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.

Hydrogen peroxide induces apoptosis of osteocytes: involvement of calcium ion and caspase activity

We hypothesized that reactive oxygen species play an important role in avascular/ischemic osteonecrosis. When isolated chick osteocytes were cultured with hydrogen peroxide, annexin V binding, which is the earliest marker of apoptosis, increased in a dose-dependent fashion. Hydrogen peroxide also induced the activation of caspase-3 and increase in cytosolic Ca2+. Treatment with BAPTA/AM (cheletor of cytosolic Ca2+) and Ac-DEVD-cho (caspase inhibitor) attenuated hydrogen peroxide-induced apoptosis. These data demonstrated the signal transduction pathways that participate in this hydrogen peroxide-induced cell damage.

[Prophylaxis of recurrence in superficial bladder carcinoma by intravesical chemotherapy--comparative study between instillation of combined double anticancer agents and single anticancer agent]

We performed a study to compare the usefulness of double or single anticancer agents in the prophylactic treatment after the transurethral resection (TUR) of superficial bladder cancer. We experienced 127 superficial bladder cancer cases. Of these cases, 42 were treated with intravesical adriamycin (ADR) and peplomycin (PEP), 56 with ADR, PEP, epirubicin (epi-ADR) or pirarubicin (THP) only, and the remaining 29 with TUR only. Nonrecurrence rates were significantly higher in the intravesical treated cases than in the cases with TUR only, and also significantly higher in the cases treated with ADR and PEP than the other treated cases. We concluded that intravesical chemotherapy with combined agents was more effective than with a single agent.

[Transurethral microwave thermotherapy for benign prostatic hyperplasia]

Transurethral microwave thermotherapy (TUMT) of prostate was administered to 10 patients with bladder outlet obstruction due to benign prostatic hyperplasia. The mean age of the patients was 74.4 years (range 63 to 85). The Prostatron device, which provides microwave heating of the prostate and conductive cooling of the urethra was used, and the prostate was heated with a calculated intraprostatic temperature of 45.5 degrees C for 55 minutes. No anesthesia was required for most of the patients. The clinical effects were evaluated at 4-6 weeks and 3 months after treatment. The symptomatic scores improved in the majority of patients. There was no significant change in prostate volume. The maximum flow rate and average flow rate were increased at 6 weeks and 3 months, but there was no significant change. The only side effects were transient hematuria and short-term obstruction secondary to urethral edema. In comparing TUMT with the transurethral resection of prostate (TUR-P), the maximum flow rate after TUMT was lower than that after TUR-P and the improvement of residual urine after TUMT was lower than that after TUR-P.

[Technique and problems of total parathyroidectomy with autotransplantation in secondary hyperparathyroidism]

Between 1982 and 1990, 20 patients with chronic renal failure underwent total para-thyroidectomies and autotransplantations as treatment for secondary hyperparathyroidism. Fourteen cases were cured of their symptoms and their serum PTH levels was restored to normal. Recurrent hyperparathyroidism developed in 6 cases. In 3 of the 6 cases, excision of parathyroid tissue from the forearm could easily be performed under local anesthesia. Of the other cases, 2 had five and one had six glands. Several localizing methods should be performed before operation, in order to overlook the parathyroid glands in different anatomic positions.

[Clinical evaluation in 69 cases with neurogenic bladder]

Clinical evaluation was made in 69 cases of neurogenic bladder experienced during the past 3 years. Thirty seven of the patients were male and 32 female, and they ranged in age from 4 to 88 years with an average of 63.2 years, The basic diseases of neurogenic bladder were brain lesions in 27 cases, spinal cord lesions in 18 cases, and peripheral nerve lesions in 13 cases. Three cases were of the mixed type and the basic disease was unknown in 8 cases. Cerebrovascular diseases were the most frequent, followed by spinal cord injuries and intrapelvic operations. Duration from the onset of urological symptoms to the first visit to our clinic was less than 1 month in half of the patients. The chief complaints at the first visit were pollakisuria in 25 cases (25.8%), incontinence in 18 cases (18.6%), urinary difficulty in 25 cases (25.8%) and urinary retention in 13 cases (13.4%). Urological conditions at the first visit were spontaneous urination in 53 cases (76.8%), indwelling catheterization in 12 cases (17.4%) and clean intermittent catheterization in 4 cases (5.8%). Urological complications seen at the first examination were urinary tract infections (UTI) in 27 cases (39.1%) and chronic renal failure in 2 cases (2.9%). The patients were classified by cystometrography into 3 patterns: 42 cases (60.9%) with underactive detrusor, 21 cases (30.4%) with overactive detrusor and 6 cases (8.7%) with normal detrusor. Detrusor sphincter dyssynergia was observed in 29 cases (42.0%), 40.7% had brain lesions, 44.4% spinal cord lesions, and 46.2% peripheral nerve lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

[Second generation shock wave lithotripsy: experience with the Siemens Lithostar]

In 1980, extracorporeal shock wave lithotripsy (ESWL) was incorporated as a nonsurgical method of stone removal in the cases of nephrolithiasis and rapidly found worldwide acceptance. Several devices commonly designated "second generation" lithotripters vs "first generation" Dornier HM3 are now under experimental or clinical trial. We report our clinical experience of ESWL using a Siemens Lithostar and compared it with that obtained using a Dornier HM3. One hundred patients were treated during the period of April through October, 1986 using an HM3, and 100 other patients were treated using a Lithostar from April to August, 1988. More cases were treated with a Lithostar than with a HM3. Nearly 10% of all patients treated by ESWL required additional therapeutic approaches (excepted ureteral stent) either with HM3 or Lithostar. However, in the cases of ureteral stone, with the Lithostar more cases required adjuvant procedures (TUL) than HM3. Significantly more shock waves were needed with Lithostar than HM3 for complete fragmentation of the same size of renal and ureteral stones. The stone-free rate during a one month period after ESWL was nearly the same for HM3 and Lithostar (HM3: 84.3%, Lithostar: 83.5%). Lithostar is a multifunctional lithotriptor which has most of the advantages required by the lithotripter.