Pseudoradial Tear of the Medial Meniscus: A Relatively Common Potential Pitfall

PURPOSE: To determine the incidence of truncated triangle appearance of anterior horn (AH) to body of medial meniscus (MM) and determine its clinical significance. MATERIALS AND METHODS: IRB approval was obtained, and informed consent waived for this study. The criteria of "pseudoradial tear" was truncated triangle appearance of the tip of AH to body of MM on one or more coronal images with adjacent fluid signal intensity at the blunted tip. Two musculoskeletal radiologists retrospectively evaluated 485 knee MR images independently for the presence and number of sections with "pseudoradial tear" of AH to body of MM using proton density-weighted coronal MR images. Inter-and intraobserver agreement was calculated using kappa coefficients. Medical records were reviewed for arthroscopic correlation. RESULTS: A pseudoradial tear in the AH to body of MM was present in 381 (78.6%) patients. Locations were 112 in AH (29.4%), 143 in AH to body (37.5%), and 126 in body (33.1%). Number of consecutive sections of pseudoradial tear were 1 in 100 (26.2%), 2 in 164 (43.0%), 3 in 94 (24.7%), 4 in 21 (5.5%), and 5 in 2 (0.5%). Interobserver agreement was 0.99 for presence and 0.43 for number of sections of pseudoradial tear. Arthroscopies were performed in 96 patients and none of the pseudoradial tears were proven as true radial tears on arthroscopy. CONCLUSION: Pseudoradial tears are frequently seen in AH to body of MM on coronal MR images and may be another pitfall that a radiologist needs to be aware of and be able to differentiate from true radial tear.

Atypical Anterior Spinal Artery Infarction due to Left Vertebral Artery Occlusion Presenting with Bilateral Hand Weakness

BACKGROUND: Infarct of the anterior spinal artery is the most common subtype of spinal cord infarct, and is characterized by bilateral motor deficits with spinothalamic sensory deficits. We experienced a case with atypical anterior-spinal-artery infarct that presented with bilateral hand weakness but without sensory deficits. CASE REPORT: A 29-year-old man presented with sudden neck pain and bilateral weakness of the hands. Magnetic resonance imaging (MRI) of the brain did not reveal any lesion. His motor symptoms improved rapidly except for mild weakness in his left wrist and fingers. Magnetic resonance angiography showed proximal occlusion of the left vertebral artery; a spine MRI revealed left cervical cord infarction. CONCLUSIONS: Bilateral or unilateral hand weakness can be the sole symptom of a cervical cord infarct.

Usefulness of Stent Implantation for Treatment of Intracranial Atherosclerotic Stenoses / 신경중재치료의학

PURPOSE: We evaluated the usefulness of intracranial stent implantation for treating patients with atherosclerotic stenosis and with recurrent, ischemic, neurological symptoms despite having undergone medical therapy. MATERIALS AND METHODS: Between March 2004 and April 2010, we attempted intracranial, stent-assisted angioplasty in 77 patients with 85 lesions (anterior circulation 73 cases, posterior circulation 12 cases) and who had ischemic neurological symptoms with more than 50% major cerebral artery stenosis. We analyzed the results regarding the technical success rate, complication rate, and restenosis rate during the mean 29.4 month follow-up period. RESULTS: Intracranial stent implantation was successfully performed in 74 cases (87.1%). In nine cases among the 11, failed cases, stent implantation failure was due to the tortuosity of the target vessel. One patient experienced middle cerebral artery rupture during the procedure, and we embolized the vessel using a microcoil. Five patients developed cerebral infarction in three weeks after the procedure, three of whom improved using conservative management, although the other, two patients expired. The mean number of residual stenoses decreased from 72.3% to 14.7%. Three patients demonstrated significant in-stent restenosis, i.e. more than 50%, during the follow-up period. CONCLUSION: As stent-assisted angioplasty in intracranial, atherosclerotic stenosis is effective and relatively safe, it can be considered as an alternative treatment for patients with recurrent, ischemic, neurologic symptoms despite having undergone medical therapy.

Foreign Body Removal by Snare Loop: During Intracranial Stent Procedure / 신경중재치료의학

We present a case of successful retrieval of an intracranial stent using a snare wire. A 52-year-old woman presented with left border zone infarction. On cerebral angiography, the C6 segment of the left internal carotid artery (ICA) showed significant stenosis. We attempted stenting of the lesion, although stent dislodgement occurred in the ICA C4 segment. We successfully removed it using a snare loop, and there were no complications during the procedure.

The Efficacy of Unenhanced MR Imaging for the Diagnosis of Acute Appendicitis: A Performance Comparison Versus Abdominal Ultrasonography

PURPOSE: To evaluate the efficacy of unenhanced MR imaging compared to the diagnostic accuracy, advantage, and limitations of abdominal ultrasonography in the diagnosis of acute appendicitis. MATERIALS AND METHODS: The study included 40 patients suspected of having acute appendicitis and who were subjected to an unenhanced MR image, as well as an abdominal ultrasonography. A T1 FLASH in an axial image, a chemical shift-selective fat suppressed T2 HASTE in an axial image, as well as a T2 HASTE in an axial and coronal image were obtained as unenhanced MR images. The diagnosis was established based on a surgical or clinical follow-up of the unenhanced MR results, which were then statistically compared to the ultrasonographic results. RESULTS: The surgical or clinical follow-up results revealed that 25 patients were positively diagnosed with appendicitis. Of these, 7 patients had symptoms of acute appendicitis with no pathologic diagnoses, whereas the 8 remaining patients were diagnosed with another condition. The sensitivity and accuracy of the unenhanced MR imaging was 92% and 90%, compared to ultrasonography which was 68% and 72.5% accurate, respectively. The differences in sensitivity and accuracy between the two methods were found to be statistically significant (p < .05, chi-square test). Based on these results, unenhanced MR imaging was superior to sonography for the diagnosis of appendicitis. CONCLUSION: Unenhanced MR imaging may be a useful modality for the diagnosis of acute appendicitis, especially for suboptimal or nondiagnostic sonographies, as well as patients that are particularly sensitive to radiation exposure.

Enteroscopy-guided Contrast Radiography of Small Bowel Lesions

PURPOSE: To introduce the method of enteroscopy-guided contrast radiography (ECR) and evaluate the diagnostic value of ECR for those patients with small bowel lesions. MATERIALS AND METHODS: From Aug 2004 to Dec 2005, 43 double-balloon enteroscopy (DBE) examinations were performed in 32 patients with suspected small bowel diseases. Among them, DBE revealed abnormal finding in 24 patients, and ECR was then performed in 13 of these 24 patients. RESULTS: ECR demonstrated abnormal findings in 11 among the 13 patients. In the cases of tumors and bezoar, the ECR images were very helpful for the surgical planning. However, for the evaluation of inflammatory lesions, DBE showed more accurate results and ECR could not demonstrate small or shallow ulcerative lesions. CONCLUSION: ECR can be helpful for surgical planning or determination of treatment effect in the cases of small bowel lesions that require surgical treatment or follow-up study.

A Case of Dialysis-related Amyloidosis of the Hip and Cervical Spine: Imaging Findings

Dialysis-related amyloidosis is a complication of long-term hemodialysis and it is characterized by the accumulation of beta2-microglobulin in the osteoarticular structures. We describe here the imaging findings of a case of dialysis-related amyloidosis involving the hip and cervical spine in a 62-year-old woman who received long-term dialysis. We focus here on the CT and MR imaging findings of the cervical spine and we include a review of the relevant literatures.

MR Imaging Findings of Acute Gouty Arthritis

PURPOSE: The purpose of this study was to describe the clinical and MR imaging features of acute gouty arthritis and to define the characteristic findings that would be helpful for differentiating acute gouty arthritis from septic arthritis. MATERIALS AND METHODS: The authors retrospectively studied seven patients who suffered from acute gouty arthritis. The MR imaging findings were analyzed by two musculoskeletal radiologists who focused on joint effusion, subchondral bone erosion, bone marrow edema, synovial thickening (regular and even, or irregular and nodular), and the soft tissue changes (edema or abscess). The clinical records of the patients were reviewed with regard to age and gender, the clinical presentation and the laboratory findings (serum uric acid, WBC, erythrocyte sedimentation rate, C-reactive protein and synovial fluid culture). RESULTS: The patients consisted of six men and one woman whose mean age was 41 years (age range: 24-65 years). The joints involved were the knee (n=6), and ankle (n=1). Two patients had medical histories of gouty attacks that involved the first metatarsophalangeal joint. In six cases, the serum uric acid level during acute attacks was elevated. In all the patients, the affected joint became swollen, hot, erythematous and extremely tender, and this was accompanied by a high ESR and a high C-reactive protein level at the time of presentation. The results of Gram stain and culture of the synovial fluid were negative. In all patients, the MR images showed large amounts of joint effusion, thick irregular and nodular synovial thickening and soft tissue edema without subchondral bone erosions and soft tissue abscess. In one case, subchondral bone marrow edema of the medial femoral condyle was present. In five cases, there were multiple low signal foci in the joint on the spin-echo T2-weighted MR image. CONCLUSION: Even though the MR imaging findings of acute gouty arthritis are nonspecific, it should be considered as a possible diagnosis when a large amount of joint effusion, irregular and nodular synovial thickening and soft tissue edema without subchondral bone erosion, bone marrow edema or soft tissue abscess are seen in the knee or ankle joint, and especially if this is accompanied by the clinical and laboratory features of infection.

Metastatic Bone Tumors with Sunburst Periosteal Reaction

PURPOSE: The purpose of this study was to describe the clinical and imaging features of metastatic bone tumors with sunburst periosteal reaction and to define the characteristic findings which would be helpful for differentiating metastatic bone tumors from primary malignant bone tumors. MATERIALS AND METHODS: The authors retrospectively reviewed the cases of nine patients with pathologically confirmed metastatic bone tumors with sunburst periosteal reaction, for which imaging studies (plain radiographs [n=9], radioisotope [RI] scans [n=4], magnetic resonance [MR] images [n=6], and computed tomographic [CT] scans [n=4]) were performed. The imaging studies of each lesion were analyzed by two musculoskeletal radiologists focusing on the metastatic site, patterns of bone response, signal intensity characteristics and pattern of contrast enhancement on MR. The clinical records of the patients were reviewed with regard to the age and sex of the subjects, the clinical presentation, and the origin of the primary tumors. RESULTS: The cases consisted of six men and three women, whose mean age was 62 years (age range, 50-88 years). The primary tumors were adenocarcinoma of the stomach [n=4], adenocarcinoma of the lung [n=2], adenocarcinoma of the prostate [n=1], hepatocellular carcinoma of the liver [n=1], and adenocarcinoma of unknown origin [n=1]. The sites of metastatic involvement exhibiting sunburst periosteal reaction were the scapula [n=2], proximal humerus [n=2], rib [n=1], iliac bone [n=1], tibia [n=1], spine [n=1], and proximal phalanx [n=1]. In all patients, the imaging findings showed osteolytic [n=3] or osteoblastic [n=6] lesions with sunburst periosteal reaction. In six cases, the lesions were iso-intense on the T1-weighted images and heterogeneously hyperintense on the T2-weighted images. The gadolinium-enhanced T1-weighted images showed a nearly homogenous enhancement of the lesions without any central necrotic portion. CONCLUSION: Although metastatic bone tumor exhibiting sunburst periosteal reaction is rare, it should be included along with primary malignant bone tumors in the differential diagnosis of bone lesions with sunburst periosteal reaction, especially in older patients with or without a known primary malignancy.

Differentiation of Tuberculous Enteritis and Crohn's Disease with Barium Study Using Bayes Theory

PURPOSE: To differentiate tuberculous enteritis and Crohn's disease with barium study using Bayes theory. MATERIALS AND METHODS: The study group consisted of 34 patients with tuberculous enteritis (age range 16-86 years, mean age 43.3 years, M:F=19:15) and 36 patients with Crohn's disease (age range 19-78 years, mean age 35.2 years, M:F=18:18). These diagnoses were confirmed by therapeutic tests (tuberculous enteritis: 15, Crohn's disease:16) or histopathological examinations (tuberculous enteritis: 19, Crohn's disease: 20) conducted from January 1993 to May 2003. Three radiologists (two abdominal specialists and one trainee) analyzed each radiological finding of tuberculous enteritis and Crohn's disease by means of a barium enema and/or small bowel series. We used Fisher's exact test to verify the statistical significance of each radiological finding and p-values less than 0.05 were considered to be significant. We calculated the likelihood ratio (LR) of tuberculous enteritis versus Crohn's disease for each finding by employing Bayes theory. RESULTS: The radiological findings associated with a high likelihood ratio for tuberculous enteritis were the involvement of the cecum (LR=2.65) and ascending colon (LR=1.99), rigid narrowing (LR=1.94), shortening of the bowel (LR=1.99), haustral loss (LR=1.97) and sacculation (LR=3.88). The radiological findings associated with a high LR for Crohn's disease (low LR for tuberculous enteritis) were age between 20 and 29 years (LR=0.53), the involvement of the jejunum (LR=0.12), terminal ileum (LR=0.19), sigmoid colon (LR=0.30) or rectum (LR=0.17), and the presence of skip lesions (LR=0.19) or strictures (LR=0.21). With these LRs, the probability of the subject having tuberculous enteritis versus Crohn's disease could be calculated using Bayes theory. CONCLUSION: The analysis of a barium study using Bayes theory could provide an objective, easy and fast method of differentiating tuberculous enteritis and Crohn's disease.

Sclerosing Peritonitis with Gross Calcification: Case Report

Sclerosing peritonitis is an uncommon complication of continuous ambulatory peritoneal dialysis (CAPD) and can lead to small bowel dysfunction involving abdominal pain, progressive loss of ultrafiltration, and small intestinal obstruction. Peritoneal thickening, in which calcification can develop, often starts as a small plaque which gradually becomes larger. We report a case of CAPD-related calcifying peritonitis.

MRI Findings of the Brain in High-Voltage Electrical Burn Patient: Case Report

We report the delayed sequelae arising in a case of electrical injury, reviewing the literature on the subject and focusing on the MRI findings of the brain. A 23-year-old male suffered burns to the left parietal scalp, both feet, and the anterior chest wall. Neurological symptoms and MRI abnormalities appeared 14 days after the insult and continued for about three months. T1-weighted MR images demonstrated homogeneous hypointensity, while T2-weighted images depicted hyperintense finger-like projections. Contrast-enhanced T1-weighted images demonstrated strong band-like enhancement, indicating meningeal hyperemia. Follow-up MR imaging showed that the lesion had disappeared, indicating that the cerebral edema and meningeal hyperemia were reversible.

The evaluation of Fat Saturation Fast Spin-Echo T2WI for Patients with Acute Spinal Trauma

PURPOSE: To determine the usefulness of fat saturation fast spin-echo T2WI for patients with mild acute trauma of the spine. MATERIALS AND METHODS: Between July 1998 and June 2002, 36 patients with acute spinal trauma underwent MRI within four months of injury. One, whose clinal symptoms indicated neurological paralysis, was excluded form our study. A superconductive 1.0-T MRI scanner was used, and conventional T1W1, T2WI, and additional fat-saturation fast spin-echo T2WI were performed. Two radiologists compared conventional T2-weighted sagittal imaging and fat-saturation T2-weighted sagittal imaging in terms of the extension of increased high signal intensities in soft tissue and vertebral bodies, bone marrow signal change, disk herniation, and signal change of the disk. RESULTS: The detection rate of focal high signal intensities in soft tissue and bone marrow was significantly higher at fat-saturation fast spin-echo T2WI than at conventional T2WI. CONCLUSION: Fat-saturation fast spin-echo T2WI is useful for the evaluation of patients with mild acute spinal trauma without neurological impairment.

Value of Real-time Compound US in Diagnosis of Malignant Tumor in Breast Comparing with Conventional US, and Pulse Inversion Harmonic Images

PURPOSE: To compare the usefulness of real-time compound US (RCUS) with that of conventional US (CUS) and pulse inversion harmonic (PIH) imaging in the diagnosis of malignant breast tumors. MATERIALS AND METHODS: In 22 female patients whose mean age was 49 years, we evaluated the RCUS findings of pathologically proven [core biopsy (n=9), mammotome tissue bigpsy (n=10), excisional bispsy (n=3)] malignant breast tumors, comparing them with the findings of CUS and PIH imaging. Evaluation of these masses was in terms of their marginal distinction, internal echogenicity, boundary and posterior echo pattern, relationship with the adjacent lactiferous ductal system, and the presence of necrosis (12/22) and calcification (6/22). RESULTS: In terms of marginal distinction, internal echogenicity, boundary echo patterns, and the relationship with adjacent ductal system, RCUS was superior to both conventional US and PIH Imaging (p<0.05). CONCLUSION: For the diagnosis of malignant breast tumors RCUS was more useful than CUS or PIH imaging.

Coil Embolization in Right Superior Thyroid Artery Pseudoaneurysm by Stab Wound

A case of coil embolization in right superior thyroid artery pseudoaneurysm by stab wound is reported. A fifty-six-year old female, laceration and some bulging in right neck side. Aortic arch angiography, right common carotid angiography was done. Angiography shows 4 2 cm sized right thyroid artery pseudoaneurysm (Fig. 1) and (Fig. 2). We selected right superior thyroid artery by 3F micorofert (CooK, Bloomington, Ind.) and embolized by 2 4 mm (diameter), 2 cm (length) sized micro tornaido coil (CooK, Bloomington, Ind.). Post procedure right common carotid angiography was done. Angiography shows no visualized right thyroid artery pseudoaneurysm (Fig. 3).

Adenocarcinoma Arising in an Ileal Duplication Cyst with Peritoneal Seeding: A Case Report

We report a case in which mucinous adenocarcinoma arose in a duplication cyst at the distal ileum with in-traperitoneal seeding. A thirty-three-year-old male patient presented with abdominal distension. Ultrasonography, CT and MR imaging revealed a dumbbell-shaped cystic mass adherent to the small intestine. The wall of the mass was thickened in two areas and contained inhomogeneous materials. A large amount of ascites with irregular masses along the greater omentum were seen present. Surgery revealed a duplication cyst adherent to the ileum. Pathologic examination proved that the thickened portions of the wall of the mass were mucinous adenocarcinoma, and that the nodules on the greater omentum were metastatic adenocarcinoma.

Degenerative Changes of Femoral Articular Cartilage in the Knee: Comparative Study of Specimen Sonography and Pathology

PURPOSE: To determine the sonographic findings of degenerative change in femoral articular cartilage of the knee by comparative study of specimen sonography and pathology. MATERIALS AND METHODS: We obtained 40 specimens of cartilage of the femur (20 medial and 20 lateral condylar) from 20 patients with osteoarthritis of the knee who had undergone total knee replacement. The specimens were placed in a saline-filled container and sonography was performed using a 10MHz linear transducer. Sonographic abnormalities were evaluated at the cartilage surface, within the cartilage, and at the bone-cartilage interface, and were compared with the corresponding pathologic findings. In addition, cartilage thickness was measured at a representative portion of each femoral cartilage specimen and was compared with the thickness determined by sonography. RESULTS: 'Dot 'lesions, irregularity or loss of the hyperechoic line, were demonstrated by sonography at the saline-cartilage interface of 14 cartilages. Pathologic examination showed that these findings corresponded to cleft, detachment, erosion, and degeneration. Irregularities in the hyperechoic line at the bone-cartilage interface were revealed by sonography in eight cartilages and were related to irregularity or loss of tidemark, downward displacement of the cartilage, and subchondral callus formation. Dot lesions, corresponding to cleft and degeneration, were noted within one cartilage. Cartilage thickness measured on specimen and by sonography showed no significant difference (p=0.446). CONCLUSION: Specimen sonography suggested that articular cartilage underwent degenerative histopathological change. Cartilage thickness measured by sonography exactly reflected real thickness.

The Radiographic Spectrum of Pulmonary Complications in Major Burn Patient

In recent years, improved antibiotic care and physiologic fluid replacement in cases involving burn wounds have led to a decrease in the rate of fatalaties caused by wound sepsis and shock. There has, however, been an upsurge and relative increase in the frequency (15 -25%) and mortality rate (50 -89 %) of pulmonary complications. Since pulmonary lesions may result from direct injury to the respiratory tract caused by smoke inhalation, from circulatory, metabolic or infectious complications in cases involving cutaneous burns, or may develop during the therapeutic management of these lesions, a wide spectrum of pulmonary abnormalities can occur during the post-burn period. There is considerable overlap between their radiographic appearances, which are often nonspecific. Since the successful management of these patients is based on the early recognition and vig-orous treatment of lesions, familiarity with all facets of these complications, based on a pathophysiology of the injury and on the knowledge of the clinical setting, enables radiologists to make more specific diagnoses.

Hepatic Infarction Complicating Acute Pancreatitis: A Case Report

Hepatic infarction is relatively uncommon and is usually related to surgery or interventional procedures. Pancreatitis-associated hepatic infarction has not been reported in the literature, and we now describe a case of hepatic infarction in a 31-year-old man with acute pancreatitis. Initial CT scanning demonstrated an enlarged pancreas with multifocal fluid collection, and a large wedge-shaped low attenuation lesion was seen in the right lobe of the liver along with thrombi in the posteroinferior branch of the right portal vein. Hepatic arteri-ography and SMA portography revealed a pseudoaneurysm in the right hepatic artery, thrombi in the main portal vein and its posteroinferior branch, and perfusion defects confined to S6 of the liver.

MRI and CT Findings of Intracranial Neurosyphilis

PURPOSE: To evaluate the CT and MRI findings of neurosyphilis. MATERIALS AND METHODS: We retrospectivelyreviewed the CT and MR imaging findings in five patients with intracranial neurosyphilis confirmed by CSF, VDRL,TPHA, and clinical follow-up. MR imaging was performed in all five cases, and CT in two. RESULTS: The MRI and CTfindings of intracranial neurosyphilis included infarction (n=3), focal inflammation (n=1) and encephalopathy(n=1). There was a total of ten infaretions : three of the basal ganglia, two each of the frontal lobe, watershedzone, and cerebellum, and one of the occipital lobe. Intaretion was most common in MCA territory (n=9; 50%),followed by the watershed zone (16.6%), posterior cerebral artery territory (16.6%), and posterior inferiorcerebellar artery territory (11.1%), The size of the lesion varied from 1cm to larger than one lobe. One patientshowed diffuse high signal intensity in the left temporal lobe, but on follow-up MRI, this had resolved. CONCLUSION: The most common finding of neurosyphilis, as seen on MRI and CT, was infarction in middle cerebralarterial territory.