Peer Review of Teleradiology at a Teleradiology Clinic: Comparison of Unacceptable Diagnosis and Clinically Significant Discrepancy between Radiology Sections and Imaging Modalities

Purpose@#The purpose of this study was to evaluate the rates of unacceptable diagnosis and clinically significant diagnostic discrepancy in radiology sections and imaging modalities through a peer review of teleradiology. @*Materials and Methods@#Teleradiology peer reviews in a Korean teleradiology clinic in 2018 and 2019 were included. The peer review scores were classified as acceptable and unacceptable diagnoses and clinically insignificant and significant diagnostic discrepancy. The diagnostic discrepancy rates and clinical significance were compared among radiology sections and imaging modalities using the chi-square test. @*Results@#Of 1312 peer reviews, 117 (8.9%) cases had unacceptable diagnoses. Of 462 diagnostic discrepancies, the clinically significant discrepancy was observed in 104 (21.6%) cases. In radiology sections, the unacceptable diagnosis was highest in the musculoskeletal section (21.4%) (p < 0.05), followed by the abdominal section (7.3%) and neuro section (1.3%) (p< 0.05). The proportion of significant discrepancy was higher in the chest section (32.7%) than in the musculoskeletal (19.5%) and abdominal sections (17.1%) (p < 0.05). Regarding modalities, the number of unacceptable diagnoses was higher with MRI (16.2%) than plain radiology (7.8%) (p < 0.05). There was no significant difference in significant discrepancy. @*Conclusion@#Peer review provides the rates of unacceptable diagnosis and clinically significant discrepancy in teleradiology. These rates also differ with subspecialty and modality.

Hypointensity on Susceptibility-Weighted Images Prior to Signal Change on Diffusion-Weighted Images in a Hyperacute Ischemic Infarction: a Case Study

Susceptibility-weighted imaging (SWI) is well known for detecting the presence of hemorrhagic transformation, microbleeds and the susceptibility of vessel signs in acute ischemic stroke. But in some cases, it can provide the tissue perfusion state as well. We describe a case of a patient with hyperacute ischemic infarction that had a slightly hypodense, patchy lesion at the left thalamus on the initial SWI, with a left proximal posterior cerebral artery occlusion on a magnetic resonance (MR) angiography and delayed time-to-peak on an MR perfusion performed two hours after symptom onset. No obvious abnormal signals at any intensity were found on the initial diffusion-weighted imaging (DWI). On a follow-up MR image (MRI), an acute ischemic infarction was seen on DWI, which is the same location as the lesion on SWI. The hypointensity on the initial SWI reflects the susceptibility artifact caused by an increased deoxyhemoglobin in the affected tissue and vessels, which reflects the hypoperfusion state due to decreasing arterial flow. It precedes the signal change on DWI that reflects a cytotoxic edema. This case highlights that, in some hyperacute stages of ischemic stroke, hypointensity on an SWI may be a finding before the hyperintensity is seen on a DWI.

Accelerated Resting-State Functional Magnetic Resonance Imaging Using Multiband Echo-Planar Imaging with Controlled Aliasing

PURPOSE: To report the use of multiband accelerated echo-planar imaging (EPI) for resting-state functional MRI (rs-fMRI) to achieve rapid high temporal resolution at 3T compared to conventional EPI. MATERIALS AND METHODS: rs-fMRI data were acquired from 20 healthy right-handed volunteers by using three methods: conventional single-band gradient-echo EPI acquisition (Data 1), multiband gradient-echo EPI acquisition with 240 volumes (Data 2) and 480 volumes (Data 3). Temporal signal-to-noise ratio (tSNR) maps were obtained by dividing the mean of the time course of each voxel by its temporal standard deviation. The resting-state sensorimotor network (SMN) and default mode network (DMN) were estimated using independent component analysis (ICA) and a seed-based method. One-way analysis of variance (ANOVA) was performed between the tSNR map, SMN, and DMN from the three data sets for between-group analysis. P < 0.05 with a family-wise error (FWE) correction for multiple comparisons was considered statistically significant. RESULTS: One-way ANOVA and post-hoc two-sample t-tests showed that the tSNR was higher in Data 1 than Data 2 and 3 in white matter structures such as the striatum and medial and superior longitudinal fasciculus. One-way ANOVA revealed no differences in SMN or DMN across the three data sets. CONCLUSION: Within the adapted metrics estimated under specific imaging conditions employed in this study, multiband accelerated EPI, which substantially reduced scan times, provides the same quality image of functional connectivity as rs-fMRI by using conventional EPI at 3T. Under employed imaging conditions, this technique shows strong potential for clinical acceptance and translation of rs-fMRI protocols with potential advantages in spatial and/or temporal resolution. However, further study is warranted to evaluate whether the current findings can be generalized in diverse settings.

Immediate Decrease in γ-AminoButyric Acid after Caffeine Intake in Adolescents: a Preliminary MRS Study

In adolescents, sleep deprivation problem is getting worse, and increased caffeine consumption is considered to relieve the stress caused by sleep deprivation and academic burden. In this study, immediate neurologic effects of caffeine intake on adolescents were evaluated in three high school students using the γ-aminobutyric acid (GABA)/creatine ratio on magnetic resonance spectroscopy (MRS). MEGA-PRESS MRS and TE 135 ms single voxel MRS were performed in the anterior cingulate cortex before and after drinking a cup of coffee, which contained 104 mg of caffeine. GABA and creatine were measured on LCModel 6.3, respectively. In all three students, GABA/creatine ratios were decreased after caffeine intake. The GABA/creatine ratios obtained before caffeine intake were decreased after caffeine intake in all the three adolescents. In this preliminary study, caffeine intake caused an immediate decrease in the GABA/creatine ratio in the brain and it may be related to the neurologic effects of caffeine on an adolescent's brain.

Immediate Decrease in γ-AminoButyric Acid after Caffeine Intake in Adolescents: a Preliminary MRS Study

In adolescents, sleep deprivation problem is getting worse, and increased caffeine consumption is considered to relieve the stress caused by sleep deprivation and academic burden. In this study, immediate neurologic effects of caffeine intake on adolescents were evaluated in three high school students using the γ-aminobutyric acid (GABA)/creatine ratio on magnetic resonance spectroscopy (MRS). MEGA-PRESS MRS and TE 135 ms single voxel MRS were performed in the anterior cingulate cortex before and after drinking a cup of coffee, which contained 104 mg of caffeine. GABA and creatine were measured on LCModel 6.3, respectively. In all three students, GABA/creatine ratios were decreased after caffeine intake. The GABA/creatine ratios obtained before caffeine intake were decreased after caffeine intake in all the three adolescents. In this preliminary study, caffeine intake caused an immediate decrease in the GABA/creatine ratio in the brain and it may be related to the neurologic effects of caffeine on an adolescent's brain.

Assessing the accuracy and reliability of ultrasonographic three-dimensional parathyroid volume measurement in a patient with secondary hyperparathyroidism: a comparison with the two-dimensional conventional method

PURPOSE: The purpose of this study was to investigate the accuracy and reliability of the semi-automated ultrasonographic volume measurement tool, virtual organ computer-aided analysis (VOCAL), for measuring the volume of parathyroid glands. METHODS: Volume measurements for 40 parathyroid glands were performed in patients with secondary hyperparathyroidism caused by chronic renal failure. The volume of the parathyroid glands was measured twice by experienced radiologists by two-dimensional (2D) and three-dimensional (3D) methods using conventional sonograms and the VOCAL with 30°angle increments before parathyroidectomy. The specimen volume was also measured postoperatively. Intraclass correlation coefficients (ICCs) and the absolute percentage error were used for estimating the reproducibility and accuracy of the two different methods. RESULTS: The ICC value between two measurements of the 2D method and the 3D method was 0.956 and 0.999, respectively. The mean absolute percentage error of the 2D method and the 3D VOCAL technique was 29.56% and 5.78%, respectively. For accuracy and reliability, the plots of the 3D method showed a more compact distribution than those of the 2D method on the Bland-Altman graph. CONCLUSION: The rotational VOCAL method for measuring the parathyroid gland is more accurate and reliable than the conventional 2D measurement. This VOCAL method could be used as a more reliable follow-up imaging modality in a patient with hyperparathyroidism.

Comparison of Ultrasonographic Findings of Biopsy-Proven Tuberculous Lymphadenitis and Kikuchi Disease

OBJECTIVE: Although tuberculous lymphadenitis and Kikuchi disease are common causes of cervical lymphadenopathy in Asians and exhibit similar clinical manifestations, their treatment strategies are totally different. The purpose of this study was to identify ultrasonographic features that distinguish these two diseases. MATERIALS AND METHODS: This study was approved by the Institutional Review Board. The study included 77 patients with tuberculous lymphadenitis and 135 patients with Kikuchi disease. The sex and age distributions of the patients were analyzed. The size and shape of lymph nodes (LNs), presence of conglomeration, increased perinodal echogenicity, echogenic hilum, posterior neck involvement, internal calcification, patterns of internal necrosis, laterality of involved LNs, and hilar vascular patterns on ultrasonography were compared between the two groups. Multiple logistic regression analysis was conducted to identify independent findings to discriminate tuberculous lymphadenitis from Kikuchi disease. Finally, diagnostic accuracies were calculated using the independent findings. RESULTS: The presence of an echogenic hilum, internal calcification, patterns of internal necrosis, and LN hilar vascular structures on power Doppler ultrasonography were independent findings that discriminated tuberculous lymphadenitis from Kikuchi disease. The diagnostic accuracy of each of these four factors was 84.9% (181/212), 76.9% (163/212), 84% (178/212), and 89.2% (189/212), respectively. A combination of internal calcification and hilar vascular structures showed the best accuracy of 89.6% (190/212) (sensitivity, 86.7% [117/135]; specificity, 94.8% [73/77]) for diagnosing Kikuchi disease. CONCLUSION: The presence of an echogenic hilum, internal calcification, pattern of internal necrosis, and LN hilar vascular structures are useful ultrasonographic findings to differentiate tuberculous lymphadenitis from Kikuchi disease.

Probable Isolated Hypertensive Brainstem Encephalopathy Combined with Intracerebral Hemorrhage: a Case Report

Hypertensive encephalopathy and basal ganglia intracerebral hemorrhage (ICH) are a medical emergency caused by a sudden elevation of systemic blood pressure. Although the relationship between hypertensive encephalopathy and large ICH has not been clarified yet, Cushing reflex in acute elevations of ICP due to large ICH may induce or aggravate hypertensive encephalopathy. We report a rare case of isolated hypertensive brainstem encephalopathy combined with hypertensive ICH.

Effects of Ascorbic Acid on Osteoblast Differentiation in MC3T3-E1 Cells

OBJECTIVE: Vitamin C is an essential agent for cell differentiation for cell. However, for osteogenic differentiation a combined medium of vitamin C, phosphoglyceride and dexamethasone is used. Individual effect of vitamin C can be observed in terms of cell growth and proliferation and eventual differentiation to assess the effect of this chemical agent for using as bone growth. This work investigates the dose dependent effect of vitamin C on MC3T3-E1 type pre-osteoblast cell on cell proliferation and differentiation. METHODS: To investigate the dose dependent effect of vitamin C on MC3T3-E1 type pre-osteoblast cell predetermined amount of vitamin C was added to the medium and the medium was used for cell culture and cell differentiation. Relative cell viability and cell proliferation were checked to see the effect of vitamin C. Effect of dose dependent gene expression was carried out by reverse transcription-polymerase chain reaction with osteogenic differentiation specific genes. RESULTS: Cell viability and cell proliferation was increased in all culture time. The pre-osteoblast cells show significantly higher expression of osteoblast formation specific gene alkaline phosphatase, osteocalcin, and osteopontin at a higher dose of vitamin C. CONCLUSION: Higher doses of vitamin C with 50 microg/uL could significantly enhance the cell proliferation.

High field strength magnetic resonance imaging of brain lesion

The primary merit of a 3 tesla (T) magnetic resonance (MR) scanner is the increase in the signal-to-noise ratio (SNR). It can offer high spatial and temporal image resolution and its diagnostic potential for brain lesions can be improved at the magnetic strength of 3T. In addition to the increased SNR, strong prolongation of T1 relaxation time at high field MR leads to overall improvements in enhancing lesions versus non-enhancing tissue on contrast-enhanced T1-weighted images and blood versus tissue contrast on time-of-flight MR angiography. Increased chemical shift and susceptibility can improve the spectral resolution in MR spectroscopy and the sensitivities in the micro-hemorrhage detection of gradient echo image, the perfusion change of perfusion MRI, and the blood oxygen level-dependent effect of functional magnetic resonance imaging (MRI). The short acquisition time of diffusion MRI at 3T can decrease motion artifacts in irritable stroke patients and it can be easier to estimate anisotrophy and to increase the efficiency of tractography in diffusion tensor imaging with high numbers of gradient directions. On the other hand, the regulation of the specific absorption rate due to increased radio-frequency energy deposition and the controls for signal loss and increased artifacts at 3T are the main clinical problems. If the drawbacks can be addressed by parallel imaging or pulse sequence changes, 3T MRI can be a useful diagnostic tool and increase the diagnostic accuracy in various brain lesions, such as stroke, trauma, epilepsy, multiple sclerosis, dementia, and brain tumors.

A Case of Gemcitabine and Cisplatin Associated Posterior Reversible Encephalopathy Syndrome / Journal of the Korean Cancer Association, 대한암학회지

A 58-year-old female receiving gemcitabine and cisplatin chemotherapy for stage IV gallbladder cancer developed the clinicoradiologic syndrome, posterior reversible encephalopathy syndrome (PRES). Just before the 4th gemcitabine chemotherapy cycle, she was admitted to the hospital with complaints of headache, dizziness, and generalized tonic-clonic seizures. A MRI was performed on the day when the seizure developed, and the findings showed patchy cortical and subcortical T2 hyperintensity without enhancement that involved both occipital and parietal lobes. Phenytoin loading and maintenance was started for prevention of recurrent seizures, which was successful. The follow-up brain MRI obtained 10 days after the seizure attack showed completely resolved radiologic findings. After the MRI findings revealed complete resolution, phenytoin maintenance was stopped. Even with discontinuation of phenytoin, she had no seizures or other clinical manifestations.

Hypoglycemic Encephalopathy With Delayed Lesion on Magnetic Resonance Imaging

We report on delayed emergence of restricted diffusion on MRI after hypoglycemia. A 56-year-old man with type 2 diabetes was admitted with mental change. Initial serum glucose was 19 mg/dl. Fifteen hours after presumed symptom onset, brain imaging did not show any definite abnormality. However, areas of restricted diffusion emerged evident in both basal ganglia 9 days later. Hypoglycemia can cause delayed cytotoxic edema even after normalization of the serum glucose.

Opacification of Portal Vein on CT during Hepatic Arteriography Via Normal Vascular Flow

PURPOSE: To evaluate the frequency, distribution, and associated factors of the opacified normal portal veinas seen on CT, during hepatic arteriography(CTHA). MATERIALS AND METHODS: One hundred and eighty-nine patientswho underwent both CTHA and CT during arterioportography (CTAP) during a three-year period were reviewed. Ofthese, 66 patients without anomalous hepatic arterial supply and arterioportal (AP) shunt on celiac angiographywere analyzed. Comparing CTHA with CTAP, we determined whether or not the portal vein(PV) is opacified within thesecond-order branch. The degree of contrast enhancement in the stomach, duodenum, and pancreas was graded asfollows : grade I, all three organs were hypodensely enhanced; grade II, some organ were isodensely enhanced, butothers hypodensely ; grade III, all three organs were isodensely enhanced relative to the CHA. The relationshipbetween opacified portal vein (OPV) and the degree of enhancement of the three organs, amount of contrast media,and Child classification was statistically examined. RESULTS: The PV was opacified in 18 of the 66 patients (27%); This was the main PV in 16, right PV in 13, and left PV in two. Of the single branches, the right post posteriorbranch was most commonly opacified. Among 18 patients with OPV, the degree of three organs (stomach, duodenum, andpancreas) was grade I in two, grade II in two, and grade III in 14 while among 48 patients with nonopacified PV, thefindings were grade I in 27, grade II in seven, and grade III in 14. The relationship between OPV and degree ofenhancement of the three organs was statistically significant (p=0.001). There was however, no statisticallysignificant difference between OPV and Child classification and the amount of contrast media. CONCLUSION: PVopacification during CTHA is not rare and this finding should not therfore be regarded as indicator of apathologic conditions such as AP shunt.

Mucinous and Nonmucinous Type of Bronchioloal veolar Carcinoma: Difference in CT Findings

PURPOSE: To search for CT findings which helpfully differentiate mucinous from nonmucinousbronchi-oloalveolar carcinoma and to assess the difference in stages between the two types of tumors. Twenty-two patients with pathologically proven bronchioloalveolar carcinoma (BAC) were included inthis study. On the basis of CT findings, tumors were classified as either solitary or multiple and as eithermass/nodule, consolidation, or mixed type. CT stages of the tumors were determined by two radiologists andconclusions were reached by consensus. RESULTS: Twelve patients had nonmucinous BACs and ten had mucinous BACs.Among the ten cases of mucinous BAC, six were solitary and four were multiple. These were mass/nodule (n=3),consolidation (n=5), and mixed pattern (n=2). In contrast, among the twelve cases of nonmucinous BAC, six weresolitary and six were multiple. All were mass/nodule, except for one mixed type. Among the mucinous BACs, threewere operable and seven (above stage IIIa) were inoperable. Among the nonmucinous BACs, four were operable andeight were inoperable. CONCLUSION: Consolidation was more common in mucinous BAC and mass/nodule was more commonin non-mucinous BAC (p0.05).

Clinical Effect of Prazosin Hydrochloride in Patient with Benign Prostatic Hypertrophy / 대한비뇨기과학회지

The clinical effect of prazosin, an alpha-1-receptor blocking agent, was studied in 31 patients with benign prostatic hypertrophy. The daily dose of 1.5-6 mg of prazosin was given for 2 weeks to 3 months. The efficacy was assessed by using uroflowmetry calculated from maximum flow rate, average flow rate and residual urine volume. The result revealed significant improvement of day time frequency, night time frequency (p<0.05) and maximum and average flow rate (p<0.05). It was suspected that prazosin was the valuable alpha-1-receptor blocker for benign prostatic hypertrophy and worth while to initiate medical treatment before undergoing any surgical intervention or when surgery is contraindicated.