• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.604-607
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• 2020

• Investigative Magnetic Resonance Imaging
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• v.9 no.2
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• pp.94-100
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• 2005

Purpose : This study was designed to evaluate the usefulness of 3T-TOF MR angiography (3T-TOF MRA) compared with transcranial Doppler sonography (TCD) and conventional angiography (CA) in patients with suspected cerebral infarction. Materials and Methods : Fifty four patients with clinical symptoms of cerebral infarction were involved in this study, and had undergone 3T-TOF MRA and TCD, with CA in 11 patients. On the basis of divisions of the carotid artery, four groups were designated: group I, both vertebral arteries and basilar artery; group II, segment between 2 cm below bifurcation of common carotid artery and genu portion of internal carotid artery; group III, segment between petrous portion of internal carotid artery and bifurcation of anterior and middle cerebral artery; group IV, from bifurcation of anterior and middle cerebral artery to thier distal branches. Two radiologists retrospectively reviewed the vascular imaging and stenosis in 3T-TOF MRA, TCD, and CA. Results : A total of 432 arteries, 108 in each group, were available. The assessment of vascular imaging quality in 3T-TOF MRA is scored 2.98, 2.96, 2.91, 2.88 in 4 groups, respectively. Agreement among 3T-TOF MR angiography, TCD, and CA was high. Conclusion : 3T-TOF MR angiography may be useful method for the assessment of stenotic lesions of cranial vasculature in patients with cerebral infarction.

• Korean Journal of Radiology
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• v.1 no.2
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• pp.91-97
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• 2000

Objective: To determine whether the time-intensity curves acquired by test and main dose contrast injections for MR angiography are similar. Materials and Methods: In 11 patients, repeated contrast-enhanced 2D-turbo-FLASH scans with 1-sec interval were obtained. Both test and main dose timeintensity curves were acquired from the abdominal aorta, and the parameters of time-intensity curves for the test and main boluses were compared. The parameters used were arterial and venous enhancement times, arterial peak enhancement time, arteriovenous circulation time, enhancement duration and enhancement expansion ratio. Results: Between the main and test boluses, arterial and venous enhancement times and arteriovenous circulation time showed statistically significant correlation (p < 0.01), with correlation coefficients of 0.95, 0.92 and 0.98 respectively. Although the enhancement duration was definitely greater than infusion time, reasonable measurement of the end enhancement point in the main bolus was impossible. Conclusion: Only arterial and venous enhancement times and arteriovenous circulation time of the main bolus could be predicted from the test-bolus results. The use of these reliable parameters would lead to improvements in the scan timing method for MR angiography.

• Korean Journal of Radiology
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• v.23 no.5
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• pp.517-528
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• 2022

Due to its excellent diagnostic performance, CT is the mainstay of diagnostic test in adults with suspected acute appendicitis in many countries. Although debatable, extensive epidemiological studies have suggested that CT radiation is carcinogenic, at least in children and adolescents. Setting aside the debate over the carcinogenic risk of CT radiation, the value of judicious use of CT radiation cannot be overstated for the diagnosis of appendicitis, considering that appendicitis is a very common disease, and that the vast majority of patients with suspected acute appendicitis are adolescents and young adults with average life expectancies. Given the accumulated evidence justifying the use of low-dose CT (LDCT) of only 2 mSv, there is no reasonable basis to insist on using radiation dose of multi-purpose abdominal CT for the diagnosis of appendicitis, particularly in adolescents and young adults. Published data strongly suggest that LDCT is comparable to conventional dose CT in terms of clinical outcomes and diagnostic performance. In this narrative review, we will discuss such evidence for reducing CT radiation in adolescents and young adults with suspected appendicitis.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.5085-5088
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• 2015

Background: The aim of this study was to assess the role of the presence of a choline peak in 3 Tesla 1H magnetic resonance spectroscopy (MRS) for differentiating benign from malignant adnexal masses. Materials and Methods: A total of 46 adnexal masses (23 malignant and 23 benign) underwent 1H MRS study prior to surgery to assess the presence of choline peak. Results: A choline peak was detected in 16 malignant masses (69.5%) and was absent in the other 7 (30.5%). A choline peak was only detected in 6 (26%) of the benign adnexal masses. The presence of an MRS choline peak had a sensitivity of 69.5%, a specificity of 74%, a positive predictive value (PPV) of 72.7%, and a negative predictive value (NPV) of 71% for diagnosing malignant adnexal masses. A significant difference between the frequency of mean choline peaks in benign and malignant adnexal masses was observed (P value < 0.01). Conclusions: A 1H MRS choline peak is seen in malignant adnexal masses more frequently than the benign masses, and may be helpful for diagnosing malignant adnexal masses.

• The Journal of the Korean dental association
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• v.55 no.11
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• pp.778-788
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• 2017

Ultrasound sonography(US) is used to evaluate various diseases of oral and maxillofacial region including salivary glands, soft tissue and jaw lesions because of easy accessibility and no hazard of ionizing radiation. Also, US can offer dynamic study showing real-time images during diagnostic or surgical procedure. US images provide accurate information about the internal features of lesions on the jaw prior to surgical treatment. Doppler images are used to visualize the vascular distribution of the lesions and to provide additional information to enhance diagnostic value. It is necessary to evaluate the diagnostic value of US and evaluate its usefulness by looking at clinical cases using US images. Therefore, US imaging may be recommended as an assistant image in evaluating jaw lesions. US images provided accurate information about the internal structure of lesions on the jaw prior to surgical treatment, and diagnostic value was enhanced by visualizing the vascular distribution of the lesion using doppler imaging. We report the protocol and suggest the effectiveness of US for various lesions and US-guided sialography.

• Korean Journal of Radiology
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• v.1 no.1
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• pp.11-18
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• 2000

Objective: To evaluate the hydrodynamic changes occurring in cerebrospinal fluid (CSF) flow in cervical spinal stenosis using the spatial modulation of magnetization (SPAMM) technique. Materials and Methods: Using the SPAMM technique, 44 patients with cervical spinal stenosis and ten healthy volunteers were investigated. The degree of cervical spinal stenosis was rated as low-, intermediate-, or high-grade. Low-grade stenosis was defined as involving no effacement of the subarachnoid space, intermediate-grade as involving effacement of this space, and high-grade as involving effacement of this space, together with compressive myelopathy. The patterns of SPAMM stripes and CSF velocity were evaluated and compared between each type of spinal stenosis and normal spine. Results: Low-grade stenosis (n = 23) revealed displacement or discontinuity of stripes, while intermediate- (n = 10) and high-grade (n = 11) showed a continuous straight band at the stenotic segment. Among low-grade cases, 12 showed wave separation during the systolic phase. Peak systolic CSF velocity at C4-5 level in these cases was lower than in volunteers (p < .05), but jet-like CSF propulsion was maintained. Among intermediate-grade cases, peak systolic velocity at C1-2 level was lower than in the volunteer group, but the difference was not significant (p > .05). In high-grade stenosis, both diastolic and systolic velocities were significantly lower (p < .05). Conclusion: Various hydrodynamic changes occurring in CSF flow in cervical spinal stenosis were demonstrated by the SPAMM technique, and this may be a useful method for evaluating CSF hydrodynamic change in cervical spinal stenosis.

• Journal of the Korean Society of Radiology
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• v.81 no.4
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• pp.972-978
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• 2020

Fentanyl intoxication has occasionally been reported since fentanyl patches became available for medical use. Delayed post-hypoxic leukoencephalopathy is a complication of hypoxia. However, its neuropsychiatric symptoms can be delayed, and it can progress to leukoencephalopathy even after full recovery from coma due to acute intoxication. Herein, we report a case of fentanyl intoxication in a 65-year-old man who was presented to the hospital because of unconsciousness for 13 hours after using ten fentanyl patches simultaneously. Initial brain CT findings were non-specific. Twenty days later, delayed neuropathologic symptoms manifested, and MRI showed bilaterally symmetrical, heterogeneous, confluent high signal intensities on T2-weighted/fluid attenuated inversion recovery MRI in the cerebral white matter with diffusion restriction. This was followed by rapid exacerbation of neuropathological symptoms with diffuse severe cerebral atrophy over 1 year.

• Journal of the Korean Society of Radiology
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• v.81 no.4
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• pp.979-984
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• 2020

Cri-du-chat syndrome is a rare genetic disorder in which the patient presents with a characteristic high-pitched monotonous cry and recurrent aspiration pneumonia, attributed to abnormalities in the larynx, epiglottis, and nervous system. The most prominent brain MRI findings are the presence of pontine and cerebellar hypoplasia, which primarily involve posterior cranial fossa structures. Although atrophy of supratentorial structures were also a common radiological finding, it was considered to be a secondary change due to pontine hypoplasia. Here, we present the case of a three-month-old patient presenting with cri-du-chat at our institution. The patient also showed the presence of prominent pontine hypoplasia similar to previously reported cases; however, contrary to other cases, there was a general delayed myelination of brain instead of decreased myelination of anterior limb of internal capsule. Since the larynx, pons, and cerebellum all originated from similar notochord level, which suggests anomaly in early stage of development, laryngeal, and brain anomaly characteristically observed in the cridu-chat syndrome.

• Korean Journal of Radiology
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• v.2 no.3
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• pp.151-158
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• 2001

Objective: To determine the ability of MR imaging to detect the pathological changes occurring in radiofrequency (RF) thermal lesions and to assess its accuracy in revealing the extent of tissue necrosis. Materials and Methods: Using an RF electrode, thermal lesions were created in the livers of 18 rabbits. The procedure involved three phases. In the acute phase, six animals were killed the day after performing thermal ablation with RF energy, and two on day 3. In the subacute and chronic phases, eight rabbits underwent percutaneous hepatic RF ablation. After performing MR imaging, two animals were sacrificed at 1, 2, 4, and 7 weeks after the procedure, and MRpathologic correlation was performed. Results: In the acute phase, the thermal ablation lesions appeared at gross examination as well-circumscribed, necrotic areas, representing early change in the coagulative necrosis seen at microscopic examination. They were hypointense on T2-weighted images, and hyperintense on T1-weighted images. Gadolinium-enhanced MR imaging showed that a thin hyperemic rim surrounded the central coagulative necrosis. In the subacute phase, ablated lesions also showed extensive coagulative necrosis and marked inflammation at microscopic examination. Beyond two weeks, the lesions showed gradual resorption of the necrotic area, with a peripheral fibrovascular rim. The size of lesions measured by MR imaging correlated well with the findings at gross pathologic examination. Conclusion: MR imaging effectively demonstrates the histopathological tissue change occurring after thermal ablation, and accurately determines the extent of the target area.