Gallbladder Perforation after Transarterial Chemoembolization in a Patient with a Huge Hepatocellular Carcinoma / 대한소화기학회지

Transarterial chemoembolization (TACE) is a common treatment for unresectable hepatocellular carcinoma (HCC). The most common complications after TACE are non-specific symptoms called post-embolization syndrome, such as abdominal pain or fever. Rare complications, such as liver failure, liver abscess, sepsis, pulmonary embolism, cholecystitis, can also occur. On the other hand, gallbladder perforation is quite rare. This paper reports a case of gallbladder perforation following TACE. A 76-year-old male with a single 9-cm-sized HCC underwent TACE. Five days after TACE, he developed persistent right upper quadrant pain and ileus. An abdomen CT scan confirmed gallbladder perforation with bile in the right paracolic gutter and pelvic cavity. Percutaneous transhepatic gallbladder drainage was performed with the intravenous administration of antibiotics. After 1 month, the patient underwent right hemihepatectomy and cholecystectomy. Physicians should consider the possibility of gallbladder perforation, which is a rare complication after TACE, when unexplained abdominal pain persists.

Spinal Enumeration by Morphologic Analysis of Spinal Variants: Comparison to Counting in a Cranial-To-Caudal Manner

OBJECTIVE: To compare the spinal enumeration methods that establish the first lumbar vertebra in patients with spinal variants. MATERIALS AND METHODS: Of the 1446 consecutive patients who had undergone computed tomography of the spine from March 2012 to July 2016, 100 patients (62 men, 38 women; mean age, 47.9 years; age range, 19–88 years) with spinal variants were included. Two radiologists (readers 1 and 2) established the first lumbar vertebra through morphologic analysis of the thoracolumbar junction, and labeled the vertebra by counting in a cranial-to-caudal manner. Inter-observer agreement was established. Additionally, reader 1 detected the 20th vertebra under the assumption that there are 12 thoracic vertebra, and then classified it as a thoracic vertebra, lumbar vertebra, or thoracolumbar transitional vertebra (TLTV), on the basis of morphologic analysis. RESULTS: The first lumbar vertebra, as established by morphologic analysis, was labeled by each reader as the 21st segment in 65.0% of the patients, as the 20th segment in 31.0%, and as the 19th segment in 4.0%. Inter-observer agreement between the two readers in determining the first lumbar vertebra, based on morphologic analysis, was nearly perfect (κ value: 1.00). The 20th vertebra was morphologically classified as a TLTV in 60.0% of the patients, as the first lumbar segment in 31.0%, as the second lumbar segment in 4.0%, and as a thoracic segment in 5.0%. CONCLUSION: The establishment of the first lumbar vertebra using morphologic characteristics of the thoracolumbar junction in patients with spinal variants was consistent with the morphologic traits of vertebral segmentation.

Malignant Nodular Hidradenoma: A Case Report

Malignant nodular hidradenoma is a rare skin appendageal tumor, and its imaging findings have not been previously described. We experienced the case of a large malignant nodular hidradenoma of the left upper arm in a 71-year-old woman. MRI revealed a large, lobular, poorly circumscribed, soft tissue mass at the left upper arm, and the mass showed homogeneous enhancement. 18F-FDG PET/CT showed hypermetabolic activity in the left upper arm mass with a maximal standard uptake value of 19.

Treatment of Malignant Gastroduodenal Obstruction with Using a Newly Designed Complex Expandable Nitinol Stent: Initial Experiences

PURPOSE: We wanted to evaluate the usefulness of a new type of a complex expandable nitinol stent that was designed to reduce the stent's propensity to migration during the treatment of malignant gastroduodenal obstructions. MATERIALS AND METHODS: Two types of expandable nitinol stent were constructed by weaving a single thread of 0.2 mm nitinol wire in a tubular configuration: an uncovered stent 18mm in diameter and a covered stent 16mm in diameter. Both ends of the covered stent were fabricated by coaxially inserting the covered stent into the tubular uncovered stent and then attaching the two stents together with using nylon monofilament. Under fluoroscopic guidance, the stent was placed in 29 consecutive patients (20 men and 9 women, mean age: 65 years) who were suffering with malignant gastric outlet obstruction (n=20), duodenal obstruction (n=6) or combined obstruction (n=3). Clinical improvement was assessed by comparing the food intake capacity before and after the procedure. The complications were investigated during the follow up period. RESULTS: Stent placement was successful in all the patients. After stent placement, the symptoms improved in all but one patient. During the follow up, stent migration occurred in one patient (3%) at 34 days after the procedure. Despite the stent migration, the patient was able to resume a soft diet. Six patients developed recurrent symptoms of obstruction with tumor overgrowth at a mean of 145 days after the procedure; all the patients underwent coaxial placement of an additional stent with good results. One patient showed recurrence of obstruction due to tumor in-growth, and this was treated by placement of a second stent. Two patients with stent placement in the duodenum suffered from jaundice 26 days and 65 days, respectively, after their procedures. CONCLUSION: Placement of the newly designed complex expandable nitinol stent seems to be effective for the palliative treatment of malignant gastroduodenal obstructions. The new stent also seems to help overcome the disadvantage of the increased migration observed for the covered stent.

CT Findings of Gastrointestinal Stromal Tumor versus Lymphoma of the Small Intestine

PURPOSE: To compare CT features of gastrointestinal stromal tumors (GIST) with those of lymphomas in the small intestine. MATERIALS AND METHODS: CT findings of 11 pathologically confirmed GIST patients and 10 lymphoma patients were retrospectively reviewed. CT findings were analyzed with regard to location, size, margin, growth patterns, internal character, enhancement, invasion, vascular encasement, lymphadenopathy, intestinal obstruction and ascites. RESULTS:An extraluminal mass was present in 82% (9/11) of the GIST patients versus 30% (3/10) of the lymphoma patients. Circumferential wall thickening was observed in 80% (8/10) of the lymphoma patients (p.05). CONCLUSION: Features revealed by CT scans are highly useful in differentiating GIST from lymphoma of the small intestine. Extraluminal growth and internal necrosis or gas are more common in patients with GIST compared with lymphoma. CT features of circumferential wall thickening and associated lymphadenopathy are more common in patients with lymphoma.

Radiologic Findings of Extraosseous Ewing's Sarcoma

PURPOSE: The purpose of this study is to evaluate the radiologic findings of the extraosseous Ewing's sarcoma. MATERIALS AND METHODS: Six patients with pathologically confirmed extraosseous Ewing's sarcoma were retrospectively reviewed. Patients included two men and four women with an average age of 21.5 years (age range 9-48 years). Plain radiographs (six patients), magnetic resonance (MR) images (five patients), computed tomographic (CT) scans (three patients) and whole body scintigraphy (two patients) were reviewed and analyzed. Images were evaluated with regard to lesion location, size, margin, muscle or bone involvement and intrinsic imaging characteristics on CT and MRI. RESULTS:The tumors were located in the thigh (three patients), back (two patients) and upper arm (one patient). The tumors ranged in size from 2.3 cm to 7.5 cm (mean, 5.2 cm), were mainly well circumscribed and showed no evidence of calcification prior to treatment. Margins were well defined in four out of the six patients. Four patients had subcutaneous lesions and the other two patients had intramuscular lesions. Muscle (two patients) and bone invasion (one patient) were present. The masses were heterogenous low signal intensity on T1 weighted images and heterogeneous high signal intensity on T2 weighted images compared with muscle. Heterogeneous enhancement within the lesion was observed in all patients on CT and MRI. Whole body scintigraphy using Tc-99 m MIBI showed increased uptake in the masses of two patients. CONCLUSION: Extraosseous Ewing's sarcomas were frequently seen as a well-circumscribed ovoid mass with nonspecific findings on CT and MRI. Despite being a relative rare tumor, it should be included in the differential diagnosis of a non-calcified soft-tissue mass, especially in subcutaneous tissue.

A New Liquid Embolic Agent(Embol) for Transcatheter Renal Artery Embolization: An Experimental Study in Rabbit

PURPOSE: To evaluate the effectiveness and safety of a new liquid embolic agent in renal arterial embolization in the rabbit, and its clinical applicability. MATERIALS AND METHODS: A new embolic agent, Embol, was obtained by partial hydrolysis of polyvinyl acetate and dissolved in a mixture of 45% ethanol and 55% non-ionic contrast medium. Its radioopacity was therefore good. An average of 0.8 cc(0.5-0.9 cc) of Embol was used to embolize the renal artery of one kidney in 15 rabbits. The immediate effect of this was examined angiographically 5 minutes after the procedure. To permit histologic examination, five rabbits in each group were sacrificed 3 days (I), 2 weeks (II), and 4 weeks (III) after embolization: prior to embolization and prior to sacrifice, one rabbit in each group underwent renal scanning, and prior to sacrifice all underwent follow-up angiography. In three rabbits, blood urea nitrogen (BUN), creatinine, sodium(Na), and potassium(K) levels were measured before and 1, 3, 5, 7 and 14 days after embolization. RESULTS: Embol was easy to use and its radiopacity was good. Five minutes after embolization, angiography showed that total occlusion of the main renal or interlobar artery had been achieved in all rabbits. Serum BUN, creatinine, Na and K levels were within normal limits. Follow-up angiogram obtained in each group showed persistent occlusion of the renal artery in all but one rabbit in group I and one in group III. Renal scans revealed no evidence of radionuclide uptake in embolized kidneys, which were slightly enlarged in group I but became gradually smaller in groups II and III. In all animals, histologic examination showed diffuse coagulation necrosis of the embolized kidneys and in group III the cortex of these was extensively calcified. In group I the renal artery showed an apparently fresh occluding thrombosis, and in groups II and III a completely organized thrombosis was present. In group III this was calcified. CONCLUSION: Because of its good radioopacity, Embol is easy to controa, and is effective for renal artery embolization. As a permanent embolic agent, it appears suitable for clinical applications.

Intraosseous Neurilemmoma of the Sternum: A Case Report

Intraosseous neurilemmoma is a rare benign neoplasm that accounts for less than 1% of all primary bone tumors. The most frequent site of involvement is the mandible. We report a case of intraosseous neurilemmoma of the sternum which was discovered incidentally.

Transarticular Invasion of the Sacroiliac Joints by Malignant Pelvic Bone Tumors

PURPOSE: To describe modes of transarticular invasion, with reference to the size and location of a tumor, the anatomic characteristics of invaded cartilage, and the existence of ankylosis in SI joint. MATERIALS AND METHODS: Eleven histologically confirmed malignant pelvic bone tumors involving transarticular invasion of sacroiliac joints, were retrospectively analysed. Transarticular invasion of a joint was defined as involvement of its opposing bones. The anatomic site and size of the tumors were analysed, and invaded sacroiliac joint was divided into upper, middle and lower parts on the basis of the anatomic characteristics of the intervening cartilage: synovial hyaline or fibrous ligamentous. The existence of ankylosis was determined, and transarticular invasion directly across a joint was classified as direct invasion. Extension of tumors around a joint from its periphery to the opposing bone were considered as indirect invasion. RESULTS: All tumors were located near the sacroiliac joint, eight at the ilium and three at the sacrum. Six invasions were indirect and five were direct. Average tumor area was larger in indirect cases than in direct: 191.8 cm2 vs. 69.6 cm2. In all indirect invasions, a huge soft tissue mass abutted onto the peripheral portion of the sacroiliac joint. In five of six cases of indirect transarticular invasion, the upper part of the joint posteriorly located fibrous ligamentous cartilage. In the other, the lower part was invaded, and this involved a detour around the joint space, avoiding the invasion of intervening cartilage. Ankylosis occurred in one of the indirect cases. Among the five cases of direct invasion, there was invasion of the posteriorly located ligamentous fibrous cartilage in three without ankylosis. In the other two cases, involving ankylosis, the synovial hyaline cartilage was invaded directly at the lower part of the joint. CONCLUSION: Transarticular invasions of sacroiliac joint via fibrous cartilage are most common. Ankylosis of the sacroiliac joint facilitates hyaline cartilage invasion. We consider that in transarticular invasion of malignant pelvic bone tumors, indirect invasion is more common than direct.

Rapidly Growing Mature Teratoma in the Anterior Mediastinum: Case Report

Mature teratoma is a benign tumor composed of a number of different types of well-differentiated tissues. Mature teratomas of the mediastinum usually grow slowly and are commonly asymptomatic. We report a case of mediastinal mature teratoma with rapid growth resulting in rupture

Malignant Duodenal Obstructions: Palliative Treatment with Covered Expandable Nitinol Stent

PURPOSE: To evaluate the feasibility and clinical effectiveness of using a polyurethane-covered expandable nitinol stent in the palliative treatment of malignant duodenal obstruction. MSTERIALS AND METHODS: Under fluoroscopic guidance, a polyurethane-covered expandable nitinol stent was placed in 12 consecutive patients with malignant duodenal obstructions. All presented with severe nausea and recurrent vomiting. The underlying causes of obstruction were duodenal carcinoma (n=4), pancreatic carcinoma (n=4), gall bladder carcinoma (n=2), distal CBD carcinoma (n=1), and uterine cervical carcinoma (n=1). The sites of obstruction were part I (n=1), part II (n=8), and part III (n=3). Due to pre-existing jaundice, eight patients with part II obstructions underwent biliary decompression prior to stent placement. An introducer sheath with a 6-mm outer diameter and stents 16 mm in diameter were employed, and to place the stent, an after-loading technique was used. RESULTS: Stent placement was technically successful in ten patients, and no procedural complications occurred. In one of two patients in whom there was technical failure, and in whom the obstructions were located in part III, the stent was placed transgastrically. Stent migration occurred in one patient four days after the procedure, and treatment involved the placement of a second, uncovered, nitinol stent. After stent placement, symptoms improved in all patients. During follow-up, obstructive symptoms [due to stent stenosis (n=1), colonic obstruction (n=1), and multiple small bowel obstructions (n=1)] recurred in three patients. Two of these were treated by placing additional stents in the duodenum and colon, respectively. One of the eight patients in whom a stent was placed in the second portion of the duodenum developed jaundice. The patients died at mean 14 (median, 9) weeks after stent placement. CONCLUSION: The placement of a polyurethane-covered expandable nitinol stent seems to be technically feasible, safe and effective for the palliative treatment of malignant duodenal obstructions.

Analysis of Normal Anatomy of Oral Cavity in Open-mouth View with CT and MRI: Comparison with Closed-mouth View

PURPOSE: When MRI and CT of the oral cavity utilize the traditional closed-mouth approach, direct contact between the tongue and surrounding structures may give rise to difficulty in recognizing the anatomy involved and demonstrating the possible presence of pathologic features. we describe a more appropriate scan technique, involving open-mouthed imaging, which may be used to demonstrate the anatomy of the oral cavity in detail. MATERIALS AND METHODS: Axial and coronal MR imaging and axial CT scanning were performed in 14 healthy volunteers, using both the closed and open-mouth approach. For the latter, a mouth-piece was put in place prior to examination. In all volunteers, open-mouth MR and CT examinations involved the same parameters as the corresponding closed-mouth procedures. The CT and MR images obtained by each method were compared, particular attention being paid to the presence and symmetry of motion artifact of the tongue and the extent of air space in the oral cavity. Comparative imaging analysis was based on the recognition of 13 structures around the boundaries of the mouth. For statistical analysis, Student 's t test was used and a p value < 0.05 was considered significant. RESULTS: Due to symmetry of the tongue, a less severe motion artifact, and increased air space in the oral cavity, the open-mouth method produced excellent images. The axial and coronal MR images thus obtained were superior in terms of demarcation of the inferior surface and dorsum of the tongue, gingiva, buccal surface and buccal vestibule to those obtained with the mouth closed (p<0.05). In addition, axial MR images obtained with the mouth open showed better demarcation of structures at the lingual margin and anterior belly of the digastric muscle (p<0.05), while coronal MR images of the base of the tongue, surface of the hard palate, soft palate, and uvula, were also superior (p<0.05). Open-mouth CT provided better images at the lingual margin, dorsum of the tongue and buccal surface than the closed-mouth approach (p<0.05). CONCLUSION: Open-mouth MRI and CT are both practical and useful for evaluation of the structures of the oral cavity. The images thus obtained are superior to those acqhired with the month closed.

Central Neurocytoma Originated from Atrium with Malignant Trans formation: A Case Report

Central neurocytoma, a cerebral intraventricular tumor, is usually benign. It frequently develops in the area of the foramen of Monro, and is usually attached to the septum pellucidum. Mild to moderate contrast enhancement is common. We encountered a case of central neurocytoma in a 60-year-old woman; the tumor arose from the atrium of the lateral ventricle, and extraventricular extension and malignant transformation were apparent. CT and MRI revealed a well-defined, slightly heterogeneous mass measuring 2.5x3x5cm with surrounding edema. There was strong contrast enhancement of the mass.

The Usefulness of Panoramic Radiography using a Lead Ruler for Dental Implant Planning

PURPOSE: If damage to the neurovascular bundle of the mandibular canal during dental implant surgery of the mandible is to be prevented, accurate measurement of the distance between the alveolar crest and the mandibular canal, as seen on panoramic radiographs, is important. The purpose of this study was to compare the accuracy of panoramic radiography using a lead ruler with that of computed tomography for the measurement of the distance between the alveolar crest and superior border of the mandibular canal and to evaluate the usefulness of panoramic radiography using a lead ruler. MATERIALS AND METHODS: For control study, panoramic radiography of the dry mandible was undertaken using a lead ruler, and computed tomography was added. The distances between the alveolar crest and the superior border of the mandibular canal and between the alveolar crest and the lowest border of the body of the mandible were measured at the level of the 2nd premolar to the 3rd molar. These measurements were compared with actual measurements of the dry mandible in the same areas. The cases of 87 patients[49 men, 38 women; age range, 20 -84 (mean, 42) years] who had undergone panoramic radiography using a lead ruler were reviewed. They were catergorized according to sex, the presence of teeth, and whether under or over 50 years of age. All measurements were compared and analyzed using the Student t-test. RESULTS: Measured values obtained from a panoramic radiograph using a lead ruler(magnification:100.32%+/-5.92) and from a computed tomograph(magnification:100.22%+/-5.55) deviated less from actual measurements on the dry mandible (p > 0.05). The distance from the 2nd premolar to the 3rd molar was greater in male adults (19.62 mm +/-3.95) than in female (17.54 mm +/-4.04) (p 0.05), except 2nd pre molar and 1st molar in the female. CONCLUSION: Panoramic radiography using a lead ruler is a simple and accurate modality for the presurgical planning of dental implant surgery. It is suggested that the successful long-term rate of dental implantation may be higher in dentulous male than in edentulous female molars.

Endobronchial Metastasis: CT Findings and Its Usefulness in Bronchoscopic Correlation

PURPOSE: To evaluate the CT findings of bronchial abnormalities in patients with endobronchial metastasis from extrapulmonary tumors, and to correlate these with the bronchoscopic findings. MATERIALS AND METHODS: The authors retrospectively reviewed the CT and bronchoscopic findings of 17 patients (M:F=9:8; mean age, 56 years) with histologically proven endobronchial metastasis from extrapulmonary primary tumors. Carcinoma of the uterine cervix (n = 5) was the most common primary site for endo-bronchial metastasis. CT findings of bronchial abnormalities with associated peribronchial and lung parenchymal lesions were analyzed and compared with the bronchoscopic findings. RESULTS: Among the 17 patients, 20 sites of bronchial abnormalities were visualized bronchoscopically. CT findings of bronchial abnormalities were smooth narrowing (n = 11), occlusion (n = 3), intraluminal mass (n= 4), and normal (n = 2). Peribronchial lesions(lymph node enlargement or parenchymal mass) were found in 12 cases. Bronchoscopy revealed bronchial narrowing due to a mucosal nodule or intraluminal polypoid mass in 16 cases, and total obstruction of the bronchus in four. With regard to the identification of bronchial abnormalities, the findings of CT and of bronchoscopy agreed in 17 cases and disagreed in three. While bronchoscopy was advantageous for detecting early mucosal abnormality, CT effectively evaluated the extent of a lesion beyond the stenosis or bronchial obstruction. CT was also useful for predicting the causes of bronchial abnormalities. CONCLUSION: CT is relatively accurate in evaluating bronchial abnormalities, and in patients with endo-bronchial metastases may be used as a complementary procedure to bronchoscopy for evaluating the extent of the lesion.

Endovascular Stent-Graft Placement for the Treatment of the Aneurysm of the Superior Vena Cava: A Case Report

Venous aneurysm of the superior vena cava(SVC) is a rare congenital lesion and can be classified morphologically as either fusiform or saccular. Although there is a controversy with regard to the need for either conservative or surgical treatment, surgery is recommended for the saccular type as major complications of the aneurysm may occur. We report a case of saccular aneurysm of the SVC, treated by means of an endoluminal stent-graft.

Endovascular Stent-Graft Placement for the Treatment of the Aneurysm of the Superior Vena Cava: A Case Report

Venous aneurysm of the superior vena cava(SVC) is a rare congenital lesion and can be classified morphologically as either fusiform or saccular. Although there is a controversy with regard to the need for either conservative or surgical treatment, surgery is recommended for the saccular type as major complications of the aneurysm may occur. We report a case of saccular aneurysm of the SVC, treated by means of an endoluminal stent-graft.

Color Doppler Ultrasound of Hepatocellular Carcinoma: Evaluation of Recurrence after Transcatheter Arterial Chemoembolization

PURPOSE: To evaluate the efficacy of color and pulsed Doppler ultrasound (US) for the detection of arterial revascularization of hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE). MATERIALS AND METHODS: One hundred and four histologically proven HCCs (0.7-12.5 cm, mean 4.14 cm) of 87 consecutive patients who had undergone TACE using a Lipiodol-chemoagent suspension were examined using color Doppler equipment. The criteria for diagnosing arterial revascularization of HCC were detection of inward blood vessels within HCC and demonstration by spectral Doppler US of pulsatile arterial flow within the vessel. Color Doppler US was prospectively performed using a multi-Hertz probe (2.5-5 Hz), and was followed by digital subtraction angiography (DSA). RESULTS: In 37 of 104 HCCs in 87 patients treated with TACE, color and spectral Doppler US demonstrated intratumoral arterial flows, with peak systolic velocity of 4.2-220 (mean, 59) cm/sec. DSA revealed neovascularity or tumor stains in 38 HCCs (3.4-12.5 cm, mean 5.9 cm in size) including 37 which on Doppler US showed arterial flow. The remaining 66 of 104 HCCs (0.7-6.3 cm, mean 3.2 cm) did not stain during DSA. Doppler US showed a false negative result in only one HCC (4.6 cm, located at segment VII of the Couinaud classification), which stained faintly during DSA. The sensitivity, specificity, and accuracy of color and spectral Doppler US used for the detection of recurrent HCC were 97.4%, 100%, and 99%, respectively. CONCLUSIONS: Color and spectral Doppler US is an effective method for the evaluation of arterial revascularization of HCC after TACE.

High Density Renal Medulla on Unenhanced CT: Significance and Relation with Hyd ration Status

PURPOSE: To assess the effect of hydration status on renal medullary attenuation and to evaluate the incidence of dense renal medulla, as seen on unenhanced CT. MATERIAL AND METHODS: We prospectively studiedunenhanced CT scans of 12 healthy volunteers. Obtained done after 10 hours and 15 hours of dehydration and afteroral intake of 2L of water. BUN/Cr, urine specific gravity, urine osmole and hematocrit were evaluated after 10hours of dehydration. CT images were reviewed for the presence of dense renal medulla and differential attenuationof dense renal and isodense medulla and cortex at the same level. The density changes of renal medulla afterhydration were evaluated. and CT findings were compared with the results of biochemical studies. In addition, weretrospectively reviewed the CT scans of 200 consecutive patients for evaluation of the incidence of dense renalmedulla. RESULTS: In 8 of 12 volunteers, dense renal medulla was seen on CT scan after dehydration. Meanattenuation was 71.3 +/-10.42HU after 10 hours of dehydration, 68.6 +/-13.54HU after 15 hours, and 34.5 +/-11.47HUafter hydration. No significant attenuation differences were detected between 10 hours and 15 hours ofdehydration, but significantly lower attenuation values were noted after hydration. For isodense medulla, the meanattenuation value was 35.7 +/-7.9HU after 10 hours of dehydration, 39.58 +/-9.66HU after 15 hours, and 36.58+/-7.77HU after hydration. The mean attenuation values of cortex were 35.9 +/-5 . 9 5 H U after 10 hours ofdehydration, 37.58 +/-5.95HU after 15 hours, and 37.08 +/-9.75HU after hydration. With regard not only to durationof dehydration, but also ti hydration, no differences in attenuation values were noted for renal cortex orisodense renal medulla. However, higher density was noted in dense renal medulla than in isodense medulla orcortex for the same duration of dehydration. After hydration, complete resolution was seen at five of eight sitesand incomplete resolution at three of eight sites. There was no correlation between CT attenuation and laboratoryresults. Dense renal medulla was seen in 17 of 200 consecutive patients. Mean attenuation values were 64.06+/-8.38HU for dense renal medulla, 37.15 +/-8 . 4 4 H U for isodense renal medulla and 35.36 +/-8.13HU for cortex. CONCLUSION: For the same duration of dehydration, dense renal medulla showed a higher attenuation value thanisodense medulla or cortex, a finding which was completely or incompletely resolved after hydration. Inconsecutive patients, the incidence of dense renal medulla was 8.5% In conclusion, this in-cidence is aphysiological, variable, reflecting dehydration status.

Quantitative Morphologic Assessment of Thoracolumbar Vertebrae in Korean Women by Morphometric X-rayAbsorptiometry

PURPOSE: To compare the accuracy of lateral radiography of the spine with that of morphometric X-rayabsorptiometry(MXA) in vertebral morphometry, and to evaluate normal vertebral morphometry using MXA in Koreanwomen. MATERIALS AND METHODS: A spine phantom was constructed using copper pipe. Its anterior and posteriorheights were measured directly, with lateral radiographs and with MXA, and the values thus obtained were compared.Inter -and intra -observer variations were evaluated by three radiologists. The vertebral morphometry of 30 youngwomen volunteers were imaged using thoracic and lumbar lateral radiographs and MXA, and analysis included themeasurement of anterior and posterior heights from T4 to L4. We also obtained the vertebral morphometry of 200normal Korean women who underwent MXA between March 1995 and February 1996, though those with osteoporosis andother spinal lesions were excluded from this study. Thoracolumbar vertebral indexes were statistically correlatedwith age, height and bone mineral. RESULTS: There were no statistically significant differences in the heights ofspine phantom measured by MXA compared with actual size (mean difference=0.28mm). Simple radiographs weremagnified by 23.7% at a phantom-table distance of 15cm, and distortion ranged from 0.5% to 22.5%, depending onphantom level and phantom-table distance. In the study of volunteers, the magnification rate between a simpleradiograph and MXA was about 26.6%. Anterior height increased progressively from the thoracic to the lumbar spine,though posterior height peaked at L2, and L4 was less than anterior height. In Korean women, indices of vertebralmorphometry decreased significantly with aging, with the most prominent decrease occurring during the seventhdecade. The mineral density of spinal bone decreased markedly after the sixth decade. CONCLUSION: Radiographsshowed more magnification and distortion than did MXA, though between morphometric X-ray absorptiometry (MXA) andactual size, there was no significant difference. The vertebral morphometric indices of Korean women and referredbone mineral density may provide useful data for determining and evaluating follow-up changes in spinalmorphology.