Kyung Sook Shin

Detection and characterization of focal hepatic lesions: comparative study of MDCT and gadobenate dimeglumine-enhanced MR imaging

The aim of this study was to compare the diagnostic performance of multidetector row helical CT (MDCT) and gadobenate dimeglumine-enhanced magnetic resonance (MR) imaging (in the detection and characterization of focal liver lesions. Two blind reviewers analyzed the MDCT and MR images of a total of 44 malignant and 85 benign lesions in 46 patients independently. Receiver operating characteristic curves were established to analyze the results for each reviewer and modality.

Diffuse Infiltrative Splenic Lymphoma: Diagnostic Efficacy of Arterial-Phase CT

Objective To evaluate the diagnostic performance of obliteration of normal heterogeneous enhancement of the spleen (ONHES) on arterial phase (AP) computed tomography (CT) images in diffuse infiltrative splenic lymphoma (DISL). Materials and Methods One hundred and thirty-six patients with lymphoma who had undergone two-phase (arterial and portal venous) abdominal CT were included in this study. We retrospectively evaluated the diagnostic performance of ONHES on AP CT in diagnosing DISL. Two observers evaluated ONHES on AP CT using the 5-point confidence level and assessed the presence or absence of subjective splenomegaly on axial CT images. Another two observers measured the splenic index as proposed by objective CT criteria. Statistical analysis included interobserver agreement and diagnostic performance of CT findings. Results Eleven of the 136 patients with lymphoma had DISL. The area under the receiver operating characteristic curve of ONHES (0.948 for observer 1 and 0.922 for observer 2) was superior to that of the splenic index (0.872 for observer 3 and 0.877 for observer 4), but the difference was not statistically significant (p > 0.05). The diagnostic performance of ONHES in conjunction with subjective splenomegaly showed higher diagnostic performance, as compared with subjective splenomegaly alone (accuracy: 100% and 85.3% for observer 1, 98.5% and 87.5% for observer 2; positive predictive value: 100% and 35.5% for observer 1, 90.9% and 39.3% for observer 2, respectively). Conclusion Obliteration of normal heterogeneous enhancement of the spleen in conjunction with subjective splenomegaly can improve the diagnostic performance for DISL. Our results suggest that ONHES on AP CT images could be useful as an adjunctive diagnostic indicator of DISL in patients with lymphoma.

Detection and characterization of focal hepatic lesions by T2-weighted imaging: comparison of navigator-triggered turbo spin-echo, breath-hold turbo spin-echo, and HASTE sequences

The aim of this study is to evaluate the diagnostic performance of T(2)-weighted (T(2)-w) images obtained using navigator-triggered turbo spin-echo (TSE), breath-hold TSE (BH-TSE), and BH haft-Fourier single-shot TSE sequences for the detection and characterization of focal hepatic lesions. Two blinded reviewers independently analyzed three types of T(2)-w image sets totaling 86 solid and 75 nonsolid lesions in 59 patients. Receiver operating characteristic curves were established to analyze reviewer and sequence results.

Apparent diffusion coefficient as a potential marker for tumour differentiation, staging and long-term clinical outcomes in gallbladder cancer

ObjectivesTo evaluate the correlation between tumour differentiation or stage of gallbladder cancer (GBC) and the apparent diffusion coefficient (ADC), as well as to assess whether ADC value can predict long-term disease-free survival (DFS) after surgery.MethodsThis retrospective study was approved by the institutional review board and the requirement for informed consent was waived. Between March 2008 and June 2016, 79 patients who underwent magnetic resonance (MR) imaging with diffusion-weighted image and subsequent surgery for GBC were included in this study. Correlations between quantitative ADC values and tumour differentiation or stage based on the American Joint Committee on Cancer (AJCC) were assessed using Spearman’s correlation analysis. Prognostic factors for DFS were identified with multivariate Cox regression analysis using imaging and clinical characteristics.ResultsAll patients were classified as having well- (n = 18), moderately (n = 35) or poorly differentiated GBCs (n = 26). The ADC value of GBCs was significantly correlated with tumour differentiation and AJCC stage (p < 0.001 and p < 0.001, respectively). Sixty-nine patients were followed up for 2.0–92.4 months (median, 23.5 months). On multivariate analysis, the significant prognostic factor for DFS was not tumour differentiation or AJCC stage but a binary tumour ADC value (hazard ratio, 4.29; p = 0.009). DFS rates were significantly different according to the classification of tumour ADC value (cut-off value = 1.04 × 10−3 mm2/s; p = 0.004).ConclusionThe ADC value of GBCs was significantly correlated with tumour differentiation as well as AJCC stage. In addition, it predicted long-term outcomes after surgery in patients with GBC.Key points• ADC values of GBC and tumour differentiation were negatively correlated.• Lower ADC values of GBC were significantly correlated with higher tumour stage.• Tumour ADC value could be useful for risk stratification of GBC patients.

Hepatic neuroendocrine tumour: Apparent diffusion coefficient as a potential marker of prognosis associated with tumour grade and overall survival

ObjectivesTo evaluate the correlation between grade of hepatic neuroendocrine tumours (NETs) according to the 2010 World Health Organization (WHO) classification and the apparent diffusion coefficient (ADC) and to assess whether ADC value can predict overall survival (OS) after diagnosis of hepatic NETs.MethodsThe study included 63 patients who underwent magnetic resonance (MR) imaging with diffusion-weighted images for the evaluation of hepatic NETs. The correlation between qualitative and quantitative MR imaging findings, including ADC values, and WHO classifications was assessed. The association between ADC value and OS was analyzed.ResultsThe ADC values and WHO classification of hepatic NETs were moderately negatively correlated in a statistically significant manner (ρ = −0.57, p < 0.001). The OS rates were significantly different according to the ADC value (low ADC vs. high ADC, p = 0.006) as well as WHO classifications (G1+ G2 vs. G3, p = 0.038). However, multivariate analysis revealed that the only independent predictor for OS was a low ADC value (hazard ratio: 3.37, p = 0.010).ConclusionThere was a significant correlation between the ADC value of hepatic NETs and the WHO tumour grade. Additionally, the ADC value of a hepatic NET might be more accurate than the current WHO tumour grade for predicting OS.Key points• ADC values of hepatic NET and WHO tumour grade were negatively correlated.• Lower ADC values of hepatic NET were significantly correlated with worse OS.• ADC value might be more accurate than WHO grade for predicting OS.

CT Predictors of Unfavorable Clinical Outcomes of Acute Right Colonic Diverticulitis

OBJECTIVE The purpose of this study was to retrospectively assess CT predictors of unfavorable outcomes of medical treatment in patients with right colonic diverticulitis. MATERIALS AND METHODS Of 394 patients with right colonic diverticulitis diagnosed on the basis of CT findings from January 2010 through August 2013, we included 328 (190 men, 138 women; mean age, 41.3 ± 12.6 years) who had undergone medical treatment as inpatients. Two radiologists retrospectively reviewed the following CT findings associated with diverticulitis: number of diverticula per 10 cm of colon; length and thickness of affected colonic wall; diameter of inflamed diverticulum and abscess; presence of pericolic fluid collection, spilled feces, and contained air; and extent of fatty infiltration. Logistic regression analysis and the Cox proportional hazards regression model were used to determine significant variables predictive of unfavorable outcomes, including surgery after failed medical treatment, recurrence, and prolonged hospital stay. RESULTS Of the 328 patients, nine underwent surgery after failed medical treatment. Of the other 319 patients, 35 had recurrence and 49 had a prolonged hospital stay. The spilled feces sign (adjusted odds ratio [OR], 111; p < 0.001) and serum WBC count (adjusted OR, 1.3; p = 0.047) were independent predictors of the need for surgery. More than five multiple diverticula per 10 cm of colon was significantly associated with recurrence (adjusted hazard ratio, 4.1; p < 0.001). Abscess larger than 4 cm (adjusted OR, 18.2; p = 0.01) and inflamed diverticulum larger than 2 cm (adjusted OR, 3.7; p = 0.001) were independent predictors of prolonged hospital stay. CONCLUSION Some specific CT findings can be useful predictors of unfavorable clinical outcomes of right colonic diverticulitis.

Inflammatory and Infectious Diseases of the Stomach and Duodenum

Gastritis has a broad histopathologic, topographical, and etiological spectrum. Since Helicobacter pylori (H. pylori) was discovered in 1983, the conceptions of the etiology of a wide variety of gastric diseases have been changed as it has become apparent that infection with H. pylori is the major cause of them, including peptic ulcer and nonimmune chronic gastritis. To give consideration to all of these changes and to clarify diagnostic confusion, the guidelines for the classification and grading of gastritis, “the Sydney System,” was published in Sydney in 1990 and revised in 1994. The updated Sydney System emphasized the importance of combining topographical, morphological, and etiological information into a schema for reproducible and clinically useful diagnosis. It should be kept in mind that histopathologically, every single patient may be exposed to more than one etiological factor, resulting in more than one type of gastritis in a same patient. However, gastritis still is a complex and often confusing topic for clinicians and radiologists because of an evolving pathogenesis, varied diagnostic criteria, and, occasionally, poor imaging correlation. A simplified classification of gastritis, which is based on the current concepts, would be adjusted for a practical approach to radiologic evaluation as follows: erosive gastritis, H. pylori gastritis, chronic atrophic gastritis, hypertrophic gastritis, and miscellaneous types, including emphysematous, parasitic, and eosinophilic gastritis, gastric tuberculosis, and gastric sarcoidosis.