The Relationship Between Tinnitus Frequency and Speech Discrimination in Patients With Hearing Loss / 대한이비인후과학회지

Background and Objectives@#Patients with hearing loss and tinnitus experience difficulty in engaging in daily conversations. However, only few studies have examined how tinnitus affects individual speech discrimination to comprehend speech. This study aimed to analyze the correlation between tinnitus frequency and speech discrimination in patients with hearing loss and tinnitus.Subjects and Method A total of 275 ears with hearing impairment were retrospectively analyzed via audiometry and tinnitogram. The ears were divided into three groups depending on the frequency of their tinnitus. Average pure tone audiometry (PTA), hearing threshold of tinnitus frequency, speech discrimination test (SDT), degree of discrepancy between tinnitus frequency and worst PTA frequency were collected and compared among the three groups. @*Results@#No significant difference was observed in PTA in the three patient groups. Hearing threshold of tinnitus frequency was the highest at 78.27 dB in the high-frequency group and the lowest at 45.14 dB in the low-frequency group. SDT was significantly lower (53.69%) in the low-frequency group. The correlation between tinnitus loudness and SDT was the strongest in the low-frequency group. The degree of discrepancy between tinnitus frequency and worst PTA frequency was also significantly observed in the low-frequency group. @*Conclusion@#Patients who are severely affected by tinnitus are found to have significant discrepancy between tinnitus frequency and worst PTA frequency, indicating decreased SDT.

Difference in Thresholds Between Auditory Brainstem Response Test and Pure Tone Audiometry by Frequency / 대한이비인후과학회지

Background and Objectives@#There is no clear standard for the difference in the thresholds of auditory brainstem response (ABR) and pure tone audiometry (PTA) when using ABR to evaluate the reliability of PTA. Therefore, we assessed the difference in the thresholds of ABR and PTA for each frequency. Consequently, we present here the actual difference values between the two tests that can be used as a reference in the clinic.Subjects and Method We retrospectively assessed the audiometry results of 129 ears. Ears in which the hearing thresholds of each frequency continuously declined were classified as the downward group. We compared the average of differences between the two tests by frequency. The differences were compared for each hearing level from 50 dB or higher. @*Results@#For all ears, the appropriate range of difference value was ±5 dB at 2 kHz. At 1 kHz, the ABR threshold was 10 dB higher than PTA, and it was 10 dB less than PTA at 4 kHz. In the downward group, the difference value increased by 10 dB at 1 kHz and 4 kHz. In the subgroups at each hearing level, the difference value showed similar results (p<0.05). @*Conclusion@#The difference in the threshold, regardless of the severity or tendency of hearing loss, was the smallest at 2 kHz and the range was ±5 dB. ABR was 10 dB higher at 1 kHz and and 10 dB lower at 4 kHz than PTA. In the downward group, the difference at 1 kHz and 4 kHz increased by 10 dB each.

Test-Retest Differences of the Speech Discrimination Score in Patients with Hearing Loss / 대한이비인후과학회지

Background and Objectives@#The diagnosis of hearing impairment is based on repeated audiometry, including pure tone audiometry (PTA), speech reception threshold test (SRT), and speech discrimination test (SDT). SDT results particularly show a wide discrepancy upon repeated testing, while malingering is suspected when having more than 12% difference between 3 individual SDT results. Therefore, in this study, we compared the proportion of malingering found in repeated SDT with that found in other audiometric tests and analyzed the characteristics of malingering group in order to reevaluate the current criteria of defining malingering.Subjects and Method We retrospectively assessed the audiometry results of 113 patients (226 ears) with hearing impairment. Each ear was divided into a malingering group and a true hearing loss group. The proportion of ears corresponding to each malingering criterion was compared using a chi-square test. An independent sample t-test was performed to identify the differences between the characteristics between the two groups. @*Results@#The number of ears that met the malingering criteria were 19 (8.41%) in PTA, 15 (6.64%) in SRT, and 75 (33.19%) in SDT. There was a significant difference in the proportion of malingering between the 3 hearing test modalities (p<0.001). There was no significant difference in auditory brainstem response, mean age and sex distribution between the malingering group and the true hearing loss group. @*Conclusion@#When conducting repeated SDT, there is a risk of misdiagnosing an actual hearing loss patient as a malingering patient under the current malingering criteria. Therefore, the current criteria on SDT requires reevaluation.

Outcomes of Bypass Surgery Versus Endovascular Therapy for TASC II C and D Femoro-Popliteal Lesions in Patients with Chronic Limb Ischemia

PURPOSE: We wanted to define the appropriate treatment modalities for Trans-Atlantic Inter-Society Consensus (TASC) II C and D femoro-popliteal lesions. So we compared the primary patency rate and several clinical factors between percutaneous balloon angioplasty with or without stenting (PTA/S) and bypass surgery (BP). METHODS: We reviewed the medical records of patients who underwent BP or PTA/S for TASC II C (BP-C, PTA/S-C) and D (BP-D, PTA/S-D) femoro-popliteal lesions from March 2001 to May 2009. We analyzed the primary and secondary patency rates, and the major limb salvage rates. RESULTS: Eighty two limbs in 74 patients (mean age: 68.7+/-10.2 years, males: 82.9%) were treated (PTA/S-C: 18, PTA/S-D 19: BP-C 12, BP-D 33). The mean follow-up duration was 30.0+/-19.0 months. The twenty four month primary patency rates was 82.4% for PTA/S-C and 73.3% for BP-C (P=0.876), and 45.3% for PTA/S-D and 66.6% for BP-D (P=0.034). The twenty four month secondary patency rates were 88.2% for PTA/S-C and 73.3% for BP-C (P=0.669), and 54.7% for PTA/S-D and 73.3% for BP-D (P=0.077). The twenty four month major limb salvage rates were 100.0% for PTA/S-C and 75.0% for BP-C (P=0.030) but there were no statistical differences between the TASC II D groups (P=0.377). CONCLUSION: Bypass surgery is a preferred initial therapeutic option for TASC II D femoro-popliteal lesions. However, several clinical factors must be carefully considered when selecting the primary treatment modality for TASC II C lesions.

The Efficacy of Metallic Stent Placement in the Treatment of Colorectal Obstruction

DBJECTIVE: To evaluate the efficacy of newly designed covered and non-covered coated colorectal stents for colonic decompression. MATERIALS AND METHODS: Twenty-six patients, (15 palliative cases and 11 preoperative) underwent treatment for the relief of colorectal obstruction using metallic stents positioned under fluoroscopic guidance. In 24 of the 26, primary colorectal carcinoma was diagnosed, and in the remaining two, recurrent colorectal carcinoma. Twenty-one patients were randomly selected to receive either a type A or type B stent; for the remaining five, type C was used. Type A, an uncovered nitinol wire stent, was lightly coated to ensure structural integrity. Type B (flare type) and C (shoulder type) stents were polyurethane covered and their diameter was 24 and 26mm, respectively. The rates of technical success, clinical success, and complications were analyzed using the chi-square test, and to analyse the mean period of patency, the Kaplan-Meier method was used. RESULTS: Thirty of 31 attempted placements in 26 patients were successful, with a technical success rate of 96.8% (30/31) and a clinical success rate of 80.0% (24/30). After clinically successful stent placement, bowel decompression occurred within 1-4 (mean, 1.58+/-0.9) days. Five of six clinical failures involved stent migration and one stent did not expand after successful placement. In the preoperative group, 11 stents, one of which migrated, were placed in ten patients, in all of whom bowel preparation was successful. In the palliative group, 19 stents were placed in 15 patients. The mean period of patency was 96.25+/-105.12 days: 146.25+/-112.93 for type-A, 78.82+/-112.26 for type-B, and 94.25+/-84.21 for type-C. Complications associated with this procedure were migration (n=6, 20%), pain (n=4, 13.3%), minor bleeding (n=5, 16.7%), incomplete expansion (n=1, 3.3%), and tumor ingrowth (n=1, 3.3%). The migration rate was significantly higher in the type-B group than in other groups (p=0.038). CONCLUSION: Newly designed covered and non-covered metallic stents of a larger diameter are effective for the treatment of colorectal obstruction. The migration rate of covered stents with flaring is higher than that of other types. For evaluation of the ideal stent configuration for the relief of colorectal obstruction, a clinical study involving a larger patient group is warranted.

Pulmonary Fat Embolism Induced Intravenous Injection of Autologous Bone Marrow in Rabbit: CT and Pathologic Correlation

PURPOSE: To evaluate the correlation between CT and pathologic findings of pulmonary fat embolism in rabbits. MATERIALS AND METHODS: In 16 rabbits, pulmonary fat embolism was induced by intravenous injection of autologous bone marrow(mean 3.3 mL). Chest CT scans were obtained immediately(within 1 hour), and 1, 3, and 7 days after embolization. The rabbits were divided into four groups. Group 1 underwent CT scanning immediately after embolization, group 2 immediately and 1 day after embolization, group 3 immediately, 1 day and 3 days after embolization, group 4 immediately, 1 day, 3 days and 7 days after embolization. Pathologic specimens were obtained immediately after the last CT scan. RESULTS: The earliest CT findings of pulmonary fat embolism in rabbits were peripheral lung lucency(16/16, 1 00 %), perivascular ground-glass (12/16, 75.0 %) and enlargement of the central pulmonary artery(11/16, 6 8 .8 %). Pathologically, perivascular ground-glass opacity correlated with extensive perivascular alveolar congestion and enlargement of the central pulmonary artery correlated with perivascular connective tissue edema and reactive pulmonary arterial engorgement. Peripheral lung lucency was probably caused by embolic occlusion of the pulmonary artery and decreased perfusion and air trapping induced by arterial and bronchial s-pasm associated with hypoxia. CT scans obtained 1 and 3 days after embolization showed nodules and patchy ground-glass opacity and consolidation. Aggregation of nodules resulted in patch opacities. Pathologically, pulmonary nodules correlated with focal inflammation surrounding an artery and parenchymal opacity correlated with parenchymal consolidation and hemorrhagic edema. CT scans and pathologic specimens obtained 7 days after embolization showed improvement of parenchymal lung abnormalities. CONCLUSION: Pulmonary fat embolism in rabbits show CT and pathologic findings which vary with dynamic change. Typical earliest findings of pulmonary fat embolism were peripheral lung lucency, perivascular ground-glass opacity and enlargement of the central pulmonary artery.

Low Attenuation on High Resolution Computed Tomography in Pulmonary Embolism: An Experimental Study in Pigs

PURPOSE: To evaluate the incidence and type of low attenuation seen on high resolution computed tomography (HRCT) performed after artificially induced pulmonary embolism. MATERIALS AND METHODS: Using permanent embolic materials, pulmonary embolism was induced in ten Yorkshire pigs. Pre- and postembolic pulmonary angiography was performed, and HRCT was performed immediately and 1, 3, and 6 weeks after embolization. The incidence and type of low attenuation of all segments, as seen on HRCT, was evaluated. Low attenuation was classified as mottled, lobular, segmental, or peripheral. The pigs were sacrified after 6 weeks and contact radiographs were obtained. RESULTS: Low attenuation developed in eight of ten pigs. Pulmonary angiography revealed arterial occlusion in 15 large and 19 small segmental arteries (34 of 45 segments). In the remaining 11 segments, follow-up HRCT demonstrated areas of low attenuation. This was present in 25 of 35 segments (71%) as seen on HRCT images obtained immediately; in 16 of 41 segments (39 %) on images obtained 1 week after embolization; in 17 of 41 segments (41 %) on those acquired at 3 weeks; and in 25 of 45 segments (56 %) on those acquired at 6 weeks. The overall incidence of low attenuation was 83/166 (50 %). The types of low attenuation were mottled in 32/83 cases, lobular in 13/83, segmental in 13/83, and peripheral in 25/83. In large segmental arterial occlusion, the incidence of low attenuation on HRCT was 100% immediately, 57% at 1 week, 60% at 3 weeks, and 80 % at 6 weeks. In small segmental arterial occlusion, the incidence was 47%, 25 %, 11 %, and 21 % respectively. The overall incidence of low attenuation was 40/55 (73 %) in large segmental arterial occlusion and 18/71 ( 25%) in small segmental arterial occlusion. CONCLUSION: Low attenuation on HRCT is a finding of pulmonary embolism and is more common on HRCT performed immediately after embolization (71%) and in large segmental arterial occlusion (73%). Low attenuation on HRCT is an ancillary finding and may be useful in the diagnosis of pulmonary embolism.

Large Deep Infarcts found in Proximal Middle Cerebral Artery Steno-occlusive Disease: MRI and AngiographicFindings

PURPOSE: To determine the nature of large deep -seated infarcts without cortical infarct in patients withsteno-occlusive disease of the proximal middle cerebral artery(MCA) using magnetic resonance images(MRI) andangiography. MATERIALS AND METHODS: By means of MRI and MR angiography(MRA), we examined 24 patients with largedeep cerebral infarctions(>3cm in size) involving the basal ganglia, corona radiata and/or centrum semiovale, aswell as steno-occlusive lesion of the proximal MCA. According to location, infarctions were classified into fivegroups, as follows: Group 1: basal ganlgia and corona radiata; 2: basal ganglia, corona radiata and centrumsemiovale; 3: corona radiata and centrum semiovale; 4: corona radiata; 5: basal ganglia only. We evaluated thetopography of the lesions and correlated the results with the findings of angiography(all 24 MRA; the 13:conventional angiography). Involvement of the head of the caudate nucleus and the internal capsule were alsoevaluated. RESULTS: Fifteen of 24 cases(63%) were assigned to group 1 (4 proximal MCA(M1) occlusion and 11stenosis), and five of 24 (21%) with M1 occlusions to group 2. Group 3 comprised only one case with M1 occlusion.Two cases with both occlusion and stenosis were included in group 4, and only one case-with M1 stenosis-in group5. Infarctions at the caudate nucleus were seen in five cases, and at the internal capsule in two. On conventionalangiography(13 cases) cortical branches of the MCA were delineated through the leptomeningeal collaterals ofanterior or posterior cerebral arteries. CONCLUSION: Most large deep cerebral infarctions found in proximal MCAdiseases are thought to extend cephalad to the corona radiata. When large deep-seated infarctions with proximalMCA occlusion is observed more frequently than stenosis.

An Experimental Study on Tissue Injury Following Intrahepatic Injection of Various Sclerosing Agents in Rats:Usefulness of 50% Acetic Acid

PURPOSE: To evaluate histopathologic change in the liver after injection of various kinds of sclerosants, andto thus determine whether 50% acetic acid, a new sclerosant, is suitable for percutaneous intrahepatic injection. MATERIALS AND METHODS: Four kinds of clinically available sclerosants were used : 50% acetic acid, 99% ethanol,10% phenol, and hot saline. Each group consisted of ten rats, and 0.1ml of each sclerosant was directly injectedinto the liver. After two days and one week, gross and histopathologic findings of resected liver in the area oftissue necrosis, as well as the degree of extrahepatic peritoneal adhesion, were assessed in each group. RESULTS:In all groups, the main pathologic changes were acute necrosis with inflammation after two days and secondaryregenerative fibrosis after week. In the 50% acetic acid injection group, the degree of necrosis was more severeand the mean diameter of the necrotic area was greater ; this latter was not, however, significantly wider than inthe 99% ethanol injection group, though was significantly wider than in the 10% phenol and hot saline injectiongroup. CONCLUSION: When used for percutaneous injection, 50% acetic acid, caused more tissue necrosis than 99%ethanol, 10% phenol, or hot saline. We therefore conclude that this acid may be useful for percutaneousintrahepatic injection of a hepatic tumor.

Efficacy of Renal Artery Embolization with 50% Acetic Acid in Rabbits, and Pathologic Findings

PURPOSE: To evaluate the embolic effect and pathologic change in the kidney after infusion of 50% acetic acidin the renal artery. MATERIALS AND METHODS: Five kidneys were embolized with 50% acetic acid mixed with saline(group A) and five were embolized with 50% acetic acid mixed with contrast medium (group B). Four rabbits(2 fromgroup A and 2 from group B) were sacrificed during the first day and the remaining six, 28 days afterembolization. To determine the effect of embolization and pathologic findings, the two groups were compared. RESULTS: Complete occlusion of the renal artery was observed in both groups; histologic findings indicatingtubular necrosis and blood clots within the renal artery were noted one day after embolization. After four weeks,complete necrosis of the renal arterial wall and tubular cells had occurred. The procedures required forembolization were easier in group B because the extent of embolization could be controlled by fluoroscopy. CONCLUSION: At 50% dilution after mixing with contrast medium, the embolie effect of acetic acid isperfect;because the embolic material is visualised the procedure was easier to control than embolization withalcohol. acetic acid can, threrfore, be used as an effective embolic agent in renal artery embolization.

Removal of Ureteral Stents by Fluoroscopic Guided Second Snare Technique: Technical Note

The snare technique has been used for the removal of ureteral stents. If, however, a stent has migrated to theupper or lower pole calyx, snaring-due to close contact between the stent and the calyceal mucosa or narrow spaceof the renal calyx-is impossible. By using the second suare technique, which involves snaring the previouslyinserted guidewire, the large renal pelvic space can be used for the removal of a migrated ureteral stent. Wedeseribe two cases and discuss the safety and efficacy of this technique.

An Experimental Study of the Radiologic-Pathologic Findings of Pulmonary Embolism

PURPOSE: To evaluate the low attenuation of mosaic pattern in pulmonary embolism, as observed on HRCT, and to correlate the findings with the pathologic features of resected lung. MATERIALS AND METHODS: Using permanent embolic materials, pulmonary embolism was induced in eight Yorkshire pigs. Pre-and post-embolic pulmonary angiography was performed and after 6 weeks, the incidence and pattern of parenchymal change in low attenuation (mosaic pattern), as seen on HRCT, was evaluated. The animals were then sacrified and contact radiography of the lung was performed. Thirty-eight segments of pathology were taken from the area in which the presence of embolism had been suggested. Pathologic and HRCT findings were then correlated. RESULTS: On HRCT, low attenuation was seen in 23 of 36 segments (64%) and showed variable patterns : crescent peripheral hyperlucency (61%, n=14), heterogeneous mottled hyperlucency (17%, n=4), lobular hyperlucency (13%, n=3), and homogeneous segmental hyperlucency (9%, n=2). Parenchymal low attenuation was seen on HRCT in 10 of 11 segments (91%) in which large segmental arterial occlusion occurred, and in 3 of 16 segments (19%) in which there was small segmental arterial occlusion. Abnormal pathologic findings were pulmonary congestion, dilatation of pulmonary arteries, interlobular septal thickening, and thrombus formation. Among the 38 pathologic segmental specimens, 29 were from the area in which HRCT findings were positive, and in which pulmonary embolism subsequently occurred. In only four of nine segments (44%) in the area in which HRCT fingings were negative was pulmonary embolism subsequently. CONCLUSION: HRCT findings of pulmonary embolism at six weeks after embolization showed variable patterns of low attenuation, diminished diameter of pulmonary arteries, and normal diameter of bronchi. In cases with large segmental arterial occlusion, the finding of low attenuation was more common ; this may be due to reduced blood flow to the embolic area, in combination with bronchiolar spasm. For the early diagnosis of pulmonary embolism, these findings may be useful.

Recurrent Pyogenic Cholangitis: Angiographic Findings and Its Significance

PURPOSE: To analyse the angiographic findings of recurrent pyogenic cholangitis. MATERIALS AND METHODS: Hepatic arteriography and portography were performed preoperatively in 34 patients with intrahepatic stones and recurrent cholangitis. Twenty five of these underwent partial resection of the liver and in nine, the biliary tract was drained. Hepatic arteriogram and portogram findings correlated with liver atrophy and were analysed retrospectively by two radiologists; angiographic and pathologic findings also correlated. RESULTS: In the arterial phase, abnormal stained areas, were seen in 17 of 34 cases, periarterial staining in 14, mass-like staining in two and a mixed pattern in one. The hepatic artery showed spastic change in 11 of 34 cases and tortuous change in 17. Arteriovenous shunting was not seen. In the portal phase, abnormal findings of the portal veins were noted in 16 cases; decreased size and nonvisualization were seen in eleven patients, and decreased size only, in five. Fifteen cases showed liver atrophy; in 13 of these, portal vein abnormalities were also present. CONCLUSION: In recurrent pyogenic cholangitis, angiographic findings may be normal or findings of abnormal periarterial staining, mass-like staining, spastic and tortuous change of the hepatic artery, and abnormal portal vein can be present. The differential diagnosis of hepatitis, hepatic mass and cirrhosis should be considered.

A Case of Takayasu's Arteritis : Managed with Percutaneous Transluminal Angioplasty

Takayasu's arteritis is a chronic vasculitic disease of the aorta, its major branches and the pulmonary arteries, resulting in stenosing, occlusive or aneurysmal lesion. While the precise etiology of Takayasu's disease is unknown, an autoimmune mechanism or active tuberculous inflammation have been suggested. It is more common in young oriental women but has a rare incidence in children. We experienced a case of Takayasu arteritis type IV in an 8years old girl. The diagnosis was made by physial examination and digital substraction aortography(DSA) which showed narrowing of left common carotid artery, right subclavin artery and left renal artery. The perfusion defect at posterior segment of right upper lobe was noted in lung perfusion scan. Medical treatment and percutaneous transluminal angioplasty(PTA) were performed. In addition to case report, a brief review of literature was added.

Evaluation of the Safety of Iatrogenic Intestinal Perforation during Placement of Percutaneous Drainage Catheter in Rabbit

PURPOSE: To evaluate the safety of transgression of the bowel during intraperitoneal percutaneous catheter placement in an animal model. MATERIALS AND METHODS: Eight 8-F straight catheters were percutaneously insertedinto the small and large bowel of eight rabbits. In four animals, the catheters were left in place until autopsy, whereas in the remaining four, the catheters were withdrawn five days after insertion. Autopsy was performed inall animals ten days after catheter placement, and gross and microscopic examination was carried out. RESULTS: Transgressing the bowel during intraperitoneal percutaneous catheter placement did not contribute to any clinically significant complications. At autopsy, there was no bowel leakage, peritonitis, or abscess, although peritoneal adhesions were found around the catheter tract. CONCLUSION: Although further study is warranted, ourstudy with an animal model indicated that transgression of the intestine during percutaneous placement of an intraabdominal catheter did not produce significant complications.

Clinical Observation on Nasolacrimal Duct Stent Intubation in Obstruction of Nasolacrimal System

This study is a clinical observation of the nasolacrimal duct stent intubation when obstruction of the nasolacrimal system is present. Ten patients with this reported condition participated in the study from September 1993 to July 1994. A polyurethane stent of 3.5cm in length, 5 Fr in outer diameter and 4 Fr in inner diameter was introduced in a retrograde direction. Surgical Results indicated that no major complications occurred in 9 out of the 10 cases longer than 3 months follow up. Pseudolumen was found in only one of the cases. In view of these results. We would like to suggest that the placement of polyurethane nasolacrimal stents may be a simple, safe, effective method of nonsurgical treatment of obstruction of the nasolacrimal system.

Fluoroscopy Guided Percutaneous Catheter Drainage of Pneumothorax in Patients with Failed Chest Tube Drainage

PURPOSE: To evaluate efficacy and the safety of percutaneous catheter drainage in patients with pneumothorax that is difficult to treat with closed thoracotomy. MATERIALS AND METHODS: We retrospectively reviewed effectivenss of percutaneous catheter drainage (PCD) in 10 patients with pneumothorax. The catheter was inserted under fluoroscopic guidance. Seven patients had spontaneous pneumothorax caused by tuberculosis (n=4), ruptured bullae (n=2), and histiocytosis-X(n=l). Three patients had iatrogenic pneumothorax caused by trauma (n=l) and surgery(n=2). All procedures were performed by modified Seldinger's method by using 8F-20F catheter. RESULTS: All catheters were inserted successfully. In 9 of 10 patients, the procedure was curative without further therapy. Duration of catheter insertion ranged from 1 day to 26 days. In the remaining 1 patient in whom multiple pneumothorax occurred after operation, catheter insertion was performed twice. CONCLUSION: Percutaneous catheter drainage under fluoroscopic guidance is effective and safe procedure for treatment of pneumothorax in patients with failed closed thoracotomy.

Fluoroscopy Guided Percutaneous Catheter Drainage of Pneumothorax in Patients with Failed Chest Tube Drainage

PURPOSE: To evaluate efficacy and the safety of percutaneous catheter drainage in patients with pneumothorax that is difficult to treat with closed thoracotomy. MATERIALS AND METHODS: We retrospectively reviewed effectivenss of percutaneous catheter drainage (PCD) in 10 patients with pneumothorax. The catheter was inserted under fluoroscopic guidance. Seven patients had spontaneous pneumothorax caused by tuberculosis (n=4), ruptured bullae (n=2), and histiocytosis-X(n=l). Three patients had iatrogenic pneumothorax caused by trauma (n=l) and surgery(n=2). All procedures were performed by modified Seldinger's method by using 8F-20F catheter. RESULTS: All catheters were inserted successfully. In 9 of 10 patients, the procedure was curative without further therapy. Duration of catheter insertion ranged from 1 day to 26 days. In the remaining 1 patient in whom multiple pneumothorax occurred after operation, catheter insertion was performed twice. CONCLUSION: Percutaneous catheter drainage under fluoroscopic guidance is effective and safe procedure for treatment of pneumothorax in patients with failed closed thoracotomy.

CT and MR Findings of Brain Abscess: Focus on Thickeness and Signal Intensity of Abscess Wall

PURPOSE: The purpose of this study is to evaluate the CT and MR findings of brain absecss with emphasis on the thickeness and signal intensity of abscess wall. MATERIALS AND METHODS: Twenty CT scans and seven MR studies of 23 patients with brain abscess (27 abscesses) were retrospectively reviewed with respect to thickeness and signal intensity of abscess wall, shape and size of abscess, etc. Thickness of abscess wall was measured in the greatest abscess diameter on the CT scans and MR images obtaihed after intravenous administration of contrast material. RESULTS: Enhancing abscess wall was 2mm--6mm (average 3mm) thick. The abscess wall was uniform in thickness in 14 cases (52%), thinner in the roedial wall than lateral wall in 8 cases (30%), and thicker in the medial wall than lateral wall in 5 cases (18%). Signal intensity of abscess wall was isointense relative to gray matter on Tl-weighted MR images and hypointense on both proton- and T2-weighted MR images in 7 out of 8 lesione (88%). The inner margin of the abscess wall was smooth in 14 (52%) and irregular in 13 lesions (48%). The outer margin was smooth in 15 (55%) and irregular in 12 lesions (45%). The size of the abscesses was variable, ranging from lcm to 6cm in diameter. They were round (16 cases), elliptical (6 cases), or multilobulated (5 cases) in shape. Satellite or daughter abscesses were found in 5 patients. CONCLUSION: Abscess wall showed variable thickness in the medial and lateral walls with no specific findings. Other CT and MR findings were also nonspecific, although hypointensity of abscess wall on T2-weighted MR images may be helpful in diagnosis of brain abscess.