenal artery, intercostal artery, cystic artery, internal mammary artery, renal or renal capsular artery, branch of the superior mesenteric artery, gastric artery, and lumbar artery. The authors suspected extrahepatic collateral vessels when (a) a tumor grew exophytically or invaded adjacent organs, (b) a tumor was in contact with the ligaments and bare area of the liver, (c) a hypertrophied extrahepatic collateral vessel was observed on a computed tomographic (CT) scan, (d) a peripheral defect of iodized oil retention within a tumor was seen during chemoembolization or on a follow-up CT scan, (e) a local recurrence developed at the peripheral portion of the treated tumor during follow-up, or (f) a sustained elevation in serum alpha-fetoprotein level was noted despite adequate embolization of the hepatic artery. When both the hepatic artery and extrahepatic collateral vessels supply a tumor, additional extrahepatic collateral vessel chemoembolization should be attempted to increase the therapeutic efficacy of TACE for hepatocellular carcinoma.

Adult↗
PubMed2004

Acute iliofemoral deep vein thrombosis: evaluation of underlying anatomic abnormalities by spiral CT venography.

PURPOSE: To evaluate the spectrum of underlying anatomic abnormalities in iliofemoral deep vein thrombosis (DVT) by spiral computed tomographic (CT) venography. MATERIALS AND METHODS: During the past 4 years, 56 patients with acute iliofemoral DVT have been evaluated by CT venography at our institution. Forty-four patients had left-sided DVT, nine had right-sided DVT, and the remaining three had DVT in both extremities. CT venography was performed with use of 2.5-3.2-mm x-ray beam collimation and a 1.25-2.0-mm reconstruction interval. Spiral scans were initiated 5 minutes after intravenous contrast medium injection. The CT venograms were correlated with catheter venograms. In addition, with use of axial sections and their three-dimensional reconstructions, including multiplanar reformation and volume rendering, the presence or absence of central obstructing lesions and their causes were evaluated. RESULTS: Among 44 patients with left-sided DVT, 37 had significant anatomic abnormalities in their iliofemoral veins or inferior vena cava (IVC). The most common lesion was left common iliac vein compression by the right common iliac artery (n = 27; exaggerated by a bony spur in nine and associated with extrinsic compression by the left internal iliac artery in two). Of the nine patients with right-sided DVT, six had significant anatomic abnormalities including encasement or extrinsic compression of their iliac veins by various causes (n = 3) and venous stricture without extrinsic lesions (n = 3). Among three patients with DVT in both extremities, two had anatomic abnormalities in the IVC. Therefore, 45 of 56 patients had anatomic abnormalities central to the thrombosed deep veins. CONCLUSION: The majority of patients with acute iliofemoral DVT had underlying anatomic abnormalities. The presence of central stenosis or obstruction and their causes can be evaluated by spiral CT venography.

Adolescent↗
PubMedDate not supplied

Collateral pathways in thoracic central venous obstruction: three-dimensional display using direct spiral computed tomography venography.

We illustrate the spectrum of venous collateral pathways caused by the thoracic central venous obstruction with direct spiral computed tomography (CT) venography and 3-dimensional reconstruction images. Venous structures that can be demonstrated with CT venography include the jugular veins; the subclavian and brachiocephalic (innominate) veins; the internal and lateral thoracic veins; the superior and inferior venae cavae; the pericardiophrenic veins; the azygos, hemiazygos, and accessory hemiazygos veins; and the intercostal veins.

Adult↗
PubMedDate not supplied

CT arthrography and virtual arthroscopy in the diagnosis of the anterior cruciate ligament and meniscal abnormalities of the knee joint.

OBJECTIVE: To determine the diagnostic accuracy of CT arthrography and virtual arthroscopy in the diagnosis of anterior cruciate ligament and meniscus pathology. MATERIALS AND METHODS: Thirty-eight consecutive patients who underwent CT arthrography and arthroscopy of the knee were included in this study. The ages of the patients ranged from 19 to 52 years and all of the patients were male. Sagittal, coronal, transverse and oblique coronal multiplanar reconstruction images were reformatted from CT arthrography. Virtual arthroscopy was performed from 6 standard views using a volume rendering technique. Three radiologists analyzed the MPR images and two orthopedic surgeons analyzed the virtual arthroscopic images. RESULTS: The sensitivity and specificity of CT arthrography for the diagnosis of anterior cruciate ligament abnormalities were 87.5%-100% and 93.3-96.7%, respectively, and those for meniscus abnormalities were 91.7%-100% and 98.1%, respectively. The sensitivity and specificity of virtual arthroscopy for the diagnosis of anterior cruciate ligament abnormalities were 87.5% and 83.3-90%, respectively, and those for meniscus abnormalities were 83.3%-87.5% and 96.1-98.1%, respectively. CONCLUSION: CT arthrography and virtual arthroscopy showed good diagnostic accuracy for anterior cruciate ligament and meniscal abnormalities.

Adult↗
PubMedDate not supplied

Comparison of transaxial source images and 3-plane, thin-slab maximal intensity projection images for the diagnosis of coronary artery stenosis with using ECG-gated cardiac CT.

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 16 x 0.75-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.

Adult↗
PubMedDate not supplied

Transcatheter arterial chemoembolization of hepatocellular carcinoma: prevalence and causative factors of extrahepatic collateral arteries in 479 patients.

OBJECTIVE: We wanted to investigate the prevalence and causative factors of extrahepatic arterial blood supply to hepatocellular carcinoma (HCC) at its initial presentation and during chemoembolization. MATERIALS AND METHODS: Between February 1998 and April 2000, consecutive 479 patients with newly diagnosed HCC were prospectively enrolled into this study. A total of 1629 sessions of transcatheter arterial chemoembolization (TACE) were performed in these patients (range: 1-15 sessions; mean: 3.4 sessions) until April 2004. For each TACE procedure, we determined the potential extrahepatic collateral arteries (ExCAs) depending on the location of the tumor, and we performed selective angiography of all suspected collaterals that could supply the tumor. The prevalence of ExCAs and the causative factors were analyzed. RESULTS: At initial presentation, 82 (17%) of these 479 patients showed 108 ExCAs supplying tumors. Univariate analysis showed that tumor size (p < 0.01), patient age (p = 0.02), a surface location (p < 0.01), and a bare area location (p < 0.01) were significantly associated with the presence of ExCAs. Multiple logistic regression analysis showed that only tumor size was predictive of ExCA formation (p < 0.01, odds ratio = 1.737, confidence interval: 1.533 to 1.969). During repeated TACE sessions, 97 additional ExCAs were detected in 70 (14%) patients. The cumulative probability of ExCAs in patients with a large tumor (> or =5 cm) was significantly higher than that for those patients with a small tumor (< 5 cm) (p < 0.01). CONCLUSION: The presence of ExCAs supplying HCC is rather common, and the tumor size is a significant causative factor for the development of these collateral arteries.

Adult↗