Dal Mo Yang

64 multidetector-row computed tomography for preoperative evaluation of gastric cancer: histological correlation.

Objective: To assess the accuracy of 64 multidetector-row computed tomography (MDCT) in the diagnosis and staging of gastric cancer. Methods: This study was approved by the institutional review board, and the patients involved gave informed consent. Forty-four patients (34 men and 10 women; mean age, 57 years) with gastric carcinoma underwent preoperative 64 MDCT (SOMATOM Sensation 64; Siemens Medical System, Forchheim, Germany; slice collimation, 0.6 mm; slice width, 5 mm; feed/rotation, 23 mm; pitch factor, 1.2; kernel, B30f; and gantry speed, 0.5 second per rotation). Gastric distension was achieved by ingestion of 8 g of effervescent granules. Scanning was performed during arterial and portal phases, as determined with bolus tracking and automated triggering technique after intravenous administration of 100 mL of contrast materials (4 mL/s). All computed tomography scans were retrospectively reviewed by 2 radiologists. Each tumor was staged according to the TNM classification system. All patients underwent surgery. Computed tomography results were compared with histological staging of tumor invasion depth and regional lymph node metastasis. Results: The accuracy of 64 MDCT for detection of gastric cancer was 90% (18/20) and 100% (24/24) in early and advanced gastric cancer, respectively, with an overall detection rate of 95% (42/44). Its accuracy for determination of tumor penetration depth was 89% (16/18) and 88% (21/24) in early and advanced gastric cancer, respectively, with an overall accuracy of 88% (37/42). Its accuracy for determination of lymph node metastasis was 90% (18/20) and 71% (17/24) in early and advanced gastric cancer, respectively, with an overall accuracy of 80% (35/44). Conclusions: The 64 MDCT is a promising technique for the detection and preoperative staging of gastric cancer.

MR Arthrography in the Differential Diagnosis of Type II Superior Labral Anteroposterior Lesion and Sublabral Recess

OBJECTIVE The objective of our study was to assess the utility of five MR arthrographic findings in differentiating type II superior labral anteroposterior (SLAP) lesion from superior sublabral recess. MATERIALS AND METHODS The MR arthrograms of 55 patients (57 cases) with either type II SLAP lesion (34 cases) or superior sublabral recess (23 cases) who underwent arthroscopic surgery and MR arthrography were retrospectively reviewed. Two independent reviewers searched for the extension, direction, and shape of high signal intensity in the superior labrum on MR arthrograms. In addition, the presence of concomitant anterosuperior labral tear and anteroposterior extension of high signal intensity on axial images was evaluated. The frequencies of these findings in cases of type II SLAP lesion and sublabral recess were evaluated, and the statistical significance of each finding in differentiation of the two groups was assessed. RESULTS Extension of high signal intensity behind the biceps anchor that extended beneath the labrum on fat-saturated oblique coronal T1-weighted images was found in 33 (97%) of the cases of type II SLAP lesion and 21 (91%) of the cases of sublabral recess. Laterally curved high signal intensity was found in 17 (50%) of the cases of type II SLAP lesion but in only four (17%) of the cases of sublabral recess. Globular or irregular shape of the superior labrum was present in 22 (65%) of the cases of type II SLAP lesion and in 10 (43%) of the cases of sublabral recess. Concomitant anterosuperior labral tear was seen in 14 (41%) of the cases of type II SLAP lesion but in only two (8.7%) of the cases of sublabral recess. Anteroposterior extension of high signal intensity in the superior labrum on fat-saturated axial T1-weighted images was detected in 33 cases of type II SLAP lesion (97%) and in 14 cases of sublabral recess (61%). CONCLUSION Although the MR arthrographic findings were similar for type II SLAP lesion and sublabral recess, laterally curved high signal intensity on oblique coronal images, concomitant anterosuperior labral tear, and anteroposterior extension of high signal intensity on axial images were helpful findings in the diagnosis of type II SLAP lesion.

Added Diagnostic Value of Multiplanar Reformation of Multidetector CT Data in Patients with Suspected Appendicitis

Computed tomography (CT) is an accurate and effective modality for the diagnosis and staging of appendicitis. CT provides rapid and complete evaluation of patients with suspected appendicitis and clearly demonstrates the typical findings of appendicitis, including a distended appendix, periappendiceal fat stranding, an appendicolith, and focal thickening of the cecum. Identification of an inflamed appendix at CT may be difficult in certain patients (eg, patients with scanty intraabdominal fat, an unusual location of the cecum and appendix, prominent cecal wall thickening and pericecal fat stranding, small bowel dilatation, or abscess formation adjacent to the right adnexa). In such cases, multiplanar reformation (MPR) of multidetector CT data may provide improved appendiceal visualization and increase the physicians confidence in diagnosing appendicitis. Moreover, the use of MPR in addition to conventional CT may provide improved visualization of the normal appendix and thereby enhance confidence in excluding appendicitis and diagnosing diseases that mimic appendicitis. Consequently, the radiologist should obtain MPR images in the evaluation of patients with suspected appendicitis to help ensure the correct diagnosis.

Acute necrotizing encephalopathy in Korean infants and children: imaging findings and diverse clinical outcome.

Objective The purpose of our study was to describe acute necrotizing encephalopathy in Korean infants and children, and we sought to evaluate the prognostic factors. Materials and Methods Acute necrotizing encephalopathy was diagnosed in 14 Korean infants and children. We retrospectively analyzed the neuroimaging findings including the follow-up changes. The clinical course of the disease was graded, and we evaluated prognostic factors including age, serum level of the aminotransferase, hemorrhage, and localized atrophy of the brain. Results This encephalopathy predominantly affected the bilateral thalami (n=14), pons (n=12), and midbrain (n=10) in a symmetrical pattern. Hemorrhage was observed in eight patients (57%). On the follow-up images (n=12), the brain lesions were reduced in extent for all patients, and generalized atrophy was seen in six patients. Localized tissue loss was observed in five patients and a complete resolution occurred for one patient. All the patients survived and two recovered completely; mild (n=6) to severe (n=6) neurological deficits persisted in the remaining 12 patients. The significant prognostic factors identified in this study were the presence of hemorrhage (p = 0.009) and localized atrophy (p = 0.015). Conclusion Acute necrotizing encephalopathy in Korean patients showed the characteristic patterns of the post-infectious encephalopathy as described in the literature. The high survival rate and the relatively favorable clinical course observed for the present study suggest a more diverse spectrum of disease severity than was previously described. The presence of hemorrhage and localized tissue loss on MR images may suggest a poor prognosis.

The various manifestations of ruptured hepatocellular carcinoma: CT imaging findings

Hepatocellular carcinoma (HCC) has a tendency to rupture spontaneously which leads to a life-threatening condition. Disruption of the tumor surface or a tear in a parasitic feeding artery can cause HCC rupture leading to hemoperitoneum. When evaluating patients with a ruptured HCC, CT can detect tumors, determine tumor extent, define the presence of tumor bleeding, and show serial hematoma density changes. Thus, familiarity with the various CT findings of ruptured HCCs is essential to ensure proper diagnosis and treatment. In this pictorial essay, the authors illustrate the usual and unusual manifestations of ruptured HCCs, as visualized by CT, and include some angiographic correlations. CT findings predictive of HCC rupture are also discussed.

Presacral epidermoid cyst: imaging findings with histopathologic correlation

AbstractBackground: The aim of this study was to determine the imaging characteristics of presacral epidermoid cysts and correlate the imaging findings with the histopathologic findings. Methods: We retrospectively reviewed sonographic, computed tomographic, and magnetic resonance examinations in four consecutive patients with a pathologically proven presacral epidermoid cyst. Imaging findings of the presacral epidermoid cyst were correlated with the histopathologic findings. Results: In all four patients, sonography showed a presacral mass with a heterogeneous low echogenicity, and computed tomography showed a discrete well-defined hypodense presacral mass with a thin wall. In the three patients who underwent magnetic resonance imaging, the mass showed a heterogeneous low signal intensity on the T1-weighted image and a high signal intensity with multiple small foci of low signal intensity in the nondependent portion of the mass on the T2-weighted image. These imaging findings correlated well with the pathologic results. Aggregates of keratinous material contributed to these imaging findings. Conclusion: In the diagnosis of the presacral epidermoid cyst, sonographic and magnetic resonance imaging findings may be helpful.

Color Doppler Twinkling Artifacts in Various Conditions During Abdominal and Pelvic Sonography

Objective. The aims of this study were to describe the mechanisms likely to be responsible for color Doppler twinkling artifacts and their associated machine factors and to illustrate the various conditions that cause twinkling artifacts and those pitfalls. Methods. We evaluated various sonographic machine‐associated factors that influence artifact appearance and identified various conditions that display twinkling artifacts during abdominal and pelvic sonography. Results. The presence of twinkling artifacts was found to be dependent on focal zones, gray scale gains, color write priorities, and pulse repetition frequencies. Twinkling artifacts were found to be associated with calcified lesions in the liver, gallbladder adenomyomatosis, hepatic bile duct hamartoma, gallstones and choledocholithiasis, chronic pancreatitis, urinary stones, encrusted indwelling urinary stents, bowel gas, and metallic foreign bodies. However, some of the twinkling artifacts were found to be associated with false‐negative and ‐positive results. Conclusions. Color Doppler twinkling artifacts are additional useful sonographic signs in the diagnosis of calcified lesions, urinary and biliary stones, gallbladder adenomyomatosis, and some miscellaneous conditions.

Sonographic Findings of Groin Masses

The groin contents consist of the spermatic cord and its fascial coverings and vascular, nervous, and muscular structures. Abnormalities in the groin region are variable. The purpose of this image presentation is to describe the sonographic findings of the various kinds of groin lesions.

Diagnostic values of sonography for assessment of sternal fractures compared with conventional radiography and bone scans.

Objective. This study was prospectively undertaken to evaluate the diagnostic value of sonography for detection of sternal fractures. We compared sonographic, conventional radiographic, and bone scan examinations of sternal fractures. Methods. Fifty consecutive patients (26 male and 24 female; mean age, 45.2 years) were evaluated. Conventional radiography and sonography were performed in all patients, and bone scans were performed in 39 patients. All patients had acute pain and tenderness in anterior midline chest areas. Sonography was performed by 2 musculoskeletal radiologists within 1 to 2 days after admission. Patients underwent conventional radiography at admission and bone scans within 4 to 7 days after admission. Two radiologists reviewed all imaging findings by means of consensus. In addition, sonography was performed in 20 asymptomatic patients in a normal control group. Results. Conventional radiography depicted sternal fractures in 12 of 50 patients. Sternal fractures were detected in 31 of 50 patients on sonography. Fractures on sonography were located in the manubrium (8 cases), upper sternal body (11 cases), mid sternal body (5 cases), and lower sternal body (7 cases). Bone scans showed sternal hot uptakes (accumulations of the radionuclide used) in 18 of 39 patients. In the control group, there were no bony defects or abnormal contours. Conclusions. We could detect sternal fractures more effectively with sonography than with conventional radiography and bone scans. In addition, sternal fracture locations showed relatively even distributions, and focal fractures in the manubrium were not easily detected on bone scans.

Torsed Appendix Testis Gray Scale and Color Doppler Sonographic Findings Compared With Normal Appendix Testis

The purpose of this study was to compare the size, shape, echogenicity, and blood flow of the appendix testis on sonography in control subjects and in patients with a torsed appendix testis and to evaluate the usefulness as well as the limitations of these criteria.