The teeth present at birth are called natal teeth, while the teeth that appear within the first thirty days following birth are called neonatal teeth. Approximately one in 2,000 to 3,500 infants experiences the eruption of teeth at birth or within the first few weeks postpartum. Many contributing factors have been suggested for the premature eruption of primary teeth. It has been suggested that upon eruption these teeth are of normal structure according to their developmental age, but after eruption, lateral movement in the cervical area leads to disturbance of the dentin and premature degeneration of Hertwig's root sheath. In most cases, they have immature, aborted structures consisting only of caps of enamel, dentin, or a combination of both. A radiograph can show the presence or absence of enamel, dentin, or root structures, as well as supernumerary teeth. These teeth may be aspirated or swallowed during feeding. Discomfort from mobile and erupting teeth often causes the infant to refuse to feed. In addition, a nursing mother's nipples may become lacerated and infected. Extraction is the indicated treatment if these neonatal teeth cause discomfort or demonstrate mobility or incomplete, immature development. Treatment decisions must be made on an individual basis from both clinical and radiographic findings. We report four cases of neonatal teeth in complete cleft lip and palate patients.
Cleft Lip* ; Dental Enamel ; Dentin ; Humans ; Infant ; Natal Teeth ; Nipples ; Nursing ; Palate* ; Parturition ; Postpartum Period ; Tooth* ; Tooth, Deciduous ; Tooth, Supernumerary

In order to evaluate the ability of spin-echo MR imaging to differentiate slow flow from mural thrombus in aortic diseases, we reviewed the spin-echo MR images of 13 patients with intraaortic thrombus documented by CT (N=11) or aortography (N=2). Six patients had aortic aneurysms and seven had aortic dissection. Intraaortic mural thrombi were accompanied by flow-related intraluminal signal of various patterns and extents in all 13 patients. On 10 gated MR studies, slow flow regions showed even-echo rephasing phenomenon (N=8), interslice variation of signal intensities of the intraluminal signal (N=7) and flow-related ghost artifact (N=2). However, these MR flow phenomena were obscured on two of three non-gated studies. Seven of 13 intraaortic thrombi remained hyperintense on T2-weighted second-echo images. In these circumstances, a hypointense boundary layer between slow flow and mural thrombus, which was caused by either 'boundary layer dephasing phenomenon' of slow flow or 'paramagnetic T2 shortening' of fresh clot at the edge of mural thrombus, was useful in discriminating the area of slow flow from that of mural thrombus. Proper interpretation of spin-echo MR images may obviate the need for phase display imaging or gradientecho imaging in differentiating slow flow and mural thrombus.
Aortic Aneurysm ; Aortic Diseases* ; Aortography ; Artifacts ; Humans ; Magnetic Resonance Imaging ; Thrombosis*

In order to evaluate the ability of spin-echo MR imaging to differentiate slow flow from mural thrombus in aortic diseases, we reviewed the spin-echo MR images of 13 patients with intraaortic thrombus documented by CT (N=11) or aortography (N=2). Six patients had aortic aneurysms and seven had aortic dissection. Intraaortic mural thrombi were accompanied by flow-related intraluminal signal of various patterns and extents in all 13 patients. On 10 gated MR studies, slow flow regions showed even-echo rephasing phenomenon (N=8), interslice variation of signal intensities of the intraluminal signal (N=7) and flow-related ghost artifact (N=2). However, these MR flow phenomena were obscured on two of three non-gated studies. Seven of 13 intraaortic thrombi remained hyperintense on T2-weighted second-echo images. In these circumstances, a hypointense boundary layer between slow flow and mural thrombus, which was caused by either 'boundary layer dephasing phenomenon' of slow flow or 'paramagnetic T2 shortening' of fresh clot at the edge of mural thrombus, was useful in discriminating the area of slow flow from that of mural thrombus. Proper interpretation of spin-echo MR images may obviate the need for phase display imaging or gradientecho imaging in differentiating slow flow and mural thrombus.
Aortic Aneurysm ; Aortic Diseases* ; Aortography ; Artifacts ; Humans ; Magnetic Resonance Imaging ; Thrombosis*

It is well known that high energy X and r-ray have high penetration power in tussue, but have lower survacedose which is called the “skin sparing effect”. However, the surface dose can be increased significantly by excessive electron contamination and it is an important factor intreatment planning in the presence of a blocktray, especially in isocentric set-up. So relaltive surface doses for 10MV-X-ray and Co-60 r-ray were measuredwith various field sizes and SSD with or withoug 1/4" lucite shadow tray, present in the beams, using pancakechamber and polystylene phantom. The results obtained are as follows. 1. A rapid increase in surface dose isapparant with increasing field size in 10MV X-ray and Co-60 r-ray. 2. high surface dose is evident for smallerdistance from the tray, so at least 25cm of skin shadow tray distance for 10MV X-ray and 20cm for Co-60 are desirable. 3. Utilization of either bolus for treatment field or electron boost should be considered in treatmentof superificial nodal disease. 4. A tray using an intermediate or high z No. filter can be reduced the surfacedose significantly.
Polymethyl Methacrylate ; Silver Sulfadiazine ; Skin

PURPOSE: MRI is known to be an effective imaging modality of the aorta and its role is steadily increasing in the evaluation of acquired aortic diseases including aortic dissections and aortic aneurysms. However, differentiation of the aortic dissections with thrombosed false lumen from the aortic aneurysm with mural thrombus in MRI has not been easy. Therefore, the authors tried to find the characteristic MR featrses which would to differentiate the two diseases. MATERIALS AND METHODS: MR images of 6 patients with thrombosed aortic dissection and 7 patients with thrombosed aortic aneurysms were reviewed retrospectively and compared in regand to shape and extent of thrombus, dimension of aorta, and luminal flow signal. RESULTS: Thrombosed aortic dissections showed sharply demarcated crescent shaped aortic wall thickening of even thickness involving long segment of the aorta, whereas thrombosed aortic aneurysms showed irregular aortic wall thickening of uneven thickness localized in the short dilated segment of the aorta. Characteristically aortic aneurysm with mural thrombus showed eccentric intraluminal slow flow signal. In contrast to the signal void of the true lumen in aortic dissections, the residual lumen of the aortic aneurysm with mural thrombus revealed intraluminal signal due to slow flow. CONCLUSION: Familiarity to these MRI findings of thrombosed aortic dissections and aortic aneurysms may lead to the accurate differential diagnosis in majority of cases.
Aorta ; Aortic Aneurysm* ; Aortic Diseases ; Diagnosis, Differential* ; Humans ; Magnetic Resonance Imaging* ; Phenobarbital ; Recognition (Psychology) ; Retrospective Studies ; Thrombosis

We performed 70 proceudres of transarterial chemoembolization (TAE) through extrahepatic collateral vessels (n=27) or parasitic feeders (n=18) in 45 hepatocellular carcinoma patients. The collaterals developed after interruption of the hapatic artery due to repeated TAE(n=17), surgical ligation(n=7) and primary celiac occlusion (n=3). Radiologic findings suggesting the existence of parasitic or collateral supply for hepatocellular carcinoma were 1) a focal defect of Lipiodol retention on CT or plain film after TAE via the hepatic artery, 2) dilated and tortuous vessels around the mass on angiography, 3) persistent elevation of the level of serum alpha fetoprotein or continuous clinical symptoms in spite of sufficient devascularization of the tumor via the hepatic artery, and 4) radiological findings of direct invasion into adjacent organ. The sites of the catheter placement were the inferior phrenic artery (n=19), omental branches (n=16), periportal collaterals (n=6), pancreaticodenal arcade (n=3), gastroduodenal artery (n=3), internal mammary artery (n=2), intercostal artery (n=2), lateral thoracic artery (n=1), bronchial artery(n=1), and colic branches(n=1). Masses feeded by the inferior phrenic and chest wall collaterals were usually located at the dome area of the liver, and the omental and gastroduodenal collaterals developed in the masses located at the inferior tip of the liver. After TAE via collateral vessels, 37 patients underwent follow-up study. In 18 cases(48%), the tumor favorably responded to TAE. Specific complications of collateral TAE were epigastric soreness (n=10), severe shoulder pain (n=4), and embolization of the spinal artery during embolization through the intercostal artey (n=1). In conclusion, various extrahepatic collaterals are important alternative or additional routes for effective chemoembolization in patients with advanced hepatoma, and early recognition of the parasitic supply and the effort to perform TAE via collaterals is very important for effective management of the patients with the hepatoma.
alpha-Fetoproteins ; Angiography ; Arteries ; Carcinoma, Hepatocellular* ; Catheters ; Colic ; Ethiodized Oil ; Follow-Up Studies ; Hepatic Artery ; Humans ; Liver ; Mammary Arteries ; Shoulder Pain ; Thoracic Arteries ; Thoracic Wall

As a new interventional procedure for the control of variceal bleeding, a portosystemic shunt can be established with the installment of metallic stent through the transjugular approach. In order to evaluate the clinical usefulness of the procedure, transjugular intrahepatic portosystemic chunt procedure were performed in 5 patients with variceal bleeding due to liver cirrhosis. The metallic stents were mainly a self expandable Wallstent(Schneider, Switzerland). An 8 to 10 mm shunt was formed by the insertion of the stent and balloon dilatation after puncture of the proximal portal vein from the right or middle hepatic vein. The patency of the shunt was proven by portography after the procedure. The portal pressure measured in 3 patients before and after the procedure improved with decrease from 31 mmHg to 25 mmHg. The procedure failed in 1 patient due to preexsisting portal vein thrombosis. During the follow-up period from 1 month to 4 months, shunts were patent in all 4 patients. However, hepatic encephalopathy occured in one patient one week following the procedure. Though the follow-up period was not long enough for full evaluation. We found the transjugular intrahepatic portosystemic shunt was a safe and effective procedure for the control of variceal bleeding by lowering the portal pressure. For the appropriate application for this procedure, the optimal size of the shunt and optimal degree of the resultant decompression are yet to be determined in the future.
Decompression ; Dilatation ; Esophageal and Gastric Varices ; Follow-Up Studies ; Hepatic Encephalopathy ; Hepatic Veins ; Humans ; Liver Cirrhosis ; Portal Pressure ; Portal Vein ; Portasystemic Shunt, Surgical ; Portography ; Punctures ; Stents ; Venous Thrombosis

Magnetic Resonance Imaging(MRI) with 2.0 Tesla superconductive magnet developed by Korea Advanced Institute ofScience was performed in 25 patients with various abdominal diseases and compared with x-ray CT. MRI was obtainedwith spin echo technique using a variety of pulse sequence and various slice orientation including axial, sgittaland coronal section in order to evaluate the diagnostic value, limitation and to determine the optimal pulsesequency in various abdominal diseases. MRI demonstrated the capability of detecting the lesions shown on CT inall cases and also detected one case of diffuse hepatocellular carcinoma which was not seen on CT. MRI showedcapability of differentiation of various liver mass including hepatocellular carcinoma, hemangnioma and simplecyst. MRI showed better anatomical resolution of tumor in retroperitoneum and pelvis, however CT delineatedalimentary tract disease better than MRI did.
Carcinoma, Hepatocellular ; Humans ; Korea ; Liver ; Magnetic Resonance Imaging ; Pelvis

Self expandable metallic stent is a good alternative of percutaneous transhepatic biliary drainage because it can eliminate numerous problems caused by external drainage catheter, such as tube dislodgement, bile leakage and psychotic problems. Authors analyzed initial results of self expandable metallic stents used in the patients with malignant biliary obstruction to evaluate the efficacy of the procedure and to find the technical problems in the procedure. Self expandable metallic stents were inserted in 14 patients: three with recurrent stomach cancer: there with gallbladder cancer: seven with Klatskin tumor: one with common duct cancer. Gianturco type stent was used in 9 cases ans Wallstent was used in 2 cases. In remaining three cases, both Z-stent and Wallstent were used in the same patient. The average period of follow up was 104 days (4-409). In 13 cases, the patency of the bile duct was restored by the stent (technical success: 92.9%). Occlusions of the stent were found in two cases, after two and 13 months, respectively. Causes of failure and stent occlusion were associated duodenal obstruction, tumor overgrowth and shortening of Wallstent. In remaining 11 patients, one patient was lost to follow up an 10 patients did not show recurrent jaundice until death or last follow up. There was no major complication related to the procedure. The insertion of self expandable metallic stent is a safe procedure and call eliminate major disadvantages of PTBD. Overstenting, overlapping land evaluation of associated GI tract obstruction is crucial for obtaining technical success and long-term patency.
Bile ; Bile Ducts ; Catheters ; Drainage ; Duodenal Obstruction ; Follow-Up Studies ; Gallbladder Neoplasms ; Gastrointestinal Tract ; Humans ; Jaundice ; Klatskin Tumor ; Lost to Follow-Up ; Self Expandable Metallic Stents* ; Stents ; Stomach Neoplasms

Self expandable metallic stent is a good alternative of percutaneous transhepatic biliary drainage because it can eliminate numerous problems caused by external drainage catheter, such as tube dislodgement, bile leakage and psychotic problems. Authors analyzed initial results of self expandable metallic stents used in the patients with malignant biliary obstruction to evaluate the efficacy of the procedure and to find the technical problems in the procedure. Self expandable metallic stents were inserted in 14 patients: three with recurrent stomach cancer: there with gallbladder cancer: seven with Klatskin tumor: one with common duct cancer. Gianturco type stent was used in 9 cases ans Wallstent was used in 2 cases. In remaining three cases, both Z-stent and Wallstent were used in the same patient. The average period of follow up was 104 days (4-409). In 13 cases, the patency of the bile duct was restored by the stent (technical success: 92.9%). Occlusions of the stent were found in two cases, after two and 13 months, respectively. Causes of failure and stent occlusion were associated duodenal obstruction, tumor overgrowth and shortening of Wallstent. In remaining 11 patients, one patient was lost to follow up an 10 patients did not show recurrent jaundice until death or last follow up. There was no major complication related to the procedure. The insertion of self expandable metallic stent is a safe procedure and call eliminate major disadvantages of PTBD. Overstenting, overlapping land evaluation of associated GI tract obstruction is crucial for obtaining technical success and long-term patency.
Bile ; Bile Ducts ; Catheters ; Drainage ; Duodenal Obstruction ; Follow-Up Studies ; Gallbladder Neoplasms ; Gastrointestinal Tract ; Humans ; Jaundice ; Klatskin Tumor ; Lost to Follow-Up ; Self Expandable Metallic Stents* ; Stents ; Stomach Neoplasms