Use of Coronary CT Angiography as a Screening Tool for Coronary Artery Disease in Asymptomatic Healthy Individuals or Patients

Early detection of potential asymptomatic coronary artery disease is very important, as patients with sudden cardiac death often do not show symptoms such as chest pain or motor dyspnea. Coronary CT angiography (CCTA) has long been unjustified as a screening tool for asymptomatic patients because of the risks posed by radiation exposure. However, there are still various opinions regarding the usefulness of CCTA for screening for coronary artery disease (CAD) in asymptomatic healthy individuals or patients. This review investigated the usefulness of coronary artery calcium score and CCTA as screening tests for CAD in asymptomatic healthy individuals or patients through various literature reviews. With the development of CT technology, recent studies have been conducted in asymptomatic CAD patients with a reduced radiation dose of less than 1 mSv. A total of 2.6% of asymptomatic subjects on CCTA found significant CAD over 70%, and it was concluded that screening CCTA for CAD showed prognostic power in predicting the future occurrence of CAD in asymptomatic people. However, after the completion of the current NIH SCOT-HEART 2 study, it may be possible to determine whether CCTA is appropriate as a screening tool for CAD in asymptomatic healthy individuals.

Interstitial Lung Abnormalities: What Radiologists Should Know

Interstitial lung abnormalities (ILAs) are radiologic abnormalities found incidentally on chest CT that are potentially related to interstitial lung diseases. Several articles have reported that ILAs are associated with increased mortality, and they can show radiologic progression. With the increased recognition of ILAs on CT, the role of radiologists in reporting them is critical. This review aims to discuss the clinical significance and radiologic characteristics of ILAs to facilitate and enhance their management.

Bronchopleural Fistula after Surgery: Therapeutic Efficacy of Bronchial Occluders

Purpose@#To evaluate the usefulness and effectiveness of bronchial occluders in the treatment of postoperative bronchopleural fistula (BPF). @*Materials and Methods@#The subjects of the study were six out of seven postoperative BPF patients who underwent surgery due to tuberculosis or lung cancer between 2009 and 2019. Each patient had a bronchial occluder inserted to treat BPF that occurred after surgery. Of the six patients, five had lung cancers and one had tuberculosis. Five were male and one was female;their ages ranged from 59 to 74 years, with an average of 69 years. The diagnosis of BPF was based on findings from bronchoscopy and CT, and treatment was initiated approximately 1 to 2 weeks after diagnosis. The technical and clinical success of the bronchial occluders in the treatment of BPF was evaluated. The study assessed the postoperative clinical effects of the occluders, survival duration, and additional treatments. @*Results@#All six patients were successfully treated. Clinical success was achieved in five patients, while partial clinical success was achieved in one; there was no clinical failure. No complications during the migration of the device or device perforations were observed. Two patients were diagnosed with BPF by CT, while four were diagnosed by bronchoscopy. Lobectomy, bilobectomy, and pneumonectomy were performed on two patients each. The periods between surgery and diagnosis ranged from 1 to 34 months; the average was 10 months. Four patients (59–103 days; an average of 80.5 days) died and two (313 days, 3331 days) survived. The causes of death were aggravation of the underlying disease (n = 2), pulmonary edema and pleural effusion (n = 1), and pneumonia (n = 1). Additional catheter drainage was performed in one patient, and a chest tube was maintained in two patients. @*Conclusion@#Bronchial occluders are useful and effective in the treatment of BPF after pulmonary resection.

Bronchopleural Fistula after Surgery: Therapeutic Efficacy of Bronchial Occluders

Purpose@#To evaluate the usefulness and effectiveness of bronchial occluders in the treatment of postoperative bronchopleural fistula (BPF). @*Materials and Methods@#The subjects of the study were six out of seven postoperative BPF patients who underwent surgery due to tuberculosis or lung cancer between 2009 and 2019. Each patient had a bronchial occluder inserted to treat BPF that occurred after surgery. Of the six patients, five had lung cancers and one had tuberculosis. Five were male and one was female;their ages ranged from 59 to 74 years, with an average of 69 years. The diagnosis of BPF was based on findings from bronchoscopy and CT, and treatment was initiated approximately 1 to 2 weeks after diagnosis. The technical and clinical success of the bronchial occluders in the treatment of BPF was evaluated. The study assessed the postoperative clinical effects of the occluders, survival duration, and additional treatments. @*Results@#All six patients were successfully treated. Clinical success was achieved in five patients, while partial clinical success was achieved in one; there was no clinical failure. No complications during the migration of the device or device perforations were observed. Two patients were diagnosed with BPF by CT, while four were diagnosed by bronchoscopy. Lobectomy, bilobectomy, and pneumonectomy were performed on two patients each. The periods between surgery and diagnosis ranged from 1 to 34 months; the average was 10 months. Four patients (59–103 days; an average of 80.5 days) died and two (313 days, 3331 days) survived. The causes of death were aggravation of the underlying disease (n = 2), pulmonary edema and pleural effusion (n = 1), and pneumonia (n = 1). Additional catheter drainage was performed in one patient, and a chest tube was maintained in two patients. @*Conclusion@#Bronchial occluders are useful and effective in the treatment of BPF after pulmonary resection.

Erratum: Structural and Functional Features on Quantitative Chest Computed Tomography in the Korean Asian versus the White American Healthy Non-Smokers

Structural and Functional Features on Quantitative Chest Computed Tomography in the Korean Asian versus the White American Healthy Non-Smokers

OBJECTIVE: Considering the different prevalence rates of diseases such as asthma and chronic obstructive pulmonary disease in Asians relative to other races, Koreans may have unique airway structure and lung function. This study aimed to investigate unique features of airway structure and lung function based on quantitative computed tomography (QCT)-imaging metrics in the Korean Asian population (Koreans) as compared with the White American population (Whites). MATERIALS AND METHODS: QCT data of healthy non-smokers (223 Koreans vs. 70 Whites) were collected, including QCT structural variables of wall thickness (WT) and hydraulic diameter (Dh) and functional variables of air volume, total air volume change in the lung (ΔVair), percent emphysema-like lung (Emph%), and percent functional small airway disease-like lung (fSAD%). Mann-Whitney U tests were performed to compare the two groups. RESULTS: As compared with Whites, Koreans had smaller volume at inspiration, ΔVair between inspiration and expiration (p < 0.001), and Emph% at inspiration (p < 0.001). Especially, Korean females had a decrease of ΔVair in the lower lobes (p < 0.001), associated with fSAD% at the lower lobes (p < 0.05). In addition, Koreans had smaller Dh and WT of the trachea (both, p < 0.05), correlated with the forced expiratory volume in 1 second (R = 0.49, 0.39; all p < 0.001) and forced vital capacity (R = 0.55, 0.45; all p < 0.001). CONCLUSION: Koreans had unique features of airway structure and lung function as compared with Whites, and the difference was clearer in female individuals. Discriminating structural and functional features between Koreans and Whites enables exploration of inter-racial differences of pulmonary disease in terms of severity, distribution, and phenotype.

Percutaneous Transabdominal Metallic Stent Placement for Palliation of Afferent Loop Syndrome: A Case Report

The authors report a successful outcome after percutaneous transabdominal placement of a self-expandable metallic stent in a patient who had afferent loop syndrome caused by recurrent common bile duct adenocarcinoma. Enhanced abdominal CT showed marked dilation of the afferent loop adjacent to the anterior peritoneum, multiple hepatic metastases and lymph node metastasis around the choledochojejunal anastomosis site without marked dilation of intrahepatic bile ducts. Percutaneous drainage catheter was successfully placed to the dilated afferent loop just below the abdominal wall. Subsequent successful palliation of the afferent loop obstruction was achieved by placing a self-expandable metallic stent via the transabdominal route with the aid of cone-beam CT.

Transcatheter Arterial Embolization for Acute Arterial Extravasation with Hematoma Formation: Classified the Group as Cause and Their Clinical Outcomes

PURPOSE@#To present our experience in transcatheter arterial embolization (TAE) for hematoma formation related to variable causes. We analyzed the factors that could affect clinical outcomes.@*MATERIALS AND METHODS@#A retrospective study was conducted on 50 patients (24 men, 36 women; mean age, 63.8 years) who were treated for a TAE to control bleeding. Computed tomography (CT) scans showed the formation of hematomas. We classified the patients into three groups depending on the underlying cause of the hematoma i.e., spontaneous, traumatic or iatrogenic groups. We evaluated relevant factors such as sex, age, hematoma size and liquefaction, extravasation on CT, injured artery, onset to procedure time, embolization material, hospital day.@*RESULTS@#TAE was successfully performed in all patients. The proportions of patients in the spontaneous, traumatic, and iatrogenic bleeding groups were 36% (18/50), 42% (21/50), and 22% (11/50), respectively. Using the Mann Whitney U test, the international normalized ratio (INR) was statistically different for the spontaneous bleeding group (p = 0.013). In addition, the INR (p = 0.038) and platelet count (p = 0.004) were significant different for the traumatic group. Also, the platelet counts were related to clinical successes (p = 0.046).@*CONCLUSION@#Based our experience, TAE is a safe and effective treatment option for the management of hematoma formation. Furthermore, the interventional radiologist should consider the cause of hematoma formation in order to perform proper treatment.

CT Quantification of Lungs and Airways in Normal Korean Subjects

OBJECTIVE: To measure and compare the quantitative parameters of the lungs and airways in Korean never-smokers and current or former smokers (“ever-smokers”). MATERIALS AND METHODS: Never-smokers (n = 119) and ever-smokers (n = 45) who had normal spirometry and visually normal chest computed tomography (CT) results were retrospectively enrolled in this study. For quantitative CT analyses, the low attenuation area (LAA) of LAA(I-950), LAA(E-856), CT attenuation value at the 15th percentile, mean lung attenuation (MLA), bronchial wall thickness of inner perimeter of a 10 mm diameter airway (Pi10), total lung capacity (TLC(CT)), and functional residual capacity (FRC(CT)) were calculated based on inspiratory and expiratory CT images. To compare the results between groups according to age, sex, and smoking history, independent t test, one way ANOVA, correlation test, and simple and multiple regression analyses were performed. RESULTS: The values of attenuation parameters and volume on inspiratory and expiratory quantitative computed tomography (QCT) were significantly different between males and females (p < 0.001). The MLA and the 15th percentile value on inspiratory QCT were significantly lower in the ever-smoker group than in the never-smoker group (p < 0.05). On expiratory QCT, all lung attenuation parameters were significantly different according to the age range (p < 0.05). Pi10 in ever-smokers was significantly correlated with forced expiratory volume in 1 second/forced vital capacity (r = −0.455, p = 0.003). In simple and multivariate regression analyses, TLC(CT), FRC(CT), and age showed significant associations with lung attenuation (p < 0.05), and only TLC(CT) was significantly associated with inspiratory Pi10. CONCLUSION: In Korean subjects with normal spirometry and visually normal chest CT, there may be significant differences in QCT parameters according to sex, age, and smoking history.

A Review of the Use of Cardiac Computed Tomography for Evaluating the Mitral Valve before and after Mitral Valve Repair

The role of cardiac computed tomography (CT) for evaluating the mitral valve (MV) has been limited since echocardiography is the main method of evaluation. However, recent advances in cardiac CT have enable detailed evaluation of the anatomy and geometry of the MV. We describe assessments of the anatomy and coaptation geometric parameters of normal MVs, and also review repair of diseased/damaged MV. We also discuss pre- and post-surgical imaging of MV pathology using cardiac CT and various CT images. We found that cardiac CT could be used as an alternative imaging modality to echocardiography for pre-operative MV evaluation and to predict clinical outcomes following repair.

A Review of the Use of Cardiac Computed Tomography for Evaluating the Mitral Valve before and after Mitral Valve Repair

The role of cardiac computed tomography (CT) for evaluating the mitral valve (MV) has been limited since echocardiography is the main method of evaluation. However, recent advances in cardiac CT have enable detailed evaluation of the anatomy and geometry of the MV. We describe assessments of the anatomy and coaptation geometric parameters of normal MVs, and also review repair of diseased/damaged MV. We also discuss pre- and post-surgical imaging of MV pathology using cardiac CT and various CT images. We found that cardiac CT could be used as an alternative imaging modality to echocardiography for pre-operative MV evaluation and to predict clinical outcomes following repair.

Comparison of Iohexol-380 and Iohexol-350 for Coronary CT Angiography: A Multicenter, Randomized, Double-Blind Phase 3 Trial

OBJECTIVE: This multi-center, randomized, double-blind, phase 3 trial was conducted to compare the safety and efficacy of contrast agents iohexol-380 and iohexol-350 for coronary CT angiography in healthy subjects. MATERIALS AND METHODS: Volunteers were randomized to receive 420 mgI/kg of either iohexol-350 or iohexol-380 using a flow rate of 4 mL/sec. All adverse events were recorded. Two blinded readers independently reviewed the CT images and conflicting results were resolved by a third reader. Luminal attenuations (ascending aorta, left main coronary artery, and left ventricle) in Hounsfield units (HUs) and image quality on a 4-point scale were calculated. RESULTS: A total of 225 subjects were given contrast media (115 with iohexol-380 and 110 with iohexol-350). There was no difference in number of adverse drug reactions between groups: 75 events in 56 (48.7%) of 115 subjects in the iohexol-380 group vs. 74 events in 51 (46.4%) of 110 subjects in the iohexol-350 group (p = 0.690). No severe adverse drug reactions were recorded. Neither group showed an increase in serum creatinine. Significant differences in mean density between the groups was found in the ascending aorta: 375.8 ± 71.4 HU with iohexol-380 vs. 356.3 ± 61.5 HU with iohexol-350 (p = 0.030). No significant differences in image quality scores between both groups were observed for all three anatomic evaluations (all, p > 0.05). CONCLUSION: Iohexol-380 provides improved enhancement of the ascending aorta and similar attenuation of the coronary arteries without any increase in adverse drug reactions, as compared with iohexol-350 using an identical amount of total iodine.

Intra-Individual, Inter-Vendor Comparison of Diffusion-Weighted MR Imaging of Upper Abdominal Organs at 3.0 Tesla with an Emphasis on the Value of Normalization with the Spleen

OBJECTIVE: To compare the apparent diffusion coefficient (ADC) values of upper abdominal organs with 2 different 3.0 tesla MR systems and to investigate the usefulness of normalization using the spleen. MATERIALS AND METHODS: Forty-one patients were enrolled in this prospective study, of which, 35 patients (M:F, 27:8; mean age ± standard deviation, 62.3 ± 12.3 years) were finally analyzed. In addition to the routine liver MR protocol, single-shot spin-echo echo-planar diffusion-weighted imaging using b values of 0, 50, 400, and 800 s/mm2 in 2 different MR systems was performed. ADC values of the liver, spleen, pancreas, kidney and liver lesion (if present) were measured and analyzed. ADC values of the spleen were used for normalization. The Pearson correlation, Spearman correlation, paired sample t test, Wilcoxon signed rank test and Bland-Altman method were used for statistical analysis. RESULTS: For all anatomical regions and liver lesions, both non-normalized and normalized ADC values from 2 different MR systems showed significant correlations (r = 0.5196-0.8488). Non-normalized ADC values of both MR systems differed significantly in all anatomical regions and liver lesions (p < 0.001). However, the normalized ADC of all anatomical regions and liver lesions did not differ significantly (p = 0.065-0.661), with significantly lower coefficient of variance than that of non-normalized ADC (p < 0.009). CONCLUSION: Normalization of the abdominal ADC values using the spleen as a reference organ reduces differences between different MR systems, and could facilitate consistent use of ADC as an imaging biomarker for multi-center or longitudinal studies.

Cryoablation of a Small Pulmonary Nodule with Pure Ground-Glass Opacity: A Case Report

Treatments for pure ground-glass nodules (GGNs) include limited resection; however, surgery is not always possible in patients with limited pulmonary functional reserve. In such patients, cryoablation may be a suitable alternative to treat a pure GGN. Here, we report our initial experience with cryoablation of a pure GGN that remained after repeated surgical resection in a patient with multiple GGNs. A 5-mm-sized pure GGN in the left lower lobe was cryoablated successfully without recurrence at the 6-month follow-up.

Primary Inflammatory Myofibroblastic Tumors of the Breast with Metastasis: Radiographic and Histopathologic Predictive Factors / 한국유방암학회지

Primary inflammatory myofibroblastic tumors (IMTs) of the breast are uncommon and metastasis of IMTs is extremely rare. To date, the natural course of this disease is not fully understood. Although patients with IMTs should undergo regular follow-up after complete surgical resection of the tumor, the appropriate interval and method of follow-up are unclear. We report the case of a patient with an IMT of the breast that metastasized 2 years after complete surgical resection. This unusual case emphasizes the importance of preoperative examinations to determine whether the IMT has atypical features that should guide the interval and method of follow-up.

A Quantitative Study of Airway Changes on Micro-CT in a Mouse Asthma Model: Comparison With Histopathological Findings

PURPOSE: To evaluate airway changes in ovalbumin-induced asthmatic mice in terms of postmortem micro-CT images and pathological findings. METHODS: Asthma was induced in mice by intraperitoneal injection and nasal instillation of ovalbumin aluminium hydroxide into mice (experimental group, n=6), and another group of mice received intraperitoneal injection and nasal instillation of distilled phosphate-buffered saline (control group, n=6). Bronchial lumen area was measured in the main bronchial lumen of the distal third bronchial branch level (6 parts per each mouse) on axial scans of Micro-CT, using a Lucion's smart pen (semi-automated) and a curve pen (manual). Bronchial wall thickness was obtained in 4 sections (2 levels on either side) after the third bronchial branch by measuring the diameter which was perpendicular to the longitudinal axis of the main bronchus on curved Multi-planar reconstruction (MPR) images. Histologic slides were obtained from the lesion that was matched with its CT images, and bronchial wall thicknesses were determined. RESULTS: The mean bronchial lumen area was 0.196+/-0.072 mm2 in the experimental group and 0.243+/-0.116 mm2 in the control group; the difference was significant. Bronchial wall thickness on micro-CT images (mean, 0.119+/-0.01 vs. 0.108+/-0.013 mm) and in pathological specimens (mean, 0.066+/-0.011 vs. 0.041+/-0.009 mm) were thicker in the experimental group than in the control group; bronchial wall thickness on micro-CT images correlated well with pathological thickness (for the experimental group, r=0.712; for the control group, r=0.46). The thick bronchial wall in the experimental group demonstrated submucosal hypertrophy along with goblet cell hyperplasia and smooth muscle hyperplasia. CONCLUSIONS: The results of this study suggest that asthma may induce thickening of bronchial wall and narrowing of the lumen area on micro-CT images and that these results may significantly correlate with pathological findings.

Serial Micro-CT Assessment of the Therapeutic Effects of Rosiglitazone in a Bleomycin-Induced Lung Fibrosis Mouse Model

OBJECTIVE: The aim of this study was to assess the therapeutic effects of rosiglitazone with serial micro-CT findings before and after rosiglitazone administration in a lung fibrosis mouse model induced with bleomycin. MATERIALS AND METHODS: We instilled the bleomycin solution directly into the trachea in twenty mice (female, C57BL/6 mice). After the instillation with bleomycin, mice were closely observed for 3 weeks and then all mice were scanned using micro-CT without sacrifice. At 3 weeks, the mice were treated with rosiglitazone on days 21 to 27 if they had abnormal CT findings (n = 9, 45%). For the mice treated with rosiglitazone, we performed micro-CT with mouse sacrifice 2 weeks after the rosiglitazone treatment completion. We assessed the abnormal CT findings (ground glass attenuation, consolidation, bronchiectasis, reticular opacity, and honeycombing) using a five-point scale at 3 and 6 weeks using Wilcoxon-signed ranked test. The micro-CT findings were correlated with the histopathologic results. RESULTS: One out of nine (11.1%) mice improved completely. In terms of consolidation, all mice (100%) showed marked decrease from 3.1 +/- 1.4 at 3 weeks to 0.9 +/- 0.9 at 6 weeks (p = 0.006). At 6 weeks, mild bronchiectasis (n = 6, 66.7%), mild reticular opacity (n = 7, 77.8%) and mild honeycomb patterns (n = 3, 33.3%) appeared. CONCLUSION: A serial micro-CT enables the evaluation of drug effects in a lung fibrosis mouse model.

Assessment of Therapeutic Response of Ablated Lesion after Radiofrequency Ablation in Patients with Unresectable Lung Malignancies by Multiphase Contrast-enhanced MRI

PURPOSE: We evaluated which phase was important to recognize local progression of an ablated zone after RFA on multiphase contrast-enhanced MRI (CE-MRI) in patients with unresectable lung malignancy. MATERIALS AND METHODS: Twenty patients who had unresectable lung malignancy underwent multiphase CE-MRI examinations immediately after RFA. We evaluated the enhancement patterns of the ablated zone on multiphase CE-MRI: type I, no enhancement of the ablated zone; type II, enhancement of the ablated margin; type III, heterogeneous enhancement of the ablated zone. We evaluated the association enhancement type with local progression of the ablated zone on the follow up CT using Spearman's ranked test. RESULTS: In complete ablation, the enhancement pattern was types I (11.1%) or II (88.9%). In unsuccessfully treated, type II (57.1%) or III (42.9%) pattern observed in the arterial phase. However, types II (21.4%) and III (78.6%) observed in the venous, and types II (7.1%) and III (92.9%) observed equilibrium phases. Local progression of the ablated zone was associated with the enhancement pattern in equilibrium phases (r=0.8, p < .05). CONCLUSION: Equilibrium phases on multiphase CE-MRI might play a more important role in evaluating an ablated zone for predicting local recurrence after RFA.

18F-FDG PET/CT and Sonographic Findings of Thyroid Incidentalomas

PURPOSE: To compare characteristic findings of 18F-FDG PET/CT with ultrasonography of malignant thyroid incidentaloma. MATERIALS AND METHODS: This study enrolled 74 patients receiving ultrasonography after thyroid incidentaloma detected on 18F-FDG PET/CT. We analyzed the size, attenuation, margin, cervical lymphadenopathy, and P-SUV of thyroid incidentaloma in 18F-FDG PET/CT and analyzed the size, internal contents, appearance, border, echo, and calcification patterns of thyroid incidentaloma in ultrasonography. Based on pathologic findings, we investigated findings of 18F-FDG PET/CT and ultrasonography for malignant thyroid incidentaloma. RESULTS: In 18F-FDG PET/CT findings, an ill-defined margin accompanied by cervical lymphadenopathy was more common in malignant (59.1%) than benign (13.2%) lesions (p < 0.05). There were no significant differences in p-SUV between malignant and benign thyroid incidentalomas (4.8+/-18.3 vs. 4.4+/-2.2). In ultrasonographic findings, being taller than wide (1.9% vs. 36.4%), having a well-defined speculated margin (75.5% vs. 22.7%), having marked hypoechoic images (18.9% vs. 31.8%), and having micro (5.7% vs. 22.7%) or macrocalcifications (3.8% vs. 27.3%) were more common in malignant thyroid incidentalomas (p < 0.05). CONCLUSION: Malignant thyroid incidentalomas in 18F-FDG PET/CT have ill-defined margins, and those in ultrasonography were the taller than wide, well defined spiculated margin, and showed micro or macrocalcification.

Three-Dimensional Brain Surface Rendering Imaging of Cortical Dysplasia

PURPOSE: The study was to evaluate the localization of the abnormal gyral and sulcal patterns obtained by means of brain surface rendering imaging. MATERIALS AND METHODS: Nineteen patients with cortical dysplasia who underwent brain surface rendering MR imaging were included in this study. We acquired MP-RAGE sequence and created the 3-D surface rendering MR images by using VoxelPlus(R). Anatomical locations and configurations of abnormal gyri and sulci were reviewed. RESULTS: Abnormal gyral and sulcal patterns were seen 18 in 19 patients. The configuration and orientation of affected gyri and sulci were clearly evaluated in the brain surface rendering images. In a lissencephaly, the a cortex was not delineated and showed markedly thick and smooth gyral pattern. In a schizencephaly, there were wheel shaped broad gyral pattern around the cleft. In a hemimegalencephaly, an affected hemisphere were enlarged and displayed thick and wide gyral pattern. In CBPS, the insular cortex was exposed and the gyri of the lesion were thickened. In focal cortical dysplasia, there were irregular serrated or thick and enlarged gyri. CONCLUSION: Brain surface rendering MR imaging is useful for the evaluation of a detailed gyral pattern and accurate involvement site of abnormal gyri.