Michael Czachowski

Quantitative imaging of airway liquid absorption in cystic fibrosis

New measures are needed to rapidly assess emerging treatments for cystic fibrosis (CF) lung disease. Using an imaging approach, we evaluated the absorptive clearance of the radiolabeled small molecule probe diethylene triamine penta-acetic acid (DTPA) as an in vivo indicator of changes in airway liquid absorption. DTPA absorption and mucociliary clearance rates were measured in 21 patients with CF (12 adults and nine children) and nine adult controls using nuclear imaging. The effect of hypertonic saline on DTPA absorption was also studied. In addition, in vitro studies were conducted to identify the determinants of transepithelial DTPA absorption. CF patients had significantly increased rates of DTPA absorption compared with control subjects but had similar mucociliary clearance rates. Treatment with hypertonic saline resulted in a decrease in DTPA absorption and an increase in mucociliary clearance in 11 out of 11 adult CF patients compared with treatment with isotonic saline. In vitro studies revealed that ∼50% of DTPA absorption can be attributed to transepithelial fluid transport. Apically applied mucus impedes liquid and DTPA absorption. However, mucus effects become negligible in the presence of an osmotic stimulus. Functional imaging of DTPA absorption provides a quantifiable marker of immediate response to treatments that promote airway surface liquid hydration. Functional imaging detects liquid absorption and mucociliary clearance in cystic fibrosis airways http://ow.ly/uPuX2

Pseudomonas infection and mucociliary and absorptive clearance in the cystic fibrosis lung.

Airway surface liquid hyperabsorption and mucus accumulation are key elements of cystic fibrosis lung disease that can be assessed in vivo using functional imaging methods. In this study we evaluated experimental factors affecting measurements of mucociliary clearance (MCC) and small-molecule absorption (ABS) and patient factors associated with abnormal absorption and mucus clearance. Our imaging technique utilises two radiopharmaceutical probes delivered by inhalation. Measurement repeatability was assessed in 10 adult cystic fibrosis subjects. Experimental factors were assessed in 29 adult and paediatric cystic fibrosis subjects (51 scans). Patient factors were assessed in a subgroup with optimal aerosol deposition (37 scans; 24 subjects). Paediatric subjects (n=9) underwent initial and 2-year follow-up scans. Control subjects from a previously reported study are included for comparison. High rates of central aerosol deposition influenced measurements of ABS and, to a lesser extent, MCC. Depressed MCC in cystic fibrosis was only detectable in subjects with previous Pseudomonas aeruginosa infection. Cystic fibrosis subjects without P. aeruginosa had similar MCC to control subjects. Cystic fibrosis subjects had consistently higher ABS rates. We conclude that the primary experimental factor affecting MCC/ABS measurements is central deposition percentage. Depressed MCC in cystic fibrosis is associated with P. aeruginosa infection. ABS is consistently increased in cystic fibrosis. Depressed mucus clearance in cystic fibrosis was only detectable in subjects with Pseudomonas aeruginosa infection http://ow.ly/YggZy

Use of intraoperative nuclear imaging leads to decreased anesthesia time and real-time confirmation of lesion removal

BACKGROUND Lymphatic mapping to guide sentinel lymph node biopsy (SLNB) typically requires lymphoscintigraphy prior to surgery. In young pediatric patients, this process often requires intubation in the nuclear medicine suite followed by transport to the operating room (OR). METHODS We reviewed 14 pediatric cases in which a portable nuclear imaging camera was utilized to perform the entirety of the SLNB in the OR. RESULTS AND CONCLUSION This method, utilizing intraoperative nuclear imaging, helped to confirm removal of the sentinel lymph node in real time, decreased anesthesia time, and avoided transport of a sedated or intubated child. LEVEL OF EVIDENCE III.

Remote-controlled automatic injection versus manual injection in ictal SPECT of seizure patients: experience from a children's hospital.

Some patients with epilepsy not controlled by medication will benefit from surgical removal of the seizure focus in the brain, if the seizure focus can be identified. The seizure focus has to be localized in one hemisphere only. This is referred to as refractory complex partial epilepsy. The problem is that identification of the seizure focus is not easily accomplished. One way to identify the seizure focus is by electrocorticography, which involves the placement of a grid of electrodes directly on the surface of the brain. This procedure is costly and invasive. Cerebral perfusion

Pediatric Brown Adipose Tissue on 18F-FDG PET: Diazepam Intervention

Brown adipose tissue (BAT) has been widely reported to affect the efficacy of 18F-FDG PET in oncology. Several small studies have found that warming the patient both before 18F-FDG injection and during the uptake phase can reduce the frequency of BAT uptake. Pharmaceutical approaches such as propranolol and diazepam have also been used. Methods: We describe two case studies that demonstrated the impact of combined patient warming and diazepam administration on BAT uptake in pediatric 18F-FDG PET images. To support these findings, we performed a retrospective analysis of 139 patients: 71 who received warming only and 68 who received warming combined with diazepam. Results: BAT uptake was significantly less frequent in patients who received diazepam (16.2%) than in those who did not (33.8%) (P = 0.0167), particularly in female patients (7.4% vs. 26.7%) (P = 0.0486). Conclusion: Although patient warming alone reduces the frequency of BAT uptake, the addition of diazepam to patient warming significantly furthers the reduction in young patients, particularly female patients.