• Korean Journal of Radiology
• /
• 제21권11호
• /
• pp.1230-1238
• /
• 2020

Objective: We aimed to assess the effects of remote ischemic pre-conditioning (RIPC) on the incidence of contrast-induced nephropathy (CIN) after an intravenous (IV) or intra-arterial injection of contrast medium (CM) in patient and control groups. Materials and Methods: This prospective, randomized, single-blinded, controlled trial included 26 patients who were hospitalized for the evaluation of the feasibility of transcatheter aortic valve implantation and underwent investigations including contrast-enhanced computed tomography (CT), with Mehran risk scores greater than or equal to six. All the patients underwent four cycles of five minute-blood pressure cuff inflation followed by five minutes of total deflation. In the RIPC group (n = 13), the cuff was inflated to 50 mm Hg above the patient's systolic blood pressure (SBP); in the control group (n = 13), it was inflated to 10 mm Hg below the patient's SBP. The primary endpoint was the occurrence of CIN. Additionally, variation in the serum levels of cystatin C was assessed. Results: One case of CIN was observed in the control group, whereas no cases were detected in the RIPC group (p = 0.48, analysis of 25 patients). Mean creatinine values at the baseline, 24 hours after injection of CM, and 48 hours after injection of CM were 88 ± 32 μmol/L, 91 ± 28 μmol/L and 82 ± 29 μmol/L, respectively (p = 0.73) in the RIPC group, whereas in the control group, they were 100 ± 36 μmol/L, 110 ± 36 μmol/L, and 105 ± 34 μmol/L, respectively (p = 0.78). Cystatin C values (median [Q1, Q3]) at the baseline, 24 hours after injection of CM, and 48 hours after injection of CM were 1.10 [1.08, 1.18] mg/L, 1.17 [0.97, 1.35] mg/L, and 1.12 [0.99, 1.24] mg/L, respectively (p = 0.88) in the RIPC group, whereas they were 1.11 [0.97, 1.28] mg/L, 1.13 [1.08, 1.25] mg/L, and 1.16 [1.03, 1.31] mg/L, respectively (p = 0.93), in the control group. Conclusion: The risk of CIN after an IV injection of CM is very low in patients with Mehran risk score greater than or equal to six and even in the patients who are unable to receive preventive hyperhydration. Hence, the Mehran risk score may not be an appropriate method for the estimation of the risk of CIN after IV CM injection.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제15권2호
• /
• pp.102-110
• /
• 2015

The main source of noise in computed tomography (CT) images is a quantum noise, which results from statistical fluctuations of X-ray quanta reaching the detector. This paper proposes a neural network (NN) based hybrid filter for removing quantum noise. The proposed filter consists of bilateral filters (BFs), a single or multiple neural edge enhancer(s) (NEE), and a neural filter (NF) to combine them. The BFs take into account the difference in value from the neighbors, to preserve edges while smoothing. The NEE is used to clearly enhance the desired edges from noisy images. The NF acts like a fusion operator, and attempts to construct an enhanced output image. Several measurements are used to evaluate the image quality, like the root mean square error (RMSE), the improvement in signal to noise ratio (ISNR), the standard deviation ratio (MSR), and the contrast to noise ratio (CNR). Also, the modulation transfer function (MTF) is used as a means of determining how well the edge structure is preserved. In terms of all those measurements and means, the proposed filter shows better performance than the guided filter, and the nonlocal means (NLM) filter. In addition, there is no severe restriction to select the number of inputs for the fusion operator differently from the neuro-fuzzy system. Therefore, without concerning too much about the filter selection for fusion, one could apply the proposed hybrid filter to various images with different modalities, once the corresponding noise characteristics are explored.

• Journal of Korean Neurosurgical Society
• /
• 제49권6호
• /
• pp.351-354
• /
• 2011

Objective : This investigation was conducted to evaluate a new, safe entry point for the C2 pedicle screw, determined using the anatomical landmarks of the C2 lateral mass, the lamina, and the isthmus of the pars interarticularis. Methods : Fifteen patients underwent bilateral C1 lateral mass-C2 pedicle screw fixation, combined with posterior wiring. The C2 pedicle screw was inserted at the entry point determined using the following method : 4 mm lateral to and 4 mm inferior to the transitional point (from the superior end line of the lamina to the isthmus of the pars interarticularis). After a small hole was made with a high-speed drill, the taper was inserted with a 30 degree convergence in the cephalad direction. Other surgical procedures were performed according to Harm's description. Preoperatively, careful evaluation was performed with a cervical X-ray for C1-C2 alignment, magnetic resonance imaging for spinal cord and ligamentous structures, and a contrast-enhanced 3-dimensional computed tomogram (3-D CT) for bony anatomy and the course of the vertebral artery. A 3-D CT was checked postoperatively to evaluate screw placement Results : Bone fusion was achieved in all 15 patients (100%) without screw violation into the spinal canal, vertebral artery injury, or hardware failure. Occipital neuralgia developed in one patient, but this subsided after a C2 ganglion block. Conclusion : C2 transpedicular screw fixation can be easily and safely performed using the entry point of the present study. However, careful preoperative radiographic evaluation, regardless of methods, is mandatory.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권1호
• /
• pp.321-326
• /
• 2015

Background: The aim of this study was to explore the prognostic role of metabolic response to chemotherapy, determined by FDG-PET, in patients with metastatic non-small-cell lung cancer (NSCLC). Materials and Methods: Thirty patients with metastatic NSCLC were analyzed for prognostic factors related to overall survival (OS) and progression free survival (PFS). Disease evaluation was conducted with FDG-PET/CT and contrast-enhanced CT prior to and at the end of first-line chemotherapy. Response evaluation of 19 of 30 patients was also performed after 2-3 cycles of chemotherapy. Morphological and metabolic responses were assessed according to RECIST and PERCIST, respectively. Results: The median OS and PFS were 11 months and 6.2 months, respectively. At the end of first-line chemotherapy, 10 patients achieved metabolic and anatomic responses. Of the 19 patients who had an interim response analysis after 2-3 cycles of chemotherapy, 3 achieved an anatomic response, while 9 achieved a metabolic response. In univariate analyses, favorable prognostic factors for OS were number of cycles of first-line chemotherapy, and achieving a response to chemotherapy at completion of therapy according to the PERCIST and RECIST. The OS of patients with a metabolic response after 2-3 cycles of chemotherapy was also significantly extended. Anatomic response at interim analysis did not predict OS, probably due to few patients with anatomic response. In multivariate analyses, metabolic response after completion of therapy was an independent prognostic factor for OS. Conclusions: Metabolic response is at least as effective as anatomic response in predicting survival. Metabolic response may be an earlier predictive factor for treatment response and OS in NSCLC patients.

• Tuberculosis and Respiratory Diseases
• /
• 제78권4호
• /
• pp.371-374
• /
• 2015

Pulmonary pneumatoceles are air-filled thin-walled spaces within the lung and are rare in adult cases of pneumonia. We report the case of a 74-year-old male who was admitted with a cough and sputum production. He had been treated with oral dexamethasone since a brain tumorectomy 6 months prior. Contrast-enhanced computed tomography (CT) of the chest revealed a large pneumatocele in the right middle lobe and peripheral pneumonic consolidation. Bronchoalveolar lavage was performed; cultures identified extended-spectrum ${\beta}$-lactamase (ESBL) producing Proteus mirabilis. A 4-week course of intravenous ertapenem was administered, and the pneumatocele with pneumonia resolved on follow-up chest CT. To the best of our knowledge, this is the first reported case of pulmonary pneumatocele caused by ESBL-producing P. mirabilis associated with pneumonia.

• Tuberculosis and Respiratory Diseases
• /
• 제56권1호
• /
• pp.85-90
• /
• 2004

Rasmussen 동맥류는 공동성 폐결핵에 동반되어 종종 대량객혈을 일으킬 수 있어 임상적으로 중요하다. 그동안 이의 존재나 치료에 대한 보고는 간헐적으로 있어왔으나 본 증례와 같이 기관지내시경으로 직접 병변을 관찰하고 나선식 CT로 Rasmussen 동맥류의 존재를 확인한 경우는 없어 이에 보고하는 바이다. 또한 기관지 내시경 검사시 발견되는 종양 형태의 병변에는 이와 같은 혈관성병변도 있을 수 있으므로 생검 등의 침습적 검사시에 보다 신중해질 필요가 있으며, 기존 질환이 진행된 공동성 폐결핵일 경우에는 더욱 주의를 필요로 한다.

• Journal of Magnetics
• /
• 제20권1호
• /
• pp.40-46
• /
• 2015

This study investigated the accuracy of magnetic resonance angiography (MRA) and computed tomography angiography (CTA) in terms of reflecting the actual vascular length. Three-dimensional time of flight (3D TOF) MRA, 3D contrast-enhanced (CE) MRA, volume-rendering after CTA and maximum intensity projection were investigated using a flow model phantom with a diameter of 2.11 mm and area of $0.26cm^2$. 1.5 and 3.0 Tesla devices were used for 3D TOF MRA and 3D CE MRA. CTA was investigated using 16 and 64 channel CT scanners, and the images were transmitted and reconstructed by volume-rendering and maximum intensity projection, followed by conduit length measurement as described above. The smallest 3D TOF MRA measure was $2.51{\pm}0.12mm$ with a flow velocity of 40 cm/s using the 3.0 Tesla apparatus, and $2.57{\pm}0.07mm$ with a velocity of 71.5 cm/s using the 1.5 Tesla apparatus; both images were magnified from the actual measurement of 2.11 mm. The measurement with the 16 channel CT scanner was smaller ($3.83{\pm}0.37mm$) than the reconstructed image on maximum intensity projection. The images from CTA from examination apparatus and reconstruction technique were all larger than the actual measurement.

• 대한영상의학회지
• /
• 제82권2호
• /
• pp.487-492
• /
• 2021

Immunoglobulin G4 (이하 IgG4)연관 질환은 풍부한 IgG4 형질세포 형태의 림프형질 세포 침윤과 현저한 섬유아세포 증식을 특징으로 하는 전신 질환이다. 일반적으로 IgG4 연관 질환의 후복막강 발현은 복부 대동맥을 둘러싸거나, 요관을 압박하여 수신증을 일으키는 연조직의 형태로 나타난다. 우리는 75세 여성 환자에서 발생한 비전형적인 IgG4 연관 질환의 후복막강 발현에 대해 보고하고자 한다. 수술 전 전산화단층촬영에서 정상 해부학적 경계를 넘어서는 침윤성 성질을 가진 불규칙한 형태의 후복막강의 종괴가 관찰되었으며, 이는 악성 혹은 염증성 상태가 의심되었다. 조영증강 촬영에서 종괴는 균일한 점진적인 조영증강을 보였다.

• 대한영상의학회지
• /
• 제82권5호
• /
• pp.1334-1340
• /
• 2021

아밀로이드증과 비호지킨림프종과의 연관관계는 이전의 연구들에서 보고된 바 있다. 림프종과 아밀로이드증과의 연관관계는 두 개의 구분되는 범주로 나뉘는데 림프종 연관 전신성 아밀로이드증과 종괴 주위 아밀로이드증이다. 저자들은 두경부 MALT 림프종 환자에서 발생한 국소적 종괴 주위 아밀로이드증의 드문 증례를 보고하고자 한다. 전산화단층촬영에서 병변은 연조직음영을 보이는 무정형석회화를 동반한 불규칙한 모양의 종괴였으며, 조영증강 시 불균일한 조영증강을 보였다. 자기공명영상에서는 종괴가 T1 강조영상과 T2 강조영상에서 모두 불균일한 낮은 신호 강도를 보였다. 종괴는 강한 조영증강을 보였으며, 내부에는 여러 개의 조영증강되지 않는 부분들을 포함하고 있었다. 림프종 환자에서 치료 전 영상검사에서 발견된 석회화들은 종괴 주위 아밀로이드증과 같은 동반된 다른 이차성 병변을 시사하는 소견이 될 수 있을 것이다.

• 대한핵의학회지
• /
• 제35권4호
• /
• pp.280-285
• /
• 2001

We present a case of a 31 year-old male patient with tuberculous pericarditis with mediastinal mass that showed increased uptake on Gallium-67 image. Gallium-67 scan was performed to evaluate the activity of the superior mediastinal mass, which was detected on chest CT. A rim of intense activity around the heart was observed, but increased uptake was not seen in the mediastinum. However, on maximal contrast-enhanced SPECT images, a small focus of faint uptake was observed in the superior mediastinum. This finding implied that there was an active tuberculosis in the pericardium and inflammation in the superior mediastinal mass. This case demonstrated that Gallium-67 scinitigraphy was helpful for the diagnosis of tuberculous pericarditis.