Successful Treatment of Fournier’s Gangrene with the Assistance of Preoperative Computed Tomography in an Elderly Man: Report of a Case

An 87-year-old man presented with inguinal pain and swelling, and was later diagnosed as having Fourniers gangrene. The information gained from preoperative computed tomography (CT) proved very useful for defining the extent of necrosis, and emergency surgery saved his life. Thus, CT should be performed prior to treatment of Fourniers gangrene, even in an emergency situation.     

Pedicled Ileal Flap to Repair Large Duodenal Defect After Right Hemicolectomy for Right Colon Cancer Invading the Duodenum

Although right-sided colon cancer occasionally invades the second part of the duodenum, there is no standard procedure for reconstructing a large duodenal defect after resection. This report describes a new approach we recently devised. After resecting the right hemicolon and the involved duodenum, a segment of terminal ileum was isolated on the vascular pedicle, sacrificing the adjacent ileum. We created a flap by opening the segment along the antimesenteric border, and used this flap to cover the defect. This method does not create a nonanatomical bypass and fewer intestinal anastomoses are required than for Roux-en-Y reconstruction.     

A randomized controlled trial of short-term versus long-term prophylactic intravesical instillation chemotherapy for recurrence after transurethral resection of Ta/T1 transitional cell carcinoma of the bladder

PURPOSE: In a prospective randomized controlled study, we investigated the optimal schedule for intravesical instillation of epirubicin for maximizing its effect on prophylaxis and disease progression after transurethral resection of newly diagnosed Ta/T1 bladder cancer. MATERIALS AND METHODS: The patients were instilled with epirubicin (30 mg/30 ml in normal saline) within 24 hours after transurethral resection and then randomized into 2 groups after a definite histopathological diagnosis of Ta/T1 bladder cancer. One group of 77 patients received 19 intravesical instillations of epirubicin in the year after transurethral resection (group 1). The second group of 73 patients received 9 intravesical instillations of epirubicin during the 3 months after transurethral resection (group 2). Nonrecurrence rates and toxicity were compared. RESULTS: In the followup period, 10 group 1 patients (13.0%) and 23 group 2 patients (31.5%) had recurrent disease. The 3-year nonrecurrence rate was 85.2% in group 1, whereas it was 63.9% in group 2. The nonrecurrence rate of group 1 was significantly higher than that of group 2 throughout the observation period (p = 0.005). The incidence and severity of toxicity were not significantly different between the 2 groups. CONCLUSIONS: Our study indicates that long-term instillation of epirubicin is more effective than short-term instillation in preventing recurrence after transurethral resection of Ta/T1 bladder cancer.     

Hepatic metastases: diffusion-weighted sensitivity-encoding versus SPIO-enhanced MR imaging

PURPOSE: To retrospectively compare accuracy of diffusion-weighted (DW) single-shot echo-planar imaging with sensitivity encoding (SENSE) with that of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging in the evaluation of hepatic metastases due to extrahepatic malignancies. MATERIALS AND METHODS: Patients provided informed consent; ethics committee approval was not required. The data of 24 patients (16 men, eight women; age range, 41-68 years; mean age, 61.9 years) with 40 resected hepatic metastases were retrospectively reviewed. Before SPIO administration, DW SENSE imaging and T2-weighted fast spin-echo (SE) and T1-weighted dual-echo fast field-echo (FFE) MR imaging were performed. After SPIO administration, T2-weighted fast SE, T1-weighted dual-echo, and T2*-weighted FFE MR examinations were performed. Images were divided into two sets: The SPIO-enhanced MR image set consisted of pre- and postcontrast T2-weighted fast SE and dual-echo T1-weighted FFE images and postcontrast T2*-weighted FFE images. The DW SENSE image set included DW SENSE images and precontrast T2-weighted fast SE and dual-echo T1-weighted FFE images. Three radiologists individually interpreted these images and sorted the confidence levels for presence of hepatic metastasis in each section into five grades. Area under the receiver operating characteristic (ROC) curve (A(z)) was calculated for each image set. RESULTS: Hepatic metastases showed higher signal intensity on DW SENSE images than on T2-weighted fast SE images. Conversely, signals from vessels and cysts were suppressed with DW SENSE imaging. ROC analysis showed higher A(z) values when the DW SENSE image set was interpreted (0.90) than when the SPIO-enhanced MR image set was interpreted (0.81). The sensitivity and specificity, respectively, of total cases were 0.66 and 0.90, for the SPIO-enhanced MR image set and 0.82 and 0.94 for the DW SENSE image set. During SPIO-enhanced MR image interpretation, lesions 1 cm in diameter or smaller showed significantly lower sensitivity than lesions larger than 1 cm in diameter. During both interpretation sessions, left lobe lesions showed significantly lower sensitivity than right lobe lesions. CONCLUSION: Combined reading of DW SENSE images and T2-weighted fast SE and dual-echo T1-weighted FFE MR images showed higher accuracy in the detection of hepatic metastases than did reading of SPIO-enhanced MR images.     

Automatic synthesis of 16 alpha-[(18)F]fluoro-17beta-estradiol using a cassette-type [(18)F]fluorodeoxyglucose synthesizer

16 alpha-[(18)F]fluoro-17beta-estradiol ([(18)F]FES) is a radiotracer for imaging estrogen receptors by positron emission tomography. We developed a clinically applicable automatic preparation system for [(18)F]FES by modifying a cassette-type [(18)F]fluorodeoxyglucose synthesizer. Two milligrams of 3-O-methoxymethyl-16,17-O-sulfuryl-16-epiestriol in acetonitrile was heated at 105 degrees C for 10 min with dried [(18)F]fluoride. The resultant solution was evaporated and hydrolyzed with 0.2 N HCl in 90% acetonitrile/water at 95 degrees C for 10 min under pressurized condition. The neutralization was carried out with 2.8% NaHCO(3), and then the high-performance liquid chromatography (HPLC) purification was performed. The desired radioactive fraction was collected and the solvent was replaced by 10 ml of saline, and then passed through a 0.22-microm filter into a pyrogen-free vial as the final product. The HPLC purification data demonstrated that [(18)F]FES was synthesized with a yield of 76.4+/-1.9% (n=5). The yield as the final product for clinical use was 42.4+/-3.2% (n=5, decay corrected). The total preparation time was 88.2+/-6.4 min, including the HPLC purification and the solvent replacement process. The radiochemical purity of the final product was >99%, and the specific activity was more than 111 GBq/micromol. The final product was stable for more than 6 h in saline containing sodium ascorbate. This new preparation system enables us to produce [(18)F]FES safe for clinical use with high and reproducible yield.     

Development of a 111In-labeled peptide derivative targeting a chemokine receptor, CXCR4, for imaging tumors

The chemokine receptor CXCR4 is highly expressed in tumor cells and plays an important role in tumor metastasis. The aim of this study was to develop a radiopharmaceutical for the imaging of CXCR4-expressing tumors in vivo. Based on structure-activity relationships, we designed a 14-residue peptidic CXCR4 inhibitor, Ac-TZ14011, as a precursor for radiolabeled peptides. For 111In-labeling, diethylenetriaminepentaacetic acid (DTPA) was attached to the side chain of d-Lys(8) which is distant from the residues indispensable for the antagonistic activity. In-DTPA-Ac-TZ14011 inhibited the binding of a natural ligand, stromal cell-derived factor-1alpha, to CXCR4 in a concentration-dependent manner with an IC50 of 7.9 nM (Ac-TZ14011: 1.2 nM). In biodistribution experiments, more 111In-DTPA-Ac-TZ14011 accumulated in the CXCR4-expressing tumor than in blood or muscle. Furthermore, the tumor-to-blood and tumor-to-muscle ratios were significantly reduced by coinjection of Ac-TZ14011, indicating a CXCR4-mediated accumulation in tumor. These findings suggested that 111In-DTPA-Ac-TZ14011 would be a potential agent for the imaging of CXCR4 expression in metastatic tumors in vivo.     

Volumetric coronary angiography using the 256-detector row computed tomography scanner: comparison in vivo and in vitro with porcine models

Purpose: To investigate the feasibility of volumetric cine imaging in human cardiac studies by comparing in vivo and in vitro coronary angiography using a 256-detector row computed tomography (CT) without ECG gating.

Material and Methods: The left and right coronary arteries of two domestic pigs were scanned in vivo and in vitro in cine mode using the 256-detector row CT. The device scanned approximately 100 mm in the cranio-caudal direction with one rotation, with a slice thickness of 0.5 mm.

Results: The coronary arteries could be observed to the third-degree branches in vitro, but could be visualized clearly only to the proximal portion (first-degree or second-degree branches) in vivo.

Conclusion: Application of cardiac volumetric cine imaging with 256-detector row CT may be a promising means of obtaining diagnostic information and has potential for adoption to human studies.     

Mutidetector-row CT and quantitative gated SPECT for the assessment of left ventricular function in small hearts: the cardiac physical phantom study using a combined SPECT/CT system

The aim of this study was to compare results of left ventricular (LV) function obtained by quantitative gated single-photon emission tomography (QGS) and multidetector-row spiral computed tomography (MDCT) with reference parameters using an electrocardiogram-gated cardiac physical phantom. The phantom study was performed using a combined SPECT/CT system. Flexible membranes formed the inner and outer walls of the simulated LV. The stroke volume was adjusted (45 mL or 58 mL) and the fixed 42-mL end-systolic volume (ESV) produced two different volume combinations. The LV function parameters were estimated by means of MDCT and QGS. Differences in true and measured volumes were compared among CT with a reconstructed image thickness of 2.5 mm and 5.0 mm and QGS volumetric values. Each scan was repeated three-times. The estimation of LV volumes using both QGS and MDCT analyses were reproducible very well. QGS overestimated ejection fraction (EF) by approximately 20%; MDCT volumetry overestimated EF by approximately 5% in each volume setting. The differences in true and measured values for EF and ESV obtained with QGS were significantly greater than obtained with MDCT. Conclusion: MDCT provides a reliable estimation of functional LV parameters, whereas QGS tends to significantly overestimate the EF in small hearts.     

Preliminary study of correction of original metal artifacts due to 1-125 seeds in postimplant dosimetry for prostate permanent implant brachytherapy

Purpose We investigated a subtraction-based reprojection approach to reduce CT metal artifacts due to I-125 seeds and evaluated the clinical implications in postimplant dosimetry for prostate permanent implant brachytherapy. Materials and Methods The raw projection data were used to reduce metal artifacts due to I-125 seeds. CT images of the metal parts only were separated from the original CT images by setting the threshold for pixel value to that of the I-125 seeds. Using these images, sinograms of CT images with and without seeds were obtained by inverse Radon transform (iRT), and the sinogram of the metal image was subtracted from that of the original image. Finally, the image was reconstructed using the sinogram by Radon transform (RT). This technique was applied to a prostate phantom and to a patient undergoing prostate permanent implant brachytherapy. Results Metal artifacts from I-125 seeds were reduced in both the phantom and patient studies. This technique decreased the density of the inner region of seeds but enhanced the density of the seed edge, thereby facilitating the identification of seed number, orientation, and location. Conclusion This method reduces metal artifacts from I-125 seeds, and has potential for decreasing the time required for and improving the accuracy of postimplant dosimetry. This study was partly supported by a Grant-in-Aid for Scientific Research (Grant No. 177908826807) of the Japan Society for the Promotion of Science (JSPS).     

EPI image reconstruction with correction of distortion and signal losses

PURPOSE: To derive and implement a method for correcting geometric distortions and recovering magnetic resonance imaging (MRI) signal losses caused by susceptibility-induced magnetic field gradients (SFGs) in regions with large static field inhomogeneities in echo-planar imaging (EPI). MATERIALS AND METHODS: Factors to account for field inhomogeneities and SFGs were added in a traditional EPI equation that was a simple Fourier transform (FT) for expressing the actual k-space data of an EPI scan. The inverse calculation of this "distorted EPI" equation was used as a kernel to correct geometric distortions and reductions in intensity during reconstruction. A step-by-step EPI reconstruction method was developed to prevent complicated phase unwrapping problems. Some EPI images of phantom and human brains were reconstructed from standard EPI k-spaces. RESULTS: All images were reconstructed using the proposed multistep method. Geometric distortions were corrected and SFG-induced MRI signal losses were recovered. CONCLUSION: Results suggest that applying our method for reconstructing EPI images to reduce distortions and MRI signal losses is feasible.