The usefulness of SPECT/CT in characterization of skeletal and soft tissue lesions — report of two cases

SPECT/CT imaging provides detailed information on the radiotracer distribution and enables simultaneous lesion morphology evaluation. This hybrid imaging delivers complementary information about patient’s disease. We present two cases in which SPECT/CT imaging and cooperation between the nuclear medicine physician and radiologist quickly clarified the diagnosis, sparing patient unnecessary diagnostic procedures or treatment

Patterns of vascular graft infection in 18F-FDG PET/CT

BACKGROUND: 18F-FDG PET/CT has become an important tool in diagnosis of prosthetic vascular graft infections (PVGI). The aim of the study was to identify the patterns of vascular graft infection in 18F-FDG PET/CT. MATERIAL AND METHODS: The study was performed in 24 patients with vascular graft infection, in 17 patients implanted in an open surgery mode and in 7 patients by endovascular aortic repair (EVAR). Vascular prostheses were evaluated by two visual scales and semi-quantitative analysis with maximum standardized uptake values (SUV max). RESULTS: In the 3-point scale: 23 patients were in grade 1 and one patient was in grade 2. In the 5-point scale: 19 patients were in grade 5 with the highest activity in the focal area, 4 patients were in grade 4 and one patient in grade 3. The visual evaluation of 18F-FDG PET/CT study revealed that peri-graft high metabolic activity was associated with occurrence of morphological abnormalities (n = 21) like gas bubbles and peri-graft fluid retention or without abnormal CT findings (n = 3). The presence of the gas bubbles was linked to higher uptake of 18F-FDG (p < 0.01, SUVmax 11.81 ± 4.35 vs 7.36 ± 2.80, 15 vs 9 pts). In EVAR procedure, the highest metabolic activity was greater than in classical prosthesis (SUVmax 21.5 vs 13). CONCLUSIONS: 18F-FDG PET/CT is a very useful tool for assessment of vascular graft infections. CT findings like gas bubbles, or peri-graft fluid retention were associated with significantly higher glucose metabolism; however, in some cases without anatomic alterations, increased metabolic activity was the only sign of infection

Subclinical hyperthyroidism in the course of autonomous nodules — clinical evaluation

Introduction: Subclinical hyperthyroidism (SCH), also known as mildly symptomatic hyperthyroidism, has recently been diagnosed more frequently. One of the main endogenous causes of this disorder is autonomously functioning thyroid nodule (AFTN). Despite the fact that it is usually asymptomatic, SCH entails repercussions on the cardiovascular system and bone, and it carries a risk of progression to overt hyperthyroidism with a typical clinical picture. Treatment is still controversial, and its benefits are widely debated in literature. Material and methods: From 459 patients authors selected a group of 49 patients (10.6% of all subjects with hyperthyroidism), 41 women (83.7%) with AFTN at the stage SCH treated in the Outpatient Endocrinological Clinic and the Department of Endocrinology of the Medical University of Lublin over a three-year period. The method applied in the study was a retrospective analysis of medical records with a particular account of medical history, physical examination, and additional tests obtained during the process of diagnostic and therapeutic procedures. Results: Forty-one patients (83.7%) suffered from typical symptoms of hyperthyroidism; only eight patients (16.3%) were asymptomatic. The most frequently reported symptoms were tachycardia in women (51.2%) and anxiety in men (50%). The type of thyrostatic drugs and the length of therapy did not affect the outcome of iodine-131 therapy. In the vast majority of the patients (87.8%) radioidodine therapy was effective; 30 patients (61.2%) reached euthyreosis and 13 patients (22.5%) developed hypothyroidism. Conclusions: Most patients with SCH in the course of AFTN suffered from typical symptoms of overt hyperthyroidism; only every sixth patient was asymptomatic. The volume of autonomous adenomas did not affect the result of 131I therapy; however, the impact of AFTN volume as well as the thyroid volume on RIT efficacy requires futher investigation. In the vast majority of patients 131I therapy was an effective method of treatment, and an earlier therapeutic effect was observed more often in the patients with focal lesions located in theright lobe.

Cardiac sympathetic dysfunction in haemodialysed patients

BACKGROUND: The aim of this study was to evaluate thecardiac sympathetic nervous system function in haemodialysed(HD), non-diabetic patients by iodine-123 meta-iodo-benzylguanidine(123I-mIBG).MATERIALS AND METHODS: Planar scintigraphy of the chestwas performed in 36 HD, male patients; 15 minutes and 4 hourspost injection of 370 MBq of 123I-mIBG. The semiquantitativeanalysis of myocardial tracer uptake was expressed as routineheart to mediastinum (H/M) ratio: 15 minutes (early H/M) and4 hour (late H/M) post administration as well as washout of thetracer from myocardium (WR). 24-hour Holter studies were recordedand heart rate variability (HRV) was evaluated. Patientswere divided into two groups according to the H/M value: groupA patients with H/M > 1.8 which has been accepted as a norm,and group B patients with H/M < 1.8.RESULTS: In 21/36 patients H/M ratio was below normal values.Significant differences between groups A and B were foundamong the following parameters: early H/M and late H/M ratios,WR and duration of haemodialysis therapy.CONCLUSIONS: In patients with abnormal function of cardiacsympathetic nervous system, expressed by means of H/M ratiobelow 1.8, duration of haemodialysis treatment was longer.Duration of HD appears to be an important factor influencingcardiac sympathetic nervous system.

CUDA accelerated Medical Segmentation metrics with MedEval3D

Medical segmentation metrics are crucial for development of correct segmentation algorithms in medical imaging domain. In case of three dimensional large arrays representing studies like CT, PET/CT or MRI of critical importance is availability of library implementing high performance metrics. MedEval3D is created in order to fulfill this need thanks to implementation of CUDA acceleration. Most of implemented metrics like Dice coefficient, Jacard coefficient etc. are based on confusion matrix, what enable effective reuse of calculations across multiple metrics improving performance in such use case. Additionally algorithms like interclass correlation and Mahalanobis distance are also introduced. In both cases their implementations are significantly faster then their counterparts from other available libraries. Lastly programming interface to all of the metrics was created in Julia programming language

Autonomic imaging:The cardiorenal axis

In this chapter, we discuss the pathophysiology of the various chronic cardiorenal interactions and their consequences on the sympathetic nervous system (SNS). Increased activity of SNS is observed in all stages of chronic renal disease. The chronic elevation of SNS activity is a major contributor of the complex pathophysiology of hypertension, heart failure, insulin resistance, sleep disorders, diuretic resistance, and progressive kidney disease. Overactivity of SNS contributes to the high incidence of cardiovascular events and cardiac mortality, especially in patients with end-stage renal failure. The dysfunction of sympathetic innervation can be visualized directly by use of [123 I]-metaiodobenzylguanidine ([123 I]-MIBG) scintigraphy.</p