• Journal of radiological science and technology
• /
• v.45 no.2
• /
• pp.145-150
• /
• 2022

The main purpose of this work was to restore the blurry chest CT images by applying a blind deconvolution algorithm. In general, image restoration is the procedure of improving the degraded image to get the true or original image. In this regard, we focused on a blind deblurring approach with chest CT imaging by using digital image processing in MATLAB, which the blind deconvolution technique performed without any whole knowledge or information as to the fundamental point spread function (PSF). For our approach, we acquired 30 chest CT images from the public source and applied three type's PSFs for finding the true image and the original PSF. The observed image might be convolved with an isotropic gaussian PSF or motion blurring PSF and the original image. The PSFs are assumed as a black box, hence restoring the image is called blind deconvolution. For the 30 iteration times, we analyzed diverse sizes of the PSF and tried to approximate the true PSF and the original image. For improving the ringing effect, we employed the weighted function by using the sobel filter. The results was compared with the three criteria including mean squared error (MSE), root mean squared error (RMSE) and peak signal-to-noise ratio (PSNR), which all values of the optimal-sized image outperformed those that the other reconstructed two-sized images. Therefore, we improved the blurring chest CT image by using the blind deconvolutin algorithm for optimal approach.

• Journal of Veterinary Science
• /
• v.23 no.6
• /
• pp.70.1-70.13
• /
• 2022

Background: Fat stranding is a non-specific finding of an increased fat attenuation on computed tomography (CT) images. Fat stranding is used for detecting the underlying lesion in humans. Objectives: To assess the clinical significance of fat stranding on CT images for identifying the underlying cause in dogs and cats. Methods: In this retrospective study, the incidence, location, extent, distribution, and pattern of fat stranding were assessed on CT studies obtained from 134 cases. Results: Fat stranding was found in 38% (51/134) of all cases and in 35% (37/107) of tumors, which was significantly higher in malignant tumors (44%) than benign tumors (12%). Moreover, fat stranding was found in more than two areas in malignant tumors (16/33) and in a single area in benign tumors (4/4). In inflammation, fat stranding was demonstrated in 54% (7/13) in a single area (7/7) as a focal distribution (6/7). In trauma, fat stranding was revealed in 50% (7/14) and most were in multiple areas (6/7). Regardless of the etiologies, fat stranding was always around the underlying lesion and a reticular pattern was the most common presentation. Logistic regression analysis revealed that multiple areas (p = 0.040) of fat stranding and a reticulonodular pattern (p = 0.022) are the significant predictors of malignant tumor. Conclusions: These findings indicated that CT fat stranding can be used as a clue for identifying the underlying lesion and can be useful for narrowing the differential list based on the extent and pattern.

• Korean Journal of Radiology
• /
• v.21 no.7
• /
• pp.891-899
• /
• 2020

Objective: To assess the diagnostic performance of a deep learning-based algorithm for automated detection of acute and chronic rib fractures on whole-body trauma CT. Materials and Methods: We retrospectively identified all whole-body trauma CT scans referred from the emergency department of our hospital from January to December 2018 (n = 511). Scans were categorized as positive (n = 159) or negative (n = 352) for rib fractures according to the clinically approved written CT reports, which served as the index test. The bone kernel series (1.5-mm slice thickness) served as an input for a detection prototype algorithm trained to detect both acute and chronic rib fractures based on a deep convolutional neural network. It had previously been trained on an independent sample from eight other institutions (n = 11455). Results: All CTs except one were successfully processed (510/511). The algorithm achieved a sensitivity of 87.4% and specificity of 91.5% on a per-examination level [per CT scan: rib fracture(s): yes/no]. There were 0.16 false-positives per examination (= 81/510). On a per-finding level, there were 587 true-positive findings (sensitivity: 65.7%) and 307 false-negatives. Furthermore, 97 true rib fractures were detected that were not mentioned in the written CT reports. A major factor associated with correct detection was displacement. Conclusion: We found good performance of a deep learning-based prototype algorithm detecting rib fractures on trauma CT on a per-examination level at a low rate of false-positives per case. A potential area for clinical application is its use as a screening tool to avoid false-negative radiology reports.

• Investigative Magnetic Resonance Imaging
• /
• v.17 no.2
• /
• pp.91-100
• /
• 2013

Purpose : To evaluate the usefulness of cervicothoracic spine sagittal T2-weighted images (CT SAG T2WIs) included in routine lumbar spine MRI. Materials and Methods: Institutional review board approval was obtained and informed consents were waived for this retrospective study. The study group comprised 2,113 patients who underwent lumbar spine MRI from January 2005 to December 2005. CT SAG T2WIs were added in the routine lumbar spine MRIs. Radiologic reports were reviewed retrospectively for pathologic lesions on CT SAG T2WIs by one radiologist. Information of additional cervical or thoracic spine MRI and/or CT for further evaluation of positive findings on CT SAG T2WIs and their treatment were collected by retrospectively reviewing medical records. Results: The CT SAG T2WIs revealed 142 pathologic lesions in 139 (6.58%) of the 2,113 patients. They were easily obtained without positional change in a scan time of less than 2 minutes. Additional cervical or thoracic spine MRI and/or CT for positive findings on CT SAG T2WIs were performed in 13 patients. Seven patients underwent surgical treatment. Conclusion: CT SAG T2WIs included in routine lumbar spine MRI were useful in finding the pathologic lesions in cervicothoracic spine for the patients who assumed to have lesions in lumbar spine.

• Nuclear Medicine and Molecular Imaging
• /
• v.42 no.3
• /
• pp.218-228
• /
• 2008

Purpose: Our purpose was to evaluate spinal bony metastasis which could be missed on an F-18 FDG PET/CT (FDG PET/CT) alone, and to characterize discordant metastatic lesions between FDG PET/CT and bone scan. Material and Methods: FDG PET/CT and bone scans of 43 patients with spinal bony metastasis were analyzed retrospectively. A McNemar test was performed comparing the FDG PET/CT alone to the FDG PET/CT plus bone scan in the spinal bony metastases. A one-way chi-square test was performed to characterize the metastases that were missed on the FDG PET/CT alone. To evaluate discordant lesions between FDG PET/CT and bone scan, we performed logistic regression analyses. The independent variables were sites (cervical, thoracic, and lumbar), size (large and small), and maximum SUVs, and the dependant variable was bone scan uptake (positive and negative MDP uptake). Results: A significant difference was found between the FDG PET/CT alone and the FDG PET/CT combined with the bone scan (p < 0.01). Using the FDG PET/CT only, diffuse osteoblastic metastasis was missed with a significantly higher frequency (p = 0.04). In the univariate analysis, cervical vertebra and small size were related to negative MDP uptake, and thoracic vertebra and large size were related to positive MDP uptake. However, in the multivariate analysis, only the large size was related to positive MDP uptake. Conclusion: A bone scan in addition to the FDG PET/CT increased the ability to evaluate spinal bony metastases, especially for diffuse osteoblastic metastasis. Large metastasis was related to positive bone scan uptake in spinal bony metastasis.

• The Korean Journal of Pain
• /
• v.12 no.2
• /
• pp.258-262
• /
• 1999

Sacral meningeal cyst is usually asymtomatic, but may be responsible for sciatic pain syndromes and other clinical symptoms. Sacral meningeal cyst might be suspected when definite explanation for the clinical symptom, such as herniation of the intervertebral disc or spinal stenosis is not found. Plain films and CT may suggest the presence of sacral meningeal cyst, but MR is the current imaging study of choice. Evaluation of the correlation between the symptom and the cyst is as important as detection of it. We have experienced a case of sacral meningeal cyst detected during caudal epidural block. The patient complained of low back pain radiating to thigh. Plain films and lumbar spine CT showed no remarkable finding except disc bulging. During caudal epidural needle insertion, there was leakage of clear CSF, and intrasacral cystic shadow was visualized by dye injection. MR confirmed sacral meningeal cyst.

• Journal of Chest Surgery
• /
• v.50 no.4
• /
• pp.295-297
• /
• 2017

A 27-year-old man was admitted with a penetrating injury at the mid-manubrium. Computed tomographic (CT) angiography showed a f illing def ect in the aortic arch. This was evaluated as a sign of injury and the patient underwent an emergency operation. No active bleeding or clot was f ound in the mediastinum during the operation. The laceration point was between the innominate and the left carotid artery posteriorly. The injury was approached using hypothermic circulatory arrest. Aortotomy and exploration showed a 2-cm-long full-thickness aortic injury with an overlying clot. A filling defect on angiography as a sign of a penetrating arch injury has never been reported previously, but was the main pathological finding on CT angiography in our case. The aorta is a high-pressure system and injuries to it should be treated aggressively.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.22 no.6
• /
• pp.571-575
• /
• 2019

We report a case of a 13-year-old girl who presented with a 2-month history of intermittent abdominal pain. Laboratory examination showed hepatitis and pancreatitis. Because of persistent vomiting, computed tomography (CT) was performed, which revealed a circumferential soft tissue density in the duodenal wall, causing partial obstruction. Supportive therapy failed. Repeat CT showed no significant change from the initial study. The patient underwent upper endoscopy, which revealed a mass in the second portion of the duodenum, which occluded most parts of the lumen. The histopathological finding was consistent with an anaplastic large cell lymphoma, a rare form of small bowel neoplasm. After the third course of chemotherapy, complete resolution of the mass was noted, and her symptoms were relieved.

• Journal of Cerebrovascular and Endovascular Neurosurgery
• /
• v.20 no.4
• /
• pp.231-234
• /
• 2018

A persistent proatlantal artery (PA) is rare. We report a type 1 persistent PA originating from the right external carotid artery (ECA). A 78-year-old woman presented with dizziness. Computed tomographic (CT) angiography showed a persistent PA originating from the right ECA. This persistent PA did not pass through the atlas transverse foramen. The extracranial segment of this artery in the atlas transverse process level had a more lateral position than a normal left vertebral artery. CT angiography well demonstrated the relationship with bony structures and the course of this persistent PA. This anomalous artery in our patient presented as an incidental finding. Surgeon should recognize a persistent PA when performing carotid endarterectomy or ligation of the ECA for avoidance of complication.

• Archives of Plastic Surgery
• /
• v.46 no.6
• /
• pp.599-602
• /
• 2019

We report a case of autologous breast reconstruction in which a thoracodorsal vessel was used as a recipient vessel after a hypoplastic internal mammary vessel was found on preoperative computed tomography (CT) angiography. A 46-year-old woman with no underlying disease was scheduled to undergo skin-sparing mastectomy and breast reconstruction using a deep inferior epigastric artery perforator flap. Preoperative CT angiography showed segmental occlusion of the right subclavian artery with severe atherosclerosis and calcification near the origin of the internal mammary artery, with distal flow maintained by collateral branches. The thoracodorsal artery was selected to be the recipient vessel because CT showed that it was of adequate size and was not affected by atherosclerosis. The patient experienced no postoperative complications, and the flap survived with no vascular complications. The breasts were symmetrical at a 6-month follow-up. This case highlights that preoperative vascular imaging modalities may help surgeons avoid using diseased vessels as recipient vessels in free flap breast reconstructions.