Journal of the Korean Society of Radiology最新文献

Purpose: This study aimed to evaluate the US features of the parathyroid glands (PTGs) using surgical specimens of normal PTGs obtained during thyroid surgery.

Materials and methods: This study included 34 normal PTGs from 17 consecutive patients who underwent thyroid surgery between December 2020 and March 2021. All normal PTGs were histologically confirmed by intraoperative frozen-section biopsy for autotransplantation. Surgically resected parathyroid specimens were scanned in sterile normal saline using high-resolution US prior to autotransplantation. The US features of echogenicity (hyperechogenicity or hypoechogenicity), echotexture (homogeneous or heterogeneous), size, and shape (ovoid or round) were retrospectively evaluated. The echogenicity of the three PTGs was compared with that of the thyroid parenchyma of the resected thyroid specimens in two patients.

Results: All PTGs showed hyperechogenicity similar to that of gauze soaked in normal saline. Homogeneous hyperechogenicity was observed in 32/34 (94.1%) patients, and the echogenicity of the three PTGs was hyperechoic compared with that of the thyroid parenchyma. The long diameter of the PTGs ranged from 5.1 mm to 9.8 mm (mean, 7.1 mm) and the shape of the PTGs was ovoid in 33/34 (97.1%) patients.

Conclusion: The echogenicity of normal PTG specimens was consistently hyperechoic, and the small ovoid homogeneously hyperechoic structure was a characteristic US feature of the PTGs.

Purpose: To investigate the MRI markers for the prediction of amyloid β (Aβ)-positivity in mild cognitive impairment (MCI) and Alzheimer's disease (AD), and to evaluate the differences in MRI markers between Aβ-positive (Aβ [+]) and -negative groups using the machine learning (ML) method.

Materials and methods: This study included 139 patients with MCI and AD who underwent amyloid PET-CT and brain MRI. Patients were divided into Aβ (+) (n = 84) and Aβ-negative (n = 55) groups. Visual analysis was performed with the Fazekas scale of white matter hyperintensity (WMH) and cerebral microbleeds (CMB) scores. The WMH volume and regional brain volume were quantitatively measured. The multivariable logistic regression and ML using support vector machine, and logistic regression were used to identify the best MRI predictors of Aβ-positivity.

Results: The Fazekas scale of WMH (p = 0.02) and CMB scores (p = 0.04) were higher in Aβ (+). The volumes of hippocampus, entorhinal cortex, and precuneus were smaller in Aβ (+) (p < 0.05). The third ventricle volume was larger in Aβ (+) (p = 0.002). The logistic regression of ML showed a good accuracy (81.1%) with mini-mental state examination (MMSE) and regional brain volumes.

Conclusion: The application of ML using the MMSE, third ventricle, and hippocampal volume is helpful in predicting Aβ-positivity with a good accuracy.

An umbilical venous catheter (UVC) is commonly placed for central venous access in preterm or critically ill full-term neonates to provide total parenteral nutrition (TPN) and medication. However, UVCs can result in complications, including infection, portal vein thrombosis, and hepatic tissue injury. The inadvertent administration of hypertonic fluid through a malpositioned UVC can also cause hepatic parenchymal damage with mass-like fluid collection that simulates a tumorous condition during imaging. Ultrasonography and radiographic examinations play an essential role in detecting UVC-related complications. This pictorial essay aims to present the imaging findings of UVC-related hepatic complications in neonates.

Gerstmann-Sträussler-Scheinker (GSS) disease is a rare hereditary prion disease which is clinically characterized by a progressive cerebellar ataxia followed by cognitive impairment. We report a rare case of GSS disease in a 39-year-old male patient who complained of a progressive gait disturbance followed by dysarthria with cognitive impairment, after five months from the onset of initial symptom. His brain MRI scan revealed multifocal symmetric diffusion restricted lesions with T2/FLAIR hyperintensities in bilateral cerebral cortices, basal ganglia, and thalami. His family members also manifested similar symptoms in their 40-50s, suggesting the possibility of a genetic disease. Finally, he was genetically diagnosed with GSS disease by real-time quaking-induced conversion and prion protein (PRNP) gene sequencing test.

Perianal fistula is a common inflammatory condition in the general population and affects the area around the anal canal. Although most cases are benign, they cause serious morbidity and require surgical treatment due to a high risk of recurrence. MR imaging is a gold standard technique for the evaluation of perianal fistulas and provides accurate information on the anatomy of the anal canal, its relationship to the anal sphincter complex, accurate identification of secondary tracts or abscesses, and reporting associated complications. MR imaging can help monitor treatment effects and determine treatment methods. Crohn's disease-related fistulas often require medical rather than surgical treatment. The radiologist is required to know the anatomy and MR imaging findings of the perianal fistula to present an accurate diagnosis to the clinician.

Immunoglobulin G4 (IgG4)-related disease is a rare systemic fibroinflammatory condition characterized by organomegaly or tumefactive lesions associated with lymphoplasmacytic infiltration rich in IgG4 plasma cells. We report a case of IgG4-related disease involving the subcutaneous layer of the left upper arm in a 48-year-old female presenting with an unusual soft tissue mass. US and MRI showed an irregular infiltrative soft tissue mass, indicating possible malignancy or inflammation. We discuss the diagnostic criteria, histopathologic features, radiological features, and treatment of IgG4-related disease.

Malignant peripheral nerve sheath tumor (MPNST), a rare soft-tissue sarcoma, is most commonly located in the trunk, extremities, and head and neck, but rare in the breast. We report a metastatic breast MPNST in a 27-year-old woman with neurofibromatosis type 1 (NF-1). Chest computed tomography revealed a well-defined, oval, mildly enhancing nodule in the right breast. US revealed a circumscribed, oval, heterogeneous echoic mass with vascularity and intermediate elasticity in the right upper outer breast. The breast mass was excised and diagnosed as MPNST on histopathology evaluation. Although rare, it should be included in the differential diagnosis of breast mass in NF-1 patient.

Purpose: This study aimed to determine the incremental value of using a structured report (SR) for US examinations of the pediatric appendix.

Materials and methods: Between January 2009 and June 2016, 1150 pediatric patients with suspected appendicitis who underwent US examinations of the appendix were included retrospectively. In November 2012, we developed a five-point scale SR for appendix US examinations. The patients were divided into two groups according to the form of the US report: free-text or SR. The primary clinical outcomes were compared between the two groups, including the rate of CT imaging following US examinations, the negative appendectomy rate (NAR), and the appendiceal perforation rate (PR).

Results: In total, 550 patients were included in the free-text group and 600 patients in the SR group. The rate of additional CT examinations decreased by 5.3% in the SR group (8.2%, p = 0.003), and the NAR decreased by 8.4% in the SR group (7.8%, p = 0.028). There was no statistical difference in the appendiceal PR (37.6% vs. 48.0%, p = 0.078).

Conclusion: The use of an SR to evaluate US examinations for suspected pediatric appendicitis results in lower CT use and fewer negative appendectomies without an increase in appendiceal PR.

Mammography has been the standard screening method for breast cancer. In women with suspicious calcifications and architectural distortion identified on mammography or digital breast tomosynthesis only without detected on breast US, stereotactic biopsy and mammography-guided preoperative localization is one of the method for pathologic diagnosis. This review aims to describe the indication, contraindication, technique of stereotactic biopsy, clip placement after stereotactic biopsy, and digital breast tomosynthesis-guided stereotactic biopsy. In addition, this article reviews mammography-guided preoperative localization using a wire or non-wire device.

The subclavian vein is an uncommon route for tunneled hemodialysis catheter (tHDC) placement because of its potency for future dialysis access. However, when favored access routes have been exhausted because of repeated catheterization or limited life expectancy, the subclavian vein can be used for urgent hemodialysis. A subclavian catheterization has a technical problem. The subclavian vein often forms a right angle with the vena cava, and advancing stiff peel-away sheath can cause a vascular injury. However, raising the patient's arm can alter the position of the guidewire and, therefore, change the angle of the vein favorable for tHDC placement. Herein, we report two patients who underwent subclavian catheterization; one experienced an injury to the superior vena cava after undergoing the conventional procedure, whereas the other patient with raised arm during the catheterization procedure had safe catheter placement.