Assessing the accuracy and reliability of ultrasonographic three-dimensional parathyroid volume measurement in a patient with secondary hyperparathyroidism: a comparison with the two-dimensional conventional method

PURPOSE: The purpose of this study was to investigate the accuracy and reliability of the semi-automated ultrasonographic volume measurement tool, virtual organ computer-aided analysis (VOCAL), for measuring the volume of parathyroid glands. METHODS: Volume measurements for 40 parathyroid glands were performed in patients with secondary hyperparathyroidism caused by chronic renal failure. The volume of the parathyroid glands was measured twice by experienced radiologists by two-dimensional (2D) and three-dimensional (3D) methods using conventional sonograms and the VOCAL with 30°angle increments before parathyroidectomy. The specimen volume was also measured postoperatively. Intraclass correlation coefficients (ICCs) and the absolute percentage error were used for estimating the reproducibility and accuracy of the two different methods. RESULTS: The ICC value between two measurements of the 2D method and the 3D method was 0.956 and 0.999, respectively. The mean absolute percentage error of the 2D method and the 3D VOCAL technique was 29.56% and 5.78%, respectively. For accuracy and reliability, the plots of the 3D method showed a more compact distribution than those of the 2D method on the Bland-Altman graph. CONCLUSION: The rotational VOCAL method for measuring the parathyroid gland is more accurate and reliable than the conventional 2D measurement. This VOCAL method could be used as a more reliable follow-up imaging modality in a patient with hyperparathyroidism.

Arterial Wall Imaging in Symptomatic Carotid Stenosis: Delayed Enhancement on MDCT Angiography / 신경중재치료의학

OBJECTIVE: To evaluate progressive enhancement in the carotid arterial wall overlying plaque in the symptomatic side for patients with cerebrovascular symptoms until delayed phase using MDCTA. MATERIALS AND METHODS: Twenty-one patients (all men; ages, 49-82 years; mean, 67.8 +/- 8.4 years) with recent stroke and severe extracranial carotid stenosis were retrospectively analyzed. Pre-, early- and delayed phase images of MDCTA were obtained, and Hounsfield units (HU) of carotid walls were measured. We also measured HU of the asymptomatic contralateral carotid arterial wall for comparison. Friedman's test and Wilcoxon signed-rank test were used to evaluate the differences between groups. RESULTS: The averaged HU of the carotid wall in the symptomatic side was higher on the delayed phase (65.8 +/- 14.2 HU) compared to early arterial phase (54.2 +/- 12.6 HU). The averaged HU difference of wall enhancement between pre-contrast and delayed phase (28.0 +/- 14.8 HU) was significantly higher than the between pre-contrast and early arterial phase (16.4 +/- 12.1 HU) with P < 0.05. In analysis of the contralateral asymptomatic side, the HU difference between pre-contrast and delayed phase (15.5 +/- 12.0 HU) showed no significant higher value than between pre-contrast and early arterial phase (14.9 +/- 10.9 HU). CONCLUSION: The pronounced enhancement of the carotid wall in the delayed phase on MDCTA was demonstrated in symptomatic patients with severe internal carotid artery stenosis. In the future, we need more comparative studies to verify this finding as one of risk stratification.

Comparison of Ultrasonographic Findings of Biopsy-Proven Tuberculous Lymphadenitis and Kikuchi Disease

OBJECTIVE: Although tuberculous lymphadenitis and Kikuchi disease are common causes of cervical lymphadenopathy in Asians and exhibit similar clinical manifestations, their treatment strategies are totally different. The purpose of this study was to identify ultrasonographic features that distinguish these two diseases. MATERIALS AND METHODS: This study was approved by the Institutional Review Board. The study included 77 patients with tuberculous lymphadenitis and 135 patients with Kikuchi disease. The sex and age distributions of the patients were analyzed. The size and shape of lymph nodes (LNs), presence of conglomeration, increased perinodal echogenicity, echogenic hilum, posterior neck involvement, internal calcification, patterns of internal necrosis, laterality of involved LNs, and hilar vascular patterns on ultrasonography were compared between the two groups. Multiple logistic regression analysis was conducted to identify independent findings to discriminate tuberculous lymphadenitis from Kikuchi disease. Finally, diagnostic accuracies were calculated using the independent findings. RESULTS: The presence of an echogenic hilum, internal calcification, patterns of internal necrosis, and LN hilar vascular structures on power Doppler ultrasonography were independent findings that discriminated tuberculous lymphadenitis from Kikuchi disease. The diagnostic accuracy of each of these four factors was 84.9% (181/212), 76.9% (163/212), 84% (178/212), and 89.2% (189/212), respectively. A combination of internal calcification and hilar vascular structures showed the best accuracy of 89.6% (190/212) (sensitivity, 86.7% [117/135]; specificity, 94.8% [73/77]) for diagnosing Kikuchi disease. CONCLUSION: The presence of an echogenic hilum, internal calcification, pattern of internal necrosis, and LN hilar vascular structures are useful ultrasonographic findings to differentiate tuberculous lymphadenitis from Kikuchi disease.

Additional Breast Ultrasound Examinations in Clustered Calcifications: for Improving Diagnostic Performance / 한국유방암학회지

PURPOSE: We wanted to determine whether additional breast ultrasound examinations are needed for patients who have clustered calcifications found by mammography for the detection of breast carcinomas. METHODS: We performed targeted ultrasound examinations in 125 consecutive patients who had clustered calcifications found by mammography. Forty-eight pathologically proven patients with 61 breast lesions were included in this study (26 invasive carcinomas, 10 ductal carcinomas in situ and 25 benign diseases). Two breast radiologists evaluated the mammography and the ultrasound findings and they graded the probability of malignancy by consensus as follows: definitely benign 1, probably benign 2, probably malignant 3, and definitely malignant 4. The diagnostic performance values, including the sensitivity, specificity, accuracy, positive predictive value and negative predictive value, for mammography and additional ultrasound were compared using McNemar's test and receiver operating characteristic (ROC) analysis. On the ROC analysis, areas under the ROC curves (AUC) and 95% confidence intervals (CI) were obtained. RESULTS: The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for making the diagnosis of breast carcinoma by mammography were 88.9%, 12.0%, 57.4%, 59.3%, and 42.9% and those for additional ultrasound were 94.4%, 64.0%, 82.0%, 79.1%, and 88.9%, respectively. The differences of specificity and accuracy were statistically significant (p=0.0003). On the ROC analysis, ACU were significantly different between mammography (AUC=0.586, 95% CI=0.453-0.711) and ultrasound (AUC=0.823, 95% CI=0.704-0.909) (p=0.003). Clustered calcifications with associated masses or ductal changes on additional breast ultrasound had high frequency of malignancies, 79% or 73%. In addition, 87% of malignant masses were invasive carcinomas and 45% of malignant ductal changes were ductal carcinomas in situ. CONCLUSION: Additional breast ultrasound examinations for the lesions with clustered calcifications on mammography can improve the diagnostic performance and significantly contribute to the specificity and accuracy of a diagnosis of breast carcinoma. In addition, the ultrasound features may predict the pathologic findings such as benignity or malignancy and invasive carcinoma or ductal carcinoma in situ.

The Role of an Axial MR Scan on the Diagnosis of a Meniscal Tear of the Knee Joint

PURPOSE: To evaluate the role of standard axial MR images for the diagnosis of meniscal tears of the knee. MATERIALS AND METHODS: Forty-five patients with a prior MRI examination that underwent arthroscopic surgery of the knee due to clinical impression of a meniscal tear were included in the study group. The sequence for meniscal evaluation was an axial fat-saturated proton density-weighted image with a 4 mm slice thickness. Axial MR images were independently reviewed by two radiologists and were compared with findings of arthroscopy. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the axial MR scan for the diagnosis of the meniscal tear were calculated. RESULTS: A total 90 menisci of 45 patients were evaluated in the axial MR scans. Forty-two patients had meniscal tears, and two of the patients had tears in both menisci; thus, a total of44 meniscal tears were found by arthroscopy. For meniscal tears, the sensitivity of the axial plane was 76.2%, the specificity was 89.1% and the accuracy was 81.1%. False negative meniscal tears were seen in 12 cases and false positive meniscal tears were seen in 5 cases on the axial MR images. CONCLUSION: In standard knee MRI examinations, axial images may be valuable for the detection and localization of meniscal tears.

Emergent Endovascular Treatment of Ruptured Dissecting Aneurysm of the Intradural Vertebral Artery Using a Self-Expandable Intracranial Stent and a Bioactive Hydrophilic coil / 신경중재치료의학

Ruptured dissecting aneurysm of the vertebral artery requires a rapid treatment because of the high rate of fatal early rebleeding. Stent-assisted coil embolization has been introduced as an effective procedure for both aneurysmal occlusion and parent artery preservation. We report a case of successful urgent treatment of ruptured dissecting aneurysm using a self-expandable, intracranial stent (Neuroform(R)) and a coated coil (HydroCoil(R)).

Spontaneous Tilting after Placement of the Gunther-Tulip Inferior Vena Caval Filter: A Case Report

Tilting of a deployed filter in the inferior vena cava (IVC) is a particular kind of periprocedural complication and this can reduce the filter's clot-trapping ability and increase the occlusion of the IVC at a later period. The authors report here on a case of spontaneous tilting of an inferior vena caval filter that was associated with thrombosis in the IVC within 2 weeks of the initially successful placement of the filter without tilting.

Femoral Arterial Puncture: Comparison of Using the Inguinal Crease and Bony Landmarks

PURPOSE: We tried to compare the accuracy of using bony landmarks and inguinal crease landmarks for performing femoral artery puncture and to determine an ideal puncture site. MATERIALS AND METHODS: We studied ninety consecutive patients who underwent femoral arterial puncture for performing angiogram. For the evaluation of bony landmarks, the pelvis and inguinal areas were divided into 8 zones according to 7 lines that were drawn parallel to the line drawn between the anterior superior iliac spine and the pubic tubercle. For evaluation of the inguinal crease as a landmark, the 8 zones above and 4 zones below the inguinal crease were determined. The zones were divided by 11 lines drawn parallel to the inguinal crease, and the interval between each line was 1cm. Locations of the inguinal ligament and femoral bifurcation were recorded for every patient according to the above zones, and an ideal zone for the femoral arterial puncture was decided upon. The ideal zone was considered if the locations of all of inguinal ligaments were above the zone and the least possibility to puncture was below the femoral bifurcation. RESULTS: On the bony landmark, the femoral bifurcations were located at zone 3 in 1 patient (1.1%), at zone 4 in 2 patients (2.2%), at zone 5 in 3 patients (3.3%), at zone 6 in 24 patients (26.7%), and at zone7 in 44 patients (48.9%). Inguinal ligaments were at zone 1 in 2 patients (3.0%), at zone 2 in 34 patients (50.7%), at zone 3 in 25 patients (37.3%), and at zone 4 in 6 patients (8.9%). When the inguinal creases were used as a landmark, the femoral bifurcations were located at zone 4 in 4 patients (4.4%), at zone 3 in 19 patients (21.1%), at zone 2 in 30 patients (33.3%), at zone 1 in 19 patients (21.1%), at zone -1 in 13 patients (14.4%), at zone -2 in 3 patients (3.3%) and at zone-4 in 2 patients (2.2%). Inguinal ligaments were at zone 8 in 7 patients (10.4%), at zone 7 in 11 patients (16.4%), at zone 6 in 19 patients (28.4%), at zone 5 in 20 patients (29.9%), at zone 4 in 7 patients (10.4%), and at zone 3 in 3 patients (4.5%). Therefore, the best zone for femoral arterial puncture was zone 5 with using bony landmarks and zone 2 with using inguinal crease landmarks. In terms of zone 5 on the bony landmark, every locations of inguinal ligaments was above it and 84 patients (93.4%) had their femoral bifurcation below it, excluding the 6 patients who had their femoral bifurcations at zones 3, 4, and 5. Therefore, zone 5 with using the bony landmarks was a good indicator for femoral arterial puncture. In case of zone 2 on the inguinal crease landmark, although every location of the inguinal ligament was above it, 53 patients (58.8%) had their femoral bifurcation above it at zones 4, 3, and 2. So, it was not a good indicator for femoral arterial puncture. CONCLUSION: Bony landmarks are more accurate indicators for performing femoral arterial puncture than the inguinal crease landmark. Zone 5 on the bony landmark is an ideal location for femoral arterial puncture.

Fibular Hemimelia: A Case Report

Fibular hemimelia is the most common congenital absence or hypoplasia of long bone. In addition to fibular absence or hypoplasia, this entity also includes various combined abnormalities of the lower limbs. We present here three cases of fibular hemimelia who underwent diagnosis and treatment in our hospital. Wee especially focus on the imaging findings of the plain radiographs, and we compare them with the findings found at another presentation.

Extramedullary Plasmacytoma of the Pancreas: Imaging Findings: Case Report

Extramedullary plasmacytoma involves organs outside the bone marrow, but involvement of the pancreas is very rare. We present the imaging findings of extramedullary plasmacytoma of the pancreas in a patient with multiple myeloma. Mixed echogenecity was noted at US, and marked enhancement at CT and MR.

MR Imaging Findings of Patellar Tendon after Anterior Cruciate Ligament Reconstruction with Bone-Tendon-Bone Autograft

PURPOSE: To evaluate the postoperative changes occurring in the patellar tendon after reconstruction of the anterior cruciate ligament (ACL) using the central one-third of the patellar tendon together with patellar and tibial bony plugs. MATERIALS AND METHODS: Ten patients with ACL injury underwent sagittal and coronal T1-weighted MR imaging of both postoperative and normal knee joints. In all cases, reconstruction of the ACL was performed using the central one-third of the patellar tendon, together with patellar and tibial bony plugs. During the follow-up period of 6-27 months, patient were clinically stable. We compared the length, signal intensity and contour of both patellar tendons, as seen on MR images. RESULTS: No defects was found in harvested patellar tendons, and MR images showed high signal intensity within harvested tendons in six of the ten patients. In seven of ten, patellar tendons had irregular margins and were poorly delineated from adjacent tissue. The mean length of patellar tendons was 44.2+/-2.9 mm in normal knee and 43.9+/-3.1mm in postoperative knee, while their mean thickness in postoperative knee, measured at mid-portion, averaged 4.3+/-1.2 mm. There were no statistically significant differences (p>0.05). The greatest mean thickness of patellar tendon was 6.9+/-1.2 mm and 4.3+/-0.5mm in normal and postoperative knee, respectively. Thus, on average, postoperative patellar tendon was 161% thicker than normal tendon (p<0.05). CONCLUSION: In clinically stable patients, patellar tendons after graft harvesting had a higher signal intensity, worse-defined margins and a greater thickness than normal. We suggest that these are the normal postoperative findings.

MR Findings of Traumatic Transient Lateral Dislocation of the Patellae

PURPOSE: To determine the magnetic resonance (MR) imaging characteristics of traumatic transient lateral dislocation of the patellae. MATERIALS AND METHODS: In eight patients (6 males, 2 females, mean age: 22.4 years) in whom transient lateral dislocation of the patella was diagnosed, the distinctive MR imaging findings reflecting known injury mechanism were retrospectively analyzed with regard to bone contusion, chondral defect, fracture, loose body, joint effusion, and the associated soft tissue abnormalities. RESULTS: All of eight patients had bone contusions in the lateral femoral condyle and medial facet of the patella, while in five, chondral defects were present in this latter region. In three patients, fractures of the on lateral femoral condyle (n=2) and medial facet of the patella (n=3) were noted, and in three others, loose bodies were noted. Joint effusion [simple effusion (n=4), lipohemarthrosis (n=3)] was observed in seven patients, and associated soft tissue injuries [to the medial patellar retinaculum (n=8), patellar tendon (n=2), and anterior cruciate ligament (n=1)] in eight. Patellar subluxation was found in seven. CONCLUSION: MR imaging is a useful technique for the diagnosis of traumatic lateral dislocation of the patella. The significant MR findings are bone contusion in the lateral femoral condyle and medial facet of the patella, chondral defect, fracture, joint effusion, injury to the medial patellar retinaculum, and patellar subluxation.

What is the Best MR Sequence to Evaluate

PURPOSE: To determine the best MR sequence for evaluation of the anatomical structures of normal kidney. MATERIALS AND METHODS: Twenty normal volunteers (M:F=15:5) took part in this study, and for each, seven sequences were performed. The T1 weighted sequences were conventional spin echo T1 (Conv-SET1), turbo spin echo T1 (TSET1), and fast low angle shot (FLASH), while the T2 weighted sequences were turbo spin echo T2 (TSET2), half-Fourier acquisition single-shot turbo spin echo (HASTE), true-fast imaging with steady-state precession (True-FISP), and echoplanar imaging (EPI). The study involved quantitative and qualitative analysis. In quantitative analysis, CNRs between cortex and adjacent fat tissue, and between cortex and medulla were calculated from SNR (signal to noise ratio), and the CNRs of sequences were statistically compared. In quantative analysis, three radiologists collectively evaluated kidney outline, corticomedullary division, the renal vessels, the pelvis/ureter, and artifacts. For each sequence a grade was assigned, and for each parameter the grades were compared. RESULTS: Between cortex and adjacent fat, the highest CNR was shown by TSET1, followed by Conv-SET1,while among T2 sequences, the CNR shown by TSET2 was highest. Between cortex and medulla, the CNR demonstrated by the three T1 sequences showed no statistically significant difference. Among T2 sequences, however, HASTE showed the highest CNR, followed by EPI, and statistically, the findings for these two were significantly different from those of other T2 sequences. Among T1 sequences, FLASH provided the best kidney outline, though among T2-sequences there was no statistically significant difference. FLASH was also the best for cortico-medullary distinction, while for this purpose the best T2 sequence was HASTE. True-FISP was best for the evaluation of renal vessels, and HASTE for evaluating the pelvis and ureter. Artifacts were most prominent on Conv SET1. CONCLUSION: For evaluating the shape of the kidney, the best T2 sequence was TSET2, but the best T1 sequence could not be determined. For cortico-medullary differentiation, the best T1 sequence was FLASH and the best T2 sequence was HASTE. For the evaluation of renal vessels, True-FISP was best, and for the pelvis and ureter, HASTE. Artifacts were most prominent on Conv-SET1.

In Vitro of MR Imaging of the Resected Normal Gastric Wall: Radiologic-Histologic Correlation

PURPOSE: To evaluate normal human gastric wall layers in vitro using magnetic resonance*(MR) imaging, to correlate the results with the histologic findings, and to determine the optimal technique for evaluation of the gastric wall. MATERIALS AND METHODS: Forty-one normal resected gastric specimens obtained from 25 patients were dissected and placed in a polyethylene tube filled with normal saline. MR imaging with four MR sequences, T1-weighted FLASH*(T1FLASH), fat-saturated T1-weighted FLASH, T2-weighted TSE*(T2TSE), and True-FISP, was performed. The number of gastric wall layers and signal intensity of each layer were determined, and after correlating MR images with the histologic findings, the conspicuity of each layer*(mucosa, submucosa, and muscle), the distinction between each layer, and overall image quality were assessed. RESULTS: The gastric wall was shown by TIFLASH to have two (n=6, 14-6%), three (n=31, 75.6%) and four layers (n=4, 9.8%); by fat-saturated TIFLASH to have two (n=6, 14.6%) and three (n=35, 85.4%) ; by T2TSE to have three (n=24, 58.5%), four (n=11, 26.8%), and five (n=6, 14.6%); and by True-FISP to have one (n=2, 4.9%), two (n=8, 19.5%), three (n=23, 56%), four (n=4, 9.8%), and five (n=4, 9.8%) . The signal intensity of each layer at T1FLASH and fat-saturated T1FLASH was high-intermediate from the lumen in two-layer cases, high-low-high/intermediate in three-layer cases, and high-low-high-intermediate in four-layer cases. The signal intensity of each layer at T2TSE was intermediate/high-low-intermediate in three-layer cases, intermediate low-high-intermediate/low in four-layer cases, and low-high-low-high-low in five-layer cases. Three-layered gastric wall corresponded mostly to mucosa, submucosa, and muscle from the inner to outer layers, respectively. T1FLASH, fat-saturated T1FLASH, and T2TSE were superior to True-FISP in evaluating the gastric wall. T1FLASH and fat-saturated T1FLASH were the best sequences for demonstrating mucosa (p<0.05), and T2TSE was the best for submucosa and the distinction between this and muscle (p<0.05). Both T1FLASH and T2TSE provided the best overall image quality (p<0.05). CONCLUSION: In-vitro MR imaging is an excellent technique for the evaluation of layers of normal gastric wall. T2TSE is the sequence which best demonstrates the conspicuity of submucosa, the distinction between submucosa and muscle, and overall image quality.

Meniscal flounce on MR: correlation with arthroscopic or surgical findings

The purpose of this study was to investigate the frequency of the meniscal flounce on MR imaging in patients who underwent arthroscopy or open surgery due to symptoms related to internal derangement of the knee, and to investigate associated findings in patients with meniscal flounce by comparing and analyzing the findings from MR imaging and surgery. MR images obtained from 116 knees before surgery were reviewed retrospectively. Seven medial menisci showed buckled, wavy flounce on sagittal MR images. None of the lateral menisci showed flounce. We reviewed the surgical records of all seven patients and the videotapes of six of the patients undergoing arthroscopy or open surgery. The frequency of flounce on sagittal MR images was 6.0% in the medial meniscus and was completely absent in the lateral meniscus. On coronal MR images, the truncated appearance of the affected meniscus was demonstrated in five patients, and a valgus deformity was seen in three patients. Five patients showed a moderate to large amount of joint effusion. On MR imaging and in surgery, ligament injuries were found in six patients (six medial collateral ligament injuries, five anterior cruciate ligament injuries, and two posterior cruciate ligament injuries). Non-specific synovitis was found in the one remaining patient. In the surgery of all seven patients, no tears were found at the meniscus itself showing flounce. In conclusion, the meniscal flounce seen on sagittal MR imaging can be a rare appearance of a transient distortion of a normal meniscus due to a valgus deformity caused by a MCL tear and/or due to an external rotation induced by cruciate ligament injury or positioning of knee joint within the magnet. The meniscal flounce should be interpreted carefully because it frequently appears truncated on the coronal scan and can simulate a meniscal tear.

Anatomical Relation between Anterior Ethmoidal Sinus and Lacrimal Sac Fossa on High Resolution CT

PURPOSE: To evaluate the anatomical relation between anterior ethmoidal sinus and the lacrimal sac fossa, and thus help prevent complications during dacryocystorhinostomy. MATERIALS AND METHODS: Fifty three people without previous history of trauma, surgery, or paranasal sinus disease were randomly selected, and the 106 lacrimal sac fossas of these subjects were evaluated by high resolution CT. A series of three 2-mm thick axial sections at least 2 mm from the inferior orbital wall were obtained. The bony landmarks of the lacrimal sac fossa were established and the location of the most anterior ethmoid sinus was classified as one of three types. In type 1, no sinuses were anterior to the posterior lacrimal crest. while in type 2, sinuses extended anterior to this crest but remained behind the suture at the anterior edge of the lacrimal bone. In type 3, sinuses extended into the frontal process of the maxilla, anterior to the lacrimal bone suture. In addition, the category of both orbits of the same patient was compared. RESULTS: Among the 106 orbits examined, only seven (6.6%) were classified as type 1, with no ethmoid air cells positioned under the lacrimal sac fossa. Seventy six (71.7%) qualified as type 2, while the remaining 23 (21.7%) were type 3, demonstrating anterior ethmoid air cells within the nasal process of the maxilla. The position of the air cells was symmetric in 41 of the 53 subjects (77.4%) and asymmetric in 12 (22.6%). CONCLUSION: In cases involving surgery of the lacrimal sac fossa, such as dacryocystorhinostomy, a knowledge of the consistent anatomic relationship between the anterior ethmoidal sinus and the lacrimal sac fossa is invaluable.

Anatomical Relation between Anterior Ethmoidal Sinus and Lacrimal Sac Fossa on High Resolution CT

PURPOSE: To evaluate the anatomical relation between anterior ethmoidal sinus and the lacrimal sac fossa, and thus help prevent complications during dacryocystorhinostomy. MATERIALS AND METHODS: Fifty three people without previous history of trauma, surgery, or paranasal sinus disease were randomly selected, and the 106 lacrimal sac fossas of these subjects were evaluated by high resolution CT. A series of three 2-mm thick axial sections at least 2 mm from the inferior orbital wall were obtained. The bony landmarks of the lacrimal sac fossa were established and the location of the most anterior ethmoid sinus was classified as one of three types. In type 1, no sinuses were anterior to the posterior lacrimal crest. while in type 2, sinuses extended anterior to this crest but remained behind the suture at the anterior edge of the lacrimal bone. In type 3, sinuses extended into the frontal process of the maxilla, anterior to the lacrimal bone suture. In addition, the category of both orbits of the same patient was compared. RESULTS: Among the 106 orbits examined, only seven (6.6%) were classified as type 1, with no ethmoid air cells positioned under the lacrimal sac fossa. Seventy six (71.7%) qualified as type 2, while the remaining 23 (21.7%) were type 3, demonstrating anterior ethmoid air cells within the nasal process of the maxilla. The position of the air cells was symmetric in 41 of the 53 subjects (77.4%) and asymmetric in 12 (22.6%). CONCLUSION: In cases involving surgery of the lacrimal sac fossa, such as dacryocystorhinostomy, a knowledge of the consistent anatomic relationship between the anterior ethmoidal sinus and the lacrimal sac fossa is invaluable.

Radiologic and Histopathologic Evaluation of Various Contrast Media for Bronchography

PURPOSE: To determine which contrast media are both efficient and safe for the imaging of airways. MATERIALS AND METHODS: We evaluated five contrast media (barium, gastrografin, iotrolan, ioxaglate, iopentol) in terms of image quality and their effects on the lungs of 25 white rabbits. For bronchography 0.5ml of contrast media was used. In each contrast group, HRCT scans were obtained immediately (n=5), 12 hours (n=4), 1 day (n=3), 2 days (n=2), and 1 week (n=1) after bronchography. Histopathologic specimens were obtained immediately, 12 hours, 1 day, 2 days, and 1 week later. Bronchograms were evaluated for image quality by three radiologists working independently, and were scored as 1(poor), 2(moderate), or 3(good) in terms of contrast quality and bronchial coating. HRCT was evaluated by two radiologists who reached a concensus; they determined the presence of contrast media, and then the pattern and extent of pulmonary opacity, and any related changes. Histopatholgic specimens were evaluated by two pathologists who sought consensus as to the extent of inflammation, pulmonary edema, and hemorrhage, and any changes in these aspects. RESULTS: Bronchography indicated that the sum of scores for contrast quality was 45 for barium, 33 for gastrografin, 28 for iotrolan, 30 for ioxaglate, and 28 for iopentol, while for each of these media, the sum of scores for bronchial coating was 39, 19, 25, 23, and 21, respectively. Barium showed the best image quality. In all rabbits, HRCT demonstrated the variable extent of groundglass attenuation and/or consolidation. Lesions were most extensive at 1-2 days and then regressed at 1 week; these HRCT findings correlated well with histologic findings. In histologic studies of all five contrast media groups, variable severe inflammatory reactions were observed, with or without necrosis, congestion, edema, and hemorrhage. It was noted that ioxaglate appeared to cause least tissue reaction. CONCLUSIONS: The imaging results of this experimental study indicate that for bronchography, barium is the best available contrast media, On the basis of the histologic and HRCT results, however, ioxaglate is the best.

MR Findings of Metastatic Adenocarcinoma and Non-adenocarcinoma in the Brain

PURPOSE: To evaluate the differences in MR findings of metastatic adenocarcinoma and non-adenocarcinoma of thebrain. MATERIALS AND METHODS: We retrospectively analyzed MR findigns of metastatic brain tumors in 32 patients;in all cases, pathologic diagnosis was estabilished by biopsy or surgical resection. The signal intensities ofbrain lesions on multiple pulse sequences were compared. The enhancement patterns, degree of peritumoral edema,and number and size of brain lesions were also compared. RESULTS: The study group consisted of 19 patients withmetastatic adenocarcinoma and 13 with metastatic non-adenocarcinoma ; there were 64 adenocarcinomas and 45non-adenocarcinomas. On T1WI, the signal intensity of the lesions was hypointense, isointense, and hyperintense in57.8%, 39.0%, and 3.2% of adenocarcinomas; and 84.5%, 13.3%, and 2.2% of non-adenocarcinomas, respectively. OnT2WI, signals were hyperintense, isointense, hypointense, and heterogeneous in 67.2%, 10.9%, 17.2%, and 4.7% ofadenocarcinomas ; and 80%, 0%, 8.9%, and 11.1% of non-adenocarcinomas, respectively. On T2WI, seven of 19 patientswith adenocarcinoma and two of 13 with non-adenocarcinoma were either hypo- or isointense relative to the whitematter. In the adenocarcinoma group, hypo- or isointensity was seen in four cases of gastrointestinal cancer, twoof lung cancer, and one of endometrial cancer ; in the non-adenocarcinoma group, this was seen in retroperitonealembryonal carcinoma and small cell carcinoma of the lung. Two cases of adenocarcinoma showed hypointensity on T2WIand hyperintensity on TIWI, and this was probably related to the presence of blood products. On histopathology,one case of adenocarcinoma showing hypointensity on T2WI was shown to contain mucin. CONCLUSION: When brainmetastasis shows hypo- or isointensity on T2WI, adenocarcinoma is more likely than non-adenocarcinoma.

CT Features of Malignant Hepatic Tumors: the Significance of Capsular Retraction

PURPOSE: To evaluate the prevalence of capsular retraction in malignant hepatic tumors and the factorsinvolved. MATERIALS AND METHODS: Between January 1994 and December 1996, we retrospectively reviewed the CT scansof 152 patients with pathologically-proven, peripherally-located, malignant hepatic tumors. We evaluated size,site, portal and hepatic venous obstruction, bile duct dilatation, and liver atrophy in 18 cases involvingcapsular retraction. RESULTS: The overall prevalence of capsular retraction among malignant hepatic tumors was18/152(12%) ; the prevalence was 9/129(7%) in hepatocellular carcinoma, 6/14(43%) in cholangiocarcinoma and3/9(33%) in metastatic cancer ; among cases of cholangiocarcinoma and metastatic cancer, the prevalence washigh(p <0.05). Portal venous obstruction was seen in six patients with hepatocellular carcinoma (a high incidence ;p=0.041) and one with cholangiocarcinoma. Hepatic venous obstruction was demonstrated in one patient withhepatocellular carcinoma and one with cholangiocarcinoma. Among cholangiocarcinoma patients, bile duct obstructionwas seen in four and liver atrophy in three, but among metastatic cancer cases there were no similar findings. CONCLUSION: The main factors causing capsular retraction were portal venous obstruction in hepatocellularcarcinoma and bile duct obstruction and liver atrophy in cholangiocarcinoma.