Mi Sung Kim

Radiologic findings of peripheral primitive neuroectodermal tumor arising in the retroperitoneum

OBJECTIVEnThe purpose of this article is to present the radiological findings of peripheral primitive neuroectodermal tumors that arise in the retroperitoneum.nnnCONCLUSIONnPeripheral primitive neuroectodermal tumors (PNETs) arising in the retroperitoneum tend to be large and aggressive. Although the imaging appearance of peripheral PNETs is nonspecific, these tumors should be considered in the differential diagnosis when one encounters a large retroperitoneal mass with aggressive features.

Intracranial Metastases: Spectrum of Mr Imaging Findings:

Intracranial metastatic lesions arise through a number of routes. Therefore, they can involve any part of the central nervous system and their imaging appearances vary. Magnetic resonance imaging (MRI) plays a key role in lesion detection, lesion delineation, and differentiation of metastases from other intracranial disease processes. This article is a reasoned pictorial review illustrating the many faces of intracranial metastatic lesions based on the location - intra-axial metastases, calvarial metastases, dural metastases, leptomeningeal metastases, secondary invasion of the meninges by metastatic disease involving the calvarium and skull base, direct or perineural intracranial extension of head and neck neoplasm, and other unusual manifestations of intracranial metastases. We also review the role of advanced MRI to distinguish metastases from high-grade gliomas, tumor-mimicking lesions such as brain abscesses, and delayed post-radiation changes in radiosurgically treated patients.

The Clinical Correlation of a New Practical MRI Method for Grading Cervical Neural Foraminal Stenosis Based on Oblique Sagittal Images

OBJECTIVEnThe purpose of this study was to determine whether each grade in a new system suggested by Park et al. (Park system) to assess cervical neural foraminal stenosis validly correlates with the associated clinical findings and to evaluate the interobserver agreement in grading between two MRI readers.nnnMATERIALS AND METHODSnWe evaluated 166 patients (98 men and 68 women; mean age, 46 years) at our institution who underwent oblique sagittal MRI of the cervical spine. Using the new Park grading system, two radiologists evaluated the MRI findings for the presence and grade of cervical neural foraminal stenosis at the most narrow point. A neurosurgeon assessed the associated clinical manifestations. A positive neurologic manifestation of the cervical neural foraminal stenosis was defined as more than one positive neurologic clinical manifestation combined with more than one positive neurologic sign. Interobserver agreements between the two radiologists were analyzed using kappa statistics. Correlation coefficients (R) to assess the relationship between the grade and neurologic manifestations were calculated with nonparametric correlation analysis (Spearman correlation). The relationship between the assigned grade and the clinical manifestations was analyzed several ways: vertebrae level (C4-5, C5-6, or C6-7) and by age group (< 46 years and ≥ 46 years).nnnRESULTSnAmong patients who were evaluated by each reader to be grade 0, only 19 (17%) and 20 patients (18%) showed positive neurologic manifestations, respectively, with most patients showing negative neurologic manifestations. Among the patients who were grade 2 and 3, one reader found all patients and the second reader found all but one patient (100% and 93%, respectively) to have positive neurologic manifestations. According to the correlation coefficients, each Park grade was moderately correlated with the associated neurologic manifestations, such that higher grades were associated with more severe clinical manifestations. If we consider grade 2 or 3 MRI findings positive for identifying positive neurologic manifestations, the sensitivities and specificities were 39.7% and 99.0% (reader 1) and 39.7% and 99.0% (reader 2), respectively.nnnCONCLUSIONnThe Park system, based on oblique sagittal MRI sections, provides a reliable and reproducible assessment of the severity of cervical neural foraminal stenosis. According to the Park system, grades 2 and 3 are associated with positive neurologic manifestations, and the Park system successfully predicts positive neurologic manifestations at these grades.

Eosinophilic cystitis associated with eosinophilic enterocolitis: case reports and review of the literature.

We report three cases of eosinophilic cystitis. Contrast-enhanced computed tomography (CT) revealed characteristic bladder wall thickening exceeding 10 mm, with preservation of the mucosal lining and intense, progressive contrast enhancement on sequential arterial and delayed scans. Eosinophilic cystitis might have been associated with eosinophilic infiltration in other organs, such as the gastrointestinal tracts and liver.

Breast-Specific Gamma Imaging: Correlations With Mammographic and Clinicopathologic Characteristics of Breast Cancer

OBJECTIVEnThe purpose of this article is to evaluate the correlations between breast-specific gamma imaging (BSGI) findings and mammographic and clinicopathologic characteristics of breast cancer.nnnMATERIALS AND METHODSnOur study included 56 breast cancers that had undergone BSGI between August 2010 and December 2012. We reviewed imaging findings (BSGI and mammography) with histopathologic findings, including tumor size, histologic type, nuclear grade, presence of ductal carcinoma in situ (DCIS), and presence of extensive intraductal component (EIC); and immunochemical features, including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (ERBB2, formerly HER2), Ki67, and p53. We classified cancers into positive or negative groups on the basis of BSGI visibility and investigated the statistical differences in mammographic and histopathologic characteristics between the BSGI-positive and -negative groups.nnnRESULTSnAmong 56 malignancies, 48 (85.7%) were shown to be BSGI positive. Patients in the BSGI-positive group were statistically significantly older than those in the BSGI-negative group (p = 0.027). BSGI-positive cancers were statistically significantly larger than BSGI-negative cancers (p = 0.002). Cancers 1.0 cm or larger, unlike those of subcentimeter size, were statistically significantly more visible on BSGI (p = 0.004). The mammographic findings and mammographic densities did not statistically significantly differ between the BSGI-positive and -negative groups. Invasiveness of cancer showed no statistically significant difference on BSGI finding. Cancers with a DCIS component tended to be BSGI positive, but without statistical significance (p = 0.051). Visibility on BSGI was not statistically significantly associated with EIC, nuclear grade, ER, PR, ERBB2, Ki67, and p53.nnnCONCLUSIONnThe sensitivity of BSGI for breast cancer was 85.7%. Breast cancers in older patients, cancers larger than 1.0 cm, and cancers with the DCIS component tended to be visible on BSGI. BSGI was an equally sensitive tool to detect the breast cancer in women with fatty and dense breast.

Radiation dose reduction in multidetector CT in fracture evaluation

OBJECTIVEnTo evaluate whether multidetector CT with low-dose radiation (low-dose CT) of joints can be useful when evaluating fractures.nnnMETHODSnOur study included CT scans of 398 patients, 103 shoulder cases, 109 wrist cases, 98 pelvis cases and 88 ankle cases. There were 191 females and 207 males. The low-dose CTs were performed using identical voltage and parameters with the exception of decreased (half of standard dose) tube current. Low-dose and standard-dose images were compared with regards to objective image quality, subjective evaluation of image quality and diagnostic performance for the fractures.nnnRESULTSnThere was no significant difference of image noise between standard-dose CT and low-dose CT in every joint (p > 0.05). Each mean value of subjective score did not show significant difference according to the dosage of the CT scan. There were no statistically significant differences in the sensitivity (96-100%), specificity (95.2-100%) or accuracy (97.9-100%) between standard-dose CT and low-dose CT (p values, 0.1336-1.000).nnnCONCLUSIONnThe evaluation of extremities for fractures using low-dose CT can reduce radiation exposure by about 50% compared with standard-dose CT without affecting image quality or diagnostic performance. Advances in knowledge: Low-dose CT of the extremities (shoulder, pelvis, ankle and wrist) can reduce radiation dose by about 50% compared with standard-dose CT and does not significantly affect image quality or diagnostic performance in fracture detection.

Evaluation of shoulder pathology: three-dimensional enhanced T1 high-resolution isotropic volume excitation MR vs two-dimensional fast spin echo T2 fat saturation MR

OBJECTIVEnTo evaluate the diagnostic accuracy of three-dimensional (3D) enhanced T1 high-resolution isotropic volume excitation (eTHRIVE) shoulder MR for the detection of rotator cuff tears, labral lesions and calcific tendonitis of the rotator cuff in comparison with two-dimensional (2D) fast spin echo T2 fat saturation (FS) MR.nnnMETHODSnThis retrospective study included 73 patients who underwent shoulder MRI using the eTHRIVE technique. Shoulder MR images were interpreted separately by two radiologists. They evaluated anatomic identification and image quality of the shoulder joint on routine MRI sequences (axial and oblique coronal T2 FS images) and compared them with the reformatted eTHRIVE images. The images were scored on a four-point scale (0, poor; 1, questionable; 2, adequate; 3, excellent) according to the degree of homogeneous and sufficient fat saturation to penetrate bone and soft tissue, visualization of the glenoid labrum and distinction of the supraspinatus tendon (SST). The diagnostic accuracy of eTHRIVE images compared with routine MRI sequences was evaluated in the setting of rotator cuff tears, glenoid labral injuries and calcific tendonitis of the SST.nnnRESULTSnFat saturation scores for eTHRIVE were significantly higher than those of the T2 FS for both radiologists. The sensitivity and accuracy of the T2 FS in diagnosing rotor cuff tears were >90%, whereas sensitivity and accuracy of the eTHRIVE method were significantly lower. The sensitivity, specificity and accuracy of both images in diagnosing labral injuries and calcific tendonitis were similar and showed no significant differences. The specificity of both images for the diagnosis of labral injuries and calcific tendonitis was higher than the sensitivities.nnnCONCLUSIONnThe accuracy of 3D eTHRIVE imaging was comparable to that of 2D FSE T2 FS for the diagnosis of glenoid labral injury and calcific tendonitis of SST. The 3D eTHRIVE technique was superior to 2D FSE T2 FS in terms of fat saturation. Overall, 3D eTHRIVE was inferior to T2 FS in the evaluation of rotator cuff tears because of poor contrast between joint fluid and tendons.nnnADVANCES IN KNOWLEDGEnThe accuracy of 3D eTHRIVE imaging is comparable to that of 2D FSE T2 FS for the diagnosis of glenoid labral injury and calcific tendonitis of SST.

Preoperative prediction model for conversion of laparoscopic to open cholecystectomy in patient with acute cholecystitis: based on clinical, laboratory, and CT parameters.

Objective To identify preoperative computed tomography (CT) predictors associated with conversion from laparoscopic to open cholecystectomy and to propose the risk scoring model for prediction of conversion by integrating clinical, laboratory, and CT parameters. Methods The institutional review board approved this retrospective study, and informed consent was waived. One hundred eighty-three patients who underwent a laparoscopic cholecystectomy for acute cholecystitis were evaluated for clinical, laboratory, and CT parameters. Associations between conversion and these parameters were assessed by using univariate and multivariate logistic regression analysis. The risk scoring model was devised using a regression coefficient–based scoring method. Results Conversion to open cholecystectomy was performed in 30 patients (17%). Multivariate analysis identified age older than 60 years, male, and pericholecystic fluid as independent predictors of conversion. The preoperative prediction model to calculate the risk score for conversion showed sensitivity of 83% and specificity of 72%, with an area under the receiver operator curve of 0.83. Conclusions Pericholecystic fluid collection was the only CT parameter with clinical parameters of age older than 60 years and male in prediction for conversion in acute cholecystitis. The preoperative prediction model using these 3 parameters can be adapted easily in clinical practice with a good discrimination.

Diagnostic performance and useful findings of ultrasound re-evaluation for patients with equivocal CT features of acute appendicitis

OBJECTIVEnTo evaluate the diagnostic performance of ultrasound and to determine which ultrasound findings are useful to differentiate appendicitis from non-appendicitis in patients who underwent ultrasound re-evaluation owing to equivocal CT features of acute appendicitis.nnnMETHODSn62 patients who underwent CT examinations for suspected appendicitis followed by ultrasound re-evaluation owing to equivocal CT findings were included. Equivocal CT findings were considered based on the presence of only one or two findings among the CT criteria, and ultrasound re-evaluation was done based on a predefined structured report form. The diagnostic performance of ultrasound and independent variables to discriminate appendicitis from non-appendicitis were assessed.nnnRESULTSnThere were 27 patients in the appendicitis group. The overall diagnostic performance of ultrasound re-evaluation was sensitivity of 96.3%, specificity of 91.2% and accuracy of 91.9%. In terms of the performance of individual ultrasound findings, probe-induced tenderness showed the highest accuracy (86.7%) with sensitivity of 74% and specificity of 97%, followed by non-compressibility (accuracy 71.7%, sensitivity 85.2% and specificity 60.6%). The independent ultrasound findings for discriminating appendicitis were non-compressibility (p = 0.002) and increased flow on the appendiceal wall (p = 0.001).nnnCONCLUSIONnUltrasound re-evaluation can be used to improve diagnostic accuracy in cases with equivocal CT features for diagnosing appendicitis. The presence of non-compressibility and increased vascular flow on the appendix wall are useful ultrasound findings to discriminate appendicitis from non-appendicitis. Advances in knowledge: Ultrasound re-evaluation is useful to discriminate appendicitis from non-appendicitis when CT features are inconclusive.

2087: Ultrasonography in the diagnosis of appendicitis: Evaluation by meta-analysis

Materials and Methods: The relevant Korean articles published between 1985 and 2003 were included in this study if the patients had clinical symptoms of acute appendicitis. The histopathologic findings were the reference standard and the data were presented for 2 2 tables. Articles were excluded if patients had no sonographic signs of appendicitis according to graded-compression US. Two reviewers independently extracted the data on study characteristics. The Hasselblad method was used to obtain the combined estimates of sensitivity and specificity for the performance of US.