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.

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.

The formation of oxalate from glycolate in rat and human liver.

In this study, we attempted to elucidate the metabolic pathway and enzymes actually involved in oxalate formation from glycolate in rat and human liver. In rat liver, the formation of oxalate from glycolate appeared to take place predominantly via glyoxylate. The oxalate formation from glycolate observed with crude enzyme preparations was almost entirely accounted for by the sequential actions of glycolate oxidase and xanthine oxidase (XOD) or lactate dehydrogenase (LDH). Under the conditions used, no significant activity was attributable to glycolate dehydrogenase, an enzyme reported to catalyze the direct oxidation of glycolate to oxalate. Among the three enzymes known to catalyze the oxidation of glyoxylate to oxalate, glycolate oxidase and XOD showed much lower activities (a higher Km and lower Vmax) toward glyoxylate than those with the respective primary substrates. As to LDH, none of the LDH subunit-deficient patients examined showed profoundly lowered urinary oxalate excretion. Based on the results obtained, the presumed efficacies in vivo of individual enzymes, as catalysts of glyoxylate oxidation, and the in vivo conditions assumed to allow their catalysis of oxalate production are discussed.

Normal bladder wall morphology in Gd-DTPA-enhanced clinical MR imaging using an endorectal surface coil and histological assessment of submucosal linear enhancement using [14C]Gd-DOTA autoradiography in an animal model.

OBJECTIVE: The purpose of this study was to investigate normal bladder wall morphology in gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced magnetic resonance (MR) imaging using an endorectal surface coil and to perform histological assessment of submucosal linear enhancement with experimental [14C]-gadolinium-tetraazacyclododecane-tetraacetic acid (Gd-DOTA) autoradiography. METHODS AND MATERIAL: MR imaging of the bladder was performed using an endorectal coil in 13 consecutive patients with bladder carcinoma and T1-, T2-, and Gd-DTPA-enhanced spin-echo images of the bladder wall were compared. After injection of [14C]Gd-DOTA into a hamster, autoradiograms of the bladder wall were obtained and compared with serial histological sections. RESULTS: The normal bladder wall appeared as a homogeneous layer of intermediate intensity on T1-weighted images. After administration of Gd-DTPA, the bladder wall was visualized as three layers: an inner thin layer of low intensity, a middle layer of marked enhancement, and a thick outer layer of intermediate intensity. The autoradiograms demonstrated dense accumulation of [14C]Gd-DOTA in the submucosal layer. Thus, the inner, middle, and outer layers corresponded to the mucosa, submucosa, and muscularis propria, respectively. The thickness of the bladder wall demonstrated on T2-weighted images was almost equal to that of the outer layer on enhanced T1-weighted images. Thus, T2-weighted images revealed only the muscle layer as an intermediate-intensity band. In the preliminary clinical study, MR imaging invariably showed accurate stages of the bladder carcinoma in 13 patients. CONCLUSION: In MR imaging of the normal bladder wall, the submucosa was strikingly enhanced after Gd-DTPA administration, separating the bladder wall into three layers. This may have a potential role in the staging of bladder tumors.

[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.

[The determination of oxalate in urine by enzymatic method using oxalate oxidase: comparison between enzymatic and gas-chromatographic methods].

Urinary oxalate is one of the most important constituents of urolithiasis, but the determination of oxalate in urine has not been performed as a routine laboratory examination. We tried to measure oxalate in urine by the enzymatic method with oxalate oxidase. The linearity of the standard curve and reproducibility of this method were confirmed. (Linearity: r = 0.996, S.D./mean: 0.5-3.6%, recovery rate: 99.5 +/- 3.3 (mean +/- S.D.)%) The correlation between this method and gas-chromatographic method was 0.926. The enzymatic method with oxalate oxidase can be utilized for determining the urinary oxalate as a routine laboratory examination.

[Combined small cell and transitional cell carcinoma of renal pelvis: a case report].

Primary small cell carcinoma of the renal pelvis is rare. We report a case of combined small cell and transitional cell carcinoma of the renal pelvis. The patient was a 78-year-old man with macrohematuria. He was diagnosed with right pelvic tumor by right retrograde pyelography and computerized tomography. A right radical nephroureterectomy was performed. Histological sections of the tumor showed a mixture of small cell and grade 2 transitional cell carcinoma. Positivity for Grimelius was noted in the small cell component. Masson-Fontana, chromogranin A, serotonin, keratin, leucocyte common antigen (LCA), neuron specific enolase (NSE), adrenocorticotropic hormone (ACTH), growth hormone (GH) and somatostatin were negative. Ultrastructurally, the tumor cells were tightly packed and attached together by scattered desmosomes. There were no neurosecretory granules. Seven months after operation, the patient died with peritonitis carcinomatosa. At autopsy, a metastatic tumor was found in the liver and retroperitoneal lymph node. Other organs were not involved. Especially, there were no abnormalities in the lungs.

[A clinical study of renal cell carcinoma with extension into the inferior vena cava].

Nineteen patients with renal cell carcinoma with tumor extension into the inferior vena cava (IVC) were investigated between January, 1973 and March, 1994. The patients were between 50 and 78 years old with a mean of 65.9 years. The male to female ratio was 1.7 to 1. Thirteen tumors were on the right side and 6 on the left side. In 12 patients, both nephrectomy and removal of the tumor thrombus were performed. The survival rate in the operated group was 60% at 5 years. Histologically, 7 cases were diagnosed as clear cell subtype and 5 cases as granular cell subtype. From this study, an extended operative intervention such as radical nephrectomy combined with tumor thrombectomy of the IVC with or without cavectomy was suggested in the case of renal cell carcinoma without any other metastatic lesions and histopathologically of the clear cell subtype.

[Oxalate as a promoter in calcium oxalate nephrolithiasis].

Oxalate transports on membranes of red blood cell, intestinal epithelium and proximal tubule cell were reviewed, and the new findings about oxalate transport across these membranes are reported. Red blood cell oxalate influx rate in a group of recurrent calcium oxalate stone formers was significantly higher than that of a control group. In the red blood cells of mammals, the band 3 protein transports oxalate. Although abnormal influx rate of red blood cells might be recognized as an expression of somatic cell abnormality of oxalate transport in some recurrent stone formers, the band 3 protein is not related to oxalate transport in both kidney and intestine. The study using brush border membrane vesicles suggested the presence of Na-oxalate co-transport. In humans, sodium intake increased the oxalate/creatinine ratio of urine. This indicated that excessive sodium intake might be a risk factor of stone formation. Further study of oxalate transport of both kidney and intestine will be required to elucidate an etiology of calcium oxalate nephrolithiasis.

[Initial chemotherapy followed by orchiectomy and retroperitoneal lymphadenectomy--a case of seminoma with a testicular tumor and enlarged regional lymph nodes].

A 43-year-old male visited our hospital with complaints of right scrotal swelling and lower abdominal mass. Computed tomographic (CT) scan showed the right testicular tumor and regional enlarged lymph nodes. However, there were no metastasis in lung, brain, liver, and bone. First, we performed chemotherapy of modified PVB regimen (cisplatinum, vinblastine, peplomycin) prior to the right orchiectomy, because a tumor lump was palpable from the right testis to the lower abdominal mass. After three courses of modified PVB chemotherapy, beta-HCG, HCG and LDH values became within normal limits and all tumors were necrotic on the CT scan. Then, we performed the right orchiectomy and retroperitoneal lymphadenectomy simultaneously. After operation, two courses of VIP chemotherapy (etoposide, ifosfamide, cisplatinum) were performed since viable cells in one of the obturator lymph nodes were pathologically noticed. The patient has been free of recurrence of the tumor for 15 months after the treatment. In the particular case, in which the primary testicular tumor was not extirpated en bloc, the initial chemotherapy followed by orchiectomy was found to be feasible.

[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.

[Renal angiomyolipoma: diagnosis and treatment].

In 10 years the diagnosis of renal angiomyolipoma (RAML) was made in 14 patients (male-to female ratio 1:3.7) at our institution; 1 case was associated with tuberous sclerosis (TS) and 1 case had regional lymph node involvement. A statistical study was done on data taken from 739 cases of RAML in the Japanese literature, including our cases. The male to female ratio was 1 to 3. Twenty eight percent of the cases were associated with TS. The ratio of bilateral cases to the unilateral one was 1 to 3. The main clinical signs were flank pain, abdominal mass, hematuria and fever elevation. Recently the ratio of nephrectomy has decreased to 30%. The percentage of detecting the fat component by ultrasonography (US), computed tomography (CT) and magnetic resonance imaging were 88.1%, 86.5% and 80.8% respectively. The percentages of visualizing hypervascularity, aneurysms, absence of arterio-venous shunt and onion peel appearance by selective renal angiography were 77.3%, 71.4%, 48.1% and 4.9% respectively. Small (less than 3 cm), asymptomatic, simple lesions with adipose component may be observed annually by CT and US until more experiences is gained with surveillance of these patients. Embolization was useful for emergency cases or pre-treatment of nephron sparing surgery, but insufficient by itself. As there still remain problems in the diagnosis of RAML, especially in the case of very small tumors, in the case with almost no adipose component and in the case associated with renal cell carcinoma, the diagnosis of RAML should be made synthetically including angiography.

[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.

[Abscess of corpus cavernosum: a case report].

A 72-year-old man was admitted to our hospital complaining of a penile mass. The local biopsy indicated an abscess formation in the corpus cavernosum. In spite of antibiotic treatment, the abscess cavity ruptured to the dorsal skin and the urethra. After cystostomy formation, dorso-caverno-urethral fistula was closed by conservative therapies. Although the patient was followed up with antibiotics on an outpatient basis, necrotic changes in the right foot were noticed and he was diagnosed with arteriosclerosis obliterance in the right lower leg. Therefore, he was referred to an orthopedic clinic for amputation of his right lower leg with cystostomy catheter. This is the 7th case reported in Japan.

[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.

[Two cases of giant condyloma of the penis treated with penis-sparing methods].

Herein, we report two cases of giant condyloma of the penis treated with penis-sparing methods. In the first case, the papillomatous tumor disappeared with topical use of fluorouracil ointment. In the second case, the tumor was treated with topical use of fluorouracil or bleomycin hydrochloride, followed by the resection of tumor. Giant condylomas reported in the recent 13 years are reviewed and methods of treatment discussed.

[Percutaneous sclerotherapy for chyluria with leg edema: a case report].

A 45-year-old woman with left leg edema was admitted to our hospital because of chyluria from the previous year. Her left leg edema appeared after Caesarean section for her first delivery and hysterectomy at the age of 31. Because microfilaria was not detected, she was diagnosed with postoperative lymphangiomatosis. The instillation of 0.1-0.5% silver nitrate into the renal pelvis was not effective. We however, after percutaneous sclerotherapy to the left inguinal lymph nodes with doxycycline, the chyluria disappeared and her left leg edema improved. Then, the surplus skin of her left lower leg was resected. We considered percutaneous sclerotherapy to be a good procedure for chyluria due to postoperative lymphangiomatosis.

[A case of metastatic ureteral tumor from rectal cancer].

A 67-year-old man was referred for further examination of left hydronephrosis. He had undergone anterior resection for rectal cancer 2 years previously and also right lobectomy for a solitary hepatic metastasis one year postoperatively. Antegrade pyelography demonstrated a filling defect in middle portion of the left ureter. Cytology of the aspirated urine was class V. Left nephrourete-rectomy was performed. Histologically metastatic adenocarcinoma with intact ureteral mucosa was demonstrated.

[A case of renal cell carcinoma with metastasis in clivus presenting as diplopia].

We report a rare case of renal cell carcinoma presenting as diplopia which was caused by a metastasis to the clivus. A 58-year-old man was admitted to our hospital with the chief complaint of diplopia. Head magnetic resonance imaging showed a mass in the clivus accompanied by bone destruction. Metastatic tumor to the skull base was suspected. Further examinations for the primary lesion revealed left renal cell carcinoma. He was relieved of diplopia by radiotherapy to the clivus and subsequently underwent left radical nephrectomy.