• Title/Summary/Keyword: Multidetector Computed Tomography

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Aortic Unfolding Measurement Using Non-Contrast Cardiac CT: Normal Range of Low-Risk Subjects (관상동맥 석회화 CT에서 측정한 대동맥 전개: 저위험 환자군에서의 정상 범위)

  • Ji Won Lee;Byoung Wook Choi
    • Journal of the Korean Society of Radiology
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    • v.83 no.2
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    • pp.360-371
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    • 2022
  • Purpose This study aimed to assess the factors influencing aortic unfolding (AU) defined by aortic width on coronary artery calcium (CAC) scan and determine the normal limits for AU. Materials and Methods In this retrospective study, we measured AU in 924 asymptomatic subjects who underwent CAC scanning during routine health screening from June 2015 to June 2018. Multivariate regression analysis was used to evaluate the factors influencing AU. After the exclusion of subjects with risk factors associated with AU, 283 subjects were included in the analysis of normal values of AU. Mean AU, standard deviation, and upper normal limit were calculated. Results Sex, age, CAC score, body mass index, body surface area, hypertension, left ventricular hypertrophy, plasma creatinine, and smoking were significantly associated with AU. The mean AU was 102.2 ± 12.8 mm for men and 93.1 ± 10.7 mm for women. AU increased with advancing age (9.6 mm per decade). Conclusion AU determined from a single measurement on CAC scans was associated with cardiovascular risk factors. The normal limits of AU were defined by age, sex, and body surface area in low-risk subjects in this study.

Added Value of the Sliding Sign on Right Down Decubitus CT for Determining Adjacent Organ Invasion in Patients with Advanced Gastric Cancer (진행성 위암 환자에서 인접 장기 침범을 결정하기 위한 우측와위 CT에서의 미끄러짐 징후의 추가적 가치)

  • Kyutae Jeon;Se Hyung Kim;Jeongin Yoo;Se Woo Kim
    • Journal of the Korean Society of Radiology
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    • v.83 no.6
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    • pp.1312-1326
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    • 2022
  • Purpose To investigate the added value of right down decubitus (RDD) CT when determining adjacent organ invasion in cases of advanced gastric cancer (AGC). Materials and Methods A total of 728 patients with pathologically confirmed T4a (pT4a), surgically confirmed T4b (sT4b), or pathologically confirmed T4b (pT4b) AGCs who underwent dedicated stomach-protocol CT, including imaging of the left posterior oblique (LPO) and RDD positions, were included in this study. Two radiologists scored the T stage of AGCs using a 5-point scale on LPO CT with and without RDD CT at 2-week intervals and recorded the presence of "sliding sign" in the tumors and adjacent organs and compared its incidence of appearance. Results A total of 564 patients (77.4%) were diagnosed with pT4a, whereas 65 (8.9%) and 99 (13.6%) patients were diagnosed with pT4b and sT4b, respectively. When RDD CT was performed additionally, both reviewers deemed that the area under the curve (AUC) for differentiating T4b from T4a increased (p < 0.001). According to both reviewers, the AUC for differentiating T4b with pancreatic invasion from T4a increased in the subgroup analysis (p < 0.050). Interobserver agreement improved from fair to moderate (weighted kappa value, 0.296-0.444). Conclusion RDD CT provides additional value compared to LPO CT images alone for determining adjacent organ invasion in patients with AGC due to their increased AUC values and improved interobserver agreement.

Comparison of Metal Artifact Reduction Algorithms in Patients with Hip Prostheses: Virtual Monoenergetic Images vs. Orthopedic Metal Artifact Reduction (고관절 인공치환술 환자에서 금속 인공물 감소 방법의 비교: 가상 단일에너지영상 대 금속 인공물 감소기법)

  • Hye Jin Yoo;Sung Hwan Hong;Ja-Young Choi;Hee Dong Chae
    • Journal of the Korean Society of Radiology
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    • v.83 no.6
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    • pp.1286-1297
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    • 2022
  • Purpose To assess the usefulness of various metal artifact reduction (MAR) methods in patients with hip prostheses. Materials and Methods This retrospective study included 47 consecutive patients who underwent hip arthroplasty and dual-energy CT. Conventional polyenergetic image (CI), orthopedic-MAR (OMAR), and virtual monoenergetic image (VMI, 50-200 keV) were tested for MAR. Quantitative analysis was performed in seven regions around the prostheses. Qualitative assessments included evaluation of the degree of artifacts and the presence of secondary artifacts. Results The lowest amount of image noise was observed in the O-MAR, followed by the VMI. O-MAR also showed the lowest artifact index, followed by high-keV VMI in the range of 120-200 keV (soft tissue) or 200 keV (bone). O-MAR had the highest contrast-to-noise ratio (CNR) in regions with severe hypodense artifacts, while VMI had the highest CNR in other regions, including the periprosthetic bone. On assessment of the CI of pelvic soft tissues, VMI showed a higher structural similarity than O-MAR. Upon qualitative analysis, metal artifacts were significantly reduced in O-MAR, followed by that in VMI, while secondary artifacts were the most frequently found in the O-MAR (p < 0.001). Conclusion O-MAR is the best technique for severe MAR, but it can generate secondary artifacts. VMI at high keV can be advantageous for evaluating periprosthetic bone.

Ossification of the Transverse Ligament of the Atlas on CT: Frequency and Associated Findings (CT를 이용한 환추횡인대 골화증의 빈도와 연관 소견)

  • Sukwoo Son;Jeong Ah Ryu;Tae Yeob Kim;Sungjun Kim;Seunghun Lee
    • Journal of the Korean Society of Radiology
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    • v.81 no.3
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    • pp.654-664
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    • 2020
  • Purpose To determine the frequency of ossification of the transverse ligament of the atlas (OTLA) and to investigate the associated findings on cervical spine CT and plain radiography. Materials and Methods We reviewed 5201 CT scans of the cervical spine of 3975 consecutive patients over an 11-year period for the presence of OTLA and compared them with those of age- and sex-matched controls. The frequency and associated findings of OTLA were investigated and statistically correlated. Results The overall frequency of OTLA was 1.1% (45 of 3975 patients) and increased with age (p < 0.005). The frequency of OTLA in patients over 80 years was 12%. The space available for the spinal cord (SAC) was smaller in patients with OTLA (p < 0.005). Mineralization of the complex of the anterior atlantooccipital membrane and Barkow ligament, ossification of the ligamentum flavum, and kyphosis of the cervical spine positively correlated to the presence of OTLA (p < 0.005). Conclusion OTLA was associated with age, SAC narrowing, cervical kyphosis, and ossification of other cervical ligaments and may be associated with degenerative spondylosis, systemic hyperostotic status, or mechanical stress or instability.

The Effect of Lung Volume on the Size and Volume of Pulmonary Subsolid Nodules on CT: Intraindividual Comparison between Total Lung Capacity and Tidal Volume (전산화단층촬영에서 폐 반고형결절의 크기와 용적에 호흡이 미치는 영향: 개인 내 전폐용량과 일호흡량 간 비교)

  • Hyunji Lee;Chansik An;Seok Jong Ryu
    • Journal of the Korean Society of Radiology
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    • v.82 no.6
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    • pp.1534-1544
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    • 2021
  • Purpose To examine the effect of lung volume on the size and volume of pulmonary subsolid nodules (SSNs) measured on CT. Materials and Methods A total of 42 SSNs from 31 patients were included. CT examination was first performed at total lung capacity (TLC), and a section containing the nodule was additionally scanned at tidal volume (TV). The diameter and volume of each SSN, as well as the cross-sectional lung area containing the nodule, were measured. The significance of the changes in measurements between TLC and TV within the same individuals was evaluated. Results The lung area and the diameter and volume of SSNs decreased significantly at TV by 12.7 cm2, 0.5 mm, and 46.4 mm3 on average, respectively (p < 0.001), compared to those at TLC. Changes in lung area between TV and TLC were positively correlated with the change in SSN diameter (p = 0.027) and volume (p = 0.014). However, after correction (by considering the change in lung area), the changes in SSN diameter (p = 0.124) and volume (p = 0.062) were not significantly different. Conclusion SSN size and volume can be significantly affected by lung volume during CT scans of the same individuals.

Diagnostic Accuracy of CT for Evaluating Circumferential Resection Margin Status in Resectable or Borderline Resectable Pancreatic Head Cancer: A Prospective Study Using Axially Sliced Surgical Pathologic Correlation

  • Ji Hoon Park;Yoo-Seok Yoon;Seungjae Lee;Hae Young Kim;Ho-Seong Han;Jun Suh Lee;Won Chang;Haeryoung Kim;Hee Young Na;Seungyeob Han;Kyoung Ho Lee
    • Korean Journal of Radiology
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    • v.23 no.3
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    • pp.322-332
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    • 2022
  • Objective: CT plays a central role in determining the resectability of pancreatic cancer, which directs the use of neoadjuvant therapy. This study aimed to assess the diagnostic accuracy of CT in predicting circumferential resection margin (CRM) involvement in patients with resectable or borderline resectable pancreatic head cancer. Materials and Methods: Seventy-seven patients who were scheduled for upfront surgery for resectable or borderline resectable pancreatic head cancer were prospectively enrolled, and 75 patients (38 male and 37 female; mean age ± standard deviation, 68 ± 11 years) were finally analyzed. The CRM status was evaluated separately for the superior mesenteric artery (SMA) and posterior and superior mesenteric vein/portal vein (SMV/PV) margins. Three independent radiologists reviewed the preoperative CT images and evaluated the resection margin status. The reference standard for CRM status was pathologic examination of pancreaticoduodenectomy specimens in an axial plane perpendicular to the axis of the second portion of the duodenum. The diagnostic accuracy of CT was assessed for overall CRM involvement, defined as involvement of the SMA or posterior margins (per-patient analysis), and involvement of each of the three resection margins (per-margin analysis). The data were pooled using a crossed random effects model. Results: Forty patients had pathologically confirmed overall CRM involvement in pancreatic cancer, while CRM involvement was not seen in 35 patients. For overall CRM involvement, the pooled sensitivity and specificity were 15% (95% confidence interval: 7%-49%) and 99% (96%-100%), respectively. For each of the resection margins, the pooled sensitivity and specificity were 14% (9%-54%) and 99% (38%-100%) for the SMA margin, 12% (8%-46%) and 99% (97%-100%) for the posterior margin; and 37% (29%-53%) and 96% (31%-100%) for the SMV/PV margin, respectively. Conclusion: CT showed very high specificity but low sensitivity in predicting pathological CRM involvement in pancreatic cancer.

Comparison of the Efficacy of Diluted Polyethylene Glycol and Low-Density (0.1% w/v) Barium Sulfate Suspension for CT Enterography (전산화단층촬영 소장조영술을 위한 희석된 폴리에틸렌 글리콜과 저밀도(0.1% w/v) 바륨 현탁액의 유용성 비교)

  • Yeon Jung Kim;Seung Ho Kim;Tae Wook Baek;Hyungin Park
    • Journal of the Korean Society of Radiology
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    • v.84 no.4
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    • pp.911-922
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    • 2023
  • Purpose To compare small bowel distension and side effects between a diluted polyethylene glycol (PEG) solution and a low-density (0.1% w/v) barium sulfate suspension (LDBSS) for CT enterography (CTE) preparation. Materials and Methods Total 173 consecutive patients who underwent CTE were enrolled in this study. The LDBSS (1 L) was used in 50 patients, and the diluted iso-osmotic PEG solution (1 L) was used in 123 patients. Two blinded radiologists independently scored jejunal and ileal distensions on a 5-point scale. To compare side effects between the two groups, the patients reported whether they had immediate complications after the administration of the oral contrast media. Results For ileal and jejunal distension, the diluted PEG solution showed no difference from the LDBSS for either reader (ileum: reader 1, median, 4; 4, interquartile range, 3-4; 3-4, p = 0.997; reader 2, median, 4; 4, interquartile range, 3.3-4.0; 3-4, p = 0.064; jejunum: reader 1, median, 2; 2, interquartile range, 2-3; 2-3, p = 0.560; reader 2, median, 3; 2, interquartile range, 2-3; 2-3, p = 0.192). None of the patients complained of immediate complications following administration of either of the oral contrast media. Conclusion The diluted PEG solution showed comparable bowel distension compared to LDBSS and no immediate side effects; thus, it can be a useful alternative.

Diagnostic Performance of Cardiac CT and Transthoracic Echocardiography for Detection of Surgically Confirmed Bicuspid Aortic Valve: Effect of Calcium Extent and Valve Subtypes (외과적으로 확진된 이첨 대동맥 판막의 진단을 위한 심장 CT 및 경흉부 심초음파의 진단적 성능: 판막 아형 및 칼슘의 양이 미치는 효과)

  • Jeongju Kim;Sung Mok Kim;Joonghyun Ahn;Jihoon Kim;Yeon Hyeon Choe
    • Journal of the Korean Society of Radiology
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    • v.84 no.6
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    • pp.1324-1336
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    • 2023
  • Purpose This study aimed to compare the diagnostic performance of cardiac CT and transthoracic echocardiogram (TTE) depending on the degree of valvular calcification and bicuspid aortic valve (BAV) subtype. Materials and Methods This retrospective study included 266 consecutive patients (106 with BAV and 160 with tricuspid aortic valve) who underwent cardiac CT and TTE before aortic valve replacement. Cardiac CT was used to evaluate the morphology of the aortic valve, and a calcium scoring scan was used to quantify valve calcium. The aortic valves were classified into fused and two-sinus types. The diagnostic accuracy of cardiac CT and TTE was calculated using a reference standard for intraoperative inspection. Results CT demonstrated significantly higher sensitivity, negative predictive value, and accuracy than TTE in detecting BAV (p < 0.001, p < 0.001, and p = 0.003, respectively). The TTE sensitivity tended to decrease as valvular calcification increased. The error rate of TTE for CT was 10.9% for the twosinus type of BAV and 28.3% for the fused type (p = 0.044). Conclusion Cardiac CT had a higher diagnostic performance in detecting BAV than TTE and may help diagnose BAV, particularly in patients with severe valvular calcification.

Detection of Monosodium Urate Crystal of Hand and Wrist in Suspected Gouty Arthritis Patients on Dual-Energy CT and Relationship with Serum Urate Level (손과 손목의 통풍관절염에서 이중에너지 CT를 이용한 요산나트륨 결정 검출과 혈중 요산 농도와의 관계)

  • Hana Choi;Jeongah Ryu;Seunghun Lee;Yeo Ju Kim;Soyoung Bang
    • Journal of the Korean Society of Radiology
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    • v.84 no.1
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    • pp.212-225
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    • 2023
  • Purpose We retrospectively investigated the characteristics of patients with monosodium urate (MSU) deposits of the hand and wrist on dual-energy CT (DECT) compared to those without. We also attempted to determine the pattern of MSU distribution in DECT. Materials and Methods In total, 93 patients were included who had undergone DECT for evaluation of the hand or wrist pain under the clinical impression of gouty arthritis. The total volume of MSU deposits on DECT was calculated and the pattern of MSU distribution on DECT was analyzed. Also, the level of the serum urate at the time of DECT and the highest level of the serum urate of the patients were obtained from their records and the relationship between MSU and serum urate level was evaluated. Results The range of the volume of MSU deposits on DECT was 0.01-16.11 cm3 (average: 1.07 cm3). The average level of serum urate was significantly higher in the MSU positive group than that in the MSU negative group. MSU deposits were most frequently observed in the wrists followed by fingers and digitorum tendons. Conclusion On DECT, MSU deposits were most frequently detected in the wrist and related with high serum urate level.

Clinicoradiological Features of Pulmonary Cryptococcosis in Immunocompetent Patients (정상 면역 환자에서 폐 크립토코쿠스증의 임상방사선학적 특징)

  • Hong Seok Choi;Yun-Hyeon Kim;Won Gi Jeong;Jong Eun Lee;Hye Mi Park
    • Journal of the Korean Society of Radiology
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    • v.84 no.1
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    • pp.253-262
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    • 2023
  • Purpose To assess the clinicoradiological features of pulmonary cryptococcosis in immunocompetent patients. Materials and Methods This retrospective study included immunocompetent patients who had been diagnosed with pulmonary cryptococcosis on the histopathologic exam and underwent chest CT between January 2008 and November 2019. Imaging features were divided into major imaging patterns, distributions, and ancillary imaging findings. Univariable analysis was performed to evaluate clinicoradiological features according to the presence of serum cryptococcal antigen. Results Thirty-one patients were evaluated (mean age: 60 years, range: 19-78 years). A single nodular lesion confined to a single lobe was the most common imaging pattern (14/31, 45.2%). Serum cryptococcal antigen tests were performed in 19 patients (19/31, 61.3%). The presence of serum cryptococcal antigen was observed in six patients (6/19, 31.6%), all of whom showed a consolidation-dominant pattern. The presence of serum cryptococcal antigen was significantly associated with the consolidationdominant pattern compared to those associated with a nodule-dominant pattern (p = 0.011). Conclusion A combination of CT findings of consolidation and a positive serum cryptococcal antigen test may be helpful for diagnosing pulmonary cryptococcosis in immunocompetent patients.