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1.
Korean Journal of Radiology ; : 752-762, 2022.
Article in English | WPRIM | ID: wpr-938767

ABSTRACT

Objective@#To compare a deep learning-based reconstruction (DLR) algorithm for pediatric abdominopelvic computed tomography (CT) with filtered back projection (FBP) and iterative reconstruction (IR) algorithms. @*Materials and Methods@#Post-contrast abdominopelvic CT scans obtained from 120 pediatric patients (mean age ± standard deviation, 8.7 ± 5.2 years; 60 males) between May 2020 and October 2020 were evaluated in this retrospective study. Images were reconstructed using FBP, a hybrid IR algorithm (ASiR-V) with blending factors of 50% and 100% (AV50 and AV100, respectively), and a DLR algorithm (TrueFidelity) with three strength levels (low, medium, and high). Noise power spectrum (NPS) and edge rise distance (ERD) were used to evaluate noise characteristics and spatial resolution, respectively. Image noise, edge definition, overall image quality, lesion detectability and conspicuity, and artifacts were qualitatively scored by two pediatric radiologists, and the scores of the two reviewers were averaged. A repeated-measures analysis of variance followed by the Bonferroni post-hoc test was used to compare NPS and ERD among the six reconstruction methods. The Friedman rank sum test followed by the Nemenyi-Wilcoxon-Wilcox all-pairs test was used to compare the results of the qualitative visual analysis among the six reconstruction methods. @*Results@#The NPS noise magnitude of AV100 was significantly lower than that of the DLR, whereas the NPS peak of AV100 was significantly higher than that of the high- and medium-strength DLR (p < 0.001). The NPS average spatial frequencies were higher for DLR than for ASiR-V (p < 0.001). ERD was shorter with DLR than with ASiR-V and FBP (p < 0.001). Qualitative visual analysis revealed better overall image quality with high-strength DLR than with ASiR-V (p < 0.001). @*Conclusion@#For pediatric abdominopelvic CT, the DLR algorithm may provide improved noise characteristics and better spatial resolution than the hybrid IR algorithm.

2.
Investigative Magnetic Resonance Imaging ; : 303-310, 2022.
Article in English | WPRIM | ID: wpr-967015

ABSTRACT

Purpose@#This study aimed to evaluate clinical significance and imaging findings of newly detected lesions on breast MRI while monitoring patients’ response to neoadjuvant chemotherapy (NAC). @*Materials and Methods@#We identified 291 patients with newly diagnosed breast cancer who underwent breast MRI to assess their response to NAC between January 2017 and August 2021. We evaluated 26 new lesions in 24 women (mean age, 49.8 years; range, 35–63 years) who were included in this study. Two radiologists assessed imaging findings of new lesions according to Breast Imaging Reporting and Data System (BI-RADS) lexicon 5th edition and evaluated follow-up MRI during NAC. Outcomes of new lesions were determined based on pathologic examination or imaging follow-up after surgery. @*Results@#All 26 new lesions were found on the first follow-up imaging. They disappeared or decreased in size on the second follow-up imaging. Lesion types included mass (n = 22, 84.6%) and non-mass enhancement (n = 4, 15.4%). The majority of the mass types showed oval to round shapes (22/22, 100%), circumscribed margins (21/22, 95.5%), and rim enhancement (18/22, 81.8%). Seven (26.9%) new lesions were ipsilateral to the index cancer, 7 (26.9%) were contralateral, and 12 (46.2%) were bilateral. None of these new lesions were malignant. @*Conclusion@#New lesions were detected in 4.7% of breast MRI during NAC. Most new lesions tended to

3.
Korean Journal of Dermatology ; : 228-234, 2022.
Article in English | WPRIM | ID: wpr-926638

ABSTRACT

Background@#Ultrasonography (US) is a simple and reliable tool that can aid in the diagnosis of benign subcutaneous lesions such as epidermal cysts and lipomas. @*Objective@#This study aimed to determine the efficacy of US for the differential diagnosis of epidermal cysts and lipomas. @*Methods@#A retrospective study of 100 patients with epidermal cysts (n=45) or lipomas (n=55) who underwent US and then received a pathological diagnosis in the dermatology department of Pusan National University Hospital was conducted. @*Results@#US and clinical impressions accurately diagnosed the epidermal cysts in 90.0% and 88.0% of the patients, respectively, and the lipomas in 92.0% and 88.0% of the patients, respectively. US combined with clinical impression significantly increased the diagnostic yield of epidermal cysts (98%) and lipomas (99%). On US, the frequency of posterior acoustic enhancement was higher for the epidermal cysts than for the lipomas (82.2% and 29.1%, respectively; p<0.001), and striated echoes such as internal linear echogenic reflections and dark clefts were more frequently found in the lipomas than in the epidermal cysts (90.9% and 6.7%, respectively; p<0.001). @*Conclusion@#This study implies that the diagnostic role of US can be greatly enhanced by knowledge of the clinical presentation.

4.
Journal of the Korean Radiological Society ; : 862-875, 2021.
Article in English | WPRIM | ID: wpr-893613

ABSTRACT

Purpose@#To investigate the MRI features associated with neural foraminal stenosis (NFS) in patients older than 60 years with lumbar (L) radiculopathy. @*Materials and Methods@#This study included 133 retrospectively selected patients older than 60 years with lumbar radiculopathy who had undergone a lumbar spine MRI (from January 2018 to April 2018). For L4/L5 and L5/sacral (S)1 levels, NFS was reviewed blindly by two radiologists. Spondylolisthesis, retrolisthesis, disc height loss, disc bulging/herniation/central canal stenosis, ligamentum flavum thickening, and facet hypertrophy were evaluated separately for the NFS and non-NFS groups, and they were compared using univariate and multivariate analyses. @*Results@#The univariate analysis revealed that disc height loss (p = 0.006) was associated with NFS for L4/L5. For L5/S1, both spondylolisthesis (p = 0.005) and facet hypertrophy (p = 0.006) were associated with NFS. The multivariate logistic analysis revealed that disc height loss was associated with NFS for L4/L5 [odds ratio (OR) = 4.272; 95% confidence interval (CI) 1.736– 10.514]. For L5/S1, spondylolisthesis (OR = 3.696; 95% CI 1.297–10.530) and facet hypertrophy (OR = 6.468; 95% CI 1.283–32.617) were associated with NFS. @*Conclusion@#Disc height loss was associated with NFS for L4/L5 and spondylolisthesis and facet hypertrophy were associated with NFS for L5/S1.

5.
Korean Journal of Radiology ; : 225-232, 2021.
Article in English | WPRIM | ID: wpr-875262

ABSTRACT

Objective@#To determine whether changes in the transiting nerve rootlet or its surroundings, as seen on MRI performed after lumbar hemilaminectomy, are associated with persistent postoperative pain (PPP), commonly known as the failed back surgery syndrome. @*Materials and Methods@#Seventy-three patients (mean age, 61 years; 43 males and 30 females) who underwent single-level partial hemilaminectomy of the lumbar spine without postoperative complications or other level spinal abnormalities between January 2010 and December 2018 were enrolled. Two musculoskeletal radiologists evaluated transiting nerve rootlet abnormalities (thickening, signal alteration, distinction, and displacement), epidural fibrosis, and intrathecal arachnoiditis on MRI obtained one year after the operations. A spine surgeon blinded to the radiologic findings evaluated each patient for PPP. Univariable and multivariable analyses were used to evaluate the association between the MRI findings and PPP. @*Results@#The presence of transiting nerve rootlet thickening, signal alteration, and ill-distinction was significantly different between the patients with PPP and those without, for both readers (p ≤ 0.020). Conversely, the presence of transiting nerve rootlet displacement, epidural fibrosis, and intrathecal arachnoiditis was not significantly different between the two groups (p ≥ 0.128). Among the above radiologic findings, transiting nerve rootlet thickening and signal alteration were the most significant findings in the multivariable analyses (p ≤ 0.009). @*Conclusion@#On MRI, PPP was associated with transiting nerve rootlet abnormalities, including thickening, signal alterations, and ill-distinction, but was not associated with epidural fibrosis or intrathecal arachnoiditis. The most relevant findings were the nerve rootlet thickening and signal alteration.

6.
Journal of the Korean Radiological Society ; : 862-875, 2021.
Article in English | WPRIM | ID: wpr-901317

ABSTRACT

Purpose@#To investigate the MRI features associated with neural foraminal stenosis (NFS) in patients older than 60 years with lumbar (L) radiculopathy. @*Materials and Methods@#This study included 133 retrospectively selected patients older than 60 years with lumbar radiculopathy who had undergone a lumbar spine MRI (from January 2018 to April 2018). For L4/L5 and L5/sacral (S)1 levels, NFS was reviewed blindly by two radiologists. Spondylolisthesis, retrolisthesis, disc height loss, disc bulging/herniation/central canal stenosis, ligamentum flavum thickening, and facet hypertrophy were evaluated separately for the NFS and non-NFS groups, and they were compared using univariate and multivariate analyses. @*Results@#The univariate analysis revealed that disc height loss (p = 0.006) was associated with NFS for L4/L5. For L5/S1, both spondylolisthesis (p = 0.005) and facet hypertrophy (p = 0.006) were associated with NFS. The multivariate logistic analysis revealed that disc height loss was associated with NFS for L4/L5 [odds ratio (OR) = 4.272; 95% confidence interval (CI) 1.736– 10.514]. For L5/S1, spondylolisthesis (OR = 3.696; 95% CI 1.297–10.530) and facet hypertrophy (OR = 6.468; 95% CI 1.283–32.617) were associated with NFS. @*Conclusion@#Disc height loss was associated with NFS for L4/L5 and spondylolisthesis and facet hypertrophy were associated with NFS for L5/S1.

7.
Journal of the Korean Radiological Society ; : 1145-1159, 2019.
Article in Korean | WPRIM | ID: wpr-916816

ABSTRACT

PURPOSE@#To determine the usefulness of diffusion weighted-MRI (DW-MRI) in the evaluation of spinal metastasis.@*MATERIALS AND METHODS@#From July to August 2017, 48 whole-spine DW-MRI to detect metastasis in patients with extra-spinal tumors were retrospectively evaluated by three radiologists. The usefulness of DW-MRI was evaluated in four groups based on the change in confidence rating between two sessions: 1 (T1- and T2-weighted and contrast-enhanced images) and 2 (additional DW-MRI). The associations of the usefulness with age, sex, primary cancer, bone type with metastasis, number of probable metastatic segments in session 1, and anatomic locations were assessed in vertebral body and posterior element cases.@*RESULTS@#According to the readers 1, 2, and 3, there were 18, 19, and 16 vertebral body cases, respectively, and 12, 13, and 9 posterior element cases, respectively. In the group with no excepted metastasis, DW-MRI was useful in 52–59% of vertebral body cases and 39–67% of posterior element cases. There were no significant differences in the usefulness with respect to the number of probable metastatic segments in session 1, age, sex, primary cancer, bone type with metastasis, or anatomic location.@*CONCLUSION@#DW-MRI could be used to evaluate spinal metastasis. However, there were no differences in the usefulness with respect to the anatomic location.

8.
Investigative Magnetic Resonance Imaging ; : 279-282, 2019.
Article in English | WPRIM | ID: wpr-764175

ABSTRACT

Neurosyphilis is an infection of the brain or spinal cord that is caused by the bacterium Treponema pallidum. Syphilitic myelitis, which involves the spinal cord, is a very rare form of neurosyphilis seen in patients with syphilis. It requires differentiation from other diseases of the spinal cord, including idiopathic transverse myelitis and spinal cord infarction. Herein, we describe the presentation and diagnosis of syphilitic myelitis in a 43-year-old woman, based on a flip-flop sign and candle guttering appearance depicted in magnetic resonance imaging and laboratory tests.


Subject(s)
Adult , Female , Humans , Brain , Diagnosis , Infarction , Magnetic Resonance Imaging , Myelitis , Myelitis, Transverse , Neurosyphilis , Spinal Cord , Syphilis , Treponema pallidum
9.
Korean Journal of Radiology ; : 1167-1175, 2019.
Article in English | WPRIM | ID: wpr-760284

ABSTRACT

OBJECTIVE: To compare the objective and subjective image quality indicators and radiation doses of computed tomography (CT) venography performed using model-based iterative reconstruction (MBIR) at 80 kVp and adaptive statistical iterative reconstruction (ASIR)-V at 70 kVp. MATERIALS AND METHODS: Eighty-three patients who had undergone CT venography of the lower extremities with MBIR at 80 kVp (Group A; 21 men and 20 women; mean age, 55.5 years) or ASIR-V at 70 kVp (Group B; 18 men and 24 women; mean age, 57.3 years) were enrolled. Two radiologists retrospectively evaluated the objective (vascular enhancement, image noise, signal-to-noise ratio [SNR], contrast-to-noise ratio [CNR]) and subjective (quantum mottle, delineation of contour, venous enhancement) image quality indicators at the inferior vena cava and femoral and popliteal veins. Clinical information, radiation dose, reconstruction time, and objective and subjective image quality indicators were compared between groups A and B. RESULTS: Vascular enhancement, SNR, and CNR were significantly greater in Group B than in Group A (p ≤ 0.015). Image noise was significantly lower in Group B (p ≤ 0.021), and all subjective image quality indicators, except for delineation of vein contours, were significantly better in Group B (p ≤ 0.021). Mean reconstruction time was significantly shorter in Group B than in Group A (1 min 43 s vs. 131 min 1 s; p < 0.001). Clinical information and radiation dose were not significantly different between the two groups. CONCLUSION: CT venography using ASIR-V at 70 kVp was better than MBIR at 80 kVp in terms of image quality and reconstruction time at similar radiation doses.


Subject(s)
Female , Humans , Male , Image Enhancement , Image Processing, Computer-Assisted , Lower Extremity , Noise , Phlebography , Popliteal Vein , Retrospective Studies , Signal-To-Noise Ratio , Veins , Vena Cava, Inferior , Venous Thrombosis
10.
Yeungnam University Journal of Medicine ; : 130-134, 2018.
Article in English | WPRIM | ID: wpr-787081

ABSTRACT

Heterotopic ossification (HO) around the hip joint is not uncommon following neurological injury. Often, surgical treatment is performed in patients with restricted motion and/or refractory pain due to grade III or IV HO according to Brooker classification. The major complication that occurs as a result of surgical HO removal is perioperative bleeding due to hyper-vascularization of the lesion. Here, we report a case of preoperative embolization in a 51-year-old male patient presenting with restricted bilateral hip range of motion (ROM) due to HO following a spinal cord injury. In the right hip without preoperative arterial embolization, massive bleeding occurred during surgical removal of HO. Thus, the patient received a transfusion postoperatively due to decreased serum hemoglobin levels. For surgery of the left hip, preoperative embolization of the arteries supplying HO was performed. Surgical treatment was completed without bleeding complications, and the patient recovered without a postoperative transfusion. This case highlights that, while completing surgical removal for ROM improvements, orthopedic surgeons should consider preoperative arterial embolization in patients with hip HO.


Subject(s)
Humans , Male , Middle Aged , Arteries , Classification , Hemorrhage , Hip Joint , Hip , Orthopedics , Ossification, Heterotopic , Pain, Intractable , Range of Motion, Articular , Spinal Cord Injuries , Surgeons
11.
Yeungnam University Journal of Medicine ; : 130-134, 2018.
Article in English | WPRIM | ID: wpr-939309

ABSTRACT

Heterotopic ossification (HO) around the hip joint is not uncommon following neurological injury. Often, surgical treatment is performed in patients with restricted motion and/or refractory pain due to grade III or IV HO according to Brooker classification. The major complication that occurs as a result of surgical HO removal is perioperative bleeding due to hyper-vascularization of the lesion. Here, we report a case of preoperative embolization in a 51-year-old male patient presenting with restricted bilateral hip range of motion (ROM) due to HO following a spinal cord injury. In the right hip without preoperative arterial embolization, massive bleeding occurred during surgical removal of HO. Thus, the patient received a transfusion postoperatively due to decreased serum hemoglobin levels. For surgery of the left hip, preoperative embolization of the arteries supplying HO was performed. Surgical treatment was completed without bleeding complications, and the patient recovered without a postoperative transfusion. This case highlights that, while completing surgical removal for ROM improvements, orthopedic surgeons should consider preoperative arterial embolization in patients with hip HO.

12.
Korean Journal of Pancreas and Biliary Tract ; : 134-138, 2018.
Article in English | WPRIM | ID: wpr-715800

ABSTRACT

Mirizzi syndrome (MS) is a rare complication of cholecystolithiasis that is characterized by obstruction of the common hepatic duct due to mechanical compression by impacted stones in the neck of the gallbladder or the cystic duct. Treatment of MS is surgical, and operative procedure would vary depending on its classification type. Biliary stricture after surgical treatment of MS is an unusual complication and endoscopic approach is not possible for patients who have undergone bilioenteric anastomosis. We report a case of a 60-year-old patient with biliary anastomotic stricture after surgical management of MS who was successfully treated with long-term percutaneous transhepatic biliary drainage.


Subject(s)
Humans , Middle Aged , Cholecystectomy , Cholecystolithiasis , Choledochostomy , Classification , Constriction, Pathologic , Cystic Duct , Drainage , Gallbladder , Hepatic Duct, Common , Mirizzi Syndrome , Neck , Postoperative Complications , Surgical Procedures, Operative
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