Ventilation/perfusion SPECT/CT in patients with pulmonary emphysema. Evaluation of software-based analysing

The purpose of this study was to evaluate the reproducibility of a new software based analysing system for ventilation/perfusion single-photon emission computed tomography/computed tomography (V/P SPECT/CT) in patients with pulmonary emphysema and to compare it to the visual interpretation.

PATIENTS, MATERIAL AND METHODS

19 patients (mean age: 68.1 years) with pulmonary emphysema who underwent V/P SPECT/CT were included. Data were analysed by two independent observers in visual interpretation (VI) and by software based analysis system (SBAS). SBAS PMOD version 3.4 (Technologies Ltd, Zurich, Switzerland) was used to assess counts and volume per lung lobe/per lung and to calculate the count density per lung, lobe ratio of counts and ratio of count density. VI was performed using a visual scale to assess the mean counts per lung lobe. Interobserver variability and association for SBAS and VI were analysed using Spearman's rho correlation coefficient.

RESULTS

Interobserver agreement correlated highly in perfusion (rho: 0.982, 0.957, 0.90, 0.979) and ventilation (rho: 0.972, 0.924, 0.941, 0.936) for count/count density per lobe and ratio of counts/count density in SBAS. Interobserver agreement correlated clearly for perfusion (rho: 0.655) and weakly for ventilation (rho: 0.458) in VI.

CONCLUSIONS

SBAS provides more reproducible measures than VI for the relative tracer uptake in V/P SPECT/CTs in patients with pulmonary emphysema. However, SBAS has to be improved for routine clinical use.

Detection of pancreatic neuroendocrine tumors (PNET) using semi-quantitative [68Ga]DOTATOC PET in combination with multiphase contrast-enhanced CT

Aim: Pancreatic neuroendocrine tumors (PNETs) pose a diagnostic challenge with respect to the physiologic somatostatin receptor expression in the uncinate process representing a potential pitfall for receptor imaging with PET/CT. Methods: We identified 49 PNETs from a total of 316 consecutive [68Ga]DOTATOC PET/CT examinations for whom the detections rates of PET and multiphase contrast enhanced (CE-) CT could be retrospectively compared and 38 PNETs for which SUV max and SUV max target-to-liver ratios could be calculated for the tumors and the uncinate process. Results: The detection rate of PET (83.7%) was higher than of the different CT phases (arterial: 59.2%, P=0.017; portal-venous: 38.8%, P<0.001; venous: 46.9%, P=0.001; multiphase: 71.4%, P=0.286). Compared to the other method PET revealed 28.6% additional lesions and multiphase CE-CT 16.3%. The portal-venous phase revealed only lesions that were also detected in the arterial or venous phase. The detection rate for PNETs in the uncinate process (N.=9) was 66.7% for PET versus 55.6% for multiphase CE-CT. SUV max and SUV max target-to-liver ratios differed significantly (P<0.001) for PNETs (mean, range: SUV max,14.6, 1.4-69.3; SUV max target-to-liver ratio, 3.2, 0.69-23.1) and uncinate process (4.32, 0.8-13.5; 0.94, 0.51-1.56), however with a wide overlap. Conclusion: Patients with PNETs should undergo [68Ga]DOTATOC PET/CT with at least an arterial and venous phase CT scan. SUV max and SUV max target-to-liver ratios provide additional information but do no reliably separate PNETs from normal tracer uptake in the uncinate process.

Technical eligibility for treatment of magnetic resonance-guided focused ultrasound surgery

PURPOSE

This study was designed to evaluate the technical eligibility for magnetic resonance-guided focused ultrasound surgery (MRgFUS) treatment of women with symptomatic fibroids.

METHODS

Technical eligibility for MRgFUS treatment without mitigation techniques was evaluated retrospectively in 783 premenopausal women (median age, 44.2 years) with symptomatic fibroids who applied for uterine artery embolization (UAE) at our institution from 2001 to 2012. Technical eligibility for MRgFUS was defined as primary study endpoint. Technical ineligibility was assessed on the basis of MRI criteria, such as bowel interposition/foreign material in the ultrasound beam path, more than five fibroids, distance from fibroid to sacral bone surface, fibroid size/shape, severe concomitant adenomyosis or extensive cutaneous scars in accordance to the US Food and Drug Administration approvals. Secondary study endpoint was defined as evaluation of the most frequent exclusion criteria and differences in technical eligibility for MRgFUS and UAE.

RESULTS

On the basis of MRI, 38.9% of women who applied for UAE were found to be technically eligible for MRgFUS treatment without mitigation techniques. Most frequent reason for ineligibility was bowel interposition in the ultrasound beam path (60.4%). Differences in technical eligibility for MRgFUS (38.9%) and UAE (99.2%) were significant (P < 0.001).

CONCLUSIONS

MRgFUS treatment is technically possible in up to 40% of women with symptomatic fibroids. The most frequent exclusion criterion is the presence of bowel in the ultrasound beam path.

Optical imaging of breast cancer using hemodynamic changes induced by valsalva maneuver

PURPOSE

To investigate whether changes in hemodynamics induced by Valsalva maneuver can be exploited for detecting and characterizing breast lesions by optical mammography.

MATERIALS AND METHODS

30 women underwent optical imaging of the breast using a DYNOT 232 system and performing Valsalva maneuvers prior to biopsy. Changes in light absorption due to changes in oxyhemoglobin and deoxyhemoglobin concentrations were recorded volumetrically and in a time-resolved manner. The parameters full width at half maximum (FWHM), time to ten (TTT), and peak amplitude (PA) of the reconstructed concentration time curves yielded color-coded maps of the breast which were separately evaluated by two experienced readers for detection rate, degree of visibility, and detection of additional lesions. ROC analysis was performed with the evaluation results.

RESULTS

10 patients were excluded from analysis due to artifacts or inadequately performed Valsalva maneuver. The resulting 20 patients showed a clear increase in oxygenated and deoxygenated hemoglobin concentration after the onset of the Valsalva maneuver. ROC analysis yielded AUC values (0.393 - 0.779) that did not differ from random probabilities. The highest AUC values were obtained for FWHM (AUC: 0.779, detection rates [60 - 70 %], identification of additional lesions [55 - 70 %]). PA analysis had the highest detection rate (70 - 90 %) but also the highest identification of false-positive additional lesions (80 - 90 %). The concordance rates of the two readers for malignant lesions were satisfactory (0.524 - 1.0).

CONCLUSION

Our study revealed susceptibility to artifacts and a large number of false-positive additional lesions, suggesting that the evaluation of hemodynamic changes after Valsalva maneuver by optical imaging is not a promising method.

[Change in health-related quality of life and change in clinical symptoms after uterine artery embolization in patients with symptomatic adenomyosis uteri - evaluation using a standardized questionnaire]

AIM

To evaluate the clinical response of uterine artery embolization (UAE) in women with symptomatic uterine adenomyosis by comparing health-related quality of life and symptom severity before and after UAE using a standardized questionnaire.

MATERIAL AND METHODS

This longitudinal study at two time points included 17 patients with a median age of 47.1 years with symptomatic uterine adenomyosis (n = 7 pure adenomyosis; n = 10 with concomitant fibroids). The diagnosis was based on clinical symptoms and magnetic resonance imaging (MRI) criteria. Data on health-related quality of life and severity of symptoms before and after UAE were obtained by the standardized "Uterine Fibroid Symptom and Quality of Life" (UFS-QOL) questionnaire and correlated in the following. Treatment failure was defined as the need for a second invasive procedure because of recurrent symptoms or persistent symptoms after UAE.

RESULTS

The median interval between the evaluation of the UFS-QOL questionnaire before and after UAE was 46.0 months. 70.6 % (12/17; 95 % confidence interval 44.0 %  - 88.6 %) of the patients had therapy response with a significant improvement of health-related quality of life and clinical symptoms (p-value = 0.002). The therapy failure rate was 29.4 % (5/17; 95 % confidence interval 11.4 %  - 56.0 %). One patient underwent dilatation and curettage and four patients underwent hysterectomy because of therapy failure.

CONCLUSION

UAE to treat symptomatic adenomyosis uteri can significantly improve the health-related quality of life and clinical symptoms. However, therapy failure is possible in up to one-third of patients.

[Targeted methods for measuring patient satisfaction in a radiological center]

PURPOSE

To investigate two event-oriented methods for evaluating patient satisfaction with radiological services like outpatient computed tomography (CT) examinations.

MATERIALS AND METHODS

159 patients (55% men, 45% women) were asked to complete a questionnaire to provide information about their satisfaction with their examination. At first, patients were asked to spontaneously recall notably positive and negative aspects (so-called "critical incidents", critical incident technique = CIT) of the examination. Subsequently a flow chart containing all single steps of the examination procedure was shown to all patients. They were asked to point out the positive and negative aspects they perceived at each step (so-called sequential incident technique = SIT).

RESULTS

The CIT-based part of the questionnaire yielded 356 comments (183 positive and 173 negative), which were assigned to one of four categories: interaction of staff with patient, procedure and organization, CT examination, and overall setting of the examination. Significantly more detailed comments regarding individual aspects of the CT examination were elicited in the second part of the survey, which was based on the SIT. There were 1413 statements with a significantly higher number of positive comments (n = 939, 66%) versus negative comments (n = 474, 34%; p < 0.001).

CONCLUSION

The critical and sequential incident techniques are suitable to measure the subjective satisfaction with the delivery of radiological services such as CT examinations. Positive comments confirm the adequacy of the existing procedures, while negative comments provide direct information about how service quality can be improved.