Diffusion-Weighted Imaging of a Prostate Cancer Xenograft Model Seen on a 7 Tesla Animal MR Scanner: Comparison of ADC Values and Pathologic Findings

OBJECTIVE: To assess the relationship between apparent diffusion coefficient (ADC) values on diffusion-weighted magnetic resonance (MR) imaging and pathologic measures of a tumor using a prostate cancer xenograft model. MATERIALS AND METHODS: Eighteen athymic nude mice with 36 PC-3-induced tumors were sacrificed to obtain specimens immediately after MR imaging in order to compare the findings on MR images with those seen on pathological specimens. Using a high-field small-animal MR scanner, T1- and T2-weighted imaging and DW MR imaging was performed. Tumors were then processed for Hematoxylin and Eosin staining to evaluate tumor cellularity, intratumoral necrosis and immunostaining using antibodies directed against CD31 and vascular endothelial growth factor (VEGF) to determine the levels of microvessel density (MVD). Mean ADC values that were measured on the solid portion within each tumor were compared with tumor volume, cellularity, degree of necrosis, VEGF expression, and MVD in the corresponding section of the pathological specimen. RESULTS: Mean ADC values of the solid portion within the PC-3-induced high-grade tumors were significantly correlated with the degree of intratumoral necrosis (r = 0.63, p < 0.0001) and MVD (r = -0.44, p = 0.008) on pathologic slides. The ADC values were not significantly correlated with tumor cellularity, VEGF expression, or tumor volume in high-grade prostate cancer tissues. CONCLUSION: In the xenografted prostate cancer model, the ADC values of the solid portion of the tumors are significantly correlated with tumor necrosis and MVD of the pathologic specimens. The ADC values may be utilized as surrogate markers for the noninvasive assessment of tumor necrosis and MVD in high-grade prostate cancer.

Added Value of Screening Low Dose Computed Tomography of the Chest for the Evaluation of Abdominal Solid Organs by Ultrasound in Physical Check-up Patients

PURPOSE: The purpose of this study was to assess the added value of screening low-dose computed tomography of the chest (LDCT) covering the abdomen in evaluating abdominal solid organs to the screening abdominal ultrasonography (US). MATERIALS AND METHODS: We prospectively enrolled a consecutive series of 393 physical check-up patients, who underwent screening abdominal US and LDCT of the chest from January to February, 2008. LDCT covered the lungs, liver, pancreas, gallbladder, spleen, and both kidneys. The 1st screening abdominal US were performed without information from the LDCT, and then abdominal images covered by LDCT were immediately evaluated. Then a 2nd US session was done with additional information from LDCT and US examination was focused to the findings of LDCT. Perpatient and per-lesion analyses were performed. RESULTS: In per-patient analysis, additional focal lesions were found in 20 patients (5.1%) for liver and 9 patients (2.3%) for kidneys in the 2nd US sessions. In per-lesion analysis, 154 and 73 focal lesions were found in liver and kidneys, respectively, in the 1st US sessions. On the 2nd US session, 186 and 86 lesions were found in liver and kidneys, respectively. 20.8% and 17.8% of focal lesions were additionally found on 2nd US session in liver and kidneys, respectively. Most (62.5%) of the additional lesions detected in liver were located in segment 7 and 8, the hepatic dome. CONCLUSION: Previewing LDCT of the chest and abdominal solid organs before performing screening abdominal US can enhance the diagnostic performance of US in physical check-up patients.

MR Findings of Synovial Sarcoma with Intraosseous Involvement: Case Report

Synovial sarcoma is rare soft tissue tumor mesenchymal origin. Osseous involvement of synovial sarco-ma is rare. A 24-year-old man presented with pain and swelling of the lower extremity. MRI of the lower extremity demonstrated a large mass encircling tibia with osseous involvement. Surgical excision of the mass was done and the mass was diagnosed as biphasic synovial sarcoma with bone marrow involvement. We also discuss the other imaging findings of synovial sarcoma on MRI.

Simple Pulmonary Eosinophilia Evaluated by Means of FDG PET: the Findings of 14 Cases

OBJECTIVE: We wanted to describe the findings of simple pulmonary eosinophilia with using 18 fluorodeoxyglucose (FDG) positron emission tomography (PET). MATERIALS AND METHODS: We analysed the findings of 14 patients who underwent thoracic computed tomography (CT) and PET, and then they were subsequently proven to have simple pulmonary eosinophilia. PET studies were performed in four patients with malignancy to evaluate for cancer metastasis, and PET scans were also done in 10 healthy subjects who underwent volunteer cancer screening. The PET scans were evaluated by using the maximum standardized uptake values (SUVs). The subjects' CT findings also were reviewed and correlated with the PET findings. RESULTS: A total of 42 nodules were detected on the CT scans. There were single nodules in three patients and multiple nodules in 11 patients (mean number of nodules: 3, range: 1-10, mean diameter: 9.5 mm+/-4.7). Twelve of 42 (28.6%) nodules showed FDG uptake and their mean maximum SUV was 2.5+/-1.6 (range: 0.6-5.3). Five of six solid nodules showed FDG uptake (2.2+/-1.1, range: 0.9-3.6), six of 11 semisolid nodules showed FDG uptake (3.1+/-1.8, range: 0.6-5.3) and one of 25 pure ground-glass opacity nodule showed a maximum SUV of 0.8. The maximum SUVs of seven nodules in five patients were greater than 2.5. The maximum SUVs were significantly different according to the nodule types (p < 0.001). CONCLUSION: Simple pulmonary eosinophilia commonly causes an increase in FDG uptake. Therefore, correlation of the PET findings with the CT findings or the peripheral eosinophil counts can help physicians arrive at the correct diagnosis of simple pulmonary eosinophilia.

Double Eyelid Operation Using Continuous Buried Suture Method Avoiding Conjunctival Injury by a Newly Made Chalazion Forcep

Nowadays, nonincisional double eyelid operation is preferred by lots of patients and surgeons. There are a variety of suture methods but all the suture procedures-including continuous buried suture methods-in the literatures penetrate the conjunctivas. So due to the pain, surgeons had to infiltrate local analgesics into the conjunctiva. This horrifies the patients, gives pain, makes the eyelids and conjunctivas swollen, and sometimes interrupts the movements of the eyelids by affecting the levator palpabrae muscles. This condition could make the eyelid folds asymmetric. Authors changed the procedure by using a chalazion forcep with a small slit which allows the suture materials to get out and we could successfully perform the suture without penetrating the conjunctiva. So we could make double folds maintaining the patient's dynamic and static conditions very well since no direct local analgesics were needed for the conjunctivas, and the results were pretty satisfactory.

Techniques of Clinical Digital Photography in Plastic Surgery

Nowadays, clinical digital photography is very prevalent, though the pitfalls, problems, and standardizing works of its techniques have not yet been discussed well enough in Korea. Digital single lens reflex cameras and macro capacity lenses are still recommended for plastic surgeons for its reproducibility and high quality of developed photographs. Since the selection of digital camera itself is as important as the choice of the film in film cameras, the selected digital equipments should not be exchanged in a center or a clinic. Eighteen percents gray card(Eastman Kodak) could be used for the strict setting of the white balance as the white balance is essential in digital imaging. Studio flash lighting is good enough in clinical digital photographing settings and, soft, even lighting effect should be achieved using flash accessories (e. g. bouncer) minimizing loss of details. Taken images could be optimized through the software working (image processing) after the monitor color balancing work. They must be always developed or printed under the uniform setup status of the whole equipments to get accurate, constant pictures.

Bone Resorption Around Pedicle Screws After Pedicle Screw Plate Fixation

PURPOSE: To determine the frequency, level, distribution, onset, and pattern of progression of bone resorption that occurring around pedicle screws after pedicle screw plate fixation. MATERIALS AND METHODS: Bone resorption around 902 pedicle screws was analyzed in post-operative, and follow-up radiographs obtained from 156 patients who underwent pedicle screw plate fixation. To determine the resorption degree, categorized arbitrarily as grade 1 (less than 1 mm), grade 2 (1 mm or more, but less than 2 mm), or grade 3 (2 mm or more), the width of radiolucent zones was measured. In 39 patients in whom resorption was graded 1, 2, or 3, the pattern of progression of 78 screws was evaluated. RESUTLS: Resorption occurred around 78 (8.6%) screws in 39 (25%) patients, 26 of whom had more than one lesion. For 99% of screws, there was evidance of resorption within 12 weeks of pedicle screw plate fixation. During follow-up, 61.5% of screws (48/78) remained stable, while 38.5% (30 screws) showed progression to higher grades. The possibility of progression to a higher grade is less when the initial grade is lower. CONCLUSION: An understanding of the radiographic patterns of bone resorption is useful for monitoring a patient after pedicle screw plate fixation.

Pigmented Villonodular Synovitis of the Spine: A Case Report

Pigmented villonodular synovitis(PVNS) is a synovial lesion of joints or tendon sheaths, characterized by villous and nodular overgrowth of the synovial membrane. It commonly occurs in synovial joints of the appendicular skeleton, particularly those of the knee and hip, but rarely affecting those of the spine. We report a case of PVNS of the lumbar spine mimicking epidural mass.

Imaging Findings of Arteriovenous Malformations Involving Lung and Liver in Hereditary Hemorrhagic Telangiectasia (Osler-Weber- Rendu Disease): Two Cases Report

Hereditary hemorrhagic telangiectasia (HHT) or Osler-Weber-Rendu disease is an autosomal dominant disorder characterized by repeated episodes of bleeding. Multiple telangiectases consisting of thin-walled, dilated vascular channels with arteriovenous communication may involve, for example, mucocutaneous tissue, the gastrointestinal tract, and the liver, lung, and brain. We report the imaging findings of two cases of HHT involving arteriovenous malformation of both the lungs and liver, a rare condition. Chest radiography revealed a round mass, while helical CT showed a feeding artery and draining vein with arteriovenous malformation in the lung. Color Doppler sonography revealed an enlarged and tortuous hepatic artery with high systolic velocity. CT demonstrated an enlarged hepatic artery, arteriovenous shunt, and early draining hepatic vein in the liver. Celiac angiography showed arteriovenous malformation.

The Significance of Alteration of Anterior Cruciate Ligament Axis as a Secondary Sign of Tear

PURPOSE: To assess the significance of alteration of the anterior cruciate ligament (ACL) axis as seen on magnetic resonance imaging of anterior cruciate ligament tear. MATERIALS AND METHODS: ACL angle (angle between lateral tibial plateau and ACL) and ACL-Blumensaat line angle (angle between ACL and Blumensaat line) were measured in 76 patients with ACL tear and 55 patients with normal ACL. The significance of the change in orientation of the ACL was evaluated. RESULTS: ACL angle was significantly smaller in the tear group (35.07 degrees +/- 10.34 degrees, mean+/-standard deviation) than in the normal group(54.11degrees+/-4.61degrees)(p<0.001); when cutoff value was less than 45 , sensitivity, specificity and accuracy were 85.5%, 98.2% and 90.8%, respectively. The ACL-Blumensaat line angle was significantly greater in the tear group (20.33degree+/-9.56degree) than in the normal group (2.55degree+/-4.86degree)(p<0.001). when cutoff value was more than 10degree, sensitivity, specificity and accuracy were 90.8%, 94.5%, and 92.4%, repectively. CONCLUSION: The change in orientation of the ACL was an important associated finding in cases of ACL tear. We suggest that cutoff values should be an ACL angle of less than 45 , and an ACL-Blumensaat line angle of more than10degree .

Anterior Cruciate Ligament Tear: Comparison of MR Features between Complete and Partial Tear

PURPOSE: To determine the MRI features which distinguish complete and partial tear of the anterior cruciate ligament (ACL) and to thus improve MRI interpretation. MATERIALS AND METHODS: In 80 patients, we analyzed MR findings of direct and indirect signs of ACL tear (complete tear, 61 cases, partial tear, 19 cases) confirmed by arthroscopy or surgery, and compared the relative incidence of each sign in cases of complete and partial tear. RESULTS: Direct and indirect signs were found in 61 (100%) and 60 cases (98.4%), respectively, in complete tears, but in 16 (84.2%) and 15 cases (78.9%), respectively, in partial tears. Poor visualization, discontinuity and hyperintensity were seen in all complete tears but in only nine case (47.4%) of partial tear. A wavy or abnormal contour was seen in 53 cases (86.9%) of complete tear and 14 (73.7%) of partial tear. A wavy contour without other direct signs was seen in only five cases (26.3%) of partial tear. Three cases (15.8%) of partial tear showed normal MR finding. Indirect signs, i. e. abnormal ACL angle, abnormal ACL-Blumensaat line angle, abnormal posterior cruciate ligament (PCL) line, abnormal PCL angle, PCL buckling, anterior displacement of tibia, posterior displacement of lateral meniscus, bone bruise, Segond fracture, tear of collateral ligaments, PCL, and tear of meniscus were commoner in complete than in partial tears. Two cases of O'Donoghue's triad and two of popliteus injury were seen only in complete tears. CONCLUSION: Direct and indirect signs of ACL tear were more commonly noted in complete than in partial tears. The latter showed MR features varying from normal to almost complete tear. We suggest that a wavy contour other direct signs is indicative of a partial tear, and that O'Donoghue's triad and popliteus muscle injury are indirect signs of a complete tear.

CT Findings of Parotid Gland Tumors: Benign versus Malignant Tumors

PURPOSE: The purpose of this study is to evaluate the characteristics of parotid gland tumors to help in the differentiation between benign and malignant lesions. MATERIAL AND METHODS: The CT findings of 22 patients with surgically proven parotid gland tumors were reviewed. Analysis was focused on the density and margin characteristics of the tumors, and the relationahip between the tumor and surrounding structures. RESULTS: Those tumors were pleomorphic adenoma (n=8), Warthin's tumor (n=5), basal cell adenoma (n=l), lipoma (n=l), dermold cyst (n=l), adenold cystic carcinoma (n=2), mucoepidermoid carcinoma (n=l), epidermold carcinoma (n=l), and carcinoma in pleomorphic adenoma (n=l). Most of benign and malignant tumors were heterogeneous in denstiy on contrast enhanced CT scans. In 5 of 6 malignant cases, the tumors had irregular or ill-defined margin and a tendancy to involve or cross the superficial layer of deep cervical fascia with obliteration of subcutaneous fat. Two malignant tumors invaded surrounding structures. CONCLUSION: Although the heterogeneous density of tumor is not a specific finding for malignancy at CT, following findings, such as, irregular or blurred margin of the lesion, the involvement of fascial plane, and the infiltration of surrounding structures may suggest the possibility of malignant parotid tumor.

Radiologic Findings of Male Breast Cancer: A Case Report

Male Breast cancer is an uncommon disease with an incidence of I per cent of all breast cancers. Male breast cancer usually appears as a small mass with well-defined contour which is eccentrically located in relation to the nipple on mammogram. We report a case of breast cancer in a 51-year-old man with mammographic appearance of large hyperdense mass with nipple inversion and axillary lymphadenopathy, gray-scale sonographic finding of homogeneous solid mass and mu Itiple tumor vessels with in the mass on color Doppler ultrasound.

CT Findings of Breast Lipoma: A Case Report

Lipoma is one of the unusual benign breast neoplasms and usually manifests at fatty breast of women at the age of 40 to 60. We experienced a case of large breast lipoma nearly replacing the whole left breast parenchymal tissue with mammographic finding of well-defined radiolucent mass, sonographic finding of hyperechoic mass with disorganized echopattern and computerized tomographic finding of very low attenuation mass, characteristic to adipose tissue, in a young woman of her dense breast.

Extrahepatic Biliary Obstruction: CT Patterns of Ductal Dilatation and Changes of Extrahepatic Ductal Wall

PURPOSE: To assess the efficacy of ancillary CT findings other than the obstructive lesion per se for the differential diagnosis of extrahepatic biliary obstruction. MATERIALS AND METHODS:CT findings of 49 patients with extrahepatic bile duct obstruction(22 benign and 27 malignant lesions) were assessed with emphasis on the patterns of ductal dilatation, contrast enhancement, and diffuse thickening of the extrahepatic ductal wall. Degree of central and peripheral intrahepratic ductal dilatation was graded by comparing with the adjacent portal radicles and hepatic parenchymal thickeness. RESULTS: Diffuse circumferential thickening and contrast enhancement of the extrahepatic ductal wall were more frequent in benign cases, but only thickening was statistically significant(p < 0.01). Peripheral intrahepatic ducts were more severely dilated by malignant causes(p < 0.01). With the same degrees of extrahepatic and central ductal dilatations, peripheral intrahepatic ducts were more severely dilated in malignant than in benign cases. CONCLUSION: These results may help to interpret the CT findings of extrahepatic biliary obstruction, particularly when the cause of biliary obstruction is uncertain.

Prenatal imaging of thanatophoric dysplasia: a case report

Thanatophoric dysplasia is the most common lethal congenital chondrodysplasia with characteristic features of narrow thorax, short rib, severe platyspondyly, short bowed limbs and skull deformity, etc. It is not a hereditary disorder and there is usually no family history of dysplasia. We experienced a case of thanatophoric dysplasia at 38 weeks of gestation with antenatal sonographic and abdominal radiographic findings of small thorax, short bowed extremities with surrounding thickened soft tissues and marked platyspondyly. Soon atter delivery, the baby died and post-mortem radiographs showed the characteristic findings of thanatophoric dysplasia.

MR imaging of dural sinus thrombosis: A case report

We present a case of angiographically-confirmed transverse and sigmoid sinus thrombosis, image with MR, in a 20 year old male with a history of otitis media and maxillary sinusitis. T1-weighted image demonstrated an isosignal intensity mass with tubular-shaped low signal intensity in right transverse and sigmoid sinus. The thrombus had high signal intensity on T2-weighted image. The signal intensity of the thrombus on Gd-DTPA enhanced T1-weighted image was unusually high similar to that of transverse sinus. Although dural sinus thrombosis has a non-specific MR signal intensity, findings of MRI in this case may serve as an aid in future evaluation of venous thrombosis.

Clival chordoma: CT and MR fidings

A retrospective analysis of CT and MR findings was performed in five patients with histologically proved chordoma including one with chondroid chordoma. All tumors were mostly isodense to gray matter on unenhanced CT, and the single intensities were iso or low and high on T1 and T2-wgighted MR iages, respectively. The tumors had an increase in their density on enhanced CT and MR in four patients, but a chondroid chordoma was poorly enhanced after injection of contrast medicum on CT. Four tumors contained calcifications in CT images and two lesions showed hemorrhage in MR images. Cavernous sinus was involved in all patients, and brain stem and basilar artery were compressed by the tumors in three cases. Pituitary gland was only displaced upward in three patients. Clivus was destroyed in all cases, and sella turcica and sphenoid bone were involved in three patients. CT is better than MR in demonstrating calcifications and bone destruction. In defining the extension of tumor, MR appears to be superior to CT in evaluation of the relationship between the tumor and the surrounding structures.

CT findings of bilateral inferior vena cava:Differentiation from dilated retroperitoneal veins

We expierienced five cases of bilateral inferior vena cava for recent one year. We evaluated the CT findings of the cases and of dilated veins located in the left retroperitoneum (seven left gonadal, seven inferior mesenteric, and two left ascending lumber veins)in the viewpoints of the size, location and relation with the surrounding structures. Bilateral inferior vena cava (IVC) may be asymmetric and the left IYC may be smaller than other retroperitoneal veins with a round contour. The left lYC was located anterior to the spinal body and corresponded with contralateral vena cava in the anteroposterior plane. The gonadal vein was located anterior or anterolateral side of the psoas and always crossed the ureter. Most of the inferior mesenteric vein showed similar location to the opposite site of the vena cava in the anterolateral side of the psoas muscle, medial to the left ureter without crossing. The left ascending lumbar vein was similarly located to the left vena cava but dilated in a short segment. It is required to trace the vessel upward and downward and observe its continuity for correct differentiation. If it is impossible, some differential points suggested in the results of our study will be helpful for distinguishing them.

A study of artifacts in MR imaging induced by metalic aneurysm clips

To investigate MR artifacts induced by metallic implants, scans were obtained using both the ferromagnetic Drake lip and the non ferromagnetic Yasargil clip. Scan were taken through the area of clips using geometrical phantom. The MRI was performed by spin echo technique and gradient echo technique on both 2.0T and 0.5T MR unit. The luthors evaluated the nature and differences of artifacts in each sequence and parameter. Artifacts induced by both lips were noted in the direction of frequency encoding gradient, and consisted of region of signal loss abutted in one side by survilinear region of bright signal. Geometric distortion of image was marked in the Drake clip, out was minimal in the Yasargil clip under both 2.0T and 0.5T. Artifacts were more pronounced in the gradient echo technique than those of the spin echo technique on both 2.0T and 0.5T. Although there were no differences n the nature of artifacts induced by the Drake clip among each parameter in the spin echo technique under 2.0T, artifacts were slightly more pronounced on T2 weighted image under the 0.5T field, but no differences were found in the nature of artifacts induced by the Yasargil clip in the spin echo technique under, both the 2.0T and 0.5T fields. Marked artifacts were induced through the small area of the Drake clip which were included in the scan plane, but induced artifacts were small when a small area of the Yasargil clip was included in the scan plane. It seemed likely hat artifacts were slightly more pronounced in the 2.0T than the 0.5T field in both clips, but objective evaluation of the difference was difficult, In conclusion, these results can be an essential basis for the interpretation of MR images or patents with metallic inplants.