Different hemodynamics of basal ganglia between moyamoya and non-moyamoya diseases using intravoxel incoherent motion imaging and single-photon emission computed tomography.

BACKGROUND: Moyamoya disease (MMD) and non-MMD have different pathogenesis, clinical presentation, and treatment policy. PURPOSE: To identify differences in hemodynamics between MMD and non-MMD using intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT). MATERIAL AND METHODS: Patients who had undergone 99mTc-ECD or 123I-IMP SPECT, and IVIM imaging were retrospectively studied. IVIM imaging was acquired using six different b-values. Cerebral blood flow ratio (CBFR) in the basal ganglia was calculated using a standardized volume-of-interest template. The cerebellum was used as a reference region. IVIM perfusion fraction (f) was obtained using a two-step fitting algorithm. Elliptical regions of interest were placed in bilateral basal ganglia on the IVIM f map. Patients were classified into MMD and non-MMD groups. The correlation between CBFR and mean IVIM f (fmean) in the basal ganglia was evaluated using Spearman's rank correlation coefficient. RESULTS: In total, 20 patients with MMD and 28 non-MMD patients were analyzed. No significant differences in fmean were observed among MMD, affected hemisphere with non-MMD (non-MMDaff), and unaffected hemispheres with non-MMD (non-MMDunaff). A negative correlation was seen between fmean and CBFR in the MMD group (r = -0.40, P = 0.0108), but not in the non-MMD group (non-MMDaff, r = 0.07, P = 0.69; non-MMDunaff, r = -0.22, P = 0.29). No significant differences were found among MMD and non-MMD patients, irrespective of SPECT tracers. CONCLUSION: The combination of IVIM MRI and SPECT appears to allow non-invasive identification of differences in hemodynamics between MMD and non-MMD.

Right entorhinal cortical thickness is associated with Mini-Mental State Examination scores from multi-country datasets using MRI.

PURPOSE: To discover common biomarkers correlating with the Mini-Mental State Examination (MMSE) scores from multi-country MRI datasets. METHODS: The first dataset comprised 112 subjects (49 men, 63 women; range, 46-94 years) at the National Hospital Organization Kyushu Medical Center. A second dataset comprised 300 subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database (177 men, 123 women; range, 57-91 years). Three-dimensional T1-weighted MR images were collected from both datasets. In total, 14 deep gray matter volumes and 70 cortical thicknesses were obtained from MR images using FreeSurfer software. Total hippocampal volume and the ratio of hippocampus to cerebral volume were also calculated. Correlations between each variable and MMSE scores were assessed using Pearson's correlation coefficient. Parameters with moderate correlation coefficients (r > 0.3) from each dataset were determined as independent variables and evaluated using general linear model (GLM) analyses. RESULTS: In Pearson's correlation coefficient, total and bilateral hippocampal volumes, right amygdala volume, and right entorhinal cortex (ERC) thickness showed moderate correlation coefficients (r > 0.3) with MMSE scores from the first dataset. The ADNI dataset showed moderate correlations with MMSE scores in more variables, including bilateral ERC thickness and hippocampal volume. GLM analysis revealed that right ERC thickness correlated significantly with MMSE score in both datasets. Cortical thicknesses of the left parahippocampal gyrus, left inferior parietal lobe, and right fusiform gyrus also significantly correlated with MMSE score in the ADNI dataset (p < 0.05). CONCLUSION: A positive correlation between right ERC thickness and MMSE score was identified from multi-country datasets.

Unilateral agenesis of internal carotid artery with interparaclinoid and contralateral carotid-anterior cerebral artery anastomoses diagnosed by magnetic resonance angiography: a case report.

PURPOSE: Unilateral agenesis of the internal carotid artery (ICA) is a rare anatomical variant. We identified a case of unilateral ICA agenesis with interparaclinoid and contralateral carotid-ACA anastomoses. METHODS: A 65-year-old female with a long history of depressive episodes underwent MR imaging including MR angiography at National Hospital Organization Kyushu Medical Center. MR imaging was performed using a 3.0-T MR scanner to rule out vascular Parkinsonism, although drug-induced Parkinsonism was suspected from her medical history. RESULTS: The proximal left ICA was not visible on MR angiography, and an anterior communicating artery (ACoA) aneurysm was identified. The left middle cerebral artery was supplied from the right ICA via an interparaclinoid anastomosis. This interparaclinoid anastomosis showed no communication with the basilar, posterior communicating, or posterior cerebral arteries. A communicating artery connecting the interparaclinoid anastomosis and anterior cerebral artery (ACA) branched off from the presumed transition point between the interparaclinoid anastomosis and left ICA. Both right and left ophthalmic arteries (OAs) originated from the clinoid segment of the ICA. The communicating artery connecting the interparaclinoid anastomosis and ACA arose proximal to the left OA, and the communicating artery was identified as the carotid-ACA anastomosis. CONCLUSION: Neuroradiologists, physicians, and neurosurgeons need to be aware of this extremely unusual anatomical variant to determine appropriate treatment strategies in cases of aneurysmal growth or anterior cranial base surgery.

Right adrenal vein identification using unenhanced magnetic resonance imaging.

Purpose: Unenhanced magnetic resonance imaging (MRI) is known to be useful in characterizing adrenal adenomas through the implementation of in-phase (IPI) and opposed-phase imaging (OPI) based on chemical shift artifacts. However, whether unenhanced MRI can contribute to the identification of right adrenal vein (RAV) remains unclear. The aim of this study was to evaluate the feasibility of unenhanced MRI for the identification of RAV. Material and methods: This retrospective study reviewed 30 patients (16 men; median age 60 years; range 34-76 years) who underwent MRI and subsequent adrenal venous sampling (AVS). Chemical shift MRI was acquired using echo times of 2.3 ms (OPI) and 4.6 ms (IPI) with a slice thickness of 3 mm and a gap of 1 mm. T2-weighted imaging (T2WI) was also performed. Identification of RAVs was performed by 2 independent radiologists. Inter-observer agreement on a 3-point rating scale was evaluated using κ statistics. The identification rate of RAVs was compared between OPI, IPI, and T2WI using McNemar's test. Results: Good inter-observer agreement was found for the OPI (κ = 0.744), whereas fair agreement was obtained for both other sequences (IPI: κ = 0.375; T2WI: 0.348). For both raters, the identification rate of RAVs was higher with OPI (36/60; 60.0%) than with other sequences (IPI: 16/60, 26.7%; T2WI: 9/60, 15.0%; p < 0.05, each). Conclusions: OPI may play a screening role in the identification of RAVs preceding AVS, which could reduce the required radiation exposure and doses of contrast agent.

MADGAN: unsupervised medical anomaly detection GAN using multiple adjacent brain MRI slice reconstruction.

BACKGROUND: Unsupervised learning can discover various unseen abnormalities, relying on large-scale unannotated medical images of healthy subjects. Towards this, unsupervised methods reconstruct a 2D/3D single medical image to detect outliers either in the learned feature space or from high reconstruction loss. However, without considering continuity between multiple adjacent slices, they cannot directly discriminate diseases composed of the accumulation of subtle anatomical anomalies, such as Alzheimer's disease (AD). Moreover, no study has shown how unsupervised anomaly detection is associated with either disease stages, various (i.e., more than two types of) diseases, or multi-sequence magnetic resonance imaging (MRI) scans. RESULTS: We propose unsupervised medical anomaly detection generative adversarial network (MADGAN), a novel two-step method using GAN-based multiple adjacent brain MRI slice reconstruction to detect brain anomalies at different stages on multi-sequence structural MRI: (Reconstruction) Wasserstein loss with Gradient Penalty + 100 [Formula: see text] loss-trained on 3 healthy brain axial MRI slices to reconstruct the next 3 ones-reconstructs unseen healthy/abnormal scans; (Diagnosis) Average [Formula: see text] loss per scan discriminates them, comparing the ground truth/reconstructed slices. For training, we use two different datasets composed of 1133 healthy T1-weighted (T1) and 135 healthy contrast-enhanced T1 (T1c) brain MRI scans for detecting AD and brain metastases/various diseases, respectively. Our self-attention MADGAN can detect AD on T1 scans at a very early stage, mild cognitive impairment (MCI), with area under the curve (AUC) 0.727, and AD at a late stage with AUC 0.894, while detecting brain metastases on T1c scans with AUC 0.921. CONCLUSIONS: Similar to physicians' way of performing a diagnosis, using massive healthy training data, our first multiple MRI slice reconstruction approach, MADGAN, can reliably predict the next 3 slices from the previous 3 ones only for unseen healthy images. As the first unsupervised various disease diagnosis, MADGAN can reliably detect the accumulation of subtle anatomical anomalies and hyper-intense enhancing lesions, such as (especially late-stage) AD and brain metastases on multi-sequence MRI scans.

A fundamental study assessing the generalized fitting method in conjunction with every possible coalition of N-combinations (G-EPOC) using the appendicitis detection task of computed tomography.

PURPOSE: Increased use of deep learning (DL) in medical imaging diagnoses has led to more frequent use of 10-fold cross-validation (10-CV) for the evaluation of the performance of DL. To eliminate some of the (10-fold) repetitive processing in 10-CV, we proposed a "generalized fitting method in conjunction with every possible coalition of N-combinations (G-EPOC)", to estimate the range of the mean accuracy of 10-CV using less than 10 results of 10-CV. MATERIAL AND METHODS: G-EPOC was executed as follows. We first provided (2N-1) coalition subsets using a specified N, which was 9 or less, out of 10 result datasets of 10-CV. We then obtained the estimation range of the accuracy by applying those subsets to the distribution fitting twice using a combination of normal, binominal, or Poisson distributions. Using datasets of 10-CVs acquired from the practical detection task of the appendicitis on CT by DL, we scored the estimation success rates if the range provided by G-EPOC included the true accuracy. RESULTS: G-EPOC successfully estimated the range of the mean accuracy by 10-CV at over 95% rates for datasets with N assigned as 2 to 9. CONCLUSIONS: G-EPOC will help lessen the consumption of time and computer resources in the development of computerbased diagnoses in medical imaging and could become an option for the selection of a reasonable K value in K-CV.

Magnetic Resonance (MR) Imaging Assessment for Glossopharyngeal Neuralgia: Value of Three-Dimensional T2-Reversed MR Imaging (3D-T2R) in Conjunction with Other Modes of 3D MR Imaging.

BACKGROUND: To retrospectively examine the usefulness of gray-scale reversal imaging of T2-weighted images (3D-T2R) in conjunction with other modes of 3D MRI for preoperative assessments in patients with glossopharyngeal neuralgia (GPN) due to neurovascular compression. MATERIAL/METHODS: Imaging findings on 3D-T2R, constructive interference in steady state (CISS), and MRA were analyzed with reference to operative charts in 10 patients with GPN. RESULTS: Offending vessels were associated with the posterior inferior cerebellar artery (PICA) in 9 of 10 patients (90%). Eight of the 10 patients (80%) had offending vessels located at the supraolivary fossette. Of those eight patients, six (75%) had a shift of the ipsilateral vertebral artery to the affected side. Five (42%) and seven (48%) contact points were associated with the root entry/exit zone and the peripheral nerve system segment, respectively. In six of nine contact points (67%), 3D-T2R demonstrated the pathomorphological features at the contact points better than CISS. CONCLUSIONS: The offending vessels were mostly associated with posterior inferior cerebellar arteries, were frequently located at the supraolivary fossette, and had attachments at the root entry/exit zone and at the peripheral segment of the glossopharyngeal nerve, which was well demonstrated on 3D-T2R.

A patient with Alzheimer's disease complicated by elderly-onset Cushing's syndrome who had undergone surgical treatment for adrenocorticotropic hormone-independent macronodular adrenal hyperplasia.

Cushing's syndrome (CS) is a rare disorder, especially in older people. Loss of brain volume and neurocognitive impairment of varying degrees has been demonstrated in patients with CS. However, there is a large difference between the median age of presentation of CS and that of Alzheimer's disease. We herein report a case of a patient with Alzheimer's disease complicated by elderly-onset CS who had undergone surgical treatment for adrenal hyperplasia. Surgical correction of hypercortisolism seems to have slowed the progression of brain volume loss and cognitive dysfunction and improved psychiatric symptoms such as visual hallucination, restlessness, and psychomotor excitement. These improvements have remarkably reduced the burden on the patient's caregivers. The present case suggests that subclinical CS may be present, particularly in rapidly progressive dementia, and that surgical treatment of CS for neuropsychiatric symptoms is useful.

Abnormal behaviours during pramipexole treatment for Cotard's syndrome: a case report.

Cotard's syndrome is a relatively rare condition that involves a delusion of negation in which an individual believes he or she has lost his or her soul, is dead, or is without functional body systems. This syndrome is observed in various neuropsychiatric disorders but most commonly in mood disorders. Pramipexole has often been used in the adjunctive treatment of both bipolar and unipolar depression, and it is known to cause rare but serious adverse effects such as compulsive behaviours in the treatment of Parkinson's disease. Here we report a case of Cotard's syndrome in treatment-resistant major depression associated with abnormal behaviours that might be caused by pramipexole. In the present case, the patient's abnormal behaviours gradually disappeared about 2 months after the discontinuation of pramipexole. The hypoperfusion in the bilateral parieto-occipital lobe found on single-photon emission computed tomography suggests the presence of Lewy body disease pathology. Nonetheless, the patient's abnormal behaviours disappeared after the discontinuation of pramipexole, indicating that they are mainly attributable to pramipexole treatment. However, the possible existence of Lewy body pathology could facilitate the emergence of abnormal behaviours after treatment with pramipexole. The patient's abnormal behaviours, such as eating other patients' food and taking her medicine before the scheduled time, might differ from typical compulsive behaviours induced by pramipexole (such as pathological gambling and hypersexuality), but they could be regarded as disinhibition. Therefore, we should follow up on the clinical course of this case carefully through neuroimaging investigation and neurocognitive assessment.

A Technical Perspective for Understanding Quantitative Arterial Spin-Labeling MR Imaging Using Continuous ASL.

The current paper describes visually the system of CBF measurement by continuous ASL using schematic illustration. I also discussed the effects of the parameters used in continuous ASL to CBF values as measured with ASL-MRI.

Arterial spin-labeling MR imaging of cerebral hemorrhages.

INTRODUCTION: The purpose of this study is to identify the characteristics of brain perfusion measured by arterial spin-labeling magnetic resonance imaging (ASL-MRI) in cerebral hemorrhages. METHODS: Brain blood flow values (CBF-ASL values) for cerebral and cerebellar hemispheres and segmented cerebral regions were measured by ASL-MRI in 19 putaminal hemorrhage patients and 20 thalamic hemorrhage patients in acute or subacute stages. We assessed the lateralities of CBF-ASL values and the relationships between CBF-ASL values and other imaging findings and clinical manifestations. RESULTS: Both the 19 putaminal hemorrhage patients and the 20 thalamic hemorrhage patients had significantly low CBF-ASL values of the contralateral cerebellum in subacute stage, suggesting that ASL-MRI might delineate crossed cerebellar diaschisis (CCD). Ipsilateral low CBF-ASL values were observed in frontal lobes and thalami with a putaminal hemorrhage and lentiform nuclei, temporal lobes, and parietal lobes with a thalamic hemorrhage, suggesting that ASL-MRI showed the ipsilateral cerebral diaschisis (ICD). In the putaminal hemorrhage patients, the hematoma volume negatively affected both the bilateral cerebellar and cerebral hemispheric CBF-ASL values. In the thalamic hemorrhage patients, a concomitant intraventricular hemorrhage caused low cerebral hemispheric CBF-ASL values. CONCLUSION: The use of ASL-MRI is sensitive to the perfusion abnormalities and could thus be helpful to estimate functional abnormalities in cerebral hemorrhage patients.

Basal ganglia cerebral microbleeds and global cognitive function: the Kashima Scan Study.

BACKGROUND: We previously showed that global cognitive function was associated with deep or infratentorial (D/I) cerebral microbleeds (CMBs) in a Japanese healthy cohort. We continually recruited participates and performed further investigation to focus on the impact of different distributions of D/I CMBs on gradient-echo magnetic resonance imaging on global cognitive function. METHODS: A total of 1392 subjects including subjects without CMBs (n = 1335), with D/I CMBs limited to the basal ganglia (BG; BG group, n = 33), thalamus (thalamus group, n = 14), and infratentorial area (infratentorial group, n = 10) were included in analyses. Subjects with strictly lobar CMBs (n = 43) were excluded, but subjects in the BG, thalamus, and infratentorial groups could also have lobar CMBs. The mini-mental state examination (MMSE) was administered to determine global cognitive function; scores less than 27 or more than 1.5 standard deviations (SDs) below the age-education-related mean were regarded as impaired. RESULTS: In the multivariable logistic regression analyses, hypertension and severe white matter hyperintensities were associated with the BG group and the thalamus group. In multivariable logistic regression analysis of the association between D/I CMBs classification and impaired MMSE score, only the BG group consistently displayed associations with both MMSE score less than 27 (odds ratio [OR], 5.96; 95% confidence interval [CI], 2.08-17.09) and MMSE score more than 1.5 SDs below the age-education-related mean (OR, 3.34; 95% CI, 1.24-8.99). In the BG group, adjusted mean scores of total MMSE and "attention and calculation" were lower compared with subjects without CMBs. CONCLUSIONS: In our study of D/I CMBs, only BG CMBs have strong association with global cognitive function. This association was independent of CMBs in other location.

Pharmacokinetics and disposition of dalcetrapib in rats and monkeys.

1. The pharmacokinetics and metabolism of dalcetrapib (JTT-705/RO4607381), a novel cholesteryl ester transfer protein inhibitor, were investigated in rats and monkeys. 2. In in vitro stability studies, dalcetrapib was extremely unstable in plasma, liver S9 and small intestinal mucosa, and the pharmacologically active form (dalcetrapib thiol) was detected as major component. Most of the active form in plasma was covalently bound to plasma proteins via mixed disulfide bond formation. 3. Following oral administration of (14)C-dalcetrapib to rats and monkeys, active form was detected in plasma. The active form was mainly metabolized to the glucuronide conjugate and the methyl conjugate at the thiol group. Several minor metabolites including mono- and di-oxidized forms of the glucuronide are also detected in the plasma and urine. 4. The administered radioactivity was widely distributed to all tissues and mainly excreted into the feces (85.7 and 62.7% of the dose in rats and monkeys, respectively). Most of the radioactivity was recovered by 168 h. Although the absorbed dalcetrapib was hydrolyzed to the active form and was bound to endogenous thiol via formation of disulfide bond, it was relatively rapidly eliminated from the body and was not retained.

Posterior condylar canals and posterior condylar emissary veins-a microsurgical and CT anatomical study.

The posterior condylar canals (PCCs) and posterior condylar emissary veins (PCEVs) are potential anatomical landmarks for surgical approaches through the lateral foramen magnum. We conducted computed tomography (CT) and microsurgical investigation of how PCCs and PCEVs can aid in planning and performing these approaches. We analyzed the microanatomy of PCCs and PCEVs using cadaveric specimens, dry skulls, and CT images. The recognition frequency and geometry of PCCs and PCEVs and their relationships with surrounding structures were evaluated. PCCs were identified in 36 of 50 sides in dry bones and 82 of 100 sides by CT. PCCs had a 3.5-mm mean diameter and a 6.8-mm mean canal length. We classified their courses into four types according to intracranial openings: the sigmoid sinus (SS) type, the jugular bulb (JB) type, the occipital sinus type, and the anterior condylar emissary vein type. In most cases, PCEV originated near the boundary between the SS and JB. PCCs and PCEVs can be useful anatomical landmarks to differentiate the transcondylar fossa approach from the transcondylar approach, thus preventing unnecessary injury of the atlantooccipital joint. They can also be used as landmarks when the jugular foramen (JF) and hypoglossal canal (HGC) are being exposed. The area anterior to the brain stem and the medial part of HGC can be accessed by removal of the lateral foramen magnum medial to PCC. JF and the lateral part of HGC can be accessed by removal of the skull base lateral to PCC without damaging the lateral rim of the foramen magnum.

Prevalence and associated factors of low vigor in patients living with HIV and hemophilia in Japan: A cross-sectional observational study.

People living with human immunodeficiency virus (HIV) are at high risk of mental health problems. However, little is known about this risk in HIV-infected patients with hemophilia (HPH) who contracted the virus through blood products. This cross-sectional, observational study assessed patients' mood states and the factors associated with them among Japanese HPH to evaluate the need for psychosocial support. HPH completed self-administered questionnaires (Profile of Mood States [POMS] and General Health Questionnaire-28), neuropsychological tests, and brain magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography/computerized tomography scans. HIV-infected patients with no hemophilia (HPnH) completed POMS and neuropsychological tests. Socio-demographic characteristics and HIV- and hemophilia-related data were obtained from participants' medical records and interviews. A Mann-Whitney U test and chi-squared analyses were conducted. Fifty-six HPH and 388 HPnH completed the questionnaires and neuropsychological tests. HPH had a significantly lower prevalence of tension-anxiety (HPH, 7%; HPnH, 18%; p = 0.049) and a significantly higher prevalence of low vigor (HPH, 63%; HPnH, 32%; p < 0.001). Low vigor in HPH was significantly associated with impaired executive function (low vigor, 66%; high vigor, 33%; p = 0.019) and a social dysfunction score ≥ 3 (moderate; low vigor, 26%; high vigor, 5%; p = 0.047). Our results highlight the high prevalence of low vigor among HPH, leading to impairments in executive and social functions. Therefore, healthcare workers need to pay attention to the vigor, executive function, and social function of HPH.

CT-gastrography for early gastric cancer visualized by wall-carving technique using contrast-enhanced MDCT for portal phase.

OBJECTIVE: The wall-carving (WC) imaging technique is used to evaluate early gastric cancer using multidetector row computed tomography (MDCT) image data for only the arterial phase. Our purpose was to investigate if WC images derived from portal phase MDCT images can enhance the visualization of early gastric cancer. SUBJECTS AND METHODS: Fourteen consecutive patients (average age/age range (years) = 75.8/61 to 86; male/female = 9/5) were enrolled. They were diagnosed with early gastric cancer and underwent contrast-enhanced MDCT before treatment. WC images of the arterial and portal phases were created from images scanned by 64-detector-row MDCT 40 and 60 seconds after the initiation of the contrast material injection, respectively. The correlation between the detection rates of lesions in the WC images and pathological findings was investigated. RESULTS: Totals of 71.4% (10/14) of arterial phase WC images and 71.4% (10/14) of portal phase WC images showed lesions. The imaging ability improved to 85.7% (12/14) when the two sets of images were combined. Well-differentiated adenocarcinomas tended to be visualized better in WC images of any phases. CONCLUSION: WC is an excellent image analysis technique for visualizing early gastric cancer lesions. The depiction rates were improved by using a combination of arterial and portal WC images. The scan timing after the contrast material injection should be carefully investigated to improve the detection rate of lesions.

Current status and challenges of percutaneous vertebroplasty (PVP).

A narrative review regarding percutaneous vertebroplasty (PVP) for osteoporotic vertebral fracture (OVF) is provided herein, addressing the epidemic of OVF in Japan, the latest response to the criticism of PVP for OVFs, the indications and potential risks of PVP for OVFs, and a future perspective for PVP. Each year in Japan, approximately 32,000 patients aged 55 years or older suffer from chronic low back pain for several months to several years due to a compression fracture. PVP is one of the surgical treatments for an OVF, and it is less invasive compared to the traditional open surgery. PVP is suitable for OVF patients who have difficulty walking as assessed by the modified Yokoyama's activities of daily living (ADL) scoring system, and for patients with Kummell's disease diagnosed by CT and MRI examinations. Serious adverse events related to PVP occur in 1.1-3.3% of the cases, but direct deaths from PVP are extremely rare at less than 1%. Recent studies demonstrated that OVF patients treated with PVP are less likely to die after the treatment than non-surgically treated patients, which conflicts with the Cochran reviews' conclusion not supporting PVP for OVFs. Novel robotic systems and procedure-support devices are being developed, providing a next step toward fully automated PVP procedures.

Assessment of skeletal muscle using deep learning on low-dose CT images.

The visceral fat area obtained by computed tomography (CT) at the navel level is clinically used as an indicator of visceral fat obesity in Japan. Analysis of skeletal muscle mass using CT images at the navel level may potentially support concurrent assessment of sarcopenia and sarcopenic obesity. The purpose of this study was to assess the performance of deep learning models (DLMs) for skeletal muscle mass measurement using low-dose abdominal CT. The primary dataset used in this study included 11,494 low-dose abdominal CT images at navel level acquired in 7,370 subjects for metabolic syndrome screening. The publicly available Cancer Imaging Archive (TCIA) dataset, including 5,801 abdominal CT images, was used as a complementary dataset. For abdominal CT image segmentation, we used the SegU-net DLM with different filter size and hierarchical depth. The segmentation accuracy was assessed by measuring the dice similarity coefficient (DSC), cross-sectional area (CSA) error, and Bland-Altman plots. The proposed DLM achieved a DSC of 0.992 ± 0.012, a CSA error of 0.41 ± 1.89%, and a Bland-Altman percent difference of -0.1 ± 3.8%. The proposed DLM was able to automatically segment skeletal muscle mass measurements from low-dose abdominal CT with high accuracy.

Analysis of "visible in retrospect" to monitor false-negative findings in radiological reports.

PURPOSE: False-negative findings in radiological reports can lead to serious adverse patient outcomes. We determined the frequency and tendency of false-negative findings in radiological reports by searching for words related to "visible in retrospect". METHODS: In the period of 34 months, we extracted radiological reports containing words related to "visible in retrospect". Of these reports, we extracted false-negative findings that were not described in past reports and were first detected retrospectively. Misinterpretations were excluded. The occurrences of the terms that we identified were analyzed by all examinations, modality, month, and anatomical and lesion classifications were analyzed. RESULTS: Of the 135,251 examinations, 941 reports (0.71%) with 962 findings were detected, with an average of 1.4 findings per business day. By modality, 713 of 81,899 (0.87%) CT examinations, 208 of 36,174 (0.57%) MR, 34 of 9,585 (0.35%) FDG-PET-CT, 2 of 2,258 (0.09%) digital radiography, and 5 of 5,335 (0.09%) other nuclear medicine examinations were found. By anatomical classification, there were 383 (40%) in chest, 353 (37%) in abdomen, 162 (17%) in head, 42 (4.4%) in face and neck, 9 (0.93%) in extremity, and 13 (1.4%) in others. By lesion classification, we identified 665 (69%) for localized lesion, 170 (18%) for vascular lesion, 83 (8.6%) for inflammatory lesion, 14 (1.5%) for traumatic lesion, 12 (1.2%) for organ dysfunction, 11 (1.1%) for degenerative lesion, and 7 (0.7%) for the others. Notable high-frequency specific site diseases by modality were 210 (22%) of localized lesions in lung on CT. CONCLUSION: Our results demonstrated that missed lung localized lesions on CT, which account for about a fifth of false-negative findings, were the most common false-negative finding.