Roles of spectral dual-layer CT, D-dimer concentration, and COVID-19 pneumonia in diagnosis of pulmonary embolism.

Purpose: To demonstrate advantages of spectral dual-layer computed tomography (CT) in diagnosing pulmonary embolism (PE). To compare D-dimer values in patients with PE and concomitant COVID-19 pneumonia to those in patients without PE and COVID-19 pneumonia. To compare D-dimer values in cases of minor versus extensive PE. Methods: A monocentric retrospective study of 1500 CT pulmonary angiographies (CTPAs). Three groups of 500 consecutive examinations: 1) using conventional multidetector CT (CTC), 2) using spectral dual-layer CT (CTS), and 3) of COVID-19 pneumonia patients using spectral dual-layer CT (COV). Only patients with known D-dimer levels were enrolled in the study. Results: Prevalence of inconclusive PE findings differed significantly between CTS and CTC (0.8 % vs. 5.4 %, p < 0.001). In all groups, D-dimer levels were significantly higher in PE positive patients than in patients without PE (CTC, 8.04 vs. 3.05 mg/L; CTS, 6.92 vs. 2.57 mg/L; COV, 10.26 vs. 2.72 mg/L, p < 0.001). There were also statistically significant differences in D-dimer values between minor and extensive PE in the groups negative for COVID-19 (CTC, 5.16 vs. 8.98 mg/L; CTS 3.52 vs. 9.27 mg/L, p < 0.001). The lowest recorded D-dimer value for proven PE in patients with COVID-19 pneumonia was 1.19 mg/L. Conclusion: CTPAs using spectral dual-layer CT reduce the number of inconclusive PE findings. Plasma D-dimer concentration increases with extent of PE. Cut-off value of D-dimer with 100 % sensitivity for patients with COVID-19 pneumonia could be doubled to 1.0 mg/L. This threshold would have saved 110 (22 %) examinations in our cohort.

Infrared thermography as option for evaluating the treatment effect of percutaneous transluminal angioplasty by patients with peripheral arterial disease.

Aim of this study was to evaluate the possible use of infrared thermography as a supplementary method to the ankle-brachial index used in assessing the treatment effect of percutaneous transluminal angioplasty. The study included 21 patients, mean age was 60.22 years. Healthy control group included 20 persons, mean age was 55.60 years. Patients with symptomatic peripheral arterial disease (Fontaine stages I-III) were admitted for endovascular treatment by percutaneous transluminal angioplasty. Thermal images and ankle-brachial index values were obtained before and after treatment by percutaneous transluminal angioplasty. Median temperature change in the treated limb was 0.4℃, for non-treated limb was -0.5℃. The median value of ankle-brachial index in the treated limb increased by 0.17 from 0.81 after the procedure. The median value of ankle-brachial index in the non-treated limb decreased by 0.03 from the value of 1.01. Significant difference between treated limb and non-treated limb in change of ankle-brachial index was found with p value = .0035. The surface temperature obtained by the infrared thermography correlates with ankle-brachial index. We present data showing that the increase of ankle-brachial index is associated with increase of skin temperature in the case of limbs treated by percutaneous transluminal angioplasty. Our results also suggest potential of the use of infrared thermography for monitoring foot temperature as a means of early detection of onset of foot ischemic disorders.

Using Noncontact Infrared Thermography for Long-term Monitoring of Foot Temperatures in a Patient with Diabetes Mellitus.

Foot complications in persons with diabetes mellitus (DM) are associated with substantial costs and loss of quality of life. Increasing evidence suggests changes in skin temperature, measured using an infrared thermographic system (IRT), may be a predictor of foot ulcer development in patients with DM. The purpose of this case study is to describe the long-term IRT findings and overall clinical outcomes of a patient with DM and peripheral vascular disease. Foot temperature measurements using IRT were obtained slightly more than 1 year before and immediately following endovascular treatment of a 76-year-old man, a nonsmoker with type 2 DM, hypertension, and ischemic heart disease with cardiac arrhythmia. Although he was otherwise asymptomatic, the infrared measurement showed an average temperature difference of 2.3˚ C between the left and right foot until he developed a small, trauma-induced wound on the left foot, at which time left foot temperature increased. He was diagnosed with rectosigmoid adenocarcinoma, underwent surgery and chemotherapy, and subsequently was evaluated for peripheral vascular disease. Before undergoing peripheral angiography and percutaneous transluminal angioplasty, IRT evaluation showed a hot spot on the left heel. Immediately following endovascular treatment, the mean temperature difference between the right and left foot was low (0.2˚ C), but a Stage I pressure ulcer was visible on the left heel. Skin breakdown in that area was observed 2 months later, and the wound continued to increase in size and depth. The patient died shortly thereafter due to complications of cancer. In this case study, a series of infrared images of foot skin temperatures appeared to show a relationship with blood circulation and wound/ulcer development and presentation. IRT has the ability to instantaneously measure the absolute temperature of the skin surface over a large area without direct skin contact. However, the devices are very sensitive and prospective clinical studies to determine the validity, reliability, sensitivity, and specificity of these measurements for routine use in patients who are at risk for vascular disease and/or foot ulcers are needed.