• Tuberculosis and Respiratory Diseases
• /
• v.41 no.2
• /
• pp.97-102
• /
• 1994

Objectives : Since Mountain proposed the new staging system of non-small cell lung cancer in 1986, the indications for operation of NSCLC have been extended. However, operative mortality is from 3 to 6%. Therefore it is important to reduce unnecessary operation and to evaluate unresectability of tumor correctly, preoperatively. The purpose of this study is to find out the causes of unresectability in patients who were initially thought to be resectable preoperatively. Methods : By retrospective analysis, 64 patients out of 291 NSCLC patients who were undergone operation for curative resection in Seoul National University Hospital from Jan. of 1987 to Dec. of 1991, were found to be unresectable at operating room, were selected for this study. Out of 64 patients, 42 were evaluable. The analysis was focused on the change of pre- & post-operative staging and the causes of unresectability of tumors. Results : Among 42 patients with unresectable tumor who could be evaluated, preoperative CT finding showed resectable tumors in 55%(23 patients) and suspicious for unresectable tumors in 45%(19 patients). The causes of unresectability were technically unresectable T3 lesions in 7%(3 patients), T4 lesions in 62%(26 patients), N2 lesions in 17%(7 patients) and N3 lesions in 14%(6 patients). Conclusion : The major causes of unresectability of NSCLC were pulmonary artery invasions. It is suggested that careful evaluation of mediastinal structure, especially great vessels by additional imaging technique other than CT(like MRI) is indicated in selected NSCLC cases.

• Investigative Magnetic Resonance Imaging
• /
• v.18 no.4
• /
• pp.303-313
• /
• 2014

Purpose : In-vivo conductivity reconstruction using transmit field ($B_1{^+}$) information of MRI was proposed. We assessed the accuracy of conductivity reconstruction in the presence of statistical noise in complex $B_1{^+}$ map and provided a parametric model of the conductivity-to-noise ratio value. Materials and Methods: The $B_1{^+}$ distribution was simulated for a cylindrical phantom model. By adding complex Gaussian noise to the simulated $B_1{^+}$ map, quantitative conductivity estimation error was evaluated. The quantitative evaluation process was repeated over several different parameters such as Larmor frequency, object radius and SNR of $B_1{^+}$ map. A parametric model for the conductivity-to-noise ratio was developed according to these various parameters. Results: According to the simulation results, conductivity estimation is more sensitive to statistical noise in $B_1{^+}$ phase than to noise in $B_1{^+}$ magnitude. The conductivity estimate of the object of interest does not depend on the external object surrounding it. The conductivity-to-noise ratio is proportional to the signal-to-noise ratio of the $B_1{^+}$ map, Larmor frequency, the conductivity value itself and the number of averaged pixels. To estimate accurate conductivity value of the targeted tissue, SNR of $B_1{^+}$ map and adequate filtering size have to be taken into account for conductivity reconstruction process. In addition, the simulation result was verified at 3T conventional MRI scanner. Conclusion: Through all these relationships, quantitative conductivity estimation error due to statistical noise in $B_1{^+}$ map is modeled. By using this model, further issues regarding filtering and reconstruction algorithms can be investigated for MREPT.

• Nuclear Medicine and Molecular Imaging
• /
• v.40 no.6
• /
• pp.322-326
• /
• 2006

A low iodine diet (LID) for $1{\sim}2$ weeks is recommended for patients who undergoing radioiodine remnant ablation. However, the LID educations for patients are different among centers because there is no concrete recommendation for protocol of LID. In this investigation, we compared two representative types of LID protocols performed in several centers in Korea using urine iodine to creatinine ratio (urine I/Cr). Methods: From 2006, April to June, patients referred to our center for radioiodine remnant ablation of thyroid cancer from several local hospitals which had different LID protocols were included. We divided into two groups, stringent LID for 1week and less stringent LID for 2 weeks, then measured their urine I/Cr ratio with spot urine when patients were admitted to the hospital. Results: Total 27 patients were included in this investigation (M:F=1:26; 13 in one-week stringent LID; 14 in two-week less stringent LID. Average of urine I/Cr ratio was $127.87{\pm}78.52{\mu}g/g$ in stringent LID for 1 week, and $289.75{\pm}188.24{\mu}g/g$ in less stringent LID for 2 weeks. It was significantly lower in stringent LID for 1 week group (p=0.008). The number of patients whose urine I/Cr ratios were below $100{\mu}g/g$ was 6 of 13 in stringent LID for 1 week group, and 3 of 14 in less stringent LID for 2 weeks group. Conclusion: Stringent LID for 1 week resulted in better urinary I/Cr ratio in our investigation compared with the other protocol. However it still resulted in plenty of inadequate range of I/Cr ratio, so more stringent protocol such as stringent LID for 2 weeks is expected more desirable.

• Nuclear Medicine and Molecular Imaging
• /
• v.40 no.6
• /
• pp.293-301
• /
• 2006

Purpose: The aim of the study was to evaluate the hemodynamic changes after successful bypass surgery in patients with atherosclerotic stenosis in ICA using $^{99m}Tc-ECD$ SPECT. Materials and Methods: Fourteen patients (M:F=8:6, mean age; $60{\pm}9$ years) who underwent STA-MCA anastomosis for unilateral atherosclerotic cerebrovascular disease were enrolled. $^{99m}Tc-ECD$ basal/acetazolamide perfusion SPECT studies were performed before, 10 days and 6 months after bypass surgery. Perfusion reserve was defined as the % changes after acetazolamide over rest image. Regional cerebral blood flow and perfusion reserve were compared preoperative, early-postoperative and late-postoperative scans. Results: The mean resting perfusion and decrease in perfusion reserve in affected ICA territory on preoperative scan was $52.4{\pm}3.5\;and\;-7.9{\pm}4.7%$, respectively. The resting perfusion was significantly improved after surgery on early-postoperative scan (mean $53.7{\pm}2.7$) and late-postoperative scan (mean $53.3{\pm}2.5$) compared with preoperative images (p<0.05, respectively). Resting perfusion did not showed further improvement on late-postoperative scan compared with early-postoperative scan. The perfusion reserve was $-3.7{\pm}2.6%$ on early-postoperative scan, and $-1.6{\pm}2.3%$ on late-postoperative scan, which was significantly improved after surgery. Additionally, further improvement of perfusion reserved as observed on late-postoperative scan (p<0.05). While, in the unaffected ICA territory, no significant changes in the resting perfusion and perfusion reserve was observed. Conclusion: The improvement of resting perfusion and perfusion reserve in early-postoperative scan reflects the immediate restoration of the cerebral blood flow by bypass surgery. In contrasts, further improvement of perfusion reserve showing on late-postoperative scan may indicate a good collateral development after surgery, which may indicate good surgical outcome after surgery.

• Nuclear Medicine and Molecular Imaging
• /
• v.40 no.6
• /
• pp.302-308
• /
• 2006

Purpose: Although several neuroanatomical models of panic disorder have been proposed, little is known regarding the neurological mechanisms underlying cognitive-behavioral therapy (CBT) in patients with panic disorder. This study was performed to identify the brain structures that show changes of regnioal cerebral blood flow (rCBF) after CBT in patients with panic disorder. Materials and Methods: Seven patients who were diagnosed as panic disorder by DSM-IV were treated with CBT for 8 weeks and twelve healthy volunteers joined in this study. Serial $^{99m}Tc-ECD$ brain perfusion SPECT images were acquisited and PDSS-SR (Self-Report version of Panic Disorder Severity Scale) and ACQ (Agoraphobic Cognitive Question) scores were measured just before and after CBT in all patients. Data were analyzed using SPM2. Results: Subjective symptoms were improved, and PDSS-SR and ACQ scores were significantly reduced ($14.9{\pm}3.9\;vs.\;7.0{\pm}1.8$, p<0.05; $30.3{\pm}8.5\;vs.\;21.6{\pm}3.4$, p<0.05, respectively) after CBT in panic patients. Before CBT, a significant increase of rCBF was found in the cingulate gylus, thalamus, midbrain, both medial frontal and temporal lobes of the panic patients compared to the normal volunteers. After CBT, we observed a significant rCBF decrease in the left parahippocamus, right insula and cingulate gyrus, both frontal and temporal lobes, and a significant rCBF increase in both the occipital lobes, left insula, both frontal and left parietal lobes. Conclusion: These data suggested that CBT is effective for panic disorder and diminish the activity of the brain areas associated with fear in panic disorder.

• Nuclear Medicine and Molecular Imaging
• /
• v.40 no.6
• /
• pp.316-321
• /
• 2006

Purpose: Differential diagnosis between arteriovenous (AVMs) aud non-arteriovenous malformations (nAVMs) is important in patients with congenital vascular malformations, because AVMs can cause hemodynamic alteration and require immediate treatment. We investigated whether transarterial lung perfusion scintigraphy (TLPS) was useful for the diagnosis and post-therapeutic evaluation of AVMs in extremities. Materials and Methods: Fifty-seven patients (M:F=26:31, $21{\pm}13$ yr, 9 upper and 48 lower extremities) suspected of congenital vascular malformations in extremities underwent TLPS using $^{99m}Tc-MAA$ before embolization/sclerotherapy. Dose-corrected shunt fraction (SF) was calculated from time-activity curve of the lung. Final diagnosis of AVMs was determined by angiography. in patients with AVMs, follow-up TLPS was done for post-therapeutic evaluation. Results: Sixteen patients (8 upper and 8 lower extremities) had AVMs, while the remaining 41 had nAVMs (1 upper and 40 lower extremities). The mean SF of AVMs on TLPS was significantly higher than that of nAVMs ($66.4{\pm}25.8%\;vs.\;2.8{\pm}4.3%$), p=0.003). The sensitivity, specificity, and accuracy of TLPS (cut-off of SF = 20.0%) in diagnosis of AVMs before treatment were 93.8% (15/16), 100% (41/41) and 98.2% (56/57), respectively. The follow-up TLPS and angiography for post-therapeutic evaluation showed concordant results in 13 of 16 patients (81.3%) with AVMs. The mean SF of TLPS was significantly decreased after embolization/sclerotherapy ($69.5{\pm}24.0%\;vs.\;41.0{\pm}34.7%$, p=0.01). Conclusion: TLPS provides hemodynamic information of AVMs in extremities semiquantitatively. Furthermore, the results of TLPS showed a high concordance rate with angiographic findings. Therefore, TLPS is useful for the diagnosis and post-therapeutic evaluation of AVMs in extremities.

• Clinical and Experimental Pediatrics
• /
• v.46 no.1
• /
• pp.56-66
• /
• 2003

Purpose : Human umbilical vein endothelial cells(HUVECs) play an important role in regulating blood flow by releasing vasoactive substances. It has been reported that endothelial impairment and dysfunction might be a primary cause of placental vascular disease, which is manifested clinically as preeclampsia in mother and intrauterine growth restriction in fetus. Furthermore, the frequency of apoptotic changes is increased in umbilical and placental tissues from growth-restricted pregnancies. However, the various mechanisms of umbilical endothelial cell apoptosis have not been broadly proposed. We investigate the effects of amiloride derivatives on apoptotic death of HUVECs and identify their ionic mechanism. Methods : HUVECs were purchased from Clonetics, and cultured on endothelial cell growth medium. MTT assay and flow cytometry were used for assessing cytotoxic effect and confirming the apoptosis. Changes in intracellular ion concentrations were measured with specific fluorescent dyes and fluorescence imaging analysis system. Results : Amiloride derivatives elicited cytotoxic effects on HUVECs with dose-dependent manners and the rank order of potency is HMA($IC_{50}\;11.2{\mu}M$), MIA>EIPA>>amiloride. HMA-induced cytotoxicity is dependent on extra- and intracellular pH, that is, increase extra- and intracellular pH augmented the cytotoxic effects of HMA. HMA dose-dependently reduced intracellular major ions, such as $K^+$ and $Cl^-$. Interestingly, the depletion of intracellular ions induced by HMA was also significantly enhanced at alkaline extracellular pH. Conclusion : Amiloride derivatives induce apoptosis of HUVECs with dose and pH dependent manners. They reduce intracellular $K^+$ and $Cl^-$ concentration, which is also extracellular pH dependent.

• Clinical and Experimental Pediatrics
• /
• v.52 no.3
• /
• pp.289-294
• /
• 2009

Purpose : To assess the usefulness of magnetic resonance imaging (MRI), karyotyping, brainstem auditory evoked potential (BAEP), electroencephalogram (EEG), tandem mass screening test, and newborn metabolic screening test in children with language delay for diagnosing underlying diseases. Methods : From January 2000 to June 2007, a retrospective chart review was performed for 122 children with language delay who visited the Child Neurology Clinic at Yeungnam University Hospital and who underwent neuropsychologic tests and other diagnostic evaluations for underlying diseases. They were grouped into phenomenological diagnostic categories, and test results were analyzed according to the underlying diseases. Results : Of 122 patients, 47 (38.5%) had mental retardation, 40 (32.8%) had developmental language disorders, 23 (18.9 %) had borderline IQ, and 12 (9.8%) had autism spectrum disorder. In 26 (21.3%) cases, the causes or relevant clinical findings to explain language delay were found. Eight (10.4%) of 77 MRIs, 6 (8.0%) of 75 EEGs, and 4 (5%) of 80 BAEPs showed abnormal results. Results directly attributed to diagnosing underlying diseases were 2 hearing defects in BAEPs and 1 bilateral perisylvian cortical dysplasia in MRIs. No abnormal results were found in karyotyping, tandem mass screening tests, and new-born screening tests. Conclusion : Commonly used tests to diagnose the cause of language delay are not very effective and should only be used selectively, according to patient characteristics. However, despite the low diagnostic yields from these tests, because many patients show abnormal results, these tests are useful when conducted in complete evaluation.

• Journal of the Korean Arthroscopy Society
• /
• v.16 no.2
• /
• pp.134-139
• /
• 2012

Purpose: To report the treatment results of arthroscopic osteochondroplasty in osteochondral lesion of the talus. Materials and Methods: This study included 32 patients who had osteochondral lesion of the talus treated with arthroscopic osteochondroplasty and were able to be followed up over 3 years from 1999 to 2007. The mean follow up period was 48 (38-108) months, and 22 male patients and 10 female patients with a mean age of 34 (20-56) years were included. Locations of lesion were evaluated with simple X-ray and magnetic resonance imaging (MRI), and severities of lesions were classified by Berndt and Harty classification. All cases were treated by arthroscopic debridement or microfracture. The treatment results were assessed by American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale and subjective and functional score of Kailkkonen. The group treated by arthroscopic microfracture was compared with the group treated by arthroscopic debridement. Results: The mean AOFAS ankle-hindfoot scale was significantly improved 53 (${\pm}7$) points preoperatively to 84 (${\pm}8$) points postoperatively (P<0.001). The mean subjective and functional score was also improved 55 (${\pm}8$) points preoperatively to 88 (${\pm}8$) points postoperatively with statistical significant (P<0.001). There were no relations between the severity of lesions and the postoperative functional score of ankle (P>0.05). There were no significant differences in the clinical results between the group treated with arthroscopic microfracture and the group treated with arthroscopic debridement (P>0.05). Conclusion: Arthroscopic osteochondroplasty of osteochondral lesion of the talus shows excellent result in terms of patients' satisfaction. There were no significant differences in the clinical results between arthroscopic microfracture group and debridement group.

• Investigative Magnetic Resonance Imaging
• /
• v.6 no.2
• /
• pp.129-136
• /
• 2002

Purpose : To evaluate the usefulness of MRCP in the diagnosis of the variable causes of common bile duct(CBD) dilatation, except stone or tumor Materials and methods : Twenty-six patients(M:F=15:11, mean age; 62 years) with both MRCP and ERCP were included in this study. Dynamic MRCP(n=12) and contrast-enhanced MRI(n=10) of abdomen were also added. Dilatation of CBD, intrahepatic ducts and pancreatic duct was evaluated, including coexistence of intrahepatic ductal stone, pancreatic pseudocyst, and papillary or papillary edema. The criteria of CBD dilatation was over than 7mm(n= 21, without cholecystectomy) or 10 mm(n=5, with cholecystecto-my) in diameter on T2-weighted coronal image. Results : The mean diameter of CBD was 12.7mm without cholecystectomy(9-19 mm) and 13.0 mm with cholecystectomy(10-15mm), respectively(p 〉0.05). Cholangitis(n=11, 42.3%), chronic pancreatitis(n=8, 30.8%), stenosis of distal CBD(n= 6, 23.1%), periampullary diverticulum(n=3, 11.5%), stenosis of ampulla of Vater(n=2, 7.7%), dysfunction of sphincter of Oddi(n=2, 7.7%), acute focal pancreatitis in the pancreatic head(n=2, 7.7%), papillitis(n=1, 3.8%), pseudocyst in the pancre atic head(n = 1, 3.8%), and ascaris in CBD(n=1, 3.8%) were noted. Pancreatic duct dilatation(n=10, 38.5%) and duodenal diverticulum(n=3, 11.5%) were also seen on MRC P. On dynamic MRCP(12 patients), distal CBD was visualized in 2 patients(16.7%), which was not shown on routine MRCP. Only 1 patient(10.0%) showed papillitis with slightly enhancing papilla on contrast-enhanced MRI (10 patients). Conclusion : MRCP was thought to be helpful in the evaluation of the causes of CBD dilatation, not caused by stone or tumor, especially in the cases of stenosis of distal CBD and chronic pancreatitis, dysfunction of sphincter of Oddi on dynamic MRCP and cholangitis and pericholangitic abnormality on contrast-enhanced MRI.