• Journal of the Korean Society of Radiology
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• v.85 no.5
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• pp.834-847
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• 2024

Artificial intelligence (AI) is transforming radiology with improved diagnostic accuracy and efficiency, but prediction uncertainty remains a critical challenge. This review examines key sources of uncertainty-out-of-distribution, aleatoric, and model uncertainties-and highlights the importance of independent confidence metrics and explainable AI for safe integration. Independent confidence metrics assess the reliability of AI predictions, while explainable AI provides transparency, enhancing collaboration between AI and radiologists. The development of zero-error tolerance models, designed to minimize errors, sets new standards for safety. Addressing these challenges will enable AI to become a trusted partner in radiology, advancing care standards and patient outcomes.

• Journal of the Korean Society of Radiology
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• v.79 no.6
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• pp.354-358
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• 2018

Epidermal cysts are common benign subcutaneous lesions that occur in or on the skin. It is not very difficult to diagnose subcutaneous epidermal cysts using ultrasound imaging because they exhibit typical sonographic features. However, the differential diagnosis can be confused when epidermal cysts are found in unusual sites. The authors report a case involving a 4-year-old girl who presented with an intramuscular epidermal cyst in the gluteus maximus muscle. Magnetic resonance imaging revealed characteristic internal features of the epidermal cyst, despite being in an uncommon site, and was very useful in the preoperative diagnosis.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1186-1195
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• 2021

Purpose In the adult emergency department of a university hospital, we investigated the frequency of major discrepancies between the preliminary reports by radiology residents and the final reports by certified radiologists. Materials and Methods Based on CT and MRI scans obtained between December 2016 and November 2019, we selected cases with diagnoses or treatment plans that could be changed due to discrepancies between preliminary and final reports and classified them by the type of discrepancy. We also examined the distributions of the major discrepancies and stratified them by residents' working time zone, experience, and subspecialty. Results Based on the 72137 preliminary reports evaluated, 1348 tests (1.9%) showed major discrepancies. Most of the major discrepancies were false negatives (72.0%), followed by misdiagnosis (26.3%) and false positives (1.7%). Acute findings (87.2%) were more common than non-acute findings (12.8%). The major discrepancy rate increased toward the second half of the 24-hour shift, with the highest rate of 2.9% occurring between 2 am and 4 am. The major discrepancy rate did not vary with experience, and it varied from 0.6% to 4.5% for each subspecialty. Conclusion The major discrepancy rate was less than 2%, and it increased with longer working hours during a 24-hour shift.

• Journal of the Korean Society of Radiology
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• v.85 no.2
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• pp.327-344
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• 2024

Parathyroid glands are small endocrine glands that regulate calcium metabolism by producing parathyroid hormone (PTH). These are located at the back of the thyroid gland. Typically, four glands comprise the parathyroid glands, although their numbers may vary among individuals. Parathyroid diseases are related to parathyroid gland dysfunction and can be caused by problems with the parathyroid gland itself or abnormal serum calcium levels arising from renal disease. In recent years, as comprehensive health checkups have become more common, abnormal serum calcium levels are often found incidentally in blood tests, after which several additional tests, including a PTH test, ultrasonography (US), technetium-99m sestamibi parathyroid scan, single-photon-emission CT (SPECT)/CT, four-dimensional CT (4D-CT), and PET/CT, are performed for further evaluation. However, the parathyroid gland remains an organ less familiar to radiologists. Therefore, the normal anatomy, pathophysiology, imaging, and clinical findings of the parathyroid gland and its associated diseases are discussed here.

• Journal of the Korean Society of Radiology
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• v.81 no.1
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• pp.225-230
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• 2020

Tracheal leiomyoma is a rare benign tumor, which is composed of transformed cells of mesenchymal origin. We describe a case in which digital tomosynthesis was useful to evaluate a tracheal tumor that was overlooked on initial chest radiographs.

• Journal of the Korean Society of Radiology
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• v.83 no.3
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• pp.699-704
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• 2022

Acute puerperal uterine inversion is a rare postpartum obstetric complication; however, without rapid diagnosis and appropriate management, it is life-threatening. Substantial bleeding hinders the verification of a partially inverted uterus, possibly delaying the treatment. Herein, we present the report of a 32-year-old female presenting with massive postpartum bleeding managed by uterine artery embolization. The peculiar course of the uterine artery bowing inferiorly along the inverted fundus during embolization could uncover the uterine inversion, which was not diagnosed by physical examination and CT. In conclusion, uterine artery embolization is not only an effective therapeutic strategy for postpartum hemorrhage but also a valuable tool for diagnosing uterine inversion.

• Journal of the Korean Society of Radiology
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• v.82 no.3
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• pp.688-692
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• 2021

Cervicovaginal venous malformations are extremely rare. Sclerotherapy is proven to be effective for superficial venous malformations but not for venous malformations in the lower genital tract of female. A 52-year-old female presented with intermittent vaginal bleeding. The amount of vaginal bleeding gradually increased over 3 months. Contrast-enhanced pelvis CT showed several phleboliths and dilated vessels, but pelvic angiography showed no early draining veins, nidus, or feeding artery. We performed transvaginal direct puncture and ethanol sclerotherapy rather than surgical treatment because she wanted to preserve the uterus. After four sessions of sclerotherapy, she had significantly decreased vaginal bleeding without complications. Here, we report the first case of cervicovaginal venous malformations successfully treated with transvaginal direct puncture and ethanol sclerotherapy.

• Journal of the Korean Society of Radiology
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• v.81 no.4
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• pp.945-952
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• 2020

True pancreaticoduodenal artery aneurysms are relatively rare, approximately 50% of which are associated with stenosis or occlusion of the celiac axis. It is imperative to treat the condition immediately after diagnosis, considering that its rupture has a mortality rate of approximately 50%. The current most commonly used method to treat pancreaticoduodenal artery aneurysms is transcatheter arterial embolization. Here, we report three cases of embolization of inferior pancreaticoduodenal artery aneurysm with celiac stenosis or occlusion along with a literature review.

• Journal of the Korean Society of Radiology
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• v.82 no.2
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• pp.447-454
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• 2021

The authors report a successful thrombectomy using the AngioJet Rheolytic Thrombectomy System (AngioJet) and an embolic protection device in a patient with femorofemoral bypass graft occlusion. Lower extremity CT angiograms showed occlusion in the left-to-right femorofemoral bypass graft. A rheolytic thrombectomy using the AngioJet and balloon angioplasty restored blood flow to the right lower extremity, and distal embolization may be effectively prevented by placing an embolic protection device within the right superficial femoral artery during the procedure.

• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1250-1254
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• 2020

The diffuse sclerosing variant of papillary thyroid carcinoma (DSPTC) is uncommon. Herein, we report a rare case of DSPTC in a 9-year-old girl who initially presented with a painless diffuse goiter. Thyroid peroxidase antibody testing yielded positive results, and the initial clinical diagnosis was Hashimoto's thyroiditis. However, thyroid ultrasonography revealed characteristic findings of DSPTC, which was confirmed through the postoperative histopathological diagnosis. Although thyroid cancers are rare in the pediatric population, DSPTC should be included in the differential diagnosis of goiter in these patients. Moreover, ultrasonography may prevent a diagnostic delay and facilitate the detection of a concomitant malignancy.