[CT and MR Imaging Findings of Structural Heart Diseases Associated with Sudden Cardiac Death]. / 급성 심장사와 ê´€ë ¨ëœ êµ¬ì¡°ì  심질환의 ì „ì‚°í™”ë‹¨ì¸µì´¬ì˜ê³¼ ìžê¸°ê³µëª ì˜ìƒ 소견.

Sudden cardiac death is an unexpected death originating from the heart that occurs within an hour of the onset of symptoms. The main cause of sudden cardiac death is arrhythmia; however, diagnosing underlying structural heart disease significantly contributes to predicting the long-term risk. Cardiovascular CT and MR provide important information for diagnosing and evaluating structural heart disease, enabling the prediction and preparation of the risk of sudden cardiac death. Therefore, we would like to focus on the various structural heart diseases that increase the risk of clinically-important sudden cardiac death and the importance of imaging findings.

Does Nasal Septal Deviation and Concha Bullosa Have Effect on Maxillary Sinus Volume and Maxillary Sinusitis?: A Retrospective Study.

Purpose: This study aimed to determine whether nasal septal deviation and concha bullosa affect the maxillary sinus volume, and whether this effect is associated with the prevalence of chronic sinusitis. Materials and Methods: This study retrospectively reviewed 209 paranasal sinus CT (PNS CT) images of patients with sinonasal symptoms from January 2017 to December 2018. The maxillary sinus volume was measured twice by a radiologist, and statistical analysis was performed using SAS 9.4. Results: Intersex comparison of the maxillary sinus volume (on left and right sides) revealed that the volume was significantly larger on both the sides (p < 0.0001) in men compared with that in women. Concha bullosa was found to occur mainly in the concave cavity of the septal deviation (p < 0.0001). No significant association was found between nasal septal deviation and maxillary sinusitis (p = 0.8756) as well as between concha bullosa and maxillary sinusitis prevalence (p = 0.3401) or maxillary sinus volume (both: p = 0.6289, Rt.: p = 0.9522, Lt.: p = 0.9201). Conclusion: Although nasal septal deviation and the location of concha bullosa may affect each other, maxillary sinus volume and maxillary sinusitis were neither associated with nasal septal deviation nor concha bullosa.

The usefulness of non-contrast abdominal computed tomography for detection of residual drugs in the stomach of patients with acute drug overdose.

Objectives: If clinicians can know that there are many life-threatening drugs left in the stomach through a non-invasive method over 60 min after drugs ingestion, it may be preferable to minimize absorption of remnant drugs through various methods according to the characteristic of the drug. Computed tomography (CT) has gained wide acceptance in the detection of drug mules. Therefore, we evaluated the prevalence of drugs in the gastric lumen using abdominal non-contrast CT, performed over 60 min after acute drug poisoning. Materials and methods: This was a prospective cohort study of patients with acute drug poisoning who were admitted to the emergency department (ED) between March 2017 and February 2018. If the patient visited the ED over 60 min after ingestion of life-threatening or unknown drugs, non-contrast CT scan was performed. "Presence of drugs" was defined in the non-contrast CT as a round-shaped lesion with higher density than the gastric mucosa. In addition, "positive radiodense image" was defined as that with higher density than the gastric mucosa regardless of drug appearance in the non-contrast CT scan. Results: Among a total of 482 patients with drug poisoning, 140 were finally included in the study. Residual drugs were detected in 36 patients (25.7%). Further, regardless of the presence of drugs, 58 patients (41.4%) showed positive radiodense image in the stomach. The median Hounsfield unit of drugs was 131.5 and that of food materials in the stomach was 34.5. Total duration of hospital stay was significantly longer in the "absence of drug" group and sustained-release drugs were detected more frequently in the "presence of drugs" group. Conclusions: Detection rate of drugs and presence of positive radiodense image, regardless of drug appearance, were as high as 25.7% and 41.4%, respectively. Sustained-release drugs were detected more frequently in the "presence of drugs" group.

Varices on computed tomography are surrogate of clinically significant portal hypertension and can predict survival in compensated cirrhosis patients.

BACKGROUND AND AIM: To investigate prognostic value of varices on computed tomography (CT) and redefine surrogate criteria for clinically significant portal hypertension (CSPH). METHODS: We retrospectively enrolled 241 patients with compensated cirrhosis who underwent hepatic venous pressure gradient (HVPG) measurement from 2008 to 2013. Using CT and upper endoscopy findings obtained within 3 months from HVPG measurement, patients were classified into three groups: presence of standard surrogate for CSPH, defined as presence of varices on upper endoscopy and/or splenomegaly associated with thrombocytopenia (Group 1, n = 139); varices on CT without standard surrogate for CSPH (Group 2, n = 41); and free from both (Group 3, n = 61). HVPG value and overall survival (OS) rates were compared among three patient groups. Revised surrogate for CSPH was defined as presence of standard surrogate and/or presence of varices on CT (i.e. both Group 1 and Group 2). RESULTS: Mean HVPG value in Group 2 was significantly higher than that in Group 3 (10.3 mmHg vs 6.5 mmHg, P < 0.001), but significantly lower than that in Group 1 (10.3 mmHg vs 13.1 mmHg, P < 0.001). Seven-year OS rates in Group 2 was similar to those in Group 1 (57.0% vs 62.7%, P = 0.591), but significantly poorer than those in Group 3 (57.0% vs 84.0%, P = 0.015). The presence of revised surrogate for CSPH was a significant predictive factor for OS (P = 0.025, Hazard ratio = 2.71 [1.14-6.45]) on multivariate analysis whereas standard surrogate for CSPH was not (P = 0.849). CONCLUSION: The presence of varices on CT was a significant sign for CSPH, predicting poor OS outcome in patients with compensated cirrhosis.

Quantitative measurement of elasticity of the appendix using shear wave elastography in patients with suspected acute appendicitis.

INTRODUCTION: Shear wave elastography (SWE) has not been studied for diagnosing appendicitis. We postulated that an inflamed appendix would become stiffer than a normal appendix. We evaluated the elastic modulus values (EMV) by SWE in healthy volunteers, patients without appendicitis, and patients with appendicitis. We also evaluated diagnostic ability of SWE for differentiating an inflamed from a normal appendix in patients with suspected appendicitis. MATERIALS AND METHODS: Forty-one patients with clinically suspected acute appendicitis and 11 healthy volunteers were prospectively enrolled. Gray-scale ultrasonography (US), SWE and multi-slice computed tomography (CT) were performed. The EMV was measured in the anterior, medial, and posterior appendiceal wall using SWE, and the highest value (kPa) was recorded. RESULTS: Patients were classified into appendicitis (n = 30) and no appendicitis groups (n = 11). One case of a negative appendectomy was detected. The median EMV was significantly higher in the appendicitis group (25.0 kPa) compared to that in the no appendicitis group (10.4 kPa) or in the healthy controls (8.3 kPa) (p<0.001). Among SWE and other US and CT features, CT was superior to any conventional gray-scale US feature or SWE. Either the CT diameter criterion or combined three CT features predicted true positive in 30 and true negative in 11 cases and yielded 100% sensitivity and 100% specificity. An EMV of 12.5 kPa for the stiffest region of the appendix predicted true positive in 28, true negative in 11, and false negative in two cases. The EMV (≥12.5 kPa) yielded 93% sensitivity and 100% specificity. CONCLUSION: Our results suggest that EMV by SWE helps distinguish an inflamed from a normal appendix. Given that SWE has high specificity, quantitative measurement of the elasticity of the appendix may provide complementary information, in addition to morphologic features on gray-scale US, in the diagnosis of appendicitis.

Comparison of the effectiveness of embolic agents for bronchial artery embolization: gelfoam versus polyvinyl alcohol.

OBJECTIVE: The purpose of this study was to compare the results of different agents for bronchial artery embolization of hemoptysis. MATERIALS AND METHODS: From March 1992 to December 2006, a bronchial artery embolization was performed on 430 patients with hemoptysis. The patients were divided into three groups. Group 1 included 74 patients treated with a gelfoam particle (1 x 1 x 1 mm), while group 2 comprised of 205 patients treated with polyvinyl alcohol (PVA) at 355-500 microm, and group 3 included 151 patients treated with PVA at 500-710 microm. We categorized the results as technical and clinical successes, and also included the mid-term results. Retrospectively, the technical success was compared immediately after the procedure. The clinical success and mid-term results (percentage of patients who were free of hemoptysis) were compared at 1 and 12 months after the procedure, respectively. RESULTS: Neither the technical successes (group 1; 85%, 2; 85%, 3; 90%) nor the clinical successes (group 1; 72%, 2; 74%, 3; 71%) showed a significant difference among the 3 groups (p > 0.05). However, the mid-term results (group 1; 45%, 2; 63%, 3; 62%) and mid-term results excluding the recurrence from collateral vessels in each of the groups (group 1; 1 patient, 2; 4 patients, 3; 2 patients) showed that group 1 was lower than the other two groups (p < 0.05). No significant difference was discovered for the mid-term results between groups 2 and 3. Moreover, the same results not including incidences of recurrence from collateral vessels also showed no statistical significance between the two groups (p > 0.05). CONCLUSION: Polyvinyl alcohol appears to be the more optimal modality compared to gelfoam particle for bronchial artery embolization in order to improve the mid-term results. The material size of PVA needs to be selected to match with the vascular diameter.

Potential conditions causing impairment of selective hepatobiliary enhancement of gadobenate dimeglumine-enhanced delayed magnetic resonance imaging.

OBJECTIVE: To identify conditions that might impair the delayed selective hepatobiliary enhancement of gadobenate dimeglumine. MATERIALS AND METHODS: Ninety-five gadobenate-enhanced magnetic resonance imaging studies were retrospectively and independently analyzed. The effects of selective hepatic enhancement and biliary excretion were each categorized into 3 grades according to the perceived difference of signal intensity between the liver parenchyma and portal vein, and signal intensity in the common bile duct of precontrast- and delayed-phase images.History of diffuse liver disease, liver cirrhosis, and renal disease; elevated levels of blood urea nitrogen (BUN)/creatinine (Cr), aspartate aminotransferase (AST)/alanine aminotransferase, bilirubin, and alkaline phosphatase (ALP); ascites; and splenomegaly were compared according to the grade of hepatic and biliary enhancement. RESULTS: Diffuse liver disease (P = 0.002); cirrhosis (P < 0.001); renal disease (P = 0.022); ascites (P = 0.001); splenomegaly (P < 0.001); and elevated levels of BUN (P = 0.001), Cr (P = 0.003), AST (P < 0.001), bilirubin (P < 0.001), and ALP (P < 0.001) were factors that impaired selective hepatic enhancement. Biliary excretion was affected by the presence of liver disease (P < 0.001), cirrhosis (P < 0.001), splenomegaly (P < 0.001), ascites (P = 0.002), and elevated levels of Cr (P = 0.013), AST (<0.001), alanine aminotransferase (P = 0.001), bilirubin (P < 0.001), and ALP (P < 0.001). CONCLUSION: Delayed selective hepatobiliary enhancement of gadobenate dimeglumine can be impaired by liver or renal disease and/or by elevated levels of bilirubin, ALP, BUN, and Cr.

Factors related to preoperative assessment of the circumferential resection margin and the extent of mesorectal invasion by magnetic resonance imaging in rectal cancer: a prospective comparison study.

BACKGROUND: This study was designed to identify factors related to inaccurate prediction of circumferential resection margin (CRM) and the extent of mesorectal invasion (EMI) in T3 tumors by preoperative magnetic resonance imaging (MRI) in rectal cancer. METHODS: A total of 66 patients with rectal cancer were enrolled prospectively in this study. CRM was defined as the distance from the outer tumor margin to the mesorectal fascia, and EMI was defined as the distance from the outer surface of the muscularis propria to the outermost tumor margin. CRM and EMI measurements on MRI were compared with corresponding measurements from whole-mount sections using 1-mm and 5-mm reference values, respectively, as prognostic indicators. The following variables were analyzed for relevance to preoperative staging: tumor distance from the anal verge (lower and middle), tumor location (anterior and posterior), tumor (T) and nodal (N) stage, and the thickness of the perirectal fat (anterior, left, right, and posterior positions). RESULTS: MRI correctly predicted CRM status in 57 of the 66 tumors and EMI status in 51 of the 58 tumors (eight T1 tumors were excluded from EMI analysis). Univariate analysis showed that T3 stage, lymph node involvement, anterior tumor location, and thin perirectal fat thickness at the anterior portion were related to incorrect prediction of CRM. Anterior tumor location and thin perirectal fat thickness at the anterior portion were related to incorrect prediction of EMI. CONCLUSIONS: Preoperative chemoradiation can be accurately guided by preoperative MRI staging, but CRM and EMI in anterior rectal tumor should be interpreted with caution.

Perfusion CT: noninvasive surrogate marker for stratification of pancreatic cancer response to concurrent chemo- and radiation therapy.

PURPOSE: To prospectively determine whether perfusion computed tomography (CT) parameters, such as volume transfer constant (K(trans)) between blood plasma and extracellular extravascular space (EES) and blood volume calculated from dynamic CT data, can be used to predict response of pancreatic cancer to concurrent chemotherapy and radiation therapy (CCRT). MATERIALS AND METHODS: This prospective study was institutional review board approved, and written informed consent was obtained. Thirty patients with pancreatic cancer underwent perfusion CT with 64-detector row CT before gemcitabine-based CCRT. Two perfusion parameters (K(trans) and blood volume) measured before treatment were compared between patients who responded to treatment and those who did not, as determined with World Health Organization criteria from first and second posttherapeutic follow-up CT examinations, which were performed at 3- and 6-month follow-up. Statistical analysis was performed with the two-sample t test. A receiver operating characteristic curve was used to determine the best cutoff value of perfusion parameters for differentiation of responders from nonresponders. RESULTS: Twenty of 30 patients examined at 3-month follow-up responded to therapy. Their pretreatment K(trans) value was significantly higher than that of nonresponders (50.8 mL/100 mL/min +/- 30.5 [standard deviation] vs 19.0 mL/100 mL/min +/- 10.8, P = .001). The best cutoff value for differentiating between responders and nonresponders was 31.8 mL/100 mL/min, which yielded 75.0% sensitivity and 90.0% specificity. Ten of 18 patients examined at 6-month follow-up responded to therapy. Their pretreatment K(trans) value was significantly higher than that of nonresponders (58.6 mL/100 mL/min +/- 43.2 vs 19.8 mL/100 mL/min +/- 10.9, P = .002). Responders also had higher blood volume values, but this difference was not significant. CONCLUSION: Tumors with a high pretreatment K(trans) value tended to respond better to CCRT than did tumors with a low pretreatment K(trans) value. Perfusion CT may be used to predict tumor response to CCRT in patients with pancreatic cancer. This might aid in development of a tailored approach to therapy in these patients.

Comparison of CT and MRI for presurgical characterization of paraaortic lymph nodes in patients with pancreatico-biliary carcinoma.

AIM: To determine the accuracy of computed tomography (CT) and magnetic resonance (MR) for presurgical characterization of paraaortic lymph nodes in patients with pancreatico-biliary carcinoma. METHODS: Two radiologists independently evaluated CT and MR imaging of 31 patients who had undergone lymphadenectomy (9 metastatic and 22 non-metastatic paraaortic nodes). Receiver operating characteristic (ROC) curve analysis was performed using a five point scale to compare CT with MRI. To re-define the morphologic features of metastatic nodes, we evaluated CT scans from 70 patients with 23 metastatic paraaortic nodes and 47 non-metastatic ones. The short axis diameter, ratio of the short to long axis, shape, and presence of necrosis were compared between metastatic and non-metastatic nodes by independent samples t-test and Fisher's exact test. P < 0.05 was considered statistically significant. RESULTS: The mean area under the ROC curve for CT (0.732 and 0.646, respectively) was slightly higher than that for MRI (0.725 and 0.598, respectively) without statistical significance (P = 0.940 and 0.716, respectively). The short axis diameter of the metastatic lymph nodes (mean = 9.2 mm) was significantly larger than that of non-metastatic ones (mean = 5.17 mm, P < 0.05). Metastatic nodes had more irregular margins (44.4%) and central necrosis (22.2%) than non-metastatic ones (9% and 0%, respectively), with statistical significance (P < 0.05). CONCLUSION: The accuracy of CT scan for the characterization of paraaortic nodes is not different from that of MRI. A short axis-diameter (> 5.3 mm), irregular margin, and presence of central necrosis are the suggestive morphologic features of metastatic paraaortic nodes.

Choledochal cyst and anomalous pancreaticobiliary ductal union in adults: radiological spectrum and complications.

Choledochal cyst and anomalous pancreaticobiliary ductal union (APBDU) are considered to be embryologically related to each other, and their complications are clinically important. This article illustrates the key imaging features of choledochal cysts and APBDU and their various associated abnormalities and complications. Complications of common bile duct are more common in APBDU with choledochal cyst, and complications of gallbladder are more common in APBDU without choledochal cyst.

Gadobenate dimeglumine-enhanced MRI of intraductal papillary mucinous tumor of the bile ducts.

We present the case of a 63-year-old male with intraductal papillary mucinous tumor (IPMT) of the bile ducts. We discuss the role of gadobenate dimeglumine (Gd-BOPTA)-enhanced T1-weighted MRI in the visualization of mucin flow, localization of the papillary tumor, and confirming the diagnosis of this uncommon disease.