Image Quality and Diagnostic Performance of Accelerated Shoulder MRI With Deep Learning-Based Reconstruction.

BACKGROUND. Shoulder MRI using standard multiplanar sequences requires long scan times. Accelerated sequences have tradeoffs in noise and resolution. Deep learning-based reconstruction (DLR) may allow reduced scan time with preserved image quality. OBJECTIVE. The purpose of this study was to compare standard shoulder MRI sequences and accelerated sequences without and with DLR in terms of image quality and diagnostic performance. METHODS. This retrospective study included 105 patients (45 men, 60 women; mean age, 57.6 ± 10.9 [SD] years) who underwent a total of 110 3-T shoulder MRI examinations. Examinations included standard sequences (scan time, 9 minutes 23 seconds) and accelerated sequences (3 minutes 5 seconds; 67% reduction), both including fast spin-echo sequences in three planes. Standard sequences were reconstructed using the conventional pipeline; accelerated sequences were reconstructed using both the conventional pipeline and a commercially available DLR pipeline. Two radiologists independently assessed three image sets (standard sequence, accelerated sequence without DLR, and accelerated sequence with DLR) for subjective image quality and artifacts using 4-point scales (4 = highest quality) and identified pathologies of the subscapularis tendon, supraspinatus-infraspinatus tendon, long head of the biceps brachii tendon, and glenoid labrum. Interobserver agreement and agreement between image sets for the evaluated pathologies were assessed using weighted kappa statistics. In 27 patients who underwent arthroscopy, diagnostic performance was calculated using arthroscopic findings as a reference standard. RESULTS. Mean subjective image quality scores for readers 1 and 2 were 10.6 ± 1.2 and 10.5 ± 1.4 for the standard sequence, 8.1 ± 1.3 and 7.2 ± 1.1 for the accelerated sequence without DLR, and 10.7 ± 1.2 and 10.5 ± 1.6 for the accelerated sequence with DLR. Mean artifact scores for readers 1 and 2 were 9.3 ± 1.2 and 10.0 ± 1.0 for the standard sequence, 7.3 ± 1.3 and 9.1 ± 0.8 for the accelerated sequence without DLR, and 9.4 ± 1.2 and 9.8 ± 0.8 for the accelerated sequence with DLR. Interobserver agreement ranged from kappa of 0.813-0.951 except for accelerated sequence without DLR for the supraspinatus-infraspinatus tendon (κ = 0.673). Agreement between image sets ranged from kappa of 0.809-0.957 except for reader 1 for supraspinatus-infraspinatus tendon (κ = 0.663-0.700). Accuracy, sensitivity, and specificity for tears of the four structures were not different (p > .05) among image sets. CONCLUSION. Accelerated sequences with DLR provide 67% scan time reduction with similar subjective image quality, artifacts, and diagnostic performance to standard sequences. CLINICAL IMPACT. Accelerated sequences with DLR may provide an alternative to standard sequences for clinical shoulder MRI.

Portal Vein Gas in Neonates: Predicting Clinical Treatment Outcomes From Ultrasound Findings.

OBJECTIVES: To identify sonographic findings that predict clinical outcomes in neonates with portal vein gas. METHODS: This retrospective study included neonates with portal vein gas detected using ultrasound (US). The US images were reviewed by a pediatric radiologist. US findings included the extent and amount of portal vein gas, mesenteric vein gas, intramural gas, bowel wall thickening or thinning, focal discontinuity of the bowel wall, ascites, free intra-abdominal gas, pseudocyst, gas in the other solid organs, and bowel distension. The imaging findings and demographic factors between survivors and non-survivors were statistically compared. RESULTS: The mortality rate was 26% (39 survivors, 14 non-survivors) when iatrogenic and idiopathic causes were excluded. The causes of portal vein gas were determined to be necrotizing enterocolitis (n = 33), bowel distension or obstruction (n = 12), fetal hydrops (n = 4), pneumothorax (n = 3), immediate postoperative state for bowel perforation (n = 1), and umbilical vein catheterization (n = 9) based on surgical findings (n = 20) and clinical information (n = 46). Gas within the mesenteric vein and the other solid organs, gestational age, and birth weight were significantly different between survivors and those who succumbed (P < .05). CONCLUSION: Gas within the mesenteric vein and other solid organs is a US finding that may predict poor outcomes in neonates with portal vein gas.

Sonographic findings of total colonic aganglionosis in a neonate with Haddad syndrome: A case report.

Haddad syndrome is a rare congenital disorder characterized by congenital central hypoventilation syndrome and Hirschsprung disease. Total colonic aganglionosis is a rare and long-segment form of Hirschsprung disease, which is primarily diagnosed using contrast enemas. However, the diagnostic performance of contrast enemas is relatively low, making the diagnosis of total colonic aganglionosis challenging. In neonates, ultrasound may be used as an additional imaging modality for the diagnosis of Hirschsprung disease. We describe the unique sonographic findings of total colonic aganglionosis in a term neonate with failure to pass meconium and respiratory distress, who was subsequently diagnosed with Haddad syndrome.

Clinical applicability of shear wave elastography for the evaluation of medial epicondylitis.

OBJECTIVES: To evaluate the ability of shear wave elastography (SWE) in diagnosing medial epicondylitis and to compare the diagnostic performance of SWE with that of grey-scale ultrasound (GSU) and strain elastography (SE). METHODS: GSU, SE, and SWE were performed on 61 elbows of 54 patients from March 2018 to April 2019. An experienced radiologist evaluated the GSU findings (swelling, cortical irregularity, hypoechogenicity, calcification, and tear), colour Doppler findings (hyperaemia), SE findings (strain ratio [SR]), and SWE findings (stiffness and shear wave velocity [SWV]). Participants were divided in two groups: patients with clinically diagnosed medial epicondylitis and patients without medial elbow pain. Findings from the two groups were compared, and the receiver operating characteristic (ROC) curves were calculated for significant features. RESULTS: Of the 54 patients, 25 patients with 28 imaged elbows were clinically diagnosed with medial epicondylitis and 29 patients with 33 imaged elbows had no medial elbow pain. Cortical irregularity, hypoechogenicity, calcification, hyperaemia, SR, stiffness, and SWV were significantly different between the two groups. The areas under the ROC curves were 0.838 for hypoechogenicity, 0.948 for SR, 0.999 for stiffness, and 0.999 for SWV. The diagnostic performances of SR, stiffness, and SWV were significantly superior compared to that of hypoechogenicity. However, there were no significant differences among SR, stiffness, and SWV. CONCLUSIONS: SWE can obtain both stiffness and SWV, which are valuable diagnostic tools in the diagnosis of medial epicondylitis. The diagnostic performance of SWE and SE is similar in detecting medial epicondylitis. KEY POINTS: • Shear wave elastography providing stiffness and shear wave velocity showed excellent performance in the diagnosis of medial epicondylitis. • There was no significant difference in the ability of SE and SWE for diagnosing medial epicondylitis.

Non-strangulated adhesive small bowel obstruction: CT findings predicting outcome of conservative treatment.

OBJECTIVES: To clarify CT findings that predict outcome of conservative treatment in patients with non-strangulated adhesive small bowel obstruction (SBO). METHODS: Unenhanced and contrast-enhanced abdominopelvic CT studies in 189 patients with adhesive SBO who had initial conservative treatment were reviewed. The CT findings included transition zone, beak signs, maximum bowel diameter, bowel diameter ratio, decreased bowel wall enhancement, increased unenhanced bowel wall attenuation, anterior parietal adhesion, bowel wall thickening, closed-loop obstruction, small bowel feces sign, whirl sign, mesenteric haziness, mesenteric, peritoneal fluid, and submucosal edema. These findings were statistically compared according to the success or failure of treatment. RESULTS: Conservative treatment succeeded in 144 patients (76.2%) and failed in 45 patients (23.8%). At multivariate analysis, the lack of small bowel feces sign, focal, diffuse mesenteric haziness, and moderate amount of mesenteric fluid were independent findings predicting failure of conservative treatment, with odds ratios of 5.23, 5.5, 13.55, and 4.89, respectively. The presence of all significant findings showed a high specificity of 97.2% with positive likelihood ratio of 8.8. If CT scans showed none of the three significant findings, the negative predictive value was 97.6% and negative likelihood ratio was 0.08. CONCLUSIONS: The lack of small bowel feces sign, focal, diffuse mesenteric haziness, and moderate amount of mesenteric fluid are independent CT findings predicting the failure of conservative treatment in patients with non-strangulated adhesive SBO. The combination of all CT findings suggests the need for surgery; absence of two or all CT findings should suggest an attempt for conservative treatment. KEY POINTS: • To minimize delayed operation, it is important to identify non-strangulated adhesive small bowel obstruction patients in whom initial conservative treatment is likely to fail. • The lack of small bowel feces sign, the presence of mesenteric haziness, and a moderate amount of mesenteric fluid are independent factors predicting the failure of conservative treatment in patients with non-strangulated adhesive small bowel obstruction. • The combination of all three CT findings suggests the need for surgery; absence of two or all three CT findings should suggest an attempt for conservative treatment.

High-Resolution Diffusion-Weighted Imaging for Evaluation of Extramural Tumor Invasion in Primary Rectal Cancer.

OBJECTIVE: The aim of this study was to determine the added value of high-resolution diffusion-weighted imaging (DWI) to T2-weighted imaging (T2WI) for evaluation of extramural tumor invasion (EMTI) in patients with primary rectal cancer. METHODS: Seventy-eight patients who had undergone 3.0-T magnetic resonance imaging including DWI (b = 0, 1000 s/mm2, 2 mm iso-voxel) and subsequent surgery were included. Two blinded radiologists independently read the T2WI first and then the combined DWI set. They recorded their confidence level using a 5-point scale. The diagnostic accuracy was calculated by receiver operating characteristic curve analysis based on the histopathological results as the reference. RESULTS: The study population consisted of EMTI positive (n = 44) and negative (n = 34). The area under the curve was not significantly increased after adding DWI to T2WI (reader 1, 0.868-0.856, P = 0.5618; reader 2, 0.848-0.865, P = 0.4539). CONCLUSION: Adding DWI to T2WI showed no additional diagnostic value for the evaluation of EMTI in patients with primary rectal cancer.

Prospective Multicenter Study of the Safety of Gadoteridol in 6163 Patients.

BACKGROUND: The safety of gadolinium-based contrast agents is of fundamental importance. PURPOSE: To determine the frequency and severity of immediate-type adverse reactions to approved doses of gadoteridol in patients referred for routine gadoteridol-enhanced MRI in actual clinical practice settings. STUDY TYPE: Prospective, observational. POPULATION: In all, 6163 subjects were enrolled (mean age: 56.7 ± 15.4 years; range: 6-93 years). FIELD STRENGTH/SEQUENCE: 1.5T and 3.0T. ASSESSMENT: Assessment was of immediate adverse reactions by the investigating radiologist using the MedDRA System Organ Class and preferred term. STATISTICAL TESTS: Summary statistics for continuous variables, descriptive statistics for demographic characteristics. RESULTS: Overall, 19 adverse events occurred in 13 (0.21%) patients, of which 15 in 10 (0.16%) patients were considered related to gadoteridol administration. These events were evenly distributed between male and female subjects and all occurred in adults. Twelve of the 15 related events in eight (0.13%) patients were considered mild in intensity (rapidly self-resolving), while the remaining three events in two patients (0.03%) were considered moderate in intensity. None were of severe intensity and no serious adverse events occurred. DATA CONCLUSION: The rate of immediate-type adverse events following exposure to approved doses of gadoteridol is extremely low, and mostly limited to transient and self-resolving symptoms. LEVEL OF EVIDENCE: 2 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2020;51:861-868.

Ultrasound Features and Rate of Upgrade to Malignancy in Atypical Apocrine Lesions of the Breast.

OBJECTIVES: To evaluate the ultrasound (US) features and rate of upgrade to malignancy in atypical apocrine lesions (AALs) of the breast, diagnosed on percutaneous needle biopsy. METHODS: This retrospective study included 17 AALs diagnosed by needle biopsy in 15 patients. For 16 of the 17 AALs, subsequent surgical excision (n = 14) or 8-gauge vacuum-assisted biopsy (n = 2) was performed. Ultrasound features were retrospectively analyzed according to the American College of Radiology Breast Imaging Reporting and Data System lexicon. RESULTS: Of 17 AALs, 13 (76.5%) were atypical apocrine hyperplasia; 3 (17.6%) were atypical apocrine adenosis; and 1 (5.9%) was combined atypical apocrine hyperplasia and atypical apocrine adenosis on needle biopsy. Subsequently, 4 of 16 AALs (25%) were upgraded to malignancy at surgical excision. On US imaging, all 17 lesions presented as masses, which were mainly irregular and noncircumscribed (n = 8) or oval/round and noncircumscribed (n = 7) with isoechogenicity or hypoechogenicity. Rarely, an AAL would show complex cystic and solid echogenicity (n = 1) or appear as a hypoechoic mass with oval shape and a circumscribed margin (n = 1). CONCLUSIONS: Atypical apocrine lesions of the breast often showed suspicious malignant features on US imaging. Given the high upgrade rate (25%), the diagnosis of an AAL by needle biopsy warrants subsequent surgical excision.

The most-cited articles in pediatric imaging: a bibliometric analysis.

INTRODUCTION: The number of citations that an article has received reflects its impact on the scientific community. The purpose of our study was to identify and characterize the 51 most-cited articles in pediatric imaging. EVIDENCE ACQUISITION: Based on the database of Journal Citation Reports, we selected 350 journals that were considered as potential outlets for pediatric imaging articles. The Web of Science search tools were used to identify the most-cited articles relevant to pediatric imaging within the selected journals. EVIDENCE SYNTHESIS: The 51 most-cited articles in pediatric imaging were published between 1952 and 2011, with 1980-1989 and 2000-2009 producing 15 articles, each. The number of citations ranged from 576-124 and the number of annual citations ranged from 49.05-2.56. The majority of articles were published in pediatric and related journals (N.=26), originated in the USA (N.=23), were original articles (N.=45), used MRI as imaging modality (N.=27), and were concerned with the subspecialty of brain (N.=34). University College London School of Medicine (N.=6) and School of Medicine University of California (N.=4) were the leading institutions and Reynolds EO (N.=7) was the most voluminous author. CONCLUSIONS: Our study presents a detailed list and an analysis of the most-cited articles in the field of pediatric imaging, which provides an insight into historical developments and allows for recognition of the important advances in this field.

Omental calcification, necrotizing enterocolitis, and undescended testes after fetal abdomino-amniotic shunting performed for the management of meconium peritonitis: A case report.

Prenatal ultrasonography (US) in a 39 year-old woman revealed massive fetal ascites. A fetal abdomino-amniotic shunting procedure was performed. Subsequently, plain radiographs demonstrated diffuse gaseous distention of the bowel and multiple punctate calcifications in the left upper abdomen. Postnatal US examination showed multiple echogenic foci in the liver and the left upper abdomen, bowel wall thickening in the right-sided abdomen, and undescended testes. There was no intra-abdominal free air or loculated fluid collections. Medical management was instituted secondary to the clinical suspicion of omental calcification, necrotizing enterocolitis, and undescended testes. Follow-up US examination showed resolution of portal vein gas and bowel wall thickening. The neonate recovered fully.

Comparison of Model-Based Iterative Reconstruction, Adaptive Statistical Iterative Reconstruction, and Filtered Back Projection for Detecting Hepatic Metastases on Submillisievert Low-Dose Computed Tomography.

OBJECTIVE: The aim of the study was to compare the diagnostic performance of model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP) on submillisievert low-dose computed tomography (LDCT) for detecting hepatic metastases. METHODS: Thirty-eight patients having hepatic metastases underwent abdomen CT. Computed tomography protocol consisted of routine standard-dose portal venous phase scan (120 kVp) and 90-second delayed low-dose scan (80 kVp). The LDCT images were reconstructed with FBP, ASIR, and MBIR, respectively. Two readers recorded the number of hepatic metastases on each image set. RESULTS: A total of 105 metastatic lesions were analyzed. For reader 1, sensitivity for detecting metastases was stationary between FBP (49%) and ASIR (52%, P = 0.0697); however, sensitivity increased in MBIR (66%, P = 0.0035). For reader 2, it was stationary for all the following sets: FBP (65%), ASIR (68%), and MBIR (67%, P > 0.05). CONCLUSIONS: The MBIR and ASIR showed a limited sensitivity for detecting hepatic metastases in submillisievert LDCT.

Autosomal dominant brachyolmia: transient metaphyseal striations.

We report transient proximal and distal femoral metaphyseal striations that have not previously been described in autosomal dominant brachyolmia. The pelvis/hip radiograph of a 13-year-old boy demonstrated bilaterally symmetrical proximal femoral metaphyseal vertical striations. Additional vertical striations were also observed at the distal femur and proximal tibia metaphysis. Radiography of the thoracolumbar spine demonstrated platyspondyly with irregular endplates and overfaced pedicles. TRPV4 mutations were confirmed in this patient. Similar proximal femoral metaphyseal vertical striations were noted in the patient's sibling. Those streaks disappeared on the follow-up radiographs, and we considered it a unique radiologic finding transiently observed in autosomal dominant brachyolmia.

Diffusion-weighted imaging for evaluating lymph node eradication after neoadjuvant chemoradiation therapy in locally advanced rectal cancer.

BACKGROUND: As lymph node (LN) eradication is the prerequisite for clinical surveillance or local excision for patients who have achieved a complete response after preoperative chemoradiation therapy (CRT), the radiological evaluation of LN eradication is important. PURPOSE: To evaluate the added value of diffusion-weighted imaging (DWI) in the evaluation of LN eradication after CRT in patients with locally advanced rectal cancer (LARC). MATERIAL AND METHODS: Ninety-five consecutive patients (64 men, 31 women; mean age, 59 years; range, 32-82 years) who underwent pre- and post-CRT 1.5-T MRI with DWI (b = 0, 1000 s/mm(2)) were enrolled. To evaluate the added value of DWI in the evaluation of LN eradication after CRT, two radiologists first independently read the pre- and post-CRT T2-weighted (T2W) images and then read the combined T2W imaging set and the pre- and post-CRT DWIs with a 4-week interval. The radiologists recorded their confidence scores for LN eradication using a 5-point scale on a per-patient basis. The diagnostic performances were compared between the two reading sessions for each reader with pair-wise comparisons of receiver-operating characteristic curves. Histopathological reports served as the reference standards for LN eradication. RESULTS: The study population consisted of an LN-eradicated group (n = 66) and a non-eradicated group (n = 29). The diagnostic performances did not significantly differ between the two reading sessions for the two readers (AUCs for reader 1, 0.770 and 0.774, P = 0.8155; for reader 2, 0.794 and 0.798, P = 0.8588). CONCLUSION: Adding DWI to T2W imaging provided no additional diagnostic benefit for the evaluation of LN eradication following CRT in patients with LARC.

Low-dose CT for patients with clinically suspected acute appendicitis: optimal strength of sinogram affirmed iterative reconstruction for image quality and diagnostic performance.

BACKGROUND: As there is increased concern over the radiation exposure particularly in adolescents and young adults, computed tomography (CT) dose reduction is needed in the diagnosis of acute appendicitis. PURPOSE: To evaluate the optimal strength of sinogram affirmed iterative reconstruction (SAFIRE) to obtain the best image quality on a 30-mAs applied low-dose CT (LDCT 30mAs) and to compare the diagnostic performances of the LDCT 30mAs with different SAFIRE strengths with that of the 100-mAs applied LDCT (LDCT 100mAs) for the diagnosis of acute appendicitis. MATERIAL AND METHODS: A total of 102 consecutive patients (47 men, 55 women; mean age, 41.2 years; range, 15-82 years) with right lower quadrant pain underwent abdominal-pelvic CT, consisting of arterial phase LDCT 100mAs and portal venous phase LDCT30mAs under a fixed 120 kV. LDCT 30mAs images were reconstructed separately with five strength levels (S1-S5). Two blinded radiologists recorded scores for the subjective image quality of the LDCT 30mAs dataset (S0-S5) and confidence scores for the diagnosis of acute appendicitis on each dataset and LDCT 100mAs. CT image noise was measured for each set. RESULTS: The study population consisted of 58 patients with confirmed appendicitis and 44 without appendicitis. There was no significant difference in diagnostic performance between LDCT 100mAs and LDCT 30mAs with any strength for both readers (AUC for reader 1, LDCT 30mAs with S0-S5 = 0.97, LDCT 100mAs = 0.93, P = 0.0936; for reader 2, LDCT 30mAs with S0-S5 = 0.96, LDCT 100mAs = 0.97, P = 0.128). The measured noise decreased as the strength increased from S0 to S5 (mean, 20.8 > 17.7 > 15.6 > 13.5 > 11.5 > 9.5, P < 0.0001). However, overall subjective image quality on S3 was better than the other strengths for both readers (S0 < S1 < S2 < S3 > S4 > S5, P < 0.0001). CONCLUSION: Although measured noise declined as SAFIRE strength increased, S3 seems optimal for the best subjective image quality on LDCT 30mAs. The diagnostic performance of LDCT 30mAs with any strength is comparable to that of LDCT 100mAs for the diagnosis of acute appendicitis.

Gray-scale and color Doppler sonographic features of complex fibroadenomas of the breast.

PURPOSE: To investigate gray-scale and color Doppler sonographic (US) features of complex fibroadenoma (FA), according to the Breast Imaging-Reporting and Data System (BI-RADS) lexicon. METHODS: From 2010 through 2013, 586 women with FAs were seen; 101 (17%) of those lesions were diagnosed as complex FAs on percutaneous needle biopsy or surgery. Among the patients with complex FAs, 67 who had US examination results available were included in this study. In addition, the results from 98 women who had simple FAs were included as controls. US features were retrospectively analyzed by two breast radiologists in consensus for shape, margin, echogenicity, posterior acoustic pattern, boundary, orientation, and associated findings. They also reassessed the BI-RADS category for FAs. Color Doppler US examination results were classified according to the amount of vascularity as absent, moderate, or marked. RESULTS: Complex FA were larger than simple FAs were (14.5 cm versus 12.1 cm, p > 0.05). On univariate analysis, a round to irregular shape, an uncircumscribed margin, the presence of associated findings, and BI-RADS categorization as 4a and 4b were more frequently revealed in complex than in simple FAs (p < 0.05). Multivariate analysis revealed that the tumor margin was a predictive factor for complex FA (odds ratio: 6.08; 95% confidence interval: 1.14-32.49, p < 0.05). On color Doppler US, the complex FAs had higher degrees of vascularity than simple FA (p < 0.05). CONCLUSIONS: Complex FAs, in comparison with simple FAs, tend to have more aggressive features and to be in higher BI-RADS categories on US examination.

Postoperative low-dose follow-up computed tomography for patients with stomach cancer: optimal blending ratio of adaptive statistical iterative reconstruction for image quality and diagnostic performance.

OBJECTIVE: To compare the diagnostic performance of adaptive statistical iterative reconstruction applied low-dose computed tomography (CT) (LDCT) with that of the standard-dose CT (SDCT) for local recurrence in patients with stomach cancer. METHODS: Seventy-nine consecutive patients who had undergone surgical resection for stomach cancer were enrolled. To monitor recurrence, SDCT (120 kilovolt peak [kVp], 200mAs) had been performed. The LDCT (120 kVp, 100 mA s) was taken, and images were reconstructed with 4 levels of adaptive statistical iterative reconstruction (ASIR) blending (0%, 30%, 50%, and 70%). Two blinded radiologists recorded the diagnostic confidence scores for local recurrence in each data set using a 5-point scale. Endoscopic biopsy results served as the reference standard. Receiver operating characteristic (ROC) curve analysis was used to calculate the diagnostic performance. RESULTS: The diagnostic performance of LDCT with variable ASIR blending ratios was comparable to that of SDCT (area under ROC curve, 0.727-0.734, 0.687, respectively, P > 0.05). CONCLUSIONS: The diagnostic performance of ASIR applied LDCT is comparable to that of SDCT.

Quarter regular dose non-enhanced CT for urinary stone: added value of adaptive statistical iterative reconstruction.

BACKGROUND: As urinary stone diseases are common in young adults and have a high recurrence rate, repetitive computed tomography (CT) scans would increase the radiation hazard. Therefore, CT radiation dose reduction is needed in the diagnosis of urinary stones. PURPOSE: To prospectively evaluate the added value of adaptive statistical iterative reconstruction (ASIR) applied to half-dose (HDCT) and quarter regular dose non-enhanced CT (QDCT) for the detection of urinary stones. MATERIAL AND METHODS: One hundred and twelve consecutive patients who presented with acute flank pain and had clinically suspected urinary stones were initially eligible. All patients underwent non-enhanced CT that consisted of HDCT (120 kVp, 100 mAs) and QDCT (120 kVp, 40 mAs). The images were reconstructed separately with a 50% ASIR blending ratio. Two radiologists independently performed a 2-week interval reading to detect urinary stones on a per stone basis (size ≥1 mm) from the QDCT images to the ASIR applied images. Two weeks later, the HDCT images were analyzed in the same manner. The CT image noise was measured for each image set. The sensitivity for urinary stone detection for each set was compared using the McNemar test. RESULTS: A total of 114 urinary stones were found in 48 patients (37 men, 11 women; mean age, 46 years; range, 19-71 years). After applying ASIR to the QDCT images, the sensitivity increased from 70% to 80% for reader 1 and from 69% to 82% for reader 2 (P = 0.001, respectively). However, in the HDCT images, the sensitivity was unchanged for both readers (reader 1, 87%; reader 2, 89%). The measured noise significantly decreased from 40.2 to 27.7 after applying ASIR to the QDCT images and from 25.1 to 17.6 after applying ASIR to the HDCT images (P = 0.001 for both). CONCLUSION: Although ASIR showed no added diagnostic value for HDCT images, it improved the sensitivity for the detection of urinary stones based on QDCT images.

Visit-to-visit variability of metabolic parameters and progression of atherosclerosis in computed tomography: follow up of an asymptomatic cohort.

Background: We aimed to examine whether intra-individual variability in traditional risk factors affects the progression of atherosclerosis on subsequent coronary computed tomography angiography (CCTA). Methods: We conducted a retrospective cohort study using asymptomatic health examination cohort data from Haeundae Paik Hospital in Korea collected between 2010-2020. A total of 387 adults met the inclusion criteria of having at least two CCTAs without specific symptoms with an interval of more than one year and having completed three or more health examinations. Visit-to-visit variability was evaluated using the average real variability (ARV) of body mass index, waist circumference, systolic and diastolic blood pressure, and plasma glucose, total cholesterol, triglyceride, high-density lipoprotein (HDL)-cholesterol, and low-density lipoprotein (LDL)-cholesterol. Progression of coronary artery atherosclerosis was defined as worsening of coronary artery stenosis from baseline to final CCTA. ARV values for various metabolic parameters were stratified into quartiles, and hazard ratios (HRs) and 95% confidence intervals (CIs) for coronary atherosclerosis progression were analyzed using multiple Cox proportional hazards models. Results: There were 126 cases of coronary artery stenosis progression (32.56%) assessed using the Coronary Artery Disease Reporting and Data System during a mean follow up of 3.91 (range, 1-9) years. In the multivariate analysis comparing ARV quartiles for LDL-cholesterol after adjusting for covariates, individuals with higher variability showed an increased risk of stenosis progression: HR 2.23 (95% CI: 1.33-3.73) for the third quartile, HR 1.56 (95% CI: 0.91-2.66) for the fourth quartile (P for trend =0.005). Triglycerides also showed a significant linear trend (P for trend =0.04), and Q4 had a greater risk of stenosis progression (HR, 2.09; 95% CI: 1.24-3.52). Meanwhile, the risk of stenosis progression was significantly reduced as the ARV of HDL-cholesterol increased: HR 0.56 (95% CI: 0.35-0.89) for the third quartile, HR 0.47 (95% CI: 0.27-0.81) for the fourth quartile (P for trend =0.01). Conclusions: High variability in LDL-cholesterol and triglyceride was an independent predictor of coronary artery stenosis progression on subsequent CCTA in our cohort. This finding highlights the importance of maintaining stable state to effectively prevent the progression of coronary artery stenosis in clinical settings.

Ultrasound findings of subpial hemorrhage in neonates.

PURPOSE: Subpial hemorrhage (SPH) is a subtype of intracranial hemorrhage characterized by damage to the adjacent brain parenchyma. The aim of this study was to describe the sonographic features of SPH in neonates. METHODS: The cranial ultrasound (US) findings of neonates with SPH confirmed by brain magnetic resonance imaging (MRI) were analyzed retrospectively. Initial and follow-up US and MRI scans were reviewed by two pediatric radiologists who were blinded to both clinical history and outcomes. The US features were compared with the MRI findings. RESULTS: Sixteen patients were included (median gestational age, 38 weeks; range, 26 to 40 weeks; 69% term). SPH was detected most often in the temporal lobe (63%), and multiple SPHs were found in seven of 16 neonates, based on MRI. Acute SPH with an underlying venous infarct (UVI) was detected on US in 15 of 16 patients: small or large fan-shaped hyperechoic lesions (n=7 and 4, respectively) and gyriform hyperechoic lesions (n=4). The sonographic yin-yang sign was observed in three of the four large fan-shaped SPH cases. The accompanying findings on US were intraventricular hemorrhage (four out of six MRI-confirmed cases), and concurrent periventricular venous infarcts (five out of nine MRI-confirmed cases). In five patients, subpial cysts were observed on follow-up US or MRI (n=4 and n=4, respectively). CONCLUSION: Acute SPH with UVI can appear as a peripheral fan-shaped or gyriform hyperechoic lesion on cranial US. SPH can be detected and suspected based on the US features of SPH with the accompanying findings.

Placental transmogrification of the lung: CT findings with pathologic correlation in six patients.

Background: Placental transmogrification of the lung is a very rare benign lung disease with a characteristic finding being alveoli resembling chorionic villi of the placenta. The purpose of this study was to assess the computed tomography (CT) findings of placental transmogrification of the lung in six patients and their relation to the histopathologic findings. Methods: Six patients with histopathologically proven placental transmogrification of the lung from 2004 to 2021 were included. Their CT findings were analyzed and their imaging features were compared with pathology specimens. Results: In four of six cases, CT showed variable sized cystic lesions confined to a unilateral lung. One case presented nodule and cystic lesion together. The other case showed solitary pulmonary nodule without cystic lesion. Moreover, nodular interlobular septal thickening and clustered interstitial nodules were observed in all six cases. In four of the six cases, these nodules merged into dense nodular consolidation. Three cases showed dilated pulmonary vasculatures of the involved lung. Conclusions: On CT, placental transmogrification of the lung typically presents as cystic lesion confined to a unilateral lung. Pulmonary nodule with or without associated cystic lesion can also be seen. Nodular interlobular septal thickening and clustered interstitial nodules were observed in all cases. This might be attributable to the proliferation of chorionic villi-like structures in interstitium which are found in histopathologic specimens.