Radiation Dose Reduction via Sinogram Affirmed Iterative Reconstruction and Automatic Tube Voltage Modulation (CARE kV) in Abdominal CT

Objective

To evaluate the feasibility of sinogram-affirmed iterative reconstruction (SAFIRE) and automated kV modulation (CARE kV) in reducing radiation dose without increasing image noise for abdominal CT examination.

Materials and Methods

This retrospective study included 77 patients who received CT imaging with an application of CARE kV with or without SAFIRE and who had comparable previous CT images obtained without CARE kV or SAFIRE, using the standard dose (i.e., reference mAs of 240) on an identical CT scanner and reconstructed with filtered back projection (FBP) within 1 year. Patients were divided into two groups: group A (33 patients, CT scanned with CARE kV); and group B (44 patients, scanned after reducing the reference mAs from 240 to 170 and applying both CARE kV and SAFIRE). CT number, image noise for four organs and radiation dose were compared among the two groups.

Results

Image noise increased after CARE kV application (p < 0.001) and significantly decreased as SAFIRE strength increased (p < 0.001). Image noise with reduced-mAs scan (170 mAs) in group B became similar to that of standard-dose FBP images after applying CARE kV and SAFIRE strengths of 3 or 4 when measured in the aorta, liver or muscle (p ≥ 0.108). Effective doses decreased by 19.4% and 41.3% for groups A and B, respectively (all, p < 0.001) after application of CARE kV with or without SAFIRE.

Conclusion

Combining CARE kV, reduction of mAs from 240 to 170 mAs and noise reduction by applying SAFIRE strength 3 or 4 reduced the radiation dose by 41.3% without increasing image noise compared with the standard-dose FBP images.     

Quantitative Shear Wave Elastography as a Prognostic Implication of Papillary Thyroid Carcinoma (PTC): Elasticity Index Can Predict Extrathyroidal Extension (ETE)

Objective

To investigate whether the quantitative elasticity index of shear wave elastography (SWE) can predict extrathyroidal extension (ETE) of papillary thyroid carcinoma (PTC) preoperatively.

Methods

A total of 208 patients with pathology confirmed PTC whom underwent SWE during preoperative staging US between April 2011 to June 2012 were included.SWE indices of E _mean, E _max, E _min of the index malignancy, the ratios between E _mean of the lesion and parenchyma (E _ratio-P), and muscle (E _ratio-M), and grayscale US findings, including ETE, multifocality, bilaterality, and central and lateral lymph node (LN) metastasis were evaluated. The correlations of SWE indices and grayscale US findings with pathologic prognostic factors of PTC were analyzed by Chi square or Fisher’s exact test, and multivariate regression analysis.

Results

ETE was associated with E _mean, E _max, E _min, and E _ratio-M (P = 0.005, 0.009, 0.016 and <0.001, respectively), multifocality was associated with E _mean, E _max, and E _min (P = 0.028, 0.007, and 0.004, respectively), and central LN metastasis was associated with E _ratio-M (P = 0.03). On multivariate analysis, E _mean and E _min were independent factors for predicting ETE (P = 0.032, 0.049, respectively).

Conclusions

Quantitative elasticity index of SWE could predict pathologic ETE, and SWE could be a complimentary method to grayscale US for preoperative prediction of prognostic factors of PTC.     

The Efficacy of Metallic Stent Placement in the Treatment of Colorectal Obstruction

Objective

To evaluate the efficacy of newly designed covered and non-covered coated colorectal stents for colonic decompression.

Materials and Methods

Twenty-six patients, (15 palliative cases and 11 preoperative) underwent treatment for the relief of colorectal obstruction using metallic stents positioned under fluoroscopic guidance. In 24 of the 26, primary colorectal carcinoma was diagnosed, and in the remaining two, recurrent colorectal carcinoma. Twenty-one patients were randomly selected to receive either a type A or type B stent; for the remaining five, type C was used. Type A, an uncovered nitinol wire stent, was lightly coated to ensure structural integrity. Type B (flare type) and C (shoulder type) stents were polyurethane covered and their diameter was 24 and 26mm, respectively. The rates of technical success, clinical success, and complications were analyzed using the chi-square test, and to analyse the mean period of patency, the Kaplan-Meier method was used.

Results

Thirty of 31 attempted placements in 26 patients were successful, with a technical success rate of 96.8% (30/31) and a clinical success rate of 80.0% (24/30). After clinically successful stent placement, bowel decompression occurred within 1-4 (mean, 1.58 ± 0.9) days. Five of six clinical failures involved stent migration and one stent did not expand after successful placement. In the preoperative group, 11 stents, one of which migrated, were placed in ten patients, in all of whom bowel preparation was successful. In the palliative group, 19 stents were placed in 15 patients. The mean period of patency was 96.25 ± 105.12 days: 146.25 ± 112.93 for type-A, 78.82 ± 112.26 for type-B, and 94.25 ± 84.21 for type-C. Complications associated with this procedure were migration (n=6, 20%), pain (n=4, 13.3%), minor bleeding (n=5, 16.7%), incomplete expansion (n=1, 3.3%), and tumor ingrowth (n=1, 3.3%). The migration rate was significantly higher in the type-B group than in other groups (p=0.038).

Conclusion

Newly designed covered and non-covered metallic stents of a larger diameter are effective for the treatment of colorectal obstruction. The migration rate of covered stents with flaring is higher than that of other types. For evaluation of the ideal stent configuration for the relief of colorectal obstruction, a clinical study involving a larger patient group is warranted.     

Intracranial and Spinal Ependymomas: Review of MR Images in 61 Patients

Objective

To compare the age distribution and characteristic MR imaging findings of ependymoma for each typical location within the neuraxis.

Materials and Methods

During a recent eleven-year period, MR images of 61 patients with histologically proven ependymomas were obtained and retrospectively reviewed in terms of incidence, peak age, location, size, signal intensity, the presence or absence of cyst and hemorrhage, enhancement pattern, and other associated findings.

Results

Among the 61 patients, tumor location was spinal in 35 (57%), infrartentorial in 19 (31%), and supratentorial in seven (12%). In four of these seven, the tumor was located in brain parenchyma, and in most cases developed between the third and fifth decade. Approximately half of the infratentorial tumors occurred during the first decade. The signal intensity of ependymomas was non-specific, regardless of their location. A cystic component was seen in 71% (5/7) of supratentorial, 74% (14/19) of infratentorial, and 14% (5/35) of spinal cord tumors. Forty-nine percent (17/35) of those in the spinal cord were associated with rostral and/or caudal reactive cysts. Intratumoral hemorrhage occurred in 57% (4/7) of supratentorial, 32% (6/19) of infratentorial, and 9% (3/35) of spinal cord tumors. In 17% (6/35) of spinal ependymomas, a curvilinear low T2 signal, suggesting marginal hemorrhage, was seen at the upper and/or lower margins of the tumors. Peritumoral edema occurred in 57% (4/7) of supratentorial, 16% (3/19) of infratentorial and 23% (8/35) of spinal cord tumors. Seventy-two percent (5/7) of supratentorial and 95% (18/19) of infratentorial tumors showed heterogeneous enhancement, while in 50% (17/34) of spinal cord tumors, enhancement was homogeneous.

Conclusion

Even though the MR imaging findings of ependymomas vary and are nonspecific, awareness of these findings, and of tumor distribution according to age, is helpful and increases the likelihood of correct preoperative clinical diagnosis.     

Increased nephron volume is not a cause of supranormal renographic differential renal function in patients with ureteropelvic junction obstruction

PURPOSE: Increasing clinical importance is being placed on the role of differential renal function (DRF) in the management of congenital ureteropelvic junction obstruction. Supranormal DRF of the hydronephrotic kidney on renal scan is a puzzling phenomenon and is hypothesized to be due to an increase in single nephron filtration or nephron volume without sound evidence. We studied the histopathological changes of hydronephrotic kidneys to determine whether glomerular hypertrophy underlies supranormal DRF. MATERIALS AND METHODS: We retrospectively evaluated the records of 3 females and 32 males with unilateral congenital hydronephrosis who underwent pyeloplasty. Mean patient age at operation was 12.6 months (range 0.1 to 144). Needle biopsies from 3 different sites at the lower pole of the kidney were performed during surgery. To evaluate the presence of glomerular hypertrophy, the maximal planar area of glomeruli was measured under light microscopy using an image analyzer. Tissue samples obtained from kidneys without a history of urinary tract disease at autopsy were used as controls. The mean glomerular areas of the patient and control groups were evaluated according to DRF and age. RESULTS: The mean glomerular area values of the patient group were smaller than those of the control group, except for 4 patients. The glomerular areas of the hydronephrotic kidneys with supranormal DRF were not significantly different from those of the control group. Instead, the probability of larger renal glomeruli increased with decreasing DRF (p = 0.1155). CONCLUSIONS: Increased nephron volume can be discounted as a cause of supranormal DRF.     

A prospective short-term outcome study of a short metaphyseal fitting total hip arthroplasty

The purpose of this study was to determine whether the short, metaphyseal fitting femoral stem would achieve stable fixation without diaphyseal fixation. A total of 126 patients (144 hips) were included in the study, and their mean age was 53.9 years (26-65 years). The mean duration of follow-up was 4.5 years (4-5 years). The predominant diagnosis was osteonecrosis of femoral head (88 of 144 hips, or 61%). The mean preoperative Harris hip score was 45 points, which improved to 96 points by the final follow-up. Western Ontario and McMaster Universities Osteoarthritis score and patient's activity score were improved substantially at the final follow-up. This short, metaphyseal fitting cementless femoral component achieved stable fixation without diaphyseal fixation, and there was minimal stress-shielding bone resorption in the calcar region.     

Novel technique for intraoperative tumor localization during totally laparoscopic distal gastrectomy: endoscopic autologous blood tattooing

Background

Knowledge of the intraoperative location of lesions is a prerequisite for deciding the proper extent of gastric resection or the choice of anastomosis technique during totally laparoscopic distal gastrectomy (TLDG) for early gastric cancer (EGC). In this study we introduce a novel tumor localization method for TLDG: endoscopic blood tattooing.

Methods

Twenty-three consecutive patients scheduled for TLDG for EGC were enrolled in this prospective study. The day before surgery, 2–3?ml of autologous blood was injected into the gastric muscle layer at 3–4?cm proximal to the lesion during endoscopy.

Results

The study subjects consisted of 15 males and 8 females with a mean age of 61?±?10.4?years. During surgery, the endoscopic blood tattooed sites were successfully identified in all 23 patients. No complications associated with the procedure occurred, and no patient had microscopic residual tumor cells at the proximal resection margin, with a mean proximal margin length of 3.3?±?2.7?cm. Eighteen patients underwent TLDG with Billroth II anastomosis, four patients with Roux-en-Y gastrojejunostomy, and one patient with laparoscopic total gastrectomy. At final pathologic examinations, 20 patients were of stage IA and 3 were of stage IB according to the UICC TNM classification (6th ed.).

Conclusions

Endoscopic blood tattooing provides a simple and useful means of localizing lesions during TLDG for EGC. Although the superiority of this technique over other localization methods needs to be evaluated further, the authors recommend endoscopic blood tattooing as an alternative to other intraoperative localization methods for laparoscopic surgery for EGC.     

Analysis of transplant outcomes after five or six human leukocyte antigen-mismatched living donor kidney transplantation

Background

Recently, the impact of human leukocyte antigen (HLA) mismatch (MM) on graft outcome has diminished since the introduction of potent immunosuppressive agents, whereas previous reports support the notion that greater numbers of HLA matches are beneficial. This study was undertaken to evaluate outcomes after five or six HLA-mismatched living donor kidney transplantations (LDKT).

Methods

The authors retrospectively reviewed graft function after 2687 LDKTs performed between June 1984 and February 2010. A database of 1364 living related and 1063 living-unrelated donor (LURD) kidney transplantations was used for this study. LURD kidney transplantations were classified into three groups; (1) zero to one HLA MM (n = 158); (2) two to four HLA MM (n = 851); and (3) five to six MM (n = 54). An acute rejection episode was diagnosed based on clinical deterioration of graft function or biopsy findings. Graft survival was calculated using the Kaplan-Meier method.

Results

Graft survivals in the zero to one HLA MM, two to four HLA MM, five to six HLA MM, and one-haplo MM LDKT were not significantly different. The rates of acute rejection episodes within 1 year after transplantation were similar irrespective of the HLA MM; (1) zero to one HLA MM (37.3%), (2) two to four HLA MM (35.3%), (3) five to six HLA MM (33.3%; P = .832).

Conclusions

Survival of five or six HLA-mismatched LDKTs was comparable to that of one-haplo MM and relatively well-matched LDKT. The study showed that the presence of five or six HLA MM was not a risk factor for graft survival after LDKT.     

Combined tadalafil and α-blocker therapy for benign prostatic hyperplasia in patients with erectile dysfunction: a multicenter, prospective study

This prospective study evaluated the safety of tadalafil 5 mg taken once a day in terms of hypotensive side effects and whether it improves lower urinary tract symptoms (LUTS) and restores sexual function in patients with erectile dysfunction who are receiving concomitant α-blocker (AB) therapy for benign prostatic hyperplasia (BPH). A total of 158 LUTS/BPH patients receiving AB therapy for ≥3 months were given tadalafil 5 mg once a day. Before treatment with tadalafil (V1), and 4 weeks (V2) and 12 weeks (V3) after starting tadalafil, blood pressure, heart rate, International Prostate Symptom Score (IPSS), maximal urine flow rate (Qmax), postvoiding residual urine volume, and International Index of Erectile Function (IIEF-5) score were measured. Of the 158 LUTS/BPH patients, a total of 119 completed the trial. Blood pressure (systolic and diastolic) and heart rate did not change. IPSS and IIEF-5 scores improved significantly, but Qmax and postvoiding residual urine volume did not; however, in the 39 men with a low baseline Qmax (≤10 mL/s), Qmax rose significantly from 7.97 ± 1.44 mL/s (baseline) to 8.91 ± 1.60 mL/s (V3; P = .012). The remaining patients (baseline Qmax >10 mL/s) did not change. At V2 and V3, adverse side effects were observed in 10 men (7.30%) and 6 men (5.04%), respectively. Facial flushing was the most common adverse side effect (6 men at V2 and 4 men at V3), followed by headache (2 men each at V2 and V3) and dizziness (2 men at V2). Two patients dropped out of the study because of adverse side effects. In conclusion, tadalafil 5 mg once a day in combination with AB appeared to have few adverse effects on hypotensive events and can improve LUTS and restore sexual function.