Thoracic Intraspinal Synovial Cyst Causing Myelopathy: A Case Report

Intraspinal synovial cysts are commonly found in the lumbar spine and occur less commonly in the cervical spine. Occurrence of a cyst in the thoracic spine causing myelopathy is extremely rare. We report here the radiological findings of a case of a thoracic intraspinal synovial cyst that caused myelopathy at the T2-3 level with an accompanying review of the clinical literature.

Pure Epidural Cavernous Hemangioma of the Cervical Spine that Presented with an Acute Sensory Deficit Caused by Hemorrhage

Pure epidural cavernous hemangioma of the spine without vertebral involvement is rare. Due to the slow growth of this lesion, the most common symptoms are chronic pain, myelopathy, and radiculopathy. In our case, the patient complained of an acute onset sensory deficit of the C4 dermatome. An MRI revealed an epidural mass with an acute hematoma. Here, we report a case of a pure epidural cavernous hemangioma that presented with acute neurologic symptoms caused by intralesional hemorrhage and an acute epidural hematoma, which were demonstrated on the patient's MRI.

Pure Epidural Cavernous Hemangioma of the Cervical Spine that Presented with an Acute Sensory Deficit Caused by Hemorrhage

Pure epidural cavernous hemangioma of the spine without vertebral involvement is rare. Due to the slow growth of this lesion, the most common symptoms are chronic pain, myelopathy, and radiculopathy. In our case, the patient complained of an acute onset sensory deficit of the C4 dermatome. An MRI revealed an epidural mass with an acute hematoma. Here, we report a case of a pure epidural cavernous hemangioma that presented with acute neurologic symptoms caused by intralesional hemorrhage and an acute epidural hematoma, which were demonstrated on the patient's MRI.

Radiological Evaluation of Percutaneous Endoscopic Lumbar Discectomy: A Three-Year Follow-Up Study

PURPOSE: We wanted to analyze the radiological changes of the patients who underwent percutaneous endoscopic lumbar discectomy (PELD) for treating soft disc herniation. MATERIALS AND METHODS: We retrospectively reviewed 30 patients (32 cases) who were observed for a minimum of 3 years after they underwent PELD. The authors investigated the postoperative radiological changes after PELD and the related clinical outcomes. All the patients received plain X-rays, CT and MRI both preoperatively and at the final follow-up. The radiological parameters were evaluated, including the disc height, the disc signal intensity, the subchondral marrow signal intensity, the sagittal plane instability and the facet joint osteoarthritis. RESULTS: The average amount of removed disc was 1.363 g and a significant correlation was detected between the narrowing of disc height and the amount of removed disc. Although the disc height and the disc height ratio were significantly decreased (-0.97 mm and 86.9%, respectively), the angle of sagittal rotation was well maintained. There were 18 (56.3%) cases of disc signal changes, six cases (18.8%) of subchondral marrow signal changes, and three cases (9.4%) of facet joint osteoarthritis. The success rate was 90.6%. CONCLUSION: Although disc height narrowing was observed, there was no postoperative instability and the overall clinical outcome was satisfactory. Our results show that PELD is a useful and minimal invasive procedure for the selected patients who are suffering with lumbar disc herniation.

Posterior Epidural Migration of Lumbar Ruptured Disc: Report of Two Cases

Disc fragment migration occurs in 35%-72% of lumbar disc herniations. Most of the herniated disc fragments migrate in the rostal, caudal and lateral directions. Posterior epidural disc fragment migration is a rare finding and posterior migration causing Cauda Equina syndrome is exceptionally rare. We report here on two cases of L4-5 disc fragment posterior epidural migration that caused Cauda Equina syndrome, and this was diagnosed by performing radiological examination, and we also include a review of the related literature.

Symptomatic Spinal Epidural Gas-Containing Cystic Lesions: Reports of 2 Cases

Symptomatic spinal epidural gas-containing cystic lesion is a rare clinical disease entity. We recently experienced two cases of symptomatic epidural gas-containing cysts that were the main cause of the patients?radiculopathy and the cysts were removed surgically. These lesions were actually gas containing ruptured disc herniations from the vacuum discs at the same level. We report herein on the radiological findings along with conducting a review of the related literature.

Capillary Hemangioma of the Cauda Equina: Case Report

Capillary hemangioma of the cauda equina is extremely rare. We present the MR imaging and histologic findings of a case of this disease. The tumor was well demarcated, 0.9x1.3 cm in diameter and 1.2 cm in length. On the MR images, the tumor showed isointensity relative to the spinal cord on the T1-weighted images, hyperintensity on the T2-weighted images, and strong homogeneous enhancement on the contrast-enhanced T1-weighted images. Capillary hemangioma should be included in the differential diagnosis of a spinal tumor of the cauda equina.

En Plaque Meningioma in Thoracic Spine: Case Report

Spinal en plaque meningioma is rarely found in the spinal canal, although lateral sphenoid wing meningioma displays a propensity for growth en plaque. We encountered a case of completely circumferential spinal en plaque meningioma, which is an even rarer condition. Herein, we report the CT & MRI findings along with a review of the related literature.

Dieulafoy's Lesion of Jejunum: Presenting Small Bowel Mass and Stricture

Dieulafoy's lesion is an uncommon cause of gastrointestinal bleeding. Hemorrhage occurs through mucosal erosion from an abnormally dilated submucosal artery. Although Dieulafoy's lesion is usually located in the stomach, it may occur anywhere in the gastrointestinal tract. We report here on a case of jejunal Dieulafoy's lesion presenting as a mass and short segment stricture on CT and enteroclysis.

Intradural Lumbar Disc Herniation with Intradural Gas: Report of Three Cases

This paper reports on three cases of an intradural lumbar disc herniation (IDLDH) that were diagnosed by a radiological examination. In all cases, an intradural vacuum (IDV) was detected on the CT scans, and the IDLDH showed iso- or lower signal intensity on the T2-weighted images. Enhanced MRI of one case revealed a small amount of air, but this was without enhancement. All the cases showed definite IDV on the CT scans, and this was an important clue for diagnosing IDLDH.

Spontaneous Epidural Hematoma at the Lumbar Facet Joint: A Case Report

Spontaneous epidural hematomas (SEHs) of the lumbar spine are rare. The pathogenesis is not entirely clear, but several reports have suggested that bleeding originating in the venous epidural plexus is the cause. This is the second report of a SEH thought to be the result of facet joint hemorrhage with no previous synovial cyst formation. A magnetic resonance image revealed a mass beginning in the left epidural space and continuing through to the left L5-S1 facet joint. Surgically, the epidural hematoma, which was covered by a very thin translucent membrane, was visualized directly. A histopathological examination revealed the wall of the epidural hematoma to be composed of very thin fibrous connective tissue with no synovium lining. The purpose of this study was to report a case of an epidural hematoma originated from lumbar facet joint, diagnosed by radiological examination, and to present a review of the subject literature.

Intradural Cervical Disc Herniation: A Case Report

Intradural cervical disc herniation is an extremely rare condition and its pathogenesis is not certain. We experienced a case of intradural cervical disc herniation at the C4-5 level in a 56-year-old man. The preoperative sagittal T1- and T2- weighted images revealed an intradural iso-intensity lesion, with the spinal cord behind the posterior longitudinal ligament at the C4-5 disc level. The post-contrast T1-weighted image revealed a peripheral enhanced intradural lesion. We report here on a case of an intradural cervical disc herniation that was diagnosed by radiological examination, and we include a review of the related literature.

Test-bolus injection for optimization of arterial phase imaging during contrast-enhanced hepatic MR imaging

Contrast enhancement during the dynamic MR imaging is important for the detection and characterization of focal liver lesions. The purpose of this study was to determine whether or not a timing examination with a injection of a 1.0-mL bolus of gadopentetate dimeglumine into the antecubital vein followed by rapid dynamic scanning and measurement of signal intensity of the aorta could help to obtain proper arterial-dominant phase images for the characterization of focal hepatic lesions during subsequent multiphase dynamic MR imaging. The imaging delay to acquisition of the first gadolinium-enhanced image for multiphase dynamic MR imaging was set to equal the time to peak aortic enhancement during the test examination. The first contrast-enhanced images of 80 patients with 160 focal liver lesions (hepatocellular carcinoma, n = 79; cavernous hemangioma, n = 51; metastatic tumor, n = 30) were then retrospectively reviewed. Peak aortic enhancement occurred between 10 and 28 seconds (mean, 16.5 seconds +/- 3.1) after starting the infusion of contrast material in 80 patients during the test-examination. Depending on the findings of intrahepatic vascular enhancement on the full-scale dynamic images, hepatic arterial phase (n = 11, 14%) or sinusoid phase (n = 65, 81%) imaging was obtained during the first gadolinium-enhanced acquisition in 76 (95%) of 80 patients. Three different lesions were well characterized and easily distinguished from each other (p < .0001) on the first-phase images depending on their enhancement pattern. In the majority of patients, timing examination with test-bolus injection was helpful in obtaining qualified images for the characterization of various focal lesions.

Early homogeneously enhancing hemangioma versus hepatocellular carcinoma: differentiation using quantitative analysis of multiphasic dynamic magnetic resonance imaging

The aim of this study was to determine the usefulness of quantitative analysis of multiphasic dynamic contrast-enhanced magnetic resonance (MR) imaging in differentiating early homogeneously enhancing hemangiomas from hepatocellular carcinomas (HCCs). Four-phased dynamic MR imaging at 10 sec (first phase of dynamic contrast-enhanced imaging, P1), 35 sec (second phase, P2), 60 sec (third phase, P3) and 300 sec (delay phase, P4) immediately after intravenous administration of 0.1 mmol/kg Gadolinium-DTPA was obtained with 1.5-T unit with breath-hold multisection FLASH (fast low angle-shot) sequence (TR/TE, 113-130 msec/4.1 msec; flip angle, 80 degrees). Thirty-three HCCs and 18 hemangiomas, homogeneously enhanced on P1, were included in the study. The images were evaluated quantitatively (SNR, signal-to-noise ratio; and CNR, contrast- to- noise ratio of lesions). Quantitatively, mean CNR was higher for hemangiomas than for HCCs on all phases, and the difference in CNRs between hemangioma and HCCs was statistically significant on P3 and P4 (p < 0.0001). When the cutoff for CNR was set at a value of 7.00 on P3 and 1.00 on P4, sensitivity, specificity and accuracy were 94.4%, 93.9%, and 94.1% on P3, and 94.4%, 81.8%, and 86.3% on P4, respectively. There was no statistically significant difference in SNRs between HCC and hemangioma. The differential diagnosis between early, homogeneously enhancing hemangiomas and HCCs was more confidently made with CNRs of lesions on P3 and P4 in dynamic contrast-enhanced MR imaging.

Comparison of Gadomer-17 and Gd-DTPA in image quality of contrast-enhanced MR angiographies using flow phantom model

The purpose of this study was to compare the image quality of 3D-TOF MR angiography (MRA) using Gadomer-17 with that using Gd-DTPA in a flow phantom model, and to present preliminary data about the proper dose concentration of Gadomer-17. In the visual analysis of vessel conspicuity, we compared the quality of pre- and post-contrast MIP images. For quantitative analysis, the signal intensities were measured in the axial base 3D-TOF images, and then the relative contrast enhancement was calculated. The results of our studies were that: 1. Maximal signal intensities were obtained at 1 mmol/L of Gadomer-17 and 4 mmol/L of Gd-DTPA. 2. Flow-related signal loss was decreased by Gd-DTPA proportional to the concentration, but Gadomer-17 did not show such a dose accumulative effect. In conclusion, after comparing the results of Gd-DTPA, it was clear that improved MRA images and higher signal intensities of vessels were obtained when lower concentrations of Gadomer-17 were used.

MR Imaging of Hepatocellular Carcinoma: Usefulness of Four-Phase Dynamic Imaging Including Early ArterialPhase

PURPOSE: To evaluate the usefulness of four-phase dynamic MR imaging technique by analyzing the imagingfeatures of hepatocellular carcinoma(HCC). MATERIALS AND METHODS: We reviewed four-phase dynamic MR images of 63lesions in 38 patients. MR imaging of the whole liver on gradient T1-weighted sequence was obtained at 10seconds(phase I), 35 seconds(phase II), 60 seconds(phase III), and 5 minutes(phase IV) after the start ofGd-DTPA(0.1mmol/kg) hand injection(3-4cc/sec) through the vein. We evaluated the degree of lesional contrastenhancement during each phase by comparing surrounding liver parenchyma, and analyzed signal intensity in lesionsover and less 2cm, respectively. RESULTS: The number of lesions showing high signal intensity compared withsurrounding liver parenchyma was 52(83%)during phase I, 30(48%) during phase II, 12(19%) during phase III, and 4(6%) during phase IV. During each phase, the number of lesions with signal intensity lower than that ofsurrounding liver parenchyma was 7(11%), 2(3%), 7(11%) and 21(33%), respectively. Thirty-four lesions wereenhanced only during phase I and eleven during only phase II. In tumors less than 2cm(n=40), more enhanced lesionswere during phase I(n=33) than more during phase II(n=16)(p=.0020). CONCLUSION: During each phase, four-phasedynamic MR imaging is useful for the effective detection of HCC showing varying degrees of contrast enhancement.

Assessment of Focal Liver Lesions with 4-Phase Dynamic FLASH MR Imaging: Usefulness of Early Image Acquisitionfor Characterization of Arterial Phase

PURPOSE: To document the usefulness of early image acquisition using the contrast-enhanced dynacic MR imagingfor characterization of various focal hepatic lesions during the arterial phase. MATERIALS AND METHODS:Seventy-nine patients with 145 focal liver lesions (71 hemangiomas, 59 hepatocellular carcinomas and 15metastases) underwent breathhold dynamic MR imaging using a fast low-angle shot sequence. After obtainingunenhanced T1-weighted images, four phase MR images were obtained 10, 35, 60 and 300 seconds after starting theinjection. Patterns of contrast enhancement were analyzed for each lesion, with an emphasis on first phase images. RESULTS: Forty-two of the 59 HCCs (71%) showed prominent contrast enhancement during the first phase. HCCssmaller than 2cm in diameter showed a more homogeneous enhancement pattern than those which measured 2cm ormore(24/25 vs 12/17;P<.05). Hemangiomas showed a globular enhancement pattern during the same phase in 51 of 71cases (72%), a finding which was more apparent in those whose diameter was 2cm or more(35/54 vs 16/17, p<.05).During the first phase of imaging, 12 of the 15 metastases showed peripheral enhancement of their thick rim. CONCLUSION: The use of early image acquisition on dynamic MR sequences is helpful in character-izing lesionsaccrding to their pattern of contrast enhancement.

Acute Pyelonephritis: Role of Enhanced CT Scan in the Prediction of Clinical Outcome

PURPOSE: To correlate the CT findings of acute pyelonephritis with its outcome and with clinical data. MATERIALS AND METHODS: Thirty five contrast enhanced CT scans in patients diagnosed as suffering from acute pyelonephritis were retrospectively analyzed. Findings based on the morphology of perfusion defect in the renal parenchyma were classified as normal, focal wedge, multifocal wedge, focal mass, or mixed form composed of wedge and mass. These findings were correlated with clinical data such as degree of fever, leukocytosis, the period after antibiotic treatment during which fever was reduced, and the presence of pyuria in each group Analysis was then performed. RESULTS: Perfusion defects were seen in 23 of 35 cases, and their morphology was classified as follows; focal wedge (n=2), multifocal wedge (n=8), focal mass (n=4), and mixed form (n=9). Twelve cases (34.3%) showed no perfusion defect. The duration of fever was significantly prolonged in patients with focal mass form(p<.05). There was no significant correlation between the morphology of perfusion defect, bilaterality, and other clinical factors. CONCLUSION: The present study shows that the clinical course of the focal mass form of perfusion defect, as seen on CT, is different from that of other types. CT could be effective in predicting clinical progress and the outcome of treatment in cases of acute pyelonephritis.

Risk Factors of Pneumothorax in Percutaneous Fine Needle Aspiration Biopsy of the Lung

PURPOSE: Percutaneous fine needle aspiration biopsy is known to be a useful diagnostic method for the diagnosis of various pulmonary diseases. Its diagnostic yield is high, and it is safe, but complications such as pneumothorax can occasionally occur. We reviewed the complications arising after needle aspiration biopsy and analyzed the risk factors of pneumothorax. MATERIALS AND METHODS: The medical records and radiographic studies of 157 patients with various pulmonary diseases who underwent needle aspiration biopsy of the lung between 1990 and 1996 were retrospectively reviewed. The clinical features, treatment, and courses of complications were reviewed, and risk factors of pneumothorax such as depth and size of lesion, diameter of needle, number of punctures, and obstructive pulmonary abnormalities were analyzed. RESULTS: Complications occurred in 40 of 157 cases (25.5%), namely pneumothorax in 26 (16.6%), hemoptysis in 11 (7%), hemothorax in two (1.3%), and recurrence of malignancy at the site of aspiration in one (0.6%). When the patients were divided into three groups according to depth of lesion, there were significant difference in the incidence of pneumothorax ; the results were as follows : less than 2cm, 12.9% ; between 2 and 4cm, 24.1% ; and larger than 4cm, 57.1% (p<0.05). In pulmonary function testing, FVC (forced vital capacity) of patients with pneumothorax was less than that of patients without (2.6+/-0.9L vs 3.1+/-0.8L, p<0.05), but FEV1 (forced expiratory volume in 1 second), FEV 1% (percentage of predicted FEV1), FEV1/FVC,and FVC%(percentage of predicted FVC) were not different between the two groups. The incidence of pneumothorax in patients with pleura-attached lesion (9%) was lower than that of those with non-attached lesion (26%, p=0.01). The age of patients, size of lesion, diameter of the needle, guidance methods and number of aspirations showed no significant relationship with pneumothorax. CONCLUSION: In needle aspiration biopsy of the lung, depth of lesion and passage of a needle through aerated lung are significant risk factors of pneumothorax.

Chemical Saturation Breath-hold Fast MR Imaging for Characterization of Regional Fatty Changes in Liver

PURPOSE: To assess the usefulness of breath-hold fast MR imaging of liver with fat suppression (FS) by application of chemical saturation technique in the diagnosis of regional fatty changed suspected in sonography. MATERIALS AND METHODS: Thirteen patients who had focal lesions with diffuse, homogeneous signal changes after FS through chemical saturation technique without additional changes of imaging parameter during MR imaging of liver were selected. T1-weighed fast low-angle shot and T2-weighted turbo spin-echo sequences were obtained with or without FS during each single breath-holding session. Subjective changes of signal intensity between the pre-FS and the FS images were compared with the sonographic findings in each lesion. RESULTS: Seven lesions of decreased signal intensity after FS on T1 or T2-weighted images, including three lesions only at FS T1 images, were regarded as focal fat infiltration. All seven lesions had compatible sonographic findings as homogenously echogenic areas. Another six lesions of subjectively increased signal intensity including two lesions only at FS T2 images were regarded as focal fat sparing. All six lesions had sonographic findings as homogenous echo poor areas suggesting focal fat sparing. In cases regarded as fat infiltration, score changes were more prominent at FS T1 images than FS T2 images(p=0.0002). In cases regarded as fat sparing, score changes were more prominent at FS T2 images than FS T1 images(p=0.042). CONCLUSION: Breath-hold fast T1 and T2-weighted MR imaging with and without chemical saturation pre-pulse may be sufficient for characterization of regional fatty changes in the different ferential diagnosis of focal hepatic lesion found at sonography.