Hepatocellular Carcinoma: Comparison Study on Detecting Tumor Vascularity among Various Imaging Techniques

PURPOSE: To compare the detectability of tumor vascularity using triphasic spiral CT, angiography, CT during hepatic arteriography(CTHA) and single-level dynamic CTHA(SLD-CTHA). MATERIALS AND METHODS: Seventy-nine pathologically confirmed nodular hepatocellular carcinomas(HCCs) in 77 patients were included in this study. Sixty patients were male and 17 were female, and their ages ranged from 31 to 77 (average, 57.4) years. HCCs were classified into three groups according to the size: less than 2 cm (n=20), 2 -4 cm (n=32), and more than 4 cm (n=27) in diameter. If a portion of tumor demonstrated greater enhancement than surrounding liver parenchyma, vascularity was deemed to be present. Detectability by each imaging technique was compared according to size and overall. RESULTS: Hypervascularity was frequently detected by SLD-CTHA [90.9%(40/44)], followed by CTHA[88.0%(66/75)], angiography [80.3%(61/76)], triphasic spiral CT [72.4%(42/58)]. In the less than 2 cm group, detectability rates for triphasic spiral CT, angiography, CTHA and SLD-CTHA were 53.3%(8/15), 55.6%(10/18), 76.5%(13/17) and 87.5%(6/7), respectively. while the 2 -4 cm group demonstrated corresponding figures of 71.4%(15/21), 78.1%(25/32), 84.4%(27/32) and 86.4%(19/22). In the more than 4 cm group, the rate for triphasic spiral CT was 86.4%(19/22), while for angiography, CTHA and dynamic CTHA, it was 100%. CONCLUSION: In the detection of hypervascularity of HCC, SLD-CTHA showed the highest rate, followed by CTHA, angiography, and triphasic spiral CT. In HCCs less than 4 cm in diameter, the corresponding ordering was SLD-CTHA, CTHA, angiography and triphasic spiral CT, but in HCCs of more than 4 cm, angiography, CTHA and SLD-CTHA detected hypervascularity equally well. Lesion size most affected the findings of angiography.

Validity analysis of for exercise tests in assessing aerobic capacity of young men

BACKGROUND: Assessment of aerobic capacity (VO2max) is one of the essential components in exercise prescription for health promotion and maintenance. This study was conducted to compare the validity of four exercise tests to assess aerobic capacity in young adult male subjects by comparing them to the values measured from maximal ergometer exercise test (criterion VO2max). METHODS: Twenty young healthy adult males (M+/-SD=21.1+/-1.5 years) volunteered as subjects. Criterion VO2max was calculated and printed out automatically by computerized analysis system of expired air samples collected during maximal ergometer exercise test. VO2max was estimated for each subject from heart rate at submaximal workloads on the cycle ergometer using the Astrand-Rhyming nomogram(A/R) and Fox protocol(FOX) and the computerized multiple extrapolation method (XTP). The score got from Havard step test(H/S) was used to compare the validity. The validity of the procedures was based on the evaluation of the predicted VO2max (from A/R, FOX, XTP, and H/S) versus the criterion VO2max via the calculation of constant error (CE=mean difference for predicted minus criterion VO2max), r value, standard error of the estimate[SEE=SD(1-r2)(1/2)], total error [TE=(sigma(predicted VO2max - criterion VO2max)(2)/n)(1/2)]. RESULTS: In relation to criterion VO2max, the XTP and A.R underpredicted (XTP: 40.8 ml/kg/min SD=4.1; A/R: 37.3 ml/kg/min SD=5.0) and the H/S and FOX overpredicted (H/S: 48.0 ml/kg/min SD=5.9: FOX 46.3 ml/kg/min SD=5.5). Dunnett post-hoc procedures revealed that there were significant (P<0.05) mean differences (CE) for VO2max from A/R versus criterion. The validity coefficients for VO2max derived from XTP, H/S, A/R, and FOX were 0.68, 0.53, 0.50, and 0.49, respectively. TE of the XTP, FOX, H/S and A/R, which accounts for the effects of both the CE and SEE, were 5.73, 6.13, 6.75, and 8.87, respectively. CONCLUSIONS: These results suggest that the XTP is recommended first for estimation VO2max in young adult males. It is also considered that further studies about female and other age groups are necessary.

Estimation of the Probability of Malignancy in Solitary Pulmonary Nodules: Comparative Study of Conventional Interpretation Method and Bayesian Analysis

PURPOSE: The aim of this study was to compare the accuracy of the conventional method and Bayesian analysisin estimating the probability of malignancy in solitary pulmonary nodules. MATERIALS AND METHODS: The studyinvolved 83 pathologically proven cases of solitary pulmon ary nodules, 44 of which were malignant, and 39,benign. To estimate the probability of malignancy in solitary pulmonary nodules, chest radiographs and CT scans ofthe 83 patients were interpreted by a team of six ; three of the six used the conventional method of subjectiveinterpretation and the others. Bayesian analysis. The smoking history of 59 of the patients was obtained, and itwas decided whether this would help determine the probability of malignancy. RESULTS: On average, those using theconventional method correctly interpreted 34.7(78.9%) of 44 cases of malignant nodules and 27.7(71%) of 39 benignnodules, while those using Bayesian analysis correctly classified 32.3 cases of malignant nodules(73.4%) and 25.3cases of benign nodules(64.9%). Between the two teams, there was no statistically significant difference in theaccuracy of qualitative assessment(P>.05). In ROC analysis conventional interpretation and Bayesian analysisshowed an accuracy of Az=80.8 and Az=76.7, respectively. Among 59 patients known to have smoked, the conventionalmethod showed an accuracy of Az=79.0 without this knowledge and Az=80.2 with the knowledge for Bayesian analysis,the corresponding figures were Az=77.2 and Az=72.5, respectively. Information relating to smoking history thus didnot significantly improve the accuracy of prediction(p>.05). CONCLUSION: For estimating the probability ofmalignancy in solitary pulmonary nodules, the accuacy of the conventional method of interpretation is notsignificantly different from that of Bayesian analysis; information relating to smoking history significantlyimprove the accuracy of neither method.

Anatomical Relationship between the Optic Nerve and Posterior Paranasal Sinuses on Ostiomeatal Unit CT

PURPOSE: To determine the anatomic variations that can lead to optic nerve damage during the sugical treatment of posterior paranasal sinus lesions MATERIALS AND METHODS: two hundred optic nerves of 100 persons were examined using ostiomeatal unit CT (OMU CT). The anatomical features of this nerve and posterior paranasal sinuses were classified into four types : the optic nerve adjacent to the sphenoid sinus without indentation of the sinus wall (type 1); the optic nerve adjacent to the sphenoid sinus, causing indentation of the sinus wall (type 2); the optic nerve passing through the sphenoid sinus (type 3); and the optic nerve adjacent to the sphenoid sinus and posterior ethmoid sinus (type 4). Bony dehiscence around the optic nerve and pneumatization of the anterior clinoid process were also evaluated. RESULTS: The anatomical classification of the optic nerve and posterior paranasal sinuses was as follows : type 1, 1326 (66%); type 2, 60 (30%); type 3, 6 (3%), and type 4, 2 (1%). Bony dehiscence around the optic nerve had developed in 58 cases (29%) and pneumatization of the anterior clinoid process in 13 (6.5%). These conditions were most common in type 3 optic nerve, and second most common in type 2. CONCLUSION: The 2 and 3 optic nerve, bony dehiscence around the optic nerve and pneumatization of the anterior clinoid process are the anatomic variations that can lead to optic nerve damage during the surgical treatment of posterior paranasal sinus lesions. To prevent optic nerve damage, these factors should be carefully evaluated by OMU CT.

Three Phase Dynamic CT with Double Spiral CT: Utility of Determination of Stomach Cancer Stage

PURPOSE: To evaluate the utillity of three phases of spiral CT in the diagnosis of stomach cancer. MATERIALS AND METHODS: Between August 1994 and March 1995, thirty eight patients with stomach cancer, demonstrated on spiral CT, underwent surgery. Twenty-eight cases were advanced and ten were early. There were 27 men, and 11 women, and their average age was 52.8 years old (33-77). After ingestion of 600 - 700ml of water, 120 - 140ml of nonionic contrast material was injected intravenously. Spiral CT scanning was performed in 10mm slice thickness and of 10 mm/sec table speed. Three phase images were obtained at 25 sec (arterial phase), 60-65 sec (venous phase) and 4min (equilibrium phase) after the start of bolus injection. On each phase, CT findings were compared with pathologic results, and tumor detectibility, depth of tumor invasion and lymph node metastasis was analysed. RESULTS: Thirty of the 38 carcinomas (79%) were detected on the arterial phase, 33 (81%) on the venous phase and 30 (79%) on the equilibrium phase. Depth of tumor invasion was measured accurately in 27 of 38 cases (71%): T1 -4/10 (40%), T2 - 8/11 (73%), T3 - 13/15 ( 87% ), T4 - 2/2 ( 100% ). We overstaged one case of T1 as T2 and two cases of T2 as T3, and understaged one case of T2 as T1 and two cases of T3 as T2. Among the 16 enlarged lymph nodes larger than 8mm, 13 cases were positive on pathologic examination and the sensitivity was 65%. CONCLUSION: With three-phase spiral CT scanning, we obtained 71% accuracy of depth of tumor invasion. The venous phase is most useful for tumor detection and for determining depth of tumor invasion and lymph node metastasis.

Comparative Validity Study of Body Fat Assessment Methods Available in the Work Places / 대한산업의학회지

No abstract available.

Triple Phase Spiral CT Findings of Hepatocellular Carcinoma

PURPOSE: To evaluate contrast enhancement patterns of hepatomas (HCCs) on arterial dominant, portal dominant,and delayed phase of CT scan by using double spiral CT. MATERIALS AND METHODS: Using double-spiral CT, three-phase dynamic liver scan was performed on 27 patients with 45 nodular HCC lesions. Non-ionic contrast medium(100-120ml) was injected intravenously with an automatic injector at the rate of 2-4 ml/sec. CT scans were obtained at 25-30sec (arterial dominant phase), 60 sec (portal dominant phase), and 5min (delayed phase) afteradministration of the contrast medium. The tumor were divided into two groups according to the diameter( or = 3cm). In each group, contrast enhancement patterns of HCCs were classified as follows : high, central high, peripheral high, iso, low, or mixed attenuation. The incidence and contrast enhancement patterns of thin peripheral rims(psevdocapsules) were also analyzed. RESULTS: There were 23 lesions with a diameter less than 3cm,while 22 lesions were 3cm or larger. On the arterial dominant phase, tumors smaller than 3cm showed high(74%), iso(17%), mixed(4%), and peripheral high(4%) attenuation, while the attenuation of tumors larger than 3cm washigh(73%), mixed(9%), iso(9%), and low(9%). On the portal dominant phase, tumors smaller than 3cm were mostcommonly iso(43%) or high(35%), while tumors larger than 3cm were low(65%) or iso(18%). On the delayed phase, tumors were most commonly low in attenuation regardless of size. A thin peripheral rim was observed in 22% of tumors smaller than 3cm and in 64% of tumors larger than 3cm. The rim showed iso(53%) or low(42%) attenuation onthe arterial dominant phase, high(47%) or iso(47%) attenuation on the portal dominant phase, and high(100%) attenuation on the delayed phase. CONCLUSIONS: For the detection and diagnois of HCCS, an understanding of their contrast enhancement patterns is useful.

Significace of Screening Mammography in the Detection of Breast Diseases

PURPOSE: To evaluate the clinical significance of the screening mammography in the detection of the breast diseases, especially breast carcinoma. MATERIALS AND METHODS: We analyzed 1,800 cases of mammography retrospectively. The mammography was done as a part of routine check in Health Counselling Center, Korea University Medical Center, during 9 months from November 1993 to July 1994. The age range was from 23 years to 76 years, mean 49.8 years, and the largest age group was 6th decade(31.4%). According to the mammographic findings, we divided the subjects into three groups; normal group, abnormal group in need of follow up study, abnormal group requiring biopsy. RESULT: On mammography, the normal group consisted of 1,534 cases(85%), and the abnormal group consisted of 266 cases(15%). The abnormal findings were benign-looking calcification(n=140), fibroadeno ma (n=29), fibrocystic changes (n=27), cyst(n=23), malignant lesion(n=15), lipoma(n=7), and others. In four of 15 cases, which were suspected to be malignant on mammograms, breast carcinoma was confirmed pathologically. In four cases of breast carcinoma, one was under 40 and the other 3 were over 50 years of age. All of the breast cancers were under 3cm in size, and the mammographic findings of breast cancer included spiculated margin(n=3), parenchymal disortion(n=3), malignant calcification(n=2) and enlarged axillary node (n=l). CONCLUSION: Screening mammogram is helpful for early detection of non-palpable breast cancer, especially for women over 50 years of age.