Utilization of a Fluorescent Marker in a Simulated Biological Fluid Spill Drill Within a Position Emission Tomography Center.

The management of uncontained spillage of radioactive material in nuclear medicine healthcare facilities is documented in their standard operating procedures (SOPs). These are supplemented by periodic training drills for staff to practice the appropriate responses and decontamination techniques. We report on the use of Glo Germ (GloGerm Co., Moab, UT, USA), a commercially available abiotic powder that fluoresces under black light, as a visual aid in these spill simulations. Glo Germ was used in a spill drill scenario within the controlled area in the nuclear medicine department. This provided immediate visual feedback for the staff involved in the simulations as well as the supervision observers. We anticipate that the use of such aids during training will enhance confidence and proficiency in managing and decontaminating radiation spills. It will also serve to flag potential gaps in decontamination protocols and allow for the refinement of SOPs.

Prospective comparison between magnetic resonance imaging and computed tomography in colorectal cancer staging.

BACKGROUND: Diffusion-weighted (DW) imaging is a functional magnetic resonance imaging (MRI) technique that detects lesions with high cellularity, such as malignant tumours. This prospective study was performed to compare the accuracy of DW-MRI with multidetector computed tomography (MDCT) in staging of colorectal cancer. METHODS: Thirty patients with histologically proven colorectal cancer were prospectively recruited. Each patient underwent both MDCT and DW-MRI of the abdomen-pelvis for primary staging. Images were evaluated for nodal and distant metastases. The reference standard was histopathological findings for nodal involvement and surveillance imaging for suspected hepatic metastases. RESULTS: The primary cancers were located in the rectum (n = 16, 53.3%), sigmoid colon (n = 9, 30%) and right colon (n = 5, 16.6%). For nodal metastases, the sensitivity and specificity of DW-MRI were 84.6% (95% confidence interval (CI): 54.6-98.1%) and 20.0% (95% CI: 2.5-55.6%) compared with 84.6% (95% CI: 54.6-98.1%) and 40.0% (95% CI: 12.2-73.8%) for MDCT. For liver metastases, the sensitivity and specificity for DW-MRI were 100.0% (95% CI: 63.1-100.0%) and 100% (95% CI: 84.6-100%) compared with 87.5% (95% CI: 47.4-99.7%) and 95.5% (95% CI: 77.2-99.9%) for MDCT. DW imaging altered the clinical management in three (10.0%) patients by detecting missed hepatic metastases in two patients and accurately diagnosing another patient with a hepatic cyst, mistaken for metastasis on MDCT. CONCLUSION: DW-MRI is more accurate for detecting hepatic metastases in colorectal cancer compared with MDCT.

Magnetic resonance elastography of liver in healthy Asians: normal liver stiffness quantification and reproducibility assessment.

PURPOSE: To determine normal liver stiffness values evaluated with magnetic resonance elastography (MRE) in healthy normal Asian volunteers and assess its reproducibility. MATERIALS AND METHODS: Liver stiffness was evaluated with MRE in 41 healthy Asians (23 females, 18 males; mean age, 41.8 years, and mean body mass index [BMI], 23.4 kg/m(2) ) on a 1.5T clinical scanner. The correlations between mean liver stiffness and age, gender, BMI, and fat fraction percentage of the liver were studied. Another 12 volunteers underwent liver MRE exams on two separate days 4-6 weeks apart under similar conditions for reproducibility assessment. Intraclass correlation coefficient (ICC) analysis was performed and within-subject coefficient of variation (CV) of stiffness was estimated. RESULTS: The mean ± standard deviation (SD) of liver stiffness in normal healthy Asian subjects was 2.09 ± 0.22 kPa (95% confidence interval [CI], 2.04-2.15 kPa; range 1.68-2.48 kPa). The mean liver stiffness did not significantly correlate with age, gender, BMI, or fat content of the liver. The ICC for mean liver stiffness was 0.90 (95% CI, 0.78-0.96) and CV ranged from 2.2%-11.4%. CONCLUSION: The liver stiffness in normal Asians is not affected by age, gender, BMI, or fat content. Liver stiffness with MRE is highly reproducible.

Imaging paradigms in assessment of rectal carcinoma: loco-regional and distant staging.

The role of imaging in the management of rectal malignancy has progressively evolved and undergone several paradigm shifts. Unlike a few decades ago when the role of a radiologist was restricted at defining the longitudinal extent of the tumour with barium enema, recent advances in imaging techniques permit highly accurate locoregional and distant staging of the disease as well as prognostication on those who are likely to have a postoperative recurrence. Computed tomography (CT) has always been the mainstay of imaging when evaluating for distant metastasis, with the advent of positron emission tomography/CT improving its specificity. In rectal malignancy, it is the local extent of the disease that often influences the surgical decision making and need for neoadjuvant therapy. Although endoscopic ultrasound has been the traditional technique for determining the depth of tumour invasion, over the last decade magnetic resonance imaging (MRI) has emerged as a very effective tool for accurate T-staging. This review intends to address the status of various imaging modalities and their advantages and limitations in detection, pretreatment staging, and assessment of therapeutic efficacy in rectal cancer, with emphasis on MRI of high spatial resolution.