1.CT-Free Registration Method for Finding Accurate Orientation of Acetabular-Cup in Total Hip Replacement Surgery.
Byung hoon KOH ; Yong San YOON ; Choong Hee WON
Journal of Korean Orthopaedic Research Society 2003;6(1):7-13
PURPOSE: This paper is proposing an improved CT-free registration method which may provide us an accurate and reliable placement of acetabular cup without CT/MRI images. DESIGN AND METHODS: The proposed method employs a T-bar shaped gauge placed on the anatomical landmarks of the pelvis for the registration. The T-bar shaped gauge has its own LED markers and the position of the gauge is obtained through OPTOTRAK3020 system. These landmark points are the anterior superior iliac spines and the symphysis pubis defining anterior pelvic plane. Two subjects were tested to compare the landmark based registration and the proposed T-bar based registration. RESULTS: The measurement deviations of the pelvic obliquity in the frontal plane, tilt in the sagittal plane, and rotation in the transverse plane were 2.08, 1.41, and 2.51 degrees respectively in the point based registration. The T-bar based registration produced 40% smaller deviations(p<0.05): the pelvic obliquity in the frontal plane, tilt in the sagittal plane, and rotation in the transverse plane were 0.84, 0.81, and 1.17 degrees respectively in the T-bar based registration. There was no outlier exceeding 5 degrees in measurement deviation by the T-bar based registration while the outliers were found by the landmark based registration. CONCLUSIONS: We found that T-bar based CT free registration method is more reliable and accurate than the landmark based registration for the acetabular cup navigation. Also, the new method produced more precise registration(p<0.05). We are expecting some offset error of the new registration method due to the skin thickness existing between the T-bar frame and the bony pelvic frame, which may be compensated if we may accumulate sufficient database of the offset.
Acetabulum
;
Arthroplasty, Replacement, Hip*
;
Pelvis
;
Skin
;
Spine
2.The Effects of brain ischemia induced by bilateral carotid artery occlusion on microcirculation of the cerebral cortex of mongolian gerbil.
Woon San KOH ; Sung Hee HWANG ; Byung Chul LEE
Journal of the Korean Neurological Association 1998;16(5):682-688
BACKGROUND AND PURPOSE: The present study was carried out to investigate transient arteriolar vasospasm following reperfusion in the gerbil as an ischemic model and relationship between vasospasm and the changes of morphologic, physiologic and regional blood flow. METHODS: The transient arteriolar vasospasm was observed under the microscope. All gerbils were perfusion fixed and ischemic neuronal damage was checked in the CA1 subfield of the dorsal hippocampus. Metabolic parameters were serially measured during the occlusion and after recirculation, and cerebral blood flow was measured with a laser Doppler flowmetry. RESULTS: 1. Among the 18 gerbils with BCAO(bilateral carotid artery occlusion) for 2 minutes, 8 gerbils showed vasospasm after reopening, namely post-ischemic vasospasm, and 10 gerbils did not show vasospasm. 2. In all animals, metabolic parameters showed decreased PaCO2 and high pH just after the occlusion but increased PaCO2 and lowered pH following the recirculation. BCAO caused marked increase in systemic blood pressure but it returned to preischemic levels following the recirculation. 3. In all animals, BCAO caused marked decrease of cerebral blood flow compared to preischemic levels immediately following the occlusion but it returned to preischemic levels following the recirculation. And it took some longer the onset and duration of the transient increase in blood volume after reopening in the animals with vasospasm than those without vasospasm. 4. There was no morphological neuronal damage in the hippocampal CA1 subfield, at 1, 3, 7 days following 2-minute ischemic insult. CONCLUSION: The present study confirmed that BCAO in gerbils resulted in forebrain ischemia caused transient cortical vasospasm in the gerbil. But there was no close relationship between vasospasm and the changes of morphologic, physiologic and regional blood flow.
Animals
;
Blood Pressure
;
Blood Volume
;
Brain Ischemia*
;
Brain*
;
Carotid Arteries*
;
Cerebral Cortex*
;
Gerbillinae*
;
Hippocampus
;
Hydrogen-Ion Concentration
;
Ischemia
;
Laser-Doppler Flowmetry
;
Microcirculation*
;
Neurons
;
Perfusion
;
Prosencephalon
;
Regional Blood Flow
;
Reperfusion
3.Comparative studies of early background of serum beta-HCG in pregnancies from ovulation induced cycles.
Young Ho KOH ; Jin Ki HONG ; Byung Hee SUH ; Jae Hyun LEE
Korean Journal of Obstetrics and Gynecology 1992;35(7):988-996
No abstract available.
Female
;
Ovulation*
;
Pregnancy*
4.Rectal Leiomyosarcoma: Report of Two Cases.
On Koo CHO ; Hyun Chul RHIM ; Byung Hee KOH ; Chang Kok HAHM ; Jung Hwan BAEK
Journal of the Korean Radiological Society 1994;31(3):511-514
PURPOSE: To evaluate the radiologic manifestations of the rectal leiomyosarcoma. MATERIALS AND METHODS: We reviewed CT and barium study of 2 cases of rectal leiomyosarcoma, which were operated and pathologically proved. RESULTS: In both cases colon studies showed a huge smooth marginated filling defect in the rectum. Precontrast CT scans showed a well-circumscribed, slightly Iobulated, inhomogeneous mass without calcification. Postcontrast scans showed minimal enhancement with internal low-density areas. In pathologic specimens there were large areas of necrosis and hemorrhage in the masses. Pericolic fat infiltration, lymph node metastasis, or distant metastasis were not detected. CONCLUSION: Leiomyosarcoma is rarely developed in the rectum, but general radiologic findings are similar to that of other part of the gastrointestinal tracts except for the tendency of intraluminal growth due to narrow pelvic space.
Barium
;
Colon
;
Gastrointestinal Tract
;
Hemorrhage
;
Leiomyosarcoma*
;
Lymph Nodes
;
Necrosis
;
Neoplasm Metastasis
;
Rectum
;
Tomography, X-Ray Computed
5.Leiomyosarcoma of the inferior vena cava: a case report.
Yong Soo KIM ; Jong Sung KIM ; Byung Hee KOH ; Heung Suk SEO ; On Koo CHO
Journal of the Korean Radiological Society 1993;29(3):421-425
A 29 year old woman with unresectable leiomyosarcoma of the inferior vena cave extending into the right atrium of the heart was presented. The upper and middle inferior vena cava involved and there were both intrinsic and extrinsic tumor growth components. The diagnosis was made by a combination of radiological studies including ultrasound, CT, inferior vena cavography and arteriography and the diagnosis was confirmed by ultrasound guided rumor biopsy. The clinical and radiological presenting features were reviewed.
Angiography
;
Biopsy
;
Diagnosis
;
Female
;
Heart
;
Heart Atria
;
Humans
;
Leiomyosarcoma*
;
Ultrasonography
;
Vena Cava, Inferior*
6.Leiomyosarcoma of the inferior vena cava: a case report.
Yong Soo KIM ; Jong Sung KIM ; Byung Hee KOH ; Heung Suk SEO ; On Koo CHO
Journal of the Korean Radiological Society 1993;29(3):421-425
A 29 year old woman with unresectable leiomyosarcoma of the inferior vena cave extending into the right atrium of the heart was presented. The upper and middle inferior vena cava involved and there were both intrinsic and extrinsic tumor growth components. The diagnosis was made by a combination of radiological studies including ultrasound, CT, inferior vena cavography and arteriography and the diagnosis was confirmed by ultrasound guided rumor biopsy. The clinical and radiological presenting features were reviewed.
Angiography
;
Biopsy
;
Diagnosis
;
Female
;
Heart
;
Heart Atria
;
Humans
;
Leiomyosarcoma*
;
Ultrasonography
;
Vena Cava, Inferior*
7.Inferior vena cava thrombosis: US and CT evaluation.
On Koo CHO ; Yoon Young CHOI ; Yong Soo KIM ; Byung Hee KOH ; Heung Suk SEO
Journal of the Korean Radiological Society 1993;29(1):69-76
Forty five patients with inferior vena cava (IVC) thrombosis were studied with the use of ultrasonography (US) and computed tomography (CT). Thirty seven cases were cased by tumor extension and the primary neoplasms were hepatocellular Ca. (26cases), renal cell Ca. (6 cases), Wilms' tumor (1 case), IVC leiomyosarcoma (1 case) and retroperitoneal metastatic tumor (3 cases). Non-tumor thrombus were 8 cases which included 5 cases of Budd-Chiari syndrome and 3 cases of thrombophlebitis. US and CT both were good for the diagnosis of IVC thrombosis. Cranial extension was better demonstrated by US whereas CT yielded better delineation of the lower extension. Even though, differentiation of tumor non-tumor thrombi by the echogenecity and density of the thrombus was not possible, the finkdings of adjacent tumor mass, complete obstructive thrombus within dilated lumen with bulging wall, and nontapered acute margin of thrombus made the possibility of tumor thrombus more likely.
Budd-Chiari Syndrome
;
Diagnosis
;
Humans
;
Leiomyosarcoma
;
Thrombophlebitis
;
Thrombosis*
;
Ultrasonography
;
Vena Cava, Inferior*
;
Wilms Tumor
8.CT in the diagnosis of pancreatic trauma.
Duk Ja BANG ; On Koo CHO ; Yong Soo KIM ; Yoon Young CHOI ; Byung Hee KOH
Journal of the Korean Radiological Society 1992;28(4):582-588
The incidence of pancreatic trauma is increasing and still remains a major source of morbidity and mortality. We have graded the pancreatic trauma on CT according to its pattern into four grades. We also determine the accuracy of CT in the evaluation of pancreatic trauma and the role of CT for delineation of pancretic ductal injury which is critical factor in outcome of pancreatic trauma. CT correctly diagnosed the pancreatic trauma and its traumatic pattern and severity in 22 of 25 cases. Pancreatic enlargement was the most common findings observed in 19 cases. Other findings were 15 cases of intrapancreatic low density hematoma, 12 cases of parenchymal fracture which were predilected in pancreatic neck area. CT grade III and IV could predict the pancreatic ductal injury, and was well correlated with severity of posttraumatic pancreatitis, duration of admission days and incidence of complications. So we concluded that CT can play a definite role for diagnosing and determining the prognosis of pancreatic trauma.
Diagnosis*
;
Hematoma
;
Incidence
;
Mortality
;
Neck
;
Pancreatic Ducts
;
Pancreatitis
;
Prognosis
9.Emphtsematous Liver Abscess in Diabetic Patient: Two Cases Report.
Yong Soo KIM ; Sung Tae KIM ; On Koo CHO ; Hyun Chul RHIM ; Byung Hee KOH
Journal of the Korean Radiological Society 1995;33(1):93-96
There has not been any report on massive air-containing liver abscess in diabetic patients, although emphysematous cholecystitis or pyelonephritis is a well-known complication in them. Authors report two cases of emphysematous liver abscess in diabetic patient, which showed typical findings of massive air-containing hepatic abscess on ultrasonography and computed tomography, but very poor progrosis in spite of immediate and successful percutanoeus drainage procedure.
Drainage
;
Emphysematous Cholecystitis
;
Humans
;
Liver Abscess*
;
Liver*
;
Pyelonephritis
;
Ultrasonography
10.Sonographic features of portal vein thrombosis
Man Gil BAE ; Hyoung Kuk SOHN ; Byung Hee KOH ; On Koo CHO ; Chang Kok HAHM
Journal of the Korean Radiological Society 1986;22(3):368-377
57 cases of portal vein thrombosis detected by ultrasonography were analized. The results were as follows: 1.Most common cause was hepatocellular carcinoma, showing 49 out of 57 cases(86%). 2. Sonographic findings revealedechogenic thrombus in the dilated portal vein. Echogenecity of thrombus was similar to the surrounding liverparenchyma, Thrombus was mainly located in the intrahepatic branch and main portal vein. 3. The location ofthrombus in hepatocellular carcinoma was related to the location of tumor, and frequently extended to the mainportal vein(68.9%). Incidence of thrombosis in hepatocellular carcinoma revealed 49 out of 157 cases, butprospective study showed 42 out of 84 cases(50%). Thrombosis was more common in large sized ill-defined diffuseinfiltrative hepatocellular carcinoma. 4. CT(only 15 cases analyzed) findings revealed low density in the portalvein in all the cases and periportal enhancement in 10 cases on post-enhanced scan. 5. Collateral circulationswere largely detected at the porta hepatis and gallblader fossa. The detection rate was lower on theultrasonography than on the CT or angiography.
Angiography
;
Carcinoma, Hepatocellular
;
Incidence
;
Portal Vein
;
Thrombosis
;
Ultrasonography
;
Venous Thrombosis