The image quality of deep-learning image reconstruction of chest CT images on a mediastinal window setting.

AIM: To assess the image quality of deep-learning image reconstruction (DLIR) of chest computed tomography (CT) images on a mediastinal window setting in comparison to an adaptive statistical iterative reconstruction (ASiR-V). MATERIALS AND METHODS: Thirty-six patients were evaluated retrospectively. All patients underwent contrast-enhanced chest CT and thin-section images were reconstructed using filtered back projection (FBP); ASiR-V (60% and 100% blending setting); and DLIR (low, medium, and high settings). Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were evaluated objectively. Two independent radiologists evaluated ASiR-V 60% and DLIR subjectively, in comparison with FBP, on a five-point scale in terms of noise, streak artefact, lymph nodes, small vessels, and overall image quality on a mediastinal window setting (width 400 HU, level 60 HU). In addition, image texture of ASiR-Vs (60% and 100%) and DLIR-high was analysed subjectively. RESULTS: Compared with ASiR-V 60%, DLIR-med and DLIR-high showed significantly less noise, higher SNR, and higher CNR (p<0.0001). DLIR-high and ASiR-V 100% were not significantly different regarding noise (p=0.2918) and CNR (p=0.0642). At a higher DLIR setting, noise was lower and SNR and CNR were higher (p<0.0001). DLIR-high showed the best subjective scores for noise, streak artefact, and overall image quality (p<0.0001). Compared with ASiR-V 60%, DLIR-med and DLIR-high scored worse in the assessment of small vessels (p<0.0001). The image texture of DLIR-high was significantly finer than that of ASIR-Vs (p<0.0001). CONCLUSIONS: DLIR-high improved the objective parameters and subjective image quality by reducing noise and streak artefacts and providing finer image texture.

Image quality of multiplanar reconstruction of pulmonary CT scans using adaptive statistical iterative reconstruction.

OBJECTIVE: We investigated the image quality of multiplanar reconstruction (MPR) using adaptive statistical iterative reconstruction (ASIR). METHODS: Inflated and fixed lungs were scanned with a garnet detector CT in high-resolution mode (HR mode) or non-high-resolution (HR) mode, and MPR images were then reconstructed. Observers compared 15 MPR images of ASIR (40%) and ASIR (80%) with those of ASIR (0%), and assessed image quality using a visual five-point scale (1, definitely inferior; 5, definitely superior), with particular emphasis on normal pulmonary structures, artefacts, noise and overall image quality. RESULTS: The mean overall image quality scores in HR mode were 3.67 with ASIR (40%) and 4.97 with ASIR (80%). Those in non-HR mode were 3.27 with ASIR (40%) and 3.90 with ASIR (80%). The mean artefact scores in HR mode were 3.13 with ASIR (40%) and 3.63 with ASIR (80%), but those in non-HR mode were 2.87 with ASIR (40%) and 2.53 with ASIR (80%). The mean scores of the other parameters were greater than 3, whereas those in HR mode were higher than those in non-HR mode. There were significant differences between ASIR (40%) and ASIR (80%) in overall image quality (p<0.01). Contrast medium in the injection syringe was scanned to analyse image quality; ASIR did not suppress the severe artefacts of contrast medium. CONCLUSION: In general, MPR image quality with ASIR (80%) was superior to that with ASIR (40%). However, there was an increased incidence of artefacts by ASIR when CT images were obtained in non-HR mode.

Reproducibility of temporal volume change in CT of lung cancer: comparison of computer software and manual assessment.

The purpose of this study was to investigate the reproducibility of volumetric software evaluation and manual evaluation of tumour growth. Three observers manually evaluated whether tumour volume was increasing, if it was unchanged, or if it had decreased in size in 2 serial CT examinations of 45 solid lung cancers. The tumour volumes were calculated 3 times using volumetric software and were evaluated using the same classifications as for manual evaluation. Both data sets were divided into three groups: growth or reduction with consistency among all three evaluations (group A), growth or reduction with consistency between only two evaluations (group B), and others (group C). The volume variation and relative volume variation were calculated from the median volumes measured by volumetric software. Although all 45 tumours were categorised in group A by volumetric software, only 21 tumours were categorised in group A by manual assessment. The relative volume variation of the manual assessment was 88.5 +/- 76.5%, 20.8 +/- 28.3% and 12.9 +/- 12.8% in group A, B and C, respectively. Significant differences were found between groups A and B (p<0.01) and between groups A and C (p<0.001). Inconsistency is often seen in manual assessment; in contrast, evaluation using volumetric software has good reproducibility, even when the relative change in tumour volume is small.

One-dimensional quantitative evaluation of peripheral lung adenocarcinoma with or without ground-glass opacity on thin-section CT images using profile curves.

The purpose of our investigation was to compare the usefulness of the subjective visual assessment of ground-glass opacity (GGO) with a quantitative method that used a profile curve to determine prognosis. 96 adenocarcinomas were studied. Three diameters ([D1]-[D3]) were defined for estimating the diameter of tumours on the monitor: the distance between two points was measured using software that displays a CT density profile across the tumour. One experienced and one less experienced radiologist independently evaluated the following six parameters: the three diameters [D1]-[D3]; the solid portion of total tumour in the two different ratios ([D2]/[D1], [D3]/[D1]); and the area ratio of GGO for total opacity to subjective visual evaluation. Interobserver agreement between the two radiologists of the diameters (mean bias+/- 1.96 standard deviations) was as follows: [D1], -0.7 +/- 6 mm; [D2], 0.4 +/- 4.4 mm; and [D3], -0.1 +/- 4.2 mm (Bland and Altman's method). Interobserver agreement was fair in evaluating the area ratio of GGO (kappa test, kappa = 0.309). Univariate logistic regression analysis revealed that two ratios ([D2]/[D1], [D3]/[D1]) might be significantly useful in estimating lymph node metastasis (p < 0.026), lymph duct invasion (p < 0.001) and recurrence (p < 0.015). Observation of the area ratio of GGO by an experienced radiologist would be necessary for estimating lymph node metastasis (p = 0.04) and lymph duct invasion (p < 0.001). We concluded that the ratio of solid component to total tumour, which is obtainable in a more objective and simple way using profile curves obtained by software, is a more useful method of estimating prognosis than is visual assessment.

Remineralization effects of gum arabic on caries-like enamel lesions.

OBJECTIVE: Gum arabic is a natural polysaccharide exudate from Acacia senegal and other related African species of Acacia. Gum arabic is considered to have an ability to enhance remineralization, because of its high concentration of Ca(2+). However, the caries preventive capacity of gum arabic has been scarcely investigated. We evaluated the cariostatic activities of gum arabic using histopathological methods to determine its effects on remineralization. DESIGN: Following incubation in demineralization solution, human third molars were exposed to 10 mg/ml of gum arabic, sodium fluoride at 1000 ppm (NaF), or double distilled water (DW, negative control), then subjected to demineralization-remineralization cycles. Before and after demineralization-remineralization cycles, contact microradiographs of each sample were taken and mineral distribution quantities were calculated. RESULTS: The remineralization ratio of the molars exposed to gum arabic was similar to that of those exposed to NaF, while the ratios of both were significantly greater than that of those exposed to DW. CONCLUSIONS: Gum arabic enhanced the remineralization of caries-like enamel lesions in vitro, suggesting its inhibitory effects towards dental caries.

Favourable association of leg fat with cardiovascular risk factors.

OBJECTIVES: To assess the association of trunk and leg fat mass (FM) and leg lean tissue mass (LTM) with conventional cardiovascular risk factors. DESIGN: Cross-sectional study. SETTING AND SUBJECTS: We studied 1249 men and 3007 women (age 20-79 years) who attended a research institute for a health checkup between October 1995 and February 2004. MAIN OUTCOME MEASURES: Body mass index, waist circumference (WC), hip circumference (HC), systolic and diastolic blood pressure, total cholesterol, HDL cholesterol, triglycerides, glucose and haemoglobin A(1C) were measured. Trunk FM, leg FM and leg LTM were obtained by dual-energy X-ray absorptiometry. We evaluated the associations between the indices for regional body composition and cardiovascular risk factors, which included hypertension, hypercholesterolaemia, hypo-HDL cholesterolaemia, hypertriglyceridaemia, dyslipidaemia and diabetes mellitus. RESULTS: Increase in WC and HC respectively showed increase and decrease in odds ratios of cardiovascular risk factors. Increase in trunk FM by 1 kg significantly increased the risk of the cardiovascular risk factors with the odds ratios ranging between 1.11 and 1.45. Increase in leg FM by 1 kg significantly decreased the risk with the odds ratios ranging between 0.52 and 0.90, except for the nonsignificant results for hypercholesterolaemia and hypo-HDL cholesterolaemia in men. Odds ratios of 1 kg increase in leg LTM were only significant for dyslipidaemia in men and hypercholesterolaemia in women (both 0.93). CONCLUSIONS: WC and HC showed opposite and independent associations with cardiovascular risk factors. The favourable association of HC was mainly attributable to that of leg FM.

[Questionnaire research of the participants in a large scale walking event Fukuoka City analysis of walking habits and related factors].

PURPOSE: We examined the walking habits of the participants in the 'AIREF Spring Walk' which was held on March 9, 1997 in the western suburb of Fukuoka City. The aim of this walking event was to motivate the citizens, especially sedentary people, to walk by providing them an opportunity to enjoy walking. METHODS: The participants walked one of three distances (5 km, 10 km or 20 km) and answered anonymously a questionnaire immediately after finishing (100% response rare). The questionnaire items covered sex, age, district of residence, the distance of the walking course, the source of information on the event, experience of participating in other walking events in the past, and walking habits. RESULTS: The participants of this event (n = 1,039, mean age 49.4 +/- 18.9 [SD] years) were characterized by high rates for females (67%), those aged < 50 years (42%), residents of Fukuoka City (89%), those who chose to walk the shorter courses of 5 or 10 km (74%), and those who took part in a walking event for the first time (61%). Information on the event was obtained through other people (32%) such as friends, acquaintances, members of community walking groups or other family members, leaflets (21%) placed in the Fukuoka Health Promotion Center and seven Fukuoka City public health centers; a newspaper published biweekly by the municipal government (13%); and direct mail (11%). For those attending the 5 km course, more participants learned about the event through other family members compared with the other two courses. Participants who answered that they walked regularly constituted 56% of those aged 20 years or older. The rates for regular walkers significantly increased with the older participants (p < 0.01) and those who chose longer courses (p < 0.001). Compared with the regular walkers, those without a walking habit tended to have acquired information on the event from friends, acquaintances or other family members, or at their work sites (35%). The average amount of time spent was 249 +/- 175 min/week (n = 375). As a whole, only 30% of the participants aged 20 years or older walked longer than the amount of time for aerobic exercise recommended by the Health, Labor and Welfare Ministry (HLWM). The rate for those who reached the HLWM recommendations was increased in older subject (p < 0.001). CONCLUSIONS: It is concluded that the aim of the walking event was partly accomplished, which was reflected by the relatively high rates of participation sedentary for people, compared with other large walking events. The sedentary participants tended to choose the relatively short distances and obtain the information about the event through other people. Walking promotion programs should be developed to motivate sedentary citizens to walk. The programs should also support regular walkers, many of whom are 50 years old or older, to maintain walking habits with the HLWM recommendations on aerobic exercise.

Effects of increased physical activity and mild calorie restriction on heart rate variability in obese women.

The effects of exercise and mild calorie restriction on heart rate variability (HRV) were investigated in 12 mildly obese, normotensive Japanese women aged 45.8+/-4.2 (SEM) years with a body mass index (BMI) of 27.3+/-0.4 kg/m2. The subjects participated in a 3-month program aimed at increasing physical activity and modifying eating behavior (intervention group). The control group consisted of 12 women (age 50.1+/-4.8 years, BMI 27.2+/-0.6 kg/m2) who did not attend the program. The frequency domain of HRV was calculated from 5-min Holter recordings while the subjects rested in a supine position. After 3 months, BMI decreased to 25.0+/-0.5 kg/m2 (p<0.001 vs baseline) in the intervention group, which was accompanied by decreases in body fat mass, waist circumference, serum total cholesterol and triglycerides, and improvement in insulin sensitivity. The mean and SD of the RR intervals, total power, and low and high frequency power of HRV significantly increased after the intervention, whereas no significant changes were seen for the controls. The changes in these HRV variables (calculated by subtracting the baseline values from the follow-up values) negatively correlated with the change in waist circumference, with the Pearson correlation coefficients being between -0.50 and -0.62 (p<0.05). A negative correlation was also seen between the changes in high frequency power and insulin resistance estimated by homeostasis model assessment (r=-0.49, p<0.05). The combination of exercise and mild calorie restriction led to changes in HRV indicative of an improvement in parasympathetic modulation.

Association of serum tumour necrosis factor-alpha with serum low-density lipoprotein-cholesterol and blood pressure in apparently healthy Japanese women.

1. The pro-inflammatory cytokine tumour necrosis factor (TNF)-alpha is considered to be involved in the development of atherosclerosis by inducing local inflammatory responses in the vascular wall. Because TNF-alpha is also known to affect lipid and glucose metabolism, the association between the circulating concentration of TNF-alpha and atherogenic risk factors was examined in 82 apparently healthy Japanese women (aged 19-69 years; mean age 48.5 years). 2. The mean (+/-SD) serum TNF-alpha concentration was 2.7+/-0.9 pg/mL (range 1.4-5.9 pg/mL). The TNF-alpha concentration showed significant correlations with age (r = 0.28; P = 0.01), body mass index (r = 0.27; P = 0.01), the waist-hip ratio (r = 0.41; P = 0.0002), percentage body fat (r = 0.30; P = 0.006), systolic (r = 0.32; P = 0.004) and diastolic (r = 0.24; P = 0.03) blood pressure, total cholesterol (r = 0.27; P = 0.02) and low-density lipoprotein-cholesterol (LDL-C; r = 0.36; P = 0.001), while the correlations with high-density lipoprotein-cholesterol (r = -0.20; P = 0.08) and insulin resistance estimated by the homeostasis model assessment (HOMA(IR); r = 0.16; P = 0.15) were not statistically significant. 3. When adjusted for age and menopause, TNF-alpha was significantly associated with systolic blood pressure (r = 0.25; P = 0.02) and LDL-C (r = 0.27; P = 0.02). The association between TNF-alpha and LDL-C remained significant when adjustment was made for age, menopause and the waist-hip ratio (r = 0.24; P = 0.03). 4. Our results indicate that TNF-alpha may play a role in modulating blood pressure and LDL-C.

Effect of increased intrareservoir pressure on upper urinary tract function in continent urinary diversion patients assessed by radioisotope renography.

To assess upper urinary tract function and determine an ideal continent reservoir capacity, we investigated the relationship between intrareservoir pressure and functional parameters using radioisotope renography. Forty-three patients for whom ileal reservoir construction was performed by Kock pouch (n = 33) or Hautmann's ileal neobladder (n = 14) approaches between November 1984 and September 1996 were studied. After the reservoir contents were catheterized, (99m)Tc-MAG 3 renoscintigraphy was carried out and time activity curves in the kidney (renogram) and reservoir (reservoirgram) were recorded, while saline solution was poured into the reservoir for monitoring of intrareservoir pressure. Three basic abnormal curves were noted in the excretory phase on renograms: a normal downward curve followed by an upward curve, a continuous upward curve associated with or without a sharp decline after the catheterization of the reservoir contents, and episodes of spike waves. Based on these curves, renograms were classified into five types: normal, high pressure, retention, obstruction, and reflux. Abnormal types were noted with 51 of 65 renal units (78.5%) in the Kock pouch group and 15 of 25 renal units (60.0%) in the neobladder group. This examination method may be useful for evaluating urodynamics in the upper urinary tract of patients with a continent ileal reservoir and provide data on adequate voiding volumes for the individual patient.

The usefulness of power Doppler ultrasonography for diagnosing prostate cancer: histological correlation of each biopsy site.

OBJECTIVE: To correlate the findings of power Doppler ultrasonography (PDUS) of the prostate with those of site-specific transrectal ultrasonography (TRUS)-guided biopsy. PATIENTS AND METHODS: The study comprised 28 patients referred to our institution for TRUS-guided prostate biopsy because of an elevated PSA level and/or abnormal digital rectal examination. PDUS findings were graded 0, 1 or 2; grades 0-1 were considered as negative and grade 2 as positive. The blood volume of each biopsy site was also determined using the mean number (MN) value that represents the average vascularity in a 5-mm square sample. PDUS values were correlated with the histological findings of 147 biopsies with 19 focal lesions. RESULTS: Grade 2 was assigned to 19 sites, grade 1 to 52 sites, and grade 0 to 76 sites. Fourteen of the 19 PDUS findings of grade 2 sites revealed carcinoma and five were grade 1. Ten of 35 TRUS-positive sites were carcinomas, three benign prostatic hyperplasia (BPH) and 22 normal. The MN value for prostatic carcinoma was 4.33, for BPH 11.7 and for normal tissue 4.7. The overall sensitivity of PDUS was 74%, the specificity 96% and the positive predictive value 74%. CONCLUSIONS: Because TRUS alone cannot detect all cancers, PDUS should be used routinely in all patients undergoing TRUS-guided biopsy, to improve the diagnostic yield of prostate cancer.

[Cyclophosphamide-induced renal pelvic tumor--a case report].

We report a case of transitional cell carcinoma in the left renal pelvis, which occurred in a 24-year-old man. He had been treated with cyclophosphamide (CPM) for a period of 27 months for retroperitoneal rhabdomyosarcoma diagnosed at the age of 10. At first 1.2 g CPM had been given twice intravenously for 3 months, followed by oral administration of 41 g CPM for 23 months. Drip infusion pyelography revealed a filling defect in the left renal pelvis. A left renal pelvic tumor was strongly suspected on computerized tomography and magnetic resonance imaging. Left nephroureterectomy was then performed. Histological diagnosis of the left renal pelvic tumor was transitional cell carcinoma, grade 2, pT1N0M0. No recurrence was defected 17 months later. This case seems to be the second case of cyclophosphamide-induced upper urothelial carcinoma reported in Japan.

[A case of female paraurethral cyst diagnosed as epithelial inclusion cyst].

The patient was a 36-year-old woman with a chief complaint of pain of the urethral meatus. A cyst existed just below the urethral meatus. The paraurethral cyst was removed completely. Histologically, the cyst was lined by stratified squamous epithelium. According to the criteria proposed by Das, paraurethral cysts are classified into 4 groups: epithelial inclusion cysts, Müllarian cysts, Gärtner duct cysts, Skene duct cysts. In this case, the cyst seemed to be an epithelial inclusion cyst. In the Japanese literature, paraurethral cysts have been incompletely classified from an etiological perspective. Differential diagnoses based on the histological findings of the cysts may be important to determine the etiology.

[Clinical study of prostate cancer: statistical analysis of 107 cases in the past 12 years].

One hundred and seven patients with prostate cancer were treated at Mie University Hospital during the past 12 years between 1988 and 1999. They were between 53 and 83 years old, with an average age of 70.8 years old. The clinical stage was defined as A, B, C and D in 3 (2.8%), 19 (17.8%), 50 (46.7%) and 35 (32.7%) patients, respectively. At initial diagnosis, the tumor was well, moderately and poorly differentiated adenocarcinoma in 26 (24.3%), 47 (43.9%) and 34 (31.8%) patients, respectively. The median follow-up period was 52.3 months. The overall 1, 3 and 5-year survival rates were 98.0%, 86.8% and 75.2%, respectively. The 5-year survival rates for stage A, B, C and D were 100%, 93.8%, 82.1% and 56.9%, respectively. A significant difference (p = 0.017) in 5-year survival rate was noted between stage C and D. The 5-year survival rate was 100% for well differentiated, 78.0% for moderately differentiated, and 53.2% for poorly differentiated adenocarcinoma. A significant difference (p = 0.0016) in the 5-year survival rate was noted between well differentiated and poorly differentiated adenocarcinoma. According to the therapy, the 5-year survival rate in stage C was 86.2% for the radical prostatectomy group and 84.0% for the endocrine therapy group. There was no significant difference between these 2 treatment groups. Endocrine therapies, classified into maximum androgen blockade (MAB) and endocrine therapy other than MAB were performed for stage D as an initial therapy. Although the prognosis in the patients treated with MAB was better than that with other endocrine therapies, there was no significant difference between these 2 endocrine treatment groups.

[A case of emphysematous pyelonephritis with emphysematous cystitis].

A 74-year-old woman with diabetes mellitus had a high fever, and was treated with antibiotics and insulin in another hospital. She was referred to our department, because CT scan showed the right hydronephrosis and the abnormal gas shadow in the right renal calyces. Ureteral catheterization was performed on the right side and cloudy urine was drained. Urine culture yielded E. coli. Since submucosal emphysematous changes were demonstrated in the bladder mucosa by cystoscopy, she was diagnosed with emphysematous pyelonephritis with emphysematous cystitis associated with diabetes mellitus. Administration of antibiotics and insulin and the ureteral catheter drainage improved her condition immediately. Abnormal gas shadow on CT scan and submucosal emphysema on cystoscopy disappeared. We reviewed 110 cases of emphysematous pyelonephritis and 23 cases of emphysematous cystitis including our case in Japan, and report their clinical characteristics.

Paravesical granuloma after inguinal herniorrhaphy. Case report and review of the literature.

Paravesical granuloma after herniorrhaphy is an unusual complication due to infected suture material and often mimics bladder or urachal malignancy. We present 3 cases of this disease and reviewed 21 previously reported cases. Our patients underwent hernial repair 2-7 years before examination and presented urinary symptoms. They were treated with antibiotics and underwent exploration of the inguinal wound infection but the symptoms did not resolve. En bloc excision and partial cystectomy were performed and resulted in complete resolution of the symptoms. It is important to consider paravesical granuloma in patients who had undergone herniorrhaphy in the differential diagnosis of bladder or urachal tumors.

[The progress in diagnostic imaging for staging of bladder and prostate cancer: endorectal magnetic resonance imaging and magnetization transfer contrast].

We retrospectively studied the staging accuracy of endorectal magnetic resonance imaging (MRI) in comparison with transrectal ultrasound examination (TRUS) for 71 localized bladder cancers and 19 localized prostate cancers (PC) radically resected. The accuracy of clinical staging for bladder cancer in endorectal MRI and TRUS was 85.9% and 69.2%, respectively. The presence or absence of the continuity of submucosal enhancement on T2-weighted MRI images could be useful for the staging of bladder cancer. The accuracy of the seminal vesicular invasion for prostate cancer in endorectal MRI and TRUS was 95% and 63%, respectively. To determine whether magnetization transfer contrast (MTC) provides additional information in the diagnosis of prostate cancer, the magnetization transfer ratios (MTRs) were calculated in 22 patients with PC, 5 with benign prostatic hyperplasia (BPH) and 4 controls. The mean MTR in the peripheral zone of the normal prostate (8.0% +/- 3.4 [standard deviation]) showed a statistically significant decrease relative to that in the inner zone of the normal prostate (27.4% +/- 3.4, p < 0.01), BPH (25.5% +/- 3.7, p < 0.01), pre-treatment PC (30.6% +/- 5.9, p < 0.01), and PC after hormonal therapy (20.3% +/- 6.3, p < 0.01). The mean MTR in pre-treatment PC was significantly higher than that in BPH, or in PC after hormonal therapy (p < 0.01). MTC was considered to be useful for conspicuity of prostate cancer lesion.

[Extracorporeal shock wave lithotripsy in patients with coagulopathies: report of three cases].

We describe our experience with extracorporeal shock wave lithotripsy (ESWL) in three patients with coagulation disorders (one case of hemophilia A, and two cases of thromboasthenia). We successfully performed ESWL using factor VIII or transfusion of platelets without any severe hemorrhagic complications, such as perirenal and subcapsural hematomas. We consider that adequate supplement of coagulation factor or platelets may lower the risk of hemorrhagic complications in coagulopathic patients who undergo ESWL.