Effect of X-ray tube on image quality and pancreatic ductal adenocarcinoma conspicuity in pancreatic protocol dual-energy CT.

AIM: To compare the radiation dose, image quality, and conspicuity of pancreatic ductal adenocarcinoma (PDAC) in pancreatic protocol dual-energy computed tomography (CT) between two X-ray tubes mounted in the same CT machine. MATERIAL AND METHODS: This retrospective study comprised 80 patients (median age, 73 years; 45 men) who underwent pancreatic protocol dual-energy CT from January 2019 to March 2022 using either old (Group A, n=41) or new (Group B, n=39) X-ray tubes mounted in the same CT machine. The imaging parameters were completely matched between the two groups, and CT data were reconstructed at 70 and 40 keV. The CT dose-index volume (CTDIvol); CT attenuation of the abdominal aorta, pancreas, and PDAC; background noise; and qualitative scores for the image noise, overall image quality, and PDAC conspicuity were compared between the two groups. RESULTS: The CTDIvol was lower in Group B than Group A (7.9 versus 9.2 mGy; p<0.001). The CT attenuation of all anatomical structures at 70 and 40 keV was comparable between the two groups (p=0.06-0.78). The background noise was lower in Group B than Group A (12 versus 14 HU at 70 keV, p=0.046; and 26 versus 30 HU at 40 keV, p<0.001). Qualitative scores for image noise and overall image quality at 70 and 40 keV and PDAC conspicuity at 40 keV were higher in Group B than Group A (p<0.001-0.045). CONCLUSION: The latest X-ray tube could reduce the radiation dose and improve image quality in pancreatic protocol dual-energy CT.

Low-tube-voltage whole-body CT angiography with extremely low iodine dose: a comparison between hybrid-iterative reconstruction and deep-learning image-reconstruction algorithms.

AIM: To evaluate arterial enhancement, its depiction, and image quality in low-tube potential whole-body computed tomography (CT) angiography (CTA) with extremely low iodine dose and compare the results with those obtained by hybrid-iterative reconstruction (IR) and deep-learning image-reconstruction (DLIR) methods. MATERIALS AND METHODS: This prospective study included 34 consecutive participants (27 men; mean age, 74.2 years) who underwent whole-body CTA at 80 kVp for evaluating aortic diseases between January and July 2020. Contrast material (240 mg iodine/ml) with simultaneous administration of its quarter volume of saline, which corresponded to 192 mg iodine/ml, was administered. CT raw data were reconstructed using adaptive statistical IR-Veo of 40% (hybrid-IR), DLIR with medium- (DLIR-M), and high-strength level (DLIR-H). A radiologist measured CT attenuation of the arteries and background noise, and the signal-to-noise ratio (SNR) was then calculated. Two reviewers qualitatively evaluated the arterial depictions and diagnostic acceptability on axial, multiplanar-reformatted (MPR), and volume-rendered (VR) images. RESULTS: Mean contrast material volume and iodine weight administered were 64.1 ml and 15.4 g, respectively. The SNRs of the arteries were significantly higher in the following order of the DLIR-H, DLIR-M, and hybrid-IR (p<0.001). Depictions of six arteries on axial, three arteries on MPR, and four arteries on VR images were significantly superior in the DLIR-M or hybrid-IR than in the DLIR-H (p≤0.009 for each). Diagnostic acceptability was significantly better in the DLIR-M and DLIR-H than in the hybrid-IR (p<0.001-0.005). CONCLUSION: DLIR-M showed well-balanced arterial depictions and image quality compared with the hybrid-IR and DLIR-H.

Deep-learning image-reconstruction algorithm for dual-energy CT angiography with reduced iodine dose: preliminary results.

AIM: To evaluate the computed tomography (CT) attenuation values, background noise, arterial depiction, and image quality in whole-body dual-energy CT angiography (DECTA) at 40 keV with a reduced iodine dose using deep-learning image reconstruction (DLIR) and compare them with hybrid iterative reconstruction (IR). MATERIAL AND METHODS: Whole-body DECTA with a reduced iodine dose (200 mg iodine/kg) was performed in 22 patients, and DECTA data at 1.25-mm section thickness with 50% overlap were reconstructed at 40 keV using 40% adaptive statistical iterative reconstruction with Veo (hybrid-IR group), and DLIR at medium and high levels (DLIR-M and DLIR-H groups). The CT attenuation values of the thoracic and abdominal aortas and iliac artery and background noise were measured. Arterial depiction and image quality on axial, multiplanar reformatted (MPR), and volume-rendered (VR) images were assessed by two readers. Quantitative and qualitative parameters were compared between the hybrid-IR, DLIR-M, and DLIR-H groups. RESULTS: The vascular CT attenuation values were almost comparable between the three groups (p=0.013-0.97), but the background noise was significantly lower in the DLIR-H group than in the hybrid-IR and DLIR-M groups (p<0.001). The arterial depictions on axial and MPR images and in almost all arteries on VR images were comparable (p=0.14-1). The image quality of axial, MPR, and VR images was significantly better in the DLIR-H group (p<0.001-0.015). CONCLUSION: DLIR significantly reduced background noise and improved image quality in DECTA at 40 keV compared with hybrid-IR, while maintaining the arterial depiction in almost all arteries.

Deep-learning-based image reconstruction in dynamic contrast-enhanced abdominal CT: image quality and lesion detection among reconstruction strength levels.

AIM: To evaluate the use of deep-learning-based image reconstruction (DLIR) algorithms in dynamic contrast-enhanced computed tomography (CT) of the abdomen, and to compare the image quality and lesion conspicuity among the reconstruction strength levels. MATERIALS AND METHODS: This prospective study included 59 patients with 373 hepatic lesions who underwent dynamic contrast-enhanced CT of the abdomen. All images were reconstructed using four reconstruction algorithms, including 40% adaptive statistical iterative reconstruction-Veo (ASiR-V) and DLIR at low, medium, and high-strength levels (DLIR-L, DLIR-M, and DLIR-H, respectively). The signal-to-noise ratio (SNR) of the abdominal aorta, portal vein, liver, pancreas, and spleen and the lesion-to-liver contrast-to-noise ratio (CNR) were calculated and compared among the four reconstruction algorithms. The diagnostic acceptability was qualitatively assessed and compared among the four reconstruction algorithms and the conspicuity of hepatic lesions was compared between <5 and ≥5 mm lesions. RESULTS: The SNR of each anatomical structure (p<0.0001) and CNR (p<0.0001) were significantly higher in DLIR-H than the other reconstruction algorithms. Diagnostic acceptability was significantly better in DLIR-M than the other reconstruction algorithms (p<0.0001). The conspicuity of hepatic lesions was highest when using 40% ASiR-V and tended to lessen as the reconstruction strength level was getting higher in DLIR, especially in <5 mm lesions; however, all hepatic lesions could be detected. CONCLUSIONS: DLIR improved the SNR, CNR, and image quality compared with 40% ASiR-V, while making it possible to decrease lesion conspicuity using higher reconstruction strength.

Virtual monochromatic image at lower energy level for assessing pancreatic ductal adenocarcinoma in fast kV-switching dual-energy CT.

AIM: To evaluate the value of virtual monochromatic images (VMIs) at lower energy levels in fast-voltage-switching dual-energy computed tomography (DECT) for assessing pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: The institutional review board approved this prospective study. Written informed consent was obtained from all patients. Seventy-four consecutive patients with PDAC underwent dynamic contrast-enhanced DECT. Two radiologists reviewed eight energy levels (40, 45, 50, 55, 60, 65, 70, and 75 keV) of the pancreatic parenchymal phase VMIs. CT attenuation of the PDAC and pancreatic parenchyma, background noise, signal-to-noise ratio (SNR) of the pancreas, tumour-to-pancreas contrast-to-noise ratio (CNR), major and minor axes of PDAC, and qualitative tumour conspicuity were compared among the VMIs at eight energy levels. RESULTS: CT attenuation of PDAC and pancreatic parenchyma, background noise, SNR, and CNR peaked on VMIs at 40 keV with statistically significant difference (p<0.0001) and gradually decreased with increasing energy levels. The reproducibility in measuring tumour size was better on VMIs at 40 keV (28.8 and 29.2 mm of major axis in readers 1 and 2, respectively) and tended to be overestimated at higher energy levels (29.8 and 30.9 mm of major axis at 75 keV in readers 1 and 2, respectively). Qualitative tumour conspicuity was also significantly superior on VMIs at 40 keV than at all other energy levels (p<0.0001). CONCLUSION: VMIs at 40 keV demonstrated significantly increased SNR of the pancreas, CNR, and tumour conspicuity and high reproducibility in measuring tumour size for assessing PDAC.

Modest overexpression of neuropeptide Y in the brain leads to obesity after high-sucrose feeding.

Neuropeptide Y (NPY), one of the most abundant peptide transmitters in the mammalian brain, is assumed to play an important role in feeding and body weight regulation. However, there is little genetic evidence that overexpression or knockout of the NPY gene leads to altered body weight regulation. Previously, we developed NPY-overexpressing mice by using the Thy-1 promoter, which restricts NPY expression strictly within neurons in the central nervous system, but we failed to observe the obese phenotype in the heterozygote. Here we report that in the homozygous mice, overexpression of NPY leads to an obese phenotype, but only after appropriate dietary exposure. NPY-overexpressing mice exhibited significantly increased body weight gain with transiently increased food intake after 50% sucrose--loaded diet, and later they developed hyperglycemia and hyperinsulinemia without altered glucose excursion during 1 year of our observation period.

Emerging functions of neuropeptide Y Y(2) receptors in the brain.

The Y(2) receptor is the predominant neuropeptide Y (NPY) receptor subtype in the brain. Y(2) receptor mRNA is discretely distributed in the brain, including specific subregions of the hippocampus and the hypothalamus, and is largely consistent with the distribution of Y(2) receptor protein demonstrated by radioligand-binding methods. Y(2) receptor-mediated effects have been reported principally based on the observations using the C-terminal fragments of NPY. Recent studies indicate an involvement of the receptor in food intake, gastrointestinal motility, cardiovascular regulation, and neuronal excitability. Very recently, Y(2) receptor selective antagonist has been developed and Y(2) receptor-deficient animals have been created. These new pharmacological tools will help to clarify the roles of this receptor in brain functions.

Combined hamartoma of the retina and retinal pigment epithelium associated with juvenile nasopharyngeal angiofibroma.

PURPOSE: To report a patient who had concomitant combined hamartoma of the retinal pigment epithelium and retina and juvenile nasopharyngeal angiofibroma. METHOD: Case report. RESULTS: An 18-year-old man presented with a juvenile nasopharyngeal angiofibroma and a combined hamartoma of the retina and retinal pigment epithelium in the ipsilateral eye. The diagnosis of juvenile nasopharyngeal angiofibroma was confirmed by histopathology, and the diagnosis of combined hamartoma was established by typical ophthalmoscopic and fluorescein angiographic findings. CONCLUSION: Juvenile nasopharyngeal angiofibroma may be associated with combined hamartoma of the retina and retinal pigment epithelium.

Optical coherence tomography of bleb-like subretinal lesions after retinal reattachment surgery.

PURPOSE: To report the optical coherence tomographic characteristics of persistent bleb-like subretinal lesions after retinal reattachment surgery, including scleral buckling and cryopexy. METHODS: Case reports. RESULTS: In two eyes of two patients yellow to yellowish-orange bleb-like lesions were found in the posterior pole after retinal reattachment surgery. The common aspects of the surgery were scleral buckling procedures and cryopexy. There were subretinal precipitates in some of the lesions. The lesions showed no associated leakage during fluorescein or indocyanine green angiography. Optical coherence tomography demonstrated that the bleb-like lesions were tiny retinal detachments. CONCLUSION: Optical coherence tomography examination of bleb-like subretinal lesions showed that they were actually retinal detachments. Our patients and previously reported patients developed these lesions after scleral buckling and cryopexy. These lesions may represent persistent retinal detachment because of the presence of protein in the subretinal fluid.

Giant air cell of the petrous apex: a possible cause of facial hypalgesia.

A giant air cell of the left petrous apex was found in a 23-year-old man with ipsilateral facial hypalgesia. The size of the giant air cell depicted on computed tomography was 1.5 x 2.0 x 2.0 cm. A coronal T1-weighted magnetic resonance image showed that the trigeminal nerve was compressed superomedially by a large signal void area that was probably a result of excessive pneumatization of the petrous apex. It is suggested that the facial hypalgesia was caused by the compression by the giant air cell of the petrous apex on the trigeminal nerve.

[The outline of in-home medical care in Japan].

In-home medical care is an issue which has come to the forefront recently, but it is as yet an undeveloped and unorganized field in Japan. However, in-home medical care is an extremely vital aspect in community medical care and the needs of the population in this field are expected to gradually expand. The human resources which will be responsible for carrying out in-home medical care is the focus of this study. Recently, the young physicians who have begun their practice as family physicians are capable of using IVH and other medical techniques. They are self-assertive in visiting their patients at home and a revolution in medical care awareness has begun to evolve. Old people's home visit nursing stations are certain to increase and the range of nursing duties which can be carried out in the home will become an issue. In addition, the role of home helpers is essential, although they are not medical personnel. The focus of in-home medical care services which will be placed under the supervision of a physician, will be the patient; and it is important that nurses, certified care workers, home helpers, etc. cooperate mutually in the care of the patient. Implementing in-home medical care as efficiently as possible will enable medical care to meet the needs of the population. In the 21 st century "in-home medical care" is anticipated to function and inseparably with hospital medical care and fully it is expected to become a fixed institution among the Japanese people.

[A role of visiting nurses in providing the terminal patients with their desirable life-discussion regarding the place of death of the patients who were registered for visiting nurse system].

AIM: To evaluate the prognosis of the patients who had visiting nurse service and discuss the place of death (life at the terminal stage). To determine the roles of visiting nurses in providing the patients at a terminal stage with their desirable life till death. METHODS: A total of 180 patients, who were registered for their home healthcare service in our Shonan Kamakura General Hospital and died between January 2000 and February 2001, were subjected to the study. All the subjects were classified into 3 groups according to the places of their death, 1) death at home, 2) death in the hospital and 3) death upon arrival after the admission to the hospital. Moreover, the following items were also surveyed and analyzed: 1) diagnosis (name of diseases), 2) cause of death, 3) age, 4) family structure, 5) whether their primary care physicians explained the prognosis and possible expected conditions to the patients and their family before hand, and 6) how the visiting nurses interact with the patients and their family members. RESULTS: Sixty-six patients died at home, 105 in the hospital and 9 upon arrival at the hospital. During this survey period, there were a total of 5,274 and 5,574 visits by primary care physicians and visiting nurses, respectively. The patients who died at home were more often observed in the patients whose primary care physicians explained their conditions to them and whose visiting nurses closely related to them. Moreover, the patients with malignant tumor also more often died at home. On the contrary, there were very few patients with chronic diseases, with whom death at home was accepted and agreed before hand, and there were some cases with chronic diseases who died inside of the ambulance transported on the way to the hospital after a sudden change in their conditions. DISCUSSION AND CONCLUSION: In order to have the patients live their desirable life till their death, it is required for the caretakers to prepare their mind for the day of the patient's death in addition to the patient's own wishes. For the patients with malignant tumor, it is easy to predict their prognosis, thus the caretakers can get prepared for the day of the patient's death. On the contrary, in case of the patients with chronic diseases, it is more difficult for the caretakers to experience an indefinite time with the patients since their prognosis is generally longer but the sudden change in their conditions may give the caretakers a high anxiety. Thus, it is essential for the visiting nurses to play a role as a mediator to interact between the patients and their family members, and their primary care physicians, and to establish a trustful relationship with the patients while their conditions are still stable. Moreover, similar to the malignant patients, the visiting nurses should explain the situations to the patients with chronic diseases, that they can choose the place of their own death and specific medical treatment at emergency and can decide the detail for their terminal stage with their family members. Thus, it was considered to be very important that the visiting nurses should frequently confirm these issues with the patients and their family according to their conditions.

[Abnormality in feeding and body weight regulation in obesity].

Obesity is, with rare exceptions, a complex phenotype resulting from interactions between environmental and genetic risk factor. Obesity is associated with diabetes, hypertension, and hyperlipidemia, leading to arteriosclerosis. Dysregulation of food intake and energy expenditure, and thus energy homeostasis, is now recognized as playing a major role in development of obesity. A detailed understanding of the physiology and genetics of the regulatory systems is critical for the development of new approaches for treating obesity and its sequelae.

Widespread cortical and subcortical brain atrophy in Parkinson's disease with excessive daytime sleepiness.

Our aim was to determine regional brain atrophy in Parkinson's disease (PD) patients with excessive daytime sleepiness (EDS) using voxel-based morphometry (VBM). From 71 consecutive probable PD patients, nine non-demented and non-hallucinating patients with an Epworth Sleepiness Scale (ESS) ≥ 10 and 13 PD patients with an ESS ≤ 3 were selected as having EDS and as not having EDS, respectively. We also enrolled 22 healthy age- and sex-matched controls. Regional brain atrophy was assessed using VBM with 3-T magnetic resonance imaging. There was no difference in the dosage of dopaminergic drugs between PD patients with EDS and PD patients without EDS. PD patients with EDS showed marked atrophy in the gray matter of the frontal lobe, temporal lobe, occipital lobe, limbic lobe including the nucleus basalis of Meynert compared to controls (false discovery rate corrected p < 0.05). In contrast, PD patients without EDS did not show any significant difference in gray matter atrophy compared to controls (false discovery rate corrected p < 0.05). PD patients with EDS showed significant atrophy of the frontal lobe, temporal lobe, occipital lobe, limbic lobe including the nucleus basalis of Meynert compared to PD patients without EDS (uncorrected p < 0.001). PD patients with EDS, even without dementia and hallucination, showed significant gray matter atrophy compared to PD patients without EDS and controls.

The role of transient receptor potential vanilloid-1 on neural responses to acids by the chorda tympani, glossopharyngeal and superior laryngeal nerves in mice.

The transient receptor potential vanilloid-1 (TRPV1) receptor acts as a polymodal nociceptor activated by capsaicin, heat, and acid. TRPV1, which is expressed in sensory neurons innervating the oral cavity, is associated with an oral burning sensation in response to spicy food containing capsaicin. However, little is known about the involvement of TRPV1 in responses to acid stimuli in either the gustatory system or the general somatosensory innervation of the oropharynx. To test this possibility, we recorded electrophysiological responses to several acids (acetic acid, citric acid and HCl) and other taste stimuli from the mouse chorda tympani, glossopharyngeal and superior laryngeal nerves, and compared potential effects of iodo-resiniferatoxin (I-RTX), a potent TRPV1 antagonist, on chemical responses of the three nerves. The results indicated that in the chorda tympani nerve, I-RTX (1-100 nM) did not affect responses to acids, sucrose and quinine HCl, but reduced responses to NaCl (I-RTX at concentrations of 10 and 100 nM) and KCl and NH(4)Cl (100 nM). In contrast, in the glossopharyngeal nerve, I-RTX significantly suppressed responses to all acids and salts, but not to sucrose and quinine HCl. Responses to acetic acid were suppressed by I-RTX even at 0.1 nM concentration. The superior laryngeal nerve responded in a concentration-dependent manner to acetic acid, citric acid, HCl, KCl, NH(4)Cl and monosodium l-glutamate. The responses to acetic acid, but not to the other stimuli, were significantly inhibited by I-RTX. These results suggested that TRPV1 may be involved in the mechanism for responses to acids presented to the posterior oral cavity and larynx. This high degree of responsiveness to acetic acid may account for the oral burning sensation, known as a flavor characteristic of vinegar.

B-type natriuretic peptide and cardiovalvulopathy in Parkinson disease with dopamine agonist.

OBJECTIVE: To elucidate the usefulness of plasma B-type natriuretic peptide (BNP) values for evaluating adverse effects of pergolide or cabergoline on cardiovalvulopathy in patients with Parkinson disease. METHODS: Twenty-five patients treated with pergolide or cabergoline (ergot group) and 25 patients never treated with ergot derivatives (non-ergot group) were enrolled. Plasma BNP values and detailed echocardiography were evaluated. Thirty age- and gender-matched controls were similarly evaluated. RESULTS: Patients with regurgitation more than grade 3 were more frequent in the ergot group than in the non-ergot group as well as control groups (24%, 0%, 3%, p = 0.001). Both composite regurgitation scores and plasma BNP values were significantly higher in the ergot group than in controls. In the ergot group, the cumulative dose correlated to both tenting area (r = 0.57, p = 0.004) and tenting distance (r = 0.62, p = 0.001). Furthermore, plasma BNP values were higher in patients with severe or multiple regurgitation groups (p < 0.001), and were correlated with composite regurgitation score (r = 0.70, p < 0.001). Multiple regression analyses revealed that BNP values were independently correlated with both composite regurgitation and left ventricular ejection fraction. CONCLUSION: The combination of comprehensive echocardiography and plasma B-type natriuretic peptide levels elucidates the presence of cardiac damage in patients with Parkinson disease using ergot derivative dopamine agonists.

A new method for direct selection of plasmid-free segregants using mercury hypersensitivity as a phenotypic marker of bacterial plasmids.

A new method was developed for direct selection of plasmid-free segregants using mercury hypersensitivity (Hg(ss)) as a phenotypic marker of bacterial plasmids. The Hg(ss) marker originated from the 4.8-kb EcoRI fragment H of the R-factor R100. Since the EcoRI fragment H spans the majority of the mercury resistance operon (mer), but lacks the intact merA gene coding for the mercury reductase enzyme, this fragment conferred the Hg(ss) phenotype. The Hg(ss) marker was introduced into high-copy-number plasmids pUC18, pBR322, and pHSG298. Segregational loss of the Hg(ss) plasmids caused a significant increase of resistance to Hg(2+), and this allowed direct selection of plasmid-free segregants on nutrient agars containing 1-2 mug HgCl(2) ml(-1). Plasmid-loss segregants were estimated to appear at frequencies ranging from 10(-3) to 10(-7) for the tested high-copy-number plasmids. THe Hg(ss) marker proved to be useful for direct selection of plasmid-free segregants from a mixed population of plasmid-harboring and plasmid-free cells.