Unusual perfusion patterns on perfusion-only SPECT/CT scans in COVID-19 patients.

PURPOSE: We aimed at examining both the incidence and extent of different lung perfusion abnormalities as well as the relationship between them on Tc-99m macroaggregated albumin (MAA) perfusion-only SPECT/CT scans in COVID-19 patients. METHODS: Ninety-one patients (71.4 ± 13.9 years; range: 29-98 years, median age: 74 years; 45 female and 46 male) with confirmed SARS-CoV-2 virus infection were included in this retrospective study. After performing perfusion-only Tc-99m MAA SPECT/CT scans, visual, semi-quantitative assessment of the subsequent perfusion abnormalities was carried out: mismatch lesions (MM; activity defects on SPECT images identical to apparently healthy parenchyma on CT images), matched lesions (MA; activity defects with corresponding parenchymal lesions on CT scans), and reverse mismatch lesions (RM; parenchymal lesions with preserved or increased tracer uptake). Lesion-based and patient-based analysis were performed to evaluate the extent, severity, and incidence of each perfusion abnormality. Statistical tests were applied to investigate the association between the experienced perfusion impairments. RESULTS: Moderately severe parenchymal lesions were detected in 87 (95.6%) patients. Although, 50 (54.95%) patients were depicted to have MM lesions, the whole patient cohort was mildly affected by this abnormality. MA lesions of average moderate severity were seen in most of the patients (89.01%). In 65 (71.43%) patients RM lesions were found with mild severity on average. Positive association was detected between total CT score and total RM score and between total CT score and total MA score. Significantly higher total CT scores were experienced in the subgroup, where RM lesions were present. CONCLUSIONS: Heterogeneous perfusion abnormalities were found in most of COVID-19 patients: parenchymal lesions with normal, decreased or increased perfusion and perfusion defects in healthy lung areas. These phenomena may be explained by the failure of the hypoxic pulmonary vasoconstriction mechanism and presence of pulmonary thrombosis and embolism.

Hystero-salpingo scintigraphy for fallopian tubal patency assessment: results from a prospective study.

OBJECTIVE: To evaluate the diagnostic accuracy of a bygone method, hystero-salpingo-scintigraphy (HSSG), for tubal patency assessment of infertile women. MATERIAL AND METHODS: Prospective cohort study involving women in the infertility workup at the University of Debrecen, Hungary. Seventy infertile patients were scheduled to either basic dynamic HSSG, post-purge dynamic HSSG, or post-purge dynamic HSSG followed by SPECT/CT for reducing tracer contamination. The primary endpoint was the evaluation of the diagnostic accuracy of HSSG for the three methods. RESULTS: During the basic dynamic group, the examination yielded a sensitivity of 87.5%, with a specificity of 71.7%, while positive and negative predictive values were 31.8%, and 97.4% respectively. Using post purge dynamic HSSG, it resulted in a sensitivity of 87.5%, a specificity of 88.7%, a positive predictive value of 53.8%, and a negative predictive value of 97.9%. Adding SPECT/CT to post-purge dynamic HSSG increased diagnostic accuracy with 100% sensitivity and 88.7% specificity, while positive and negative predictive values were 57.1% and 100%, respectively. CONCLUSION: HSSG is a non-invasive and well-tolerated technique for tubal patency. It could be used initially to predict tubal patency in case of infertility. Its diagnostic accuracy is higher when it is carried out by adding SPECT/CT to the post-purge dynamic method.

[Hybrid imaging: clinical evidence, opportunities]. / Hibrid képalkotás: klinikai evidenciák, lehetoségek.

Nowadays the hybrid imaging technologies which combine the modern equipments of radiology and nuclear medicine play an important role in both the translational research process and clinical diagnostics. Among the routine diagnostic imaging procedures positron emission tomography and single photon emission computed tomography combined with computed tomography or magnetic resonance imaging currently belong to the most advanced techniques allowing that functional and morphological images can be superimposed on each other in the same position. The hybrid imaging equipments provide useful information about the pathological processes in the body due to their high sensibility and resolution. Furthermore, with the help of these imaging modalities we can get acquainted with the biochemical and pathobiochemical processes that are essential for understanding and treating diseases, or getting acquainted with the behaviour of a new drug candidate. With the help of the clinical and preclinical non-invasive in vivo molecular imaging systems the drug developing process can be shortened and its costs can be reduced.