Incidence of Bowel Wall Swelling Induced by Iodine-Contrast Media and Its Association With Gastrointestinal Manifestation.

PURPOSE: The aim of this study was to investigate the incidence of bowel wall swelling after iodine-contrast media injection and its relationship with gastrointestinal symptoms. METHODS: The incidence of bowel wall swelling was examined in 75 patients who showed adverse reactions to iodine-contrast media (AR[+] group) and 75 controls without adverse reactions (AR[-] group). Bowel wall swelling was identified if there was increased wall thickness on postcontrast computed tomography when compared with precontrast computed tomography. Swelling less than 2-fold of the original wall thickness was defined as grade 1 bowel angioedema, and swelling more than 2-fold was defined as grade 2. RESULTS: The incidence of bowel wall swelling was significantly higher in the AR(+) group (26.6%) than in the AR(-) group (10.6%) ( P = 0.01). Grade 1 bowel wall swelling was observed in 12.0% and 10.7% of AR(+) and AR(-) groups, respectively, whereas grade 2 was observed in 14.7% and 0%, respectively. Bowel wall swelling was observed in the duodenum and jejunum but not in the stomach, ileum, or colon in any patient in either group. In the AR(+) group, nausea and/or vomiting was observed in 15 patients, among whom bowel wall swelling was observed in 9 patients (60%). The frequency of nausea and/or vomiting was significantly higher in the patients with bowel wall swelling (45.0%, 9/20) compared with those without (10.9%, 6/55). CONCLUSION: Bowel wall swelling was more frequent and severe in patients with adverse reactions to iodine-contrast media than those without and was associated with nausea and/or vomiting.

The Relationship Between Conventionally Obtained Serum-Based Liver Function Indices and Intravoxel Incoherent Motion Diffusion-Weighted Imaging and Magnetic Resonance Elastography in Patients With Hepatocellular Carcinoma.

OBJECTIVES: To investigate the relationship between conventionally obtained serum-based biochemical indices and intravoxel incoherent motion imaging (IVIM) parameters compared with magnetic resonance elastography (MRE). METHODS: Patients with hepatocellular carcinoma who underwent ≥2 liver magnetic resonance imaging (MRI) scan, including IVIM and MRE, between 2017 and 2020 and biochemical testing within 1 week before or after MRI were included in this study. Biochemical tests were performed to determine the albumin-bilirubin (ALBI) score and modified ALBI (mALBI) grade, aspartate aminotransferase to platelet ratio index (APRI), and fibrosis-4 index (FIB-4). The diffusion coefficient ( D ), pseudo-diffusion coefficient ( D *), fractional volume occupied by flowing spins ( f ), and apparent diffusion coefficient were calculated for IVIM. The correlations between (1) the imaging parameters and biochemical indices and (2) the changes in mALBI grades and imaging parameters were evaluated. RESULTS: This study included 98 scans of 40 patients (31 men; mean age, 67.7 years). The correlation analysis between the biochemical and IVIM parameters showed that ALBI score and D* had the best correlation ( r = -0.3731, P < 0.001), and the correlation was higher than that with MRE ( r = 0.3289, P < 0.001). However, among FIB-4, APRI, and MRI parameters, MRE outperformed IVIM parameters (MRE and FIB-4, r = 0.3775, P < 0.001; MRE and APRI, r = 0.4687, P < 0.001). There were significant differences in the changes in MRE among the 3 groups (improved, deteriorated, and unchanged mALBI groups) in the analysis of covariance ( P = 0.0434). There were no significant changes in IVIM. CONCLUSIONS: Intravoxel incoherent motion imaging has the potential to develop into a more readily obtainable method of liver function assessment.

Respiratory Displacement of the Right Adrenal Vein: Comparison of Inspiratory and Expiratory Computed Tomography With Catheter Venography.

OBJECTIVE: The aim of the study is to reveal the respiratory displacement of the right adrenal vein (RAV) to predict the exact location of the RAV during adrenal venous sampling (AVS). METHODS: Computed tomography (CT) scans obtained 45 seconds (breath-hold at inhalation) and 70 seconds (breath-hold at exhalation) after contrast material injection were compared to venograms of the RAV of patients with primary aldosteronism who underwent AVS between January 2016 and December 2020. The craniocaudal distance between the center of the Th11/12 disc and the RAV orifice was measured; the craniocaudal location of the RAV orifice was also specified relative to vertebral bodies and intervertebral discs on inspiratory phase CT (In-CT), expiratory phase CT (Ex-CT), and catheter venography. The transverse and vertical angles of the RAV and the position of the RAV orifice on the inferior vena cava (IVC) circumference were measured on In-CT and Ex-CT. RESULTS: In total, 51 patients (30 males, 21 females; mean age, 54.9 ± 11.1 years) were included. Craniocaudal distances between the center of the Th11/12 disc and RAV orifice were significantly different among the following 3 acquisitions: catheter venography versus In-CT (15.2 ± 8.4 mm); venography versus Ex-CT (5.6 ± 4.1 mm); and In-CT versus Ex-CT (19.6 ± 8.0 mm) (all, P < 0.001). The craniocaudal location of the RAV orifice on venography was significantly closer to that on Ex-CT than on In-CT (P < 0.001); measurements using venograms compared with In-CT and Ex-CT scans were within 1 level difference in 18 (35.3%) and 47 (92.2%) patients, respectively (P < 0.001). The vertical angle of the RAV was significantly more likely to be smaller on In-CT than on Ex-CT (P < 0.001). CONCLUSIONS: RAV locations and angles change with respiratory motion. It is crucial to consider the respiratory phase of CT because it can enable a more accurate prediction of the location of the RAV during AVS.

Prognostic significance of left atrial strain combined with left ventricular strain using cardiac magnetic resonance feature tracking in patients with heart failure with preserved ejection fraction.

We aimed to evaluate the prognostic value of left ventricular global longitudinal strain (LVGLS) and left atrial strain (LAS) obtained from magnetic resonance imaging (MRI) feature tracking in patients with heart failure with preserved ejection fraction (HFpEF). We retrospectively enrolled consecutive patients with HFpEF admitted to our hospital who underwent cardiac MRI. LVGLS and LAS were obtained from cine MRI by feature tracking. The end point was defined as a composite of all-cause death, myocardial infarction, and hospitalization due to decompensated HF. One-hundred patients with HFpEF were enrolled. Mean LVGLS and LAS were - 13.7 ± 3.7% and 22.5 ± 11.6%, respectively. During follow-up of 4.4 ± 1.9 years, 24 events occurred. Multivariate Cox proportional hazards model analysis demonstrated LAS was independently associated with adverse cardiac events. Kaplan-Meier curve analysis revealed that the patients with both LVGLS and LAS worse than the median (LVGLS ≥ - 12.2% and LAS ≤ 13.8%) had a significantly lower event-free rate compared to those with preserved strain (Log-rank P < 0.001). Simultaneous assessment of LVGLS and LAS using MRI was useful for risk stratification in the patients with HFpEF.

Simultaneous assessment of left ventricular mechanical dyssynchrony using integrated 13N-ammonia PETMR system: direct comparison of PET phase analysis and MR feature tracking.

BACKGROUND: To compare phase analysis with positron emission tomography (PA) and magnetic resonance feature tracking derived myocardial strain (FT) for left ventricular (LV) mechanical dyssynchrony using PETMR system in patients with ischemic heart disease. METHODS AND RESULTS: Patients who underwent rest-pharmacological stress 13N ammonia PETMR were enrolled. Histogram bandwidth (BW) and phase standard deviation (PSD) were compared to global longitudinal, long axis radial, short axis circumferential, and radial strain (GLS, GRS, SA Circ, and SA Rad) obtained from FT. LV dyssynchrony index (SDI) derived from PA and FT were compared. BW and PSD showed significant correlations with FT (a Pearson's coefficient r = 0.64, P < .0001, and r = 0.51, P < .0001 for SA Circ; r = 0.67, P < .0001, and r = 0.74, P < .0001 for GLS; r = - 0.60, P < .0001, r = - 0.61, P < .0001 for SA Rad; r = - 0.62, P < .0001, and r = - 0.68, P < .0001 for GRS, respectively). Bland-Altman plots for SDI showed a preferable agreement (95% limit of agreement - 0.12 to 0.075, - 0.20 to 0.098, - 0.38 to 0.077, and - 0.37 to 0.032; bias 0.0068 ± 0.056, 0.026 ± 0.068, 0.11 ± 0.088, and 0.13 ± 0.079 for SA Circ, SA Rad, GLS, and GRS, respectively). CONCLUSION: In simultaneous acquisition using PETMR, comparison of PET phase analysis and MR strain showed a good correlation.

Prediction of Anemia From Cerebral Venous Sinus Attenuation on Deep-Learning Reconstructed Brain Computed Tomography Images.

OBJECTIVE: The aim of the study is to evaluate whether the prediction of anemia is possible using quantitative analyses of unenhanced cranial computed tomography (CT) with deep learning reconstruction (DLR) compared with conventional methods. METHODS: This cross-sectional retrospective study included 116 participants (76 males; mean age, 66.7) who had hemoglobin (Hb) levels obtained within 24 hours of unenhanced cranial CT, which included 2 reconstruction methods: DLR and hybrid iterative reconstruction. Regions of interest were the confluence of sinuses (CoS) and the right and left transverse sinuses. In addition, edge rise distance of cerebrospinal fluid and venous was measured. RESULTS: Spearman rank correlation coefficient demonstrated a positive association between Hb levels and sinus attenuation values. Among these, the CoS in DLR had the best correlation ( r = 0.703, P < 0.001). For the prediction of anemia (Hb < 11 g/dL), the area under the curve of CoS in DLR (area under the curve = 0.874; 95% confidence interval, 0.798-0.949; P < 0.001) was the highest; however, there were no significant differences among reconstruction method and sinus. The attenuation values of DLR were significantly higher than those of hybrid iterative reconstruction ( P < 0.001, paired t test), and the differences between the 2 methods were 4.1 (standard deviation [SD], 1.6) for CoS, 5.2 (SD, 2.2) for right transverse sinuses, and 5.8 (SD, 2.4) for left transverse sinuses. The signal-to-noise ratio ( P < 0.001, paired t test) and edge rise distance ( P < 0.001, Wilcoxon signed rank test) of DLR was significantly higher. CONCLUSIONS: Higher CT attenuation values should be considered for predicting anemia based on brain DLR images.

Relationship between lumbar spinal stenosis and cauda equina movement during the Valsalva maneuver.

OBJECTIVE: To confirm the relationship between lumbar spinal stenosis (LSS) and cauda equina movement during the Valsalva maneuver. MATERIALS AND METHODS: Two radiologists at our institution independently evaluated cauda equina movement on pelvic cine MRI, which was performed for urethrorrhea after prostatectomy or pelvic prolapse in 105 patients (99 males; mean age: 69.0 [range: 50-78] years), who also underwent abdominopelvic CT within 2 years before or after the MRI. The qualitative assessment of the cine MRI involved subjective determination of the cauda equina movement type (non-movement, flutter, and inchworm-manner). The severity of LSS on abdominopelvic CT was quantified using our LSS scoring system and performed between L1/2 and L5/S1. We calculated the average LSS scores of two analysts and extracted the worst scores among all levels. RESULTS: Cauda equina movement was observed in 15 patients (14%), inchworm-manner in 10 patients, and flutter in five patients. Participants with cauda equina movement demonstrated significantly higher LSS scores than those without movement (P < 0.001, Wilcoxon's rank-sum test). A significant difference was observed in the worst LSS scores between participants without movement and those with inchworm-manner movement (P < 0.001, Bonferroni's corrected). There were no significant differences between participants without movement and those with flutter movement (P = 0.3156) and between participants with flutter movement and those with inchworm-manner movement (P = 0.4843). CONCLUSION: Cauda equina movement in cine MRI during the Valsalva maneuver is occasionally observed in patients with severe LSS, and may be associated with pathogenesis of redundant nerve roots.

Lumbar intradural space reduction during the Valsalva maneuver observed using cine MRI and MR myelography: a single-case experimental study.

BACKGROUND: Previous studies have shown that the Valsalva maneuver (VM) causes spinal canal object movements. We hypothesized that this occurs because of cerebrospinal fluid (CSF) flow generated from intradural space reduction. Previous studies using myelograms reported lumbar CSF space changes during inspiration. However, no similar studies have been conducted using modern MRI. Therefore, this study analyzed intradural space reduction during the VM using cine magnetic resonance imaging (MRI). METHODS: The participant was a 39-year-old, healthy, male volunteer. Cine MRI involved fast imaging employing steady-state acquisition cine sequence during three resting and VM sets for 60 s each. The axial plane was at the intervertebral disc and vertebral body levels between Th12 and S1 during cine MRI. This examination was performed on 3 separate days; hence, data from nine resting and VM sets were available. Additionally, two-dimensional myelography was performed during rest and the VM. RESULTS: Intradural space reduction was observed during the VM using cine MRI and myelography. The intradural space cross-sectional area during the VM (mean: 129.3 mm2; standard deviation [SD]: 27.4 mm2) was significantly lower than that during the resting period (mean: 169.8; SD: 24.8; Wilcoxon signed-rank test, P < 0.001). The reduction rate of the vertebral body level (mean: 26.7%; SD: 9.4%) was larger than that of the disc level (mean: 21.4%; SD: 9.5%; Wilcoxon rank sum test, P = 0.0014). Furthermore, the reduction was mainly observed on the ventral and bilateral intervertebral foramina sides at the vertebral body and intervertebral disc levels, respectively. CONCLUSION: The intradural space was reduced during the VM, possibly because of venous dilatation. This phenomenon may be associated with CSF flow, intradural object movement, and nerve compression, potentially leading to back pain.

Neoadjuvant Superselective Intra-Arterial Cisplatin Chemoradiotherapy Combined With Surgery in Patients With T4 Squamous Cell Carcinoma of the Maxillary Sinus.

PURPOSE: Squamous cell carcinoma of the maxillary sinus (SCC-MS) is often diagnosed at a locally advanced stage, which is associated with poor prognosis. The purpose of the present study was to investigate clinical outcomes in patients with locally advanced T4 SCC-MS including originally inoperable T4b disease treated with neoadjuvant superselective intra-arterial chemoradiotherapy combined with surgery. METHODS: This study is a retrospective case series. We examined clinical outcomes in the patients with T4 SCC-MS between 2005 and 2017. The outcome variables were 5-year overall survival rate, 5-year disease-free survival rate, and 5-year local control rate. Covariates included age, sex, T classification, N classification, stage classification, type of surgery, number of administrations and total dose of cisplatin, and radiation dose. Descriptive statistics were computed for each study variable. RESULTS: Ten patients with T4 SCC-MS (6 T4a and 4 T4b) were treated. All patients were men, and the median age was 60.5 years (range, 45 to 77). Total maxillectomy was performed in 4 patients, and extended total maxillectomy in 6. The total number of intra-arterial chemotherapy administrations ranged between 2 and 4 for patients with T4a disease and between 3 and 4 for those with T4b disease. The median intra-arterial cisplatin dose was 360 mg (range, 250 to 400) for patients with T4a disease and 360 mg (range, 320 to 480) for those with T4b disease. The 5-year overall survival, 5-year disease-free survival, and 5-year local control rates of all patients were 100%, 70%, and 80%, respectively. The 5-year disease-free survival rate and 5-year local control rate were 83% and 83%, respectively, in the 6 T4a patients and 50% and 75%, respectively, in the 4 T4b patients. CONCLUSION: Neoadjuvant intra-arterial chemoradiotherapy in patients with T4 SCC-MS can achieve good clinical outcomes, and it may enable surgical resection of T4b lesions.

Usefulness of Model-Based Iterative Reconstruction in Brain CT as Compared With Hybrid Iterative Reconstruction.

OBJECTIVE: The aim of this study was to compare the contrast of gray to white matter between forward-projected model-based iterative reconstruction solution (FIRST) and hybrid iterative reconstruction (IR) by measuring computed tomography value of brain parenchyma. METHODS: Computed tomography values of the gray and white matter in 15 areas of 21 patients (7 males, 14 females; average age, 49.5 ± 10.7 years) were measured and compared between FIRST and hybrid IR with filtered back projection (FBP) using 2 different reconstruction kernels FC21 and FC26. RESULTS: The ratio of gray to white matter obtained using FIRST (1.25 ± 0.08) was significantly higher than that obtained using FBP with both kernel FC21 (1.13 ± 0.03) and kernel FC26 (1.22 ± 0.06). CONCLUSIONS: FIRST increases the contrast between the gray and white matter, and decreases noise in brain computed tomography compared with FBP with hybrid IR.

Evaluation of Computed Tomography Attenuation Value of Proximal Femoral Marrow to Diagnose and Differentiate Hematologic Malignancies, Myelofibrosis, and Aplastic Anemia.

OBJECTIVE: The aim of this study was to diagnose hematologic diseases using computed tomography (CT) number of proximal femoral marrow. METHODS: The average CT number of marrow in hematologic diseases was measured on the caudal side of the greater trochanter. RESULTS: The CT numbers were -60.3 ± 16.8 in 12 patients with aplastic anemia, -53.2 ± 19.4 in 11 patients with monoclonal gammopathy of undetermined significance, -44.2 ± 21.1 in 10 normal controls, -30.9 ± 42.3 in 9 patients with chronic lymphatic leukemia, -29.8 ± 29.9 in 17 patients with benign anemia, -13.7 ± 40.9 in 33 patients with multiple myeloma, 0.32 ± 44.6 in 17 patients with myelodysplastic syndrome (MDS), 18.7 ± 40.0 in 44 patients with acute myeloid leukemia, 50.3 ± 27.4 in 13 patients with acute lymphatic leukemia, 51.5 ± 16.8 in 8 patients with myelofibrosis, and 56.4 ± 15.6 in 9 patients with chronic myeloid leukemia. Significant differences were observed between acute myeloid leukemia and MDS, between MDS and aplastic anemia, and between multiple myeloma and monoclonal gammopathy of undetermined significance (P < 0.01). CONCLUSION: The marrow CT numbers may be indicators of hematologic diseases and can be used as a diagnostic tool.

PET/MR imaging for the evaluation of cervical cancer during pregnancy.

BACKGROUND: Malignancy during pregnancy is increasing, and the most common type of malignancy is uterine cervical cancer. When planning the treatment of cervical cancer, it is important to look for signs of metastasis before surgery, especially metastasis to the lymph nodes. In this report, we assessed the diagnostic value of positron emission tomography/magnetic resonance imaging (PET/MRI) for evaluating cervical cancer propagation before surgery, with a focus on pregnant women. CASE PRESENTATION: 18F Fluorodeoxyglucose (FDG)-PET/MRI was performed in seven pregnant cervical cancer patients (28-34 years old) at 9-18 gestational weeks. In case #5, a second PET/MRI was performed at 24 gestational weeks. Of seven FDG-PET/MRI examination series in six cases (cases #1-6), FDG-PET/MR imaging could detect cervical tumors with abnormal FDG accumulation; these tumors were confirmed with a standardized uptake value max (SUV max) titer of 4.5-16. A second PET/MRI examination in case #5 revealed the same SUV max titer as the first examination. In these six imaging series (cases #1-5), there were no signs of cancer metastasis to the parametrium and lymph nodes. However, in case #6, abnormal FDG accumulation in the left parametrial lymph nodes was also detectable. Pathological examination showed lymph node metastasis in case #6. In case #7, PET/MRI could not detect any abnormal FDG accumulation in the cervix and other sites. Cone biopsy demonstrated only micro-invasive squamous cell carcinoma. After treatment for cervical cancer, all seven patients have had no recurrence of disease within the follow-up period (2.8-5.6 years), and their children have developed appropriately. CONCLUSION: PET/MRI is an effective imaging tool to evaluate cervical cancer progression in pregnancy.

Detectability of Malignant Lesions by Whole-Body Magnetic Resonance Imaging Using Whole-Body Integrated Positron Emission Tomography/Magnetic Resonance Imaging.

PURPOSE: To assess the diagnostic ability of whole-body magnetic resonance imaging (MRI) using integrated positron emission tomography/MRI(PET/MRI). METHODS: Axial T2-weighted image (T2WI), diffusion-weighted imaging (DWI), coronal T1-weighted image (T1WI), axial volumetric interpolated breath-hold examination in the lung field, and 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG-PET) were evaluated in combination with T2WI alone, T2WI + DWI, T2WI + DWI + T1WI, T2WI + DWI + T1WI + volumetric interpolated breath-hold examination (all MRI images), and all MRI + FDG-PET. RESULTS: A total of 370 lesions were observed in 90 (62.5%) of the 144 patients. The lesion-based sensitivities were 62%, 74%, 74%, 76%, and 94%, and the patient-based sensitivities were 70%, 77%, 77%, 77%, and 81% using T2WI, T2WI + DWI, T2WI + DWI + T1WI, all MRI, and all MRI + FDG-PET, respectively. There were significant differences in the lesion-based sensitivity between T2WI and other sequence combinations and between all MRI and all MRI + FDG-PET. No significant differences were observed between any combinations among the patient-based sensitivities. CONCLUSION: The sensitivity of whole-body MRI was lower when lesion based, but almost equivalent when patient based compared with PET/MRI.

Unique Learning System for Uterine Artery Embolization for Symptomatic Myoma and Adenomyosis for Obstetrician-Gynecologists in Cooperation with Interventional Radiologists: Evaluation of UAE From the Point of View of Gynecologists Who Perform UAE.

STUDY OBJECTIVE: To evaluate a unique learning system for uterine artery embolization (UAE) and examine its feasibility and clinical outcomes for the treatment of symptomatic uterine leiomyomas and adenomyosis when performed by obstetrician-gynecologists in cooperation with interventional radiologists (IVRs). DESIGN: Retrospective study (Canadian Task Force classification II-2). SETTING: University hospital. PATIENTS: One hundred seventy-three patients who underwent UAE for symptomatic leiomyomas and adenomyosis. INTERVENTIONS: We examined the medical records of patients who underwent UAE for symptomatic uterine leiomyomas and adenomyosis at our department between 2003 and 2012 using our learning system for UAE for obstetrician-gynecologists in cooperation with IVRs. The charts of all patients were reviewed, and data on etiologic factors, past medical history of leiomyomas and adenomyosis, symptoms, details of UAE, and clinical outcomes after UAE were extracted. MEASUREMENTS AND MAIN RESULTS: A total of 173 patients who underwent 177 UAEs were identified, including 4 patients who underwent embolization twice because of primary treatment failure or symptom recurrence. During the study period, 2 gynecologists successfully acquired endovascular skills. The technical success rate was 97.7% (174 of 177). The duration of fluoroscopy in procedures performed by obstetrician-gynecologists who acquired endovascular skills was not significantly different from that in procedures performed by IVRs at our institution; however, this duration was significantly longer in procedures performed by obstetrician-gynecologists who did not have sufficient experience with our learning protocol for UAE because of inadequate live observation of UAEs performed by skilled IVRs. Complications that necessitated discontinuation of the procedure occurred in 2.3% of cases (4 of 177). The clinical outcomes were similar to those reported in previous studies. Adverse events after UAE included myeloid passages in 7.0% (11 of 158), infections in 2.5% (4 of 158), vaginal discharge in 2.5% of patients with leiomyomas (4 of 158), and vaginal discharge in 7.1% of patients with adenomyosis (1 of 14). All the adverse events were adequately treated by the obstetrician-gynecologists themselves. The timing of hysterectomy due to complications or recurrence of symptoms after UAE varied widely. CONCLUSION: UAE performed by obstetrician-gynecologists in cooperation with radiologists can be achieved safely and successfully with acceptable clinical outcomes. Live observation of the procedure performed by skilled IVRs is essential to improving the skills and reducing the fluoroscopic time of obstetrician-gynecologists.

Normative data of dopaminergic neurotransmission functions in substantia nigra measured with MRI and PET: Neuromelanin, dopamine synthesis, dopamine transporters, and dopamine D2 receptors.

The central dopaminergic system is of major importance in the pathophysiology of Parkinson's disease, schizophrenia, and other neuropsychiatric disorders. In the present study, the normative data of dopaminergic neurotransmission functions in the midbrain, consisting of neuromelanin, dopamine synthesis, dopamine transporters and dopamine D2 receptors, were constructed using magnetic resonance (MR) imaging and positron emission tomography (PET). PET studies with L-[ß-11C]DOPA, [18F]FE-PE2I and [11C]FLB457 and MRI studies were performed on healthy young men. Neuromelanin accumulation measured by MRI was compared with dopaminergic functions, dopamine synthesis capacity, dopamine transporter binding and dopamine D2 receptor binding measured by PET in the substantia nigra. Although neuromelanin is synthesized from DOPA and dopamine in dopaminergic neurons, neuromelanin accumulation did not correlate with dopamine synthesis capacity in young healthy subjects. The role of dopamine transporters in the substantia nigra is considered to be the transport of dopamine into neurons, and therefore dopamine transporter binding might be related to neuromelanin accumulation; however, no significant correlation was observed between them. A positive correlation between dopamine D2 receptor binding and neuromelanin accumulation was observed, indicating a feedback mechanism by dopaminergic autoreceptors. Discrepancies in regional distribution between neuromelanin accumulation and dopamine synthesis capacity, dopamine transporter binding or dopamine D2 receptor binding were observed in the substantia nigra.

Coil embolization of a celiac artery pseudoaneurysm under balloon-assisted flow control: A case report.

Coil migration can occur when coil embolization is used for treating pseudoaneurysms associated with large arteries. The double microcatheter technique is useful for preventing coil migration; the balloon catheter can reduce blood flow and active bleeding upon balloon inflation, and can also compress the bleeding point and arrest bleeding temporarily. We report a case describing the management of a pseudoaneurysm with coil embolization using double microcatheters and a balloon catheter to control blood flow and prevent coil migration. A 73-year-old male patient presented with a pseudoaneurysm of the celiac artery arising from the splenic artery stump following surgery. Coil embolization of the pseudoaneurysm using a double microcatheter embolization technique with a balloon catheter was considered. A balloon catheter was inserted into the celiac artery and active bleeding was temporarily arrested with the inflated balloon. First, a microcatheter was inserted into the balloon catheter, and another microcatheter was placed in the celiac artery. An electrical detachable coil was inserted into the proximal common hepatic artery just distal to the pseudoaneurysm. The second electrically detachable coil was inserted while the first coil remained attached. After detachment of the second coil, additional electrically detachable coils were inserted for similar embolization. The balloon was gradually deflated. Finally, the first coil was detached and we confirmed absence of the bleeding. Our case report demonstrated that a balloon catheter can control the flow vessels, and the double microcatheter embolization technique with a balloon catheter is useful for coil embolization in high-flow or large vessels.

Reduced dopamine transporter availability in drug-naive adult attention-deficit/hyperactivity disorder.

Aim: This study aimed to clarify the abnormalities in dopamine transporter (DAT) availability in drug-naive adult patients with attention-deficit/hyperactivity disorder (ADHD) and the relationship between ADHD symptoms and abnormalities in DAT availability. Methods: Single-photon emission tomography (SPECT) was performed using iodine-123-ß-carbomethoxy-3ß-(4-iodophenyltropane) (I-123 ß CIT) as a tracer to measure in vivo DAT availability in 20 drug-naive patients with ADHD [mean age ± standard deviation (SD)]: 25 ± 3.44 years; male:female = 11:9] and 20 age- and sex-matched healthy controls (HCs) (mean age ± SD: 23.9 ± 2.27 years). Comparisons of DAT availability between HCs and adult patients with ADHD and the association between symptom severity and DAT availability within the ADHD group were analyzed using Statistical Parametric Mapping 12. Results: Drug-naive adults with ADHD showed significantly reduced DAT availability in the bilateral nucleus accumbens compared with HCs. Correlation analyses revealed a negative correlation between the severity of inattentive symptoms in adult patients with ADHD and DAT availability in the bilateral heads of the caudate nucleus, indicating the association between severe inattentive symptoms and lower DAT availability in the caudate nucleus. Conclusion: In drug-naive adult patients with ADHD, DAT availability was reduced in the nucleus accumbens, an important part of the reward system. This finding indicates the importance of the DAT in the reward system in the pathogenesis of ADHD. Inattentiveness was associated with DAT availability in the caudate nucleus, suggesting involvement of the cortico-striato-thalamo-cortical circuit.

Investigation of factors affecting CT attenuation and glucose metabolism of bone marrow as seen on PET/CT scans.

The aim of this study is to determine the factors affecting the CT attenuation of bone marrow, and its correlation with 18F-FDG uptake. The mean standardized uptake value (SUV) of vertebral bone marrow (Vertebral-SUV) and femoral bone marrow (Femoral-SUV) as well as CT number of bone marrow (BM-CT number) were measured in 243 patients who had undergone 18F-FDG PET/CT. The correlations among BM-CT number, Femoral-SUV, and Vertebral-SUV were investigated. The relationships of Femoral-SUV, Vertebral-SUV, and BM-CT number with blood parameters, age, blood sugar, and body weight were analyzed by correlation and multi-regression analyses. The Mann-Whitney U test and chi-square test and Binomial logistic analysis were used to examine the relationships between high BM-CT number (≥ 0 HU) and the above parameters. Significant correlations were observed between: BM-CT number and Femoral-SUV (r = 0.73, P < 0.01); Vertebral-SUV and Femoral-SUV (r = 0.78, P < 0.01); and BM-CT number and Vertebral-SUV (r = 0.52, P < 0.01). BM-CT number was correlated with patients' age in both univariable (r = -0.27) and multivariable analyses (ß = -0.20). Positive BM-CT number correlated with WBC in both univariable (P = 0.04) and multivariable (P < 0.01) analyses. Bone marrow glucose metabolism had a tendency to decrease with age, was increased in patients with elevated CRP. In conclusion, CT attenuation of bone marrow correlated well with bone marrow metabolism and also tended to decrease with age. High bone marrow attenuation (≥ 0 HU) could predict elevated serum WBC.

Impact of iodine contrast media on gamma camera-based GFR and factors affecting the difference between serum creatinine-based estimated GFR and Gate's GFR.

OBJECTIVE: We aimed to elucidate the factors underlying the difference between estimated glomerular filtration rate (eGFR) calculated from serum creatinine and Gate's GFR (gGFR) measured using technetium-99m diethylene triamine pentaacetic acid ( 99m Tc-DTPA) scintigraphy. METHODS: This study was based on consecutive patients who underwent 99m Tc-DTPA scintigraphy at our hospital between January 2021 and December 2022 and whose blood serum creatinine data were obtained on the same day as the 99m Tc-DTPA scintigraphy. Relationships between the ratio of gGFR and eGFR (gGFR/eGFR) and age, sex, BMI, visceral fat, psoas muscle index (PMI), serum blood urea nitrogen, and creatinine level were investigated based on 75 patients. Additionally, for 44 patients who had two or more follow-up DTPA studies, we compared gGFR values for studies that used iodine contrast media (ICM) for computed tomography before same-day 99m Tc-DTPA studies and those that did not in the same patients. RESULTS: Weak correlations were observed between gGFR/eGFR and PMI ( r  = 0.30), BMI ( r  = 0.24), and the visceral fat area ( r  = 0.33). Multi-regression analyses showed that gGFR/eGFR was correlated with PMI ( ß â€…= 0.34, P  < 0.01) and approached significance with the visceral fat area ( ß â€…= 0.24, P  = 0.05). A significant difference was observed in gGFR between patients who received ICM before the 99m Tc-DTPA renogram and those who did not ( P  < 0.001, eGFR 80.5 ±â€…19.0 vs. 91.7 ±â€…27.8 ml/min). CONCLUSION: ICM administration temporarily decreased gGFR, and increased muscle mass increased the difference between eGFR and gGFR values.

Differential centiloid scale normalization techniques: comparison between hybrid PET/MRI and independently acquired MRI.

OBJECTIVE: Centiloid (CL) scales play an important role in semiquantitative analyses of amyloid-ß (Aß) PET. CLs are derived from the standardized uptake value ratio (SUVR), which needs Aß positron emission tomography (PET) normalization processing. There are two methods to collect the T1-weighted imaging (T1WI) for normalization: (i) anatomical standardization using simultaneously acquired T1WI (PET/MRI), usually adapted to PET images from PET/MRI scanners, and (ii) T1WI from a separate examination (PET + MRI), usually adapted to PET images from PET/CT scanners. This study aimed to elucidate the correlations and differences in CLs between when using the above two T1WI collection methods. METHODS: Among patients who underwent Aß PET/MRI (using 11C-Pittuberg compound B (11C-PiB) or 18F-flutemetamol (18F-FMM)) at our institution from 2015 to 2023, we selected 49 patients who also underwent other additional MRI examinations, including T1WI for anatomic standardization within 3 years. Thirty-one of them underwent 11C-PiB PET/MRI, and 18 participants underwent 18F-FMM PET/MRI. Twenty-five of them, additional MRI acquisition parameters were identical to simultaneous MRI during PET, and 24 participants were different. After normalization using PET/MRI or PET + MRI method each, SUVR was measured using the Global Alzheimer's Association Initiative Network cerebral cortical and striatum Volume of Interest templates (VOI) and whole cerebellum VOI. Subsequently, CLs were calculated using the previously established equations for each Aß PET tracer. RESULTS: Between PET/MRI and PET + MRI methods, CLs correlated linearly in 11C-PiB PET (y = 1.00x - 0.11, R2 = 0.999), 18F-FMM PET (y = 0.97x - 0.12, 0.997), identical additional MRI acquisition (y = 1.00x + 0.33, 0.999), different acquisition (y = 0.98x - 0.43, 0.997), and entire study group (y = 1.00x - 0.24, 0.999). Wilcoxon signed-rank test revealed no significant differences: 11C-PiB (p = 0.49), 18F-FMM (0.08), and whole PET (0.46). However, significant differences were identified in identical acquisition (p = 0.04) and different acquisition (p = 0.02). Bland-Altman analysis documented only a small bias between PET/MRI and PET + MRI in 11C-PiB PET, 18F-FMM PET, identical additional MRI acquisition, different acquisition, and whole PET (- 0.05, 0.67, - 0.30, 0.78, and 0.21, respectively). CONCLUSIONS: Anatomical standardizations using PET/MRI and using PET + MRI can lead to almost equivalent CL. The CL values obtained using PET/MRI or PET + MRI normalization methods are consistent and comparable in clinical studies.