Contrast enhanced ultrasound imaging can predict vascular-targeted photodynamic therapy induced tumor necrosis in small animals

AimsTo evaluate the accuracy of contrast-enhanced ultrasound (CEUS) for monitoring tumor necrosis following WST-11 vascular targeted photodynamic therapy (VTP) using imaging-pathology correlation.MethodsRenal adenocarcinoma cells were injected into the hindlimb of 13 BalB/c mice resulting in tumors ranging from 9.8 to 194.3 mm³. US guidance was used to place a laser fiber into the tumor, and VTP was performed. CEUS was performed prior to animal sacrifice, 24 h post-VTP. Whole tumors were extracted for histopathologic analysis using H&E and TUNEL staining. Pathology samples corresponding to the CEUS imaging plane were prepared in order to compare the size and extents of tumor necrosis.ResultsTumor necrosis following VTP appeared as a central region of non-enhancement on CEUS, while viable tumor appeared as patchy regions of enhancement in the tumor periphery. The region of tumor necrosis measured in mean 66% and 64.8% of total tumor area on CEUS and pathology respectively (p = 0.2). The size and location of the necrosis on CEUS images and pathology samples were found correlative with no inter-observer difference (weighted kappa of 0.771 and 0.823, respectively).ConclusionCEUS allows accurate monitoring of VTP induced tumor necrosis in a small animal model.     

Factors influencing incidental 18F-FDG uptake in the gallbladder in a large cohort of patients: A retrospective study

ObjectivesThis study aims to assess the incidence of incidental activity in the gallbladder and the factors that may contribute to it in a large cohort of patients undergoing ¹⁸F-fluorodeoxyglucose-PET/CT for cancer evaluation.Methods8096 PET/CTs were retrospectively reviewed. Data pertaining to patient demographics and PET/CT parameters were collected. Patients' records were reviewed for gallbladder disorders for up to 3 years after the exam. The presence/absence of gallbladder uptake was visually assessed. Findings were classified as focal, diffuse increased and diffuse increased wall uptake, or no uptake. Volumetric measurements of the gallbladder and SUVmax of the gallbladder, liver and blood pool were measured. Chi-square and Student's t-test were used for statistical analysis.Results54 cases (0.67%) of incidental gallbladder uptake were detected (uptake group). 162 exams without uptake were selected as control (no uptake group). The injection-to-scan interval, SUVmax of the liver and blood pool, and the gallbladder volume did not differ significantly between both groups. Higher blood glucose levels were observed in the uptake (109.9 ± 32.5) vs. no uptake group (97.4 ± 18) (p = 0.01), with levels >150 mg/dL more common in the uptake group (p = 0.004). The incidence of gallbladder disease within 3 years after imaging was higher for the uptake group (12/36) compared to the no uptake group (15/115) (p = 0.02). Diffuse increased wall uptake was more likely in the group who later developed a pathology (4/12) (p = 0.03).ConclusionIncidental gallbladder uptake in patients is independent of the injected FDG dose, injection-to-scan interval or gallbladder volume, but may be related to blood glucose level. There's a higher incidence of gallbladder pathology three years after the exam particularly in cases of diffuse increased wall uptake.     

Contrast enhanced ultrasound quantitative parameters for assessing neoadjuvant chemotherapy response in patients with locally advanced breast cancer

Objectives:To evaluate the role of contrast-enhanced ultrasound (CEUS) quantitative parameters in predicting neoadjuvant chemotherapy (NACT) response in patients with locally advanced breast cancer (LABC).Methods:30 patients with histologically proven LABC scheduled for NACT were recruited. CEUS was performed using a contrast bolus of 4.8 ml and time intensity curves (TICs) were obtained by contrast dynamics software. CEUS quantitative parameters assessed were peak enhancement (PE), time-to-peak (TTP), area under the curve (AUC) and mean transit time (MTT). The parameters were documented on four consecutive instances: before NACT and 3 weeks after each of the three cycles. The gold-standard was pathological response using Miller Payne Score obtained pre NACT and post-surgery.Results:A decrease in mean values of PE and an increase in mean values of TTP and MTT was observed with each cycle of NACT among responders. Post each cycle of NACT (compared with baseline pre-NACT), there was a statistically significant difference in % change of mean values of PE, TTP and MTT between good responders and poor responders (p-value < 0.05). The diagnostic accuracy of TTP post-third cycle was 87.2% (p = 0.03), and MTT post--second and third cycle was 76.7% (p = 0.004) and 86.7% (p = 0.006) respectively.Conclusion:In responders, a decrease in the tumor vascularity was reflected in the CEUS quantitative parameters as a reduction in PE, and a prolongation in TTP, MTT.Advances in knowledge:Prediction of NACT response by CEUS has the potential to serve as a diagnostic modality for modification of chemotherapy regimens during ongoing NACT among patients with LABC, thus affecting patient prognosis.     

Small nodules (1–2 cm) in liver cirrhosis: Characterization with contrast-enhanced ultrasound

ObjectiveTo determine the diagnostic efficacy of arterial phase contrast-enhanced ultrasound (CEUS) for characterizing small hepatic nodules (1–2 cm) in patients with high-risk for hepatocellular carcinoma (HCC).Materials and methodsOver 12 months, CEUS was performed in 59 patients at high-risk for HCC with small hepatic nodules (1–2 cm; mean, 1.5 cm). Based only on arterial phase (<45 s) vascular intensity and pattern, lesions were prospectively diagnosed as HCC if there was hypervascularity without known features of hemangioma. The diagnosis of HCC was made regardless of the presence or absence of washout. Verification of diagnosis was made by liver transplantation (n = 13), biopsy (n = 12), resection (n = 3) or clinical and imaging follow-up for at least 12 months (n = 31).ResultsAt of the time of CEUS, the 59 nodules were diagnosed as HCC in 26 and benign lesions in 33, including 20 regenerative/dysplastic nodules (RN/DN), 11 hemangiomas, and 2 focal fat sparing. All 26 nodules with arterial phase hypervascularity without hemangioma-like features were HCC. However, CEUS misdiagnosed HCC as RN/DN in 4 cases with arterial iso- (n = 3) or hypovascularity (n = 1). CEUS correctly diagnosed all 11 hemangiomas. The sensitivity, specificity, and accuracy of CEUS for diagnosing HCC were 86.7, 100, and 93.2%.ConclusionsArterial phase vascular intensity and pattern of CEUS are highly accurate for the diagnosis of small (1–2 cm) HCC and hemangioma in liver cirrhosis. On CEUS, arterial phase hypervascularity without a hemangioma-pattern alone may be sufficient for diagnosis of small HCC. Infrequent iso/hypovascular HCC may erroneously suggest RN/DN necessitating biopsy or close follow-up.     

胆囊息肉的CT仿真内窥镜表现与病理分型的关系

目的 :研究胆囊息肉的CT仿真内窥镜 (CTVE)表现与病理类型之间的关系。材料和方法 :选择 3 2例术前行CTVE检查并经手术病理证实为胆囊息肉者 ,比较其病理类型与CTVE表现的关系。结果 :不同病理类型胆囊息肉的数目、大小、形态、部位、基底有无蒂结构CTVE所见均不同。结论 :胆囊息肉的CT仿真内窥镜表现与病理类型密切相关。胆固醇息肉是一种多发于体、颈部有蒂的直径小于 10mm的球型或乳头型息肉 ,炎性息肉是一种无蒂的多发于胆囊体部的球型或不规则型息肉。     

The added diagnostic value of 64-row multidetector CT combined with contrast-enhanced US in the evaluation of hepatocellular nodule vascularity: implications in the diagnosis of malignancy in patients with liver cirrhosis

The aim of this study was to assess the added diagnostic value of contrast-enhanced US (CEUS) combined with 64-row multidetector CT (CT) in the assessment of hepatocellular nodule vascularity in patients with liver cirrhosis. One hundred and six cirrhotic patients (68 male, 38 female; mean age ± SD, 70 ± 7 years) with 121 biopsy-proven hepatocellular nodules (72 hepatocellular carcinomas, 10 dysplastic and 15 regenerative nodules, 12 hemangiomas, and 12 other benignancies) detected during US surveillance were prospectively recruited. Each nodule was scanned by CEUS during the arterial (10–40 s), portal venous (45–90 s), and delayed sinusoidal phase (from 100 s after microbubble injection to microbubble disappearance). Nodule vascularity at CEUS, CT, and combined CEUS/CT was evaluated side-by-side by two independent blinded readers who classified nodules as benign or malignant according to reference diagnostic criteria. The combined assessment of CEUS/CT provided higher sensitivity (97%, both readers) than did separate assessment of CEUS (88% reader 1; 87% reader 2) and CT (74% reader 1; 71% reader 2; P < 0.05), while no change in specificity was provided by combined analysis. The combined assessment of hepatocellular nodule vascularity at CT and CEUS improved sensitivity in the diagnosis of malignancy in patients with liver cirrhosis.     

Analysis of comparative performance of CEUS and CECT/MR LI-RADS classification: Can CEUS dichotomize LI-RADS indeterminate lesions on CT or MRI?

PurposeTo study the comparative performance of contrast-enhanced ultrasound (CEUS) and contrast-enhanced CT or MRI (CECT/MR) in evaluating liver lesions using the LI-RADS guidelines.MethodsRetrospective analysis of radiology database from July 2010 to April 2017 revealed 228 patients who had CECT/MR and CEUS. Patients at risk of hepatocellular carcinoma (HCC), had contemporaneous CEUS and CECT/CEMR studies within 3 months and adequate follow up were included; reviewed (2 reviewers) and graded according to the 2017 CEUS and 2018 CECT/MR LI-RADS guidelines. Reference standard was multidisciplinary clinical decisions, histology or follow-up imaging.ResultsThe study cohort consisted of 45 patients with 46 lesions. HCC were significantly larger than non-malignant (mean sizes of 2.5 and 1.4 cm, respectively, p<0.001). Intraclass correlation coefficient for CEUS review (0.941) was higher than of CECT/MR review (0.643). Mean area-under-ROC curve (AUC) for CEUS (0.994) was significantly higher than of CECT/MR (0.760) for all lesions (p=0.01). For lesions scored LR-3 by CECT/MR, the AUC was significantly higher for CEUS (0.978) than CECT/MR (0.500) (p<0.001). Twenty-one (of 27) lesions, classified LR-3 or LR-4 by CECT/MR were upgraded by CEUS and 20 were found to be HCC. Six lesions that were LR-3 on both CECT/MR and CEUS were found to be non-malignant. There was good concordance for LR-5 lesions between both techniques.ConclusionCEUS is useful for reassessment of lesions with intermediate probability (LR-3) or probable for HCC (LR-4) on CECT/MR. Lesions upgraded by CEUS tend to be HCC. Lesions that remain LR-3 on CEUS tend to be non-malignant.     

Evaluation of the choroidal vascular index and choroidal changes in migraine subgroups

PurposeTo investigate binarized choroidal structural parameters, retinal nerve fiber layer (RNFL) thickness, and retina changes duringattack-free periods in patients with migraine using enhanced depth imaging optic coherence tomography (EDI-OCT), and compare patients with migraine with aura and without aura (MwA and MoA, respectively) and aura subgroups (visual aura, non-visual aura), with age and sex-matched healthy subjects.MethodThis observational, prospective study included 102 patients with migraine and 36 healthy controls. Central macular thickness (CMT), retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and choroidal thickness (CT) were measured using a Spectralis OCT device. The choroid vascularity index (CVI) was evaluated using the Image-J software. CVI was calculated as the proportion of the luminal area (LA) to the total choroidal area (TCA). RNFL, CMT, CT, and CVI measurements were compared statistically.ResultsChoroidal thickness at 1500 µm temporal of the fovea was found to be statistically significantly thinner in the MwA and MoA groups compared with the control group (p ≤ 0.01). There was a significant difference in the subfoveal CT values of the MwA and control groups (p < 0.05). The mean RNFL thickness of patients with migraine with visual aura was found to be statistically significantly thinner than in the migraine group with non-visual aura (98.73 ± 8.4 and 109.4 ± 16.8) (p < 0.05). There were no statistically significant differences between the RNFL CMT, GCC, and CVI values in the MwA, MoA, and control groups (p > 0.05).ConclusionWe found that the choroidal thickness was significantly decreased in patients with migraine, especially in the MwA group. In the visual aura subgroup, the mean RNFL thickness was significantly decreased compared with the non-visual aura subgroup.     

Evaluation of peripapillary - macular microvascularity and choroidal vascularity index after refractive surgery

BackgroundTo evaluate the microvascularity and choroidal vascularity index (CVI) using optical coherence tomography angiography (OCTA) and OCT following femtosecond laser-assisted in-situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE) procedures.MethodsPatients with myopia (<-6.0D sphere) or myopic astigmatism (<-4.0D astigmatism) were enroled. The percentage of vessel density and foveal avascular zone (FAZ) size, optic disc flux index and perfusion were noted and the CVI was calculated before and after surgery.ResultsTwenty-nine eyes of 16 patients in the FS-LASIK group and 30 eyes of 16 patients in the SMILE group were enroled. Macular vessel density, FAZ size, and optic disc flux index were significantly higher on postoperative 1st day compared to preoperative day (p = 0.001, p = 0.007, and p < 0.001, respectively). There was no significant difference in terms of macular and peripapillary CVI between postoperative 1st day and preoperative day (p > 0.05). All microvascular parameters were similar on postoperative 7th day and preoperative day (p > 0.05).ConclusionsIt was detected that there is a transient alteration in macular and peripapillary microvascularity after FS-LASIK/SMILE, whereas choroidal circularity is not significantly affected by these refractive surgeries.     

Contrast enhanced gray-scale sonography in assessment of joint vascularity in rheumatoid arthritis: results from the IACUS study group

The purpose of this study way to assess the value of contrast enhanced gray-scale ultrasound (CEUS) in detection of vascularity in joints of patients with rheumatoid arthritis (RA) in a multicenter study of the International Arthritis Contrast Ultrasound (IACUS) study group. We assessed 113 joints in 113 patients (44 men, 69 women; mean age 51±14 years) with clinical diagnosis of RA. Gray-scale ultrasound (US), power Doppler US (PDUS) and CEUS, using a low mechanical index US technique, was performed. CEUS was done by bolus administration of the contrast agent SonoVue (Bracco, Milan, Italy) with a dosage of 4.8-ml SonoVue flushed with 10 ml saline. Detection of joint vascularity was performed for differentiation of active synovitis from inactive intra-articular thickening (synovitis/effusion). With the use of US and PDUS, active synovitis could be differentiated from inactive intra-articular thickening in 68/113 joints (60.1%), whereas CEUS enabled differentiation in 110/113 (97.3%) joints (p<0.0001). Thickness measurement of active synovitis was significantly improved after contrast administration (p=0.008). In conclusion, CEUS improves the differentiation of active synovitis from inactive intra-articular thickening. Since CEUS has shown an ability to improve assessment of vascularized synovial proliferation in RA affected joints, this technique may have further potential in monitoring therapy.     

Application of contrast-enhanced ultrasound in the diagnosis of solid pancreatic lesions—A comparison of conventional ultrasound and contrast-enhanced CT

Objective

To explore the diagnostic value of contrast-enhanced ultrasound (CEUS) by comparison with conventional ultrasound (US) and contrast-enhanced CT (CECT) in solid pancreatic lesions.

Method

Ninety patients with solid pancreatic focal lesions were enrolled, including 36 cases of pancreatic carcinoma, 28 cases of pancreatitis, 6 cases of pancreatic neuroendocrine tumor, 12 cases of solid pseudopapillary tumor of the pancreas, 6 cases of pancreatic metastases, 1 case of cavernous hemolymphangioma and 1 case of lymphoma. US and CEUS were applied respectively for the diagnosis of a total of 90 cases of solid pancreatic lesions. The diagnostic results were scored on a 5-point scale. Results of CEUS were compared with CECT.

Results

(1) 3-score cases (undetermined) diagnosed by CEUS were obviously fewer than that of US, while the number of 1-score (definitely benign) and 5-score (definitely malignant) cases diagnosed by CEUS was significantly more than that of US. There was a significant difference in the distribution of final scores using the two methods (p < 0.001). The overall diagnostic accuracies of the 90 cases for CEUS and US were 83.33% and 44.44%, respectively, which indicated an obvious advantage for CEUS (p < 0.001). (2) The diagnostic consistency among three ultrasound doctors: the kappa values calculated for US were 0.537, 0.444 and 0.525, compared with 0.748, 0.645 and 0.795 for CEUS. The interobserver agreement for CEUS was higher than that for US. (3) The sensitivity, specificity and accuracy of the diagnosis of pancreatic carcinoma with CEUS and CECT were 91.7% and 97.2%, 87.0% and 88.9%, and 88.9% and 92.2%, respectively, while for the diagnosis of pancreatitis, the corresponding indices were 82.1% and 67.9%, 91.9% and 100%, and 88.9% and 90%, respectively, showing no significant differences (p > 0.05).

Conclusion

CEUS has obvious superiority over conventional US in the general diagnostic accuracy of solid pancreatic lesions and in the diagnostic consistency among doctors. The performances of CEUS are similar to that of CECT in the diagnosis of pancreatic carcinoma and focal pancreatitis.     

Ultrasound echogenicity reveals the response of breast cancer to chemotherapy

PurposeTo evaluate the ultrasound (US) response in patients with breast cancer (BC) during neoadjuvant chemotherapy (NAC).MethodsProspective US analysis was performed on 19 malignant tumors prior to NAC treatment and 7 days after each first four courses of NAC in 13 patients (median age = 57 years). Echogenicity, size, vascularity, and sonoelastography were measured and compared with posttreatment scores of residual cancers burden.ResultsChanges in the echogenicity of tumors after 3 courses of NAC had the most statistically strong correlation with the percentage of residual malignant cells used in histopathology to assess the response to treatment (odds ratio = 60, p < 0.05). Changes in lesion size and elasticity were also significant (p < 0.05).ConclusionsThere is a statistically significant relationship between breast tumors' echogenicity in US, neoplasm size, and stiffness and the response to NAC. In particular, our results show that the change in tumor echogenicity could predict a pathological response with satisfactory accuracy and may be considered in NAC monitoring.     

Comparison of choroidal structural changes between children born preterm without retinopathy of prematurity and age-matched children born at full term

AimTo evaluate the effect of prematurity on choroidal structure in children born preterm with no history of retinopathy of prematurity (ROP) by comparing them with age-matched healthy children born at full term.MethodsEnhanced depth imaging optical coherence tomography (EDI-OCT) scans of children aged 5 to 9 years with a history of prematurity but no history of ROP, and age-matched full-term healthy children were evaluated, retrospectively. Choroidal thicknesses (CTs) were measured at subfoveal (SFCT), 1000 µm temporal and nasal from the fovea (T1, N1), and 2000 µm temporal and nasal (T2, N2) from the fovea. The EDI-OCT images were binarized to stromal (SA) and luminal areas (LA) using the ImageJ software. The choroidal vascularity index (CVI) was calculated by dividing LA by the total choroidal area (TCA).ResultsTwenty-nine eyes of 15 preterm children and 41 eyes of 26 full-term children were included. Demographic characteristics including axial length (AL), eye side, age, and the sex of the children in the groups were similar (p>0.05). There was no statistically significant difference in the mean CVI, SFCT, N1, and T1 values between the groups (p>0.05); however, the mean T2 and N2 values were significantly higher in the full-term group than in the preterm group (p<0.05). There was a significant positive correlation between the birth week and the T1 (p<0.05)ConclusionPrematurity can affect CT even with no history of ROP. The decreases in CTs were significant at 2000 µm nasal and temporal from the fovea. The impairment of temporal choroidal region was more evident than nasal choroidal region. The mean CVI values were similar between the groups.     

Choroidal structural alterations and choroidal vascularity index in bipolar disorder patients

PurposeThe aim of this study was to compare bipolar disorder (BD) patients with age- and sex-matched healthy individuals in order to assess the choroidal structural alterations, retinal nerve fiber layer (RNFL) thickness, and retinal changes in BD patients using encanhed depth imaging optic coherence tomography (EDI-OCT).MethodFor this research, 39 eyes of BD patients and 36 eyes of age-matched healthy volunteers were used. Five locations were used to assess the choroidal thickness (CT): subfoveal, 500 µm nasal and 1500 µm nasal to the fovea, 500 µm temporal and 1500 µm temporal to the fovea. Image-J was used to determine the total choroidal area (TCA), luminal area (LA), and choroidal vascularity index (CVI). The Spectralis-OCT device was used to evaluate the central macular thickness (CMT), retinal nerve fiber layer (RNFL), and ganglion cell layer (GCL). The data were statistically compared.ResultsBD patients had significantly decreased subfoveal, nasal, and temporal CTs than controls (for all three, p = 0.0001). The results of CMT and GCL were found to be thinner than controls. (for all p = 0.0001) In comparison to the controls, the mean TCA and LA were decreased in the BD group. (p = 0.0001, p = 0.0001, respectively,). Between the RNFL and CVI values in the BD and control groups, there was no statistically significant difference (p>0.05).ConclusionThe results of this investigation showed that the retina and choroid of patients with BD had considerable anatomical changes.     

Muscle thickness and echo-intensity changes of the quadriceps femoris muscle during a strength training program

IntroductionUltrasound (US) has an important role in musculoskeletal (MSK) evaluation, allowing the study of muscle morphology and function. Muscle thickness (MT) and muscle echo-intensity (EI) are two important parameters that may quantify muscle structural adaptations to a variety of stimuli. The aim was to explore the potential of quantitative US imaging for assessing the adaptations and responses of the muscle tissue to increased contractile activity using B-mode US. This study was centred on the quadriceps femoris muscle contractile activity on MT and EI.Methods and materialsTwenty-eight young male adults participated in the study, divided in a control group and two training groups performing concentric or eccentric strength training, respectively. The effect of a 15-week strength program was studied on MT and EI in several regions of the heads of the quadriceps femoris using B-mode US. All images acquisitions and measurements were done by the same experience sonographer.ResultsStrength training resulted in an increase of MT at all muscles and sites (p < 0.05), except the VM. Strength training failed in changing EI in most of the quadriceps femoris, except in the VI and some regions of the VL. No statistically significant differences were observed in our quantitative US parameters between concentric and eccentric training (p > 0.05).ConclusionThese results emphasise the value of MT as a quantifiable muscle US method for evaluating muscle adaptation to exercise training. However, the inconsistency of the EI values indicates that more studies are needed to develop it as an accurate diagnostic tool.     

The role of contrast-enhanced ultrasound in the diagnosis of malignant non-mass breast lesions and exploration of diagnostic criteria

Objectives:To assess the value of contrast-enhanced ultrasound (CEUS) for diagnosing malignant non-mass breast lesions (NMLs) and to explore the CEUS diagnostic criteria.Methods:A total of 116 patients with 119 NMLs detected by conventional US were enrolled. Histopathological results were used as the reference standard. The enhancement characteristics of NMLs in CEUS were compared between malignant and benign NMLs. The CEUS diagnostic criteria for malignant NMLs were established using independent diagnostic indicators identified by binary logistic regression analysis. The diagnostic performance of Breast Imaging Reporting and Data System-US (BI-RADS-US), CEUS, and BI-RADS-US combined with CEUS was evaluated and compared.Results:Histopathological results showed 63 and 56 benign and malignant NMLs. Enhancement degree (OR = 5.75, p = 0.003), enhancement area (OR = 4.25, p = 0.005), and radial or penetrating vessels (OR = 7.54, p = 0.003) were independent diagnostic indicators included to establish the CEUS diagnostic criteria. The sensitivity and specificity of BI-RADS-US, CEUS, and BI-RADS-US combined with CEUS were 100 and 30.2%, 80.4 and 74.6%, and 94.6 and 77.8%, respectively; the corresponding areas under the receiver operating characteristic curve (AUC) were 0.819, 0.775, and 0.885, respectively.Conclusions:CEUS has a high specificity in malignant NML diagnosis based on the diagnostic criteria including enhancement degree, enhancement area, and radial or penetrating vessels, but with lower sensitivity than BI-RADS-US. The combination of CEUS and BI-RADS-US is an effective diagnostic tool with both high sensitivity and specificity for the diagnosis of malignant NMLs.Advances in knowledge:In this study, we assessed the diagnostic value of CEUS for malignant NMLs and constructed a feasible diagnostic criterion. We further revealed that the combination of CEUS and BI-RADS-US has a high diagnostic value for malignant NMLs.     

Retrobulbar ocular blood flow and choroidal vascular changes in patients recovering from COVID-19 infection

BackgroundTo evaluate the effects of COVID-19 infection on the ocular vascular structure including choroidal thickness and retrobulbar blood flow values in comparison with healthy subjects.MethodsNinety eyes of 90 patients were included in this study. Participants were divided into Group 1 (n = 30) with mild COVID-19 infection, Group 2 (n = 31) with moderate disease, and Group 3 with age- and sex-matched healthy subjects (n = 29). Choroidal thickness was measured at the subfoveal area and at 500-µm intervals nasal and temporal to the fovea up to a distance of 1500 µm, using the enhanced depth imaging (EDI) technique of spectral coherence tomography (SD-OCT). The peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI), and pulsatility index (PI) values of the central retinal artery (CRA) and ophthalmic artery (OA) were evaluated with color Doppler ultrasonography (CDU).ResultsThe choroidal thickness was significantly thinner in Group 1 and Group 2 than in Group 3 at all measurement points (p <0.001). This difference was not present between Group 1 and Group 2 who had COVID-19 disease of different severity (p>0.05).Among the retrobulbar blood flow parameters, OA PSV value was significantly lower in Group 1 and Group 2 compared to Group 3 (p = 0.025, p = 0.016, respectively). However, the CRA PSV and EDV and OA EDV values, and the CRA and OA PI and RI values were not statistically different between the groups (p> 0.05).ConclusionCOVID-19 infection may predispose patients to ocular vascular pathologies by affecting both choroidal and retrobulbar blood flow.     

Investigation of changes in retinal vascular parameters and choroidal vascular index values during the early recovery period of COVID-19: The COVID-OCTA study

BackgroundCOVID-19 effects microvasculature in many tissues. This study investigated whether the choroidal structure is also affected.MethodsThis cross-sectional study included 80 patients with COVID-19 and the same number of age- and gender-matched healthy individuals. All participants' right eye measurements were examined. Optical coherence tomography angiography (OCTA) was used for imaging. Otherwise, two independent researchers used the Choroidal vascular index (CVI) for choroidal parameters calculation.ResultsSuperior and deep flow values were lower in the COVID-19 group than in the control group, and vascular density (VD) values were lower in all regions in this group. Except for the superior mean VD, there was no statistically significant difference (p = 0.003). However, the COVID-19 group had significantly lower subfoveal choroidal thickness (SFChT) measurements than the control group (p = 0.001). In addition, no significant difference was observed between the groups in evaluating mean CVI values (p>0.05).ConclusionNoninvasive diagnostic tools such as OCTA and EDI-OCT can be used to monitor early changes in diseases affecting microvessels, such as from COVID-19.     

Change in retinal vessel diameter and choroidal thickness in patients with severe COVID-19: Change In Retinal Parameters In Patients With Severe COVID-19

Purpose: To compare the differences in retinal vascular structure and choroidal thickness between the active disease and post-recovery periods in COVID-19 patients and healthy controls.Material and Methods: This prospective, cross-sectional study included 30 eyes from 30 patients with severe COVID-19 and 30 eyes of 30 sex-matched healthy controls. Central macular thickness (CMT), subfoveal choroidal thickness (CT) and retinal vascular changes of patients were measured after positive polymerase chain reaction (PCR) (where the patient had COVID-19-related symptoms) and then three months after two negative PCRs. Laboratory parameters, including C-reactive protein and d-dimer levels, were also recorded.Results: The mean age of the patients was 47.90 ± 9.06 years in patients group, 49.07 ± 8.41 years in control goups (p = 0.467). In terms of choroidal thicknesses subfoveal, nasal and temporal region were significantly higher in the active disease period than control group (p = 0.019, p = 0.036, p = 0.003, respectively). When the after recovery period was compared with the control group in terms of choroidal thickness, although the choroidal thickness was higher in all regions, this difference was not found statistically significant. There was no statistically significant difference in CMT between groups (p = 0.506).The mean venous and arterial wall thicknesses were significantly higher in the active period than after recovery (p = 0.023, p = 0.013, respectively) but there were no differences between after recovery and control groups in the pairwise comparison (p = 0.851, p = 0.715, respectively).Conclusion: In patients with severe COVID-19, there are changes in thickness of the choroid and retinal vessel walls. While vascular wall thickness increases due to inflammation, the absence of lumen changes may be associated with hemodynamic variables.     

Quantitative Analysis of Microperfusion in Contrast-Induced Nephropathy Using Contrast-Enhanced Ultrasound: An Animal Study

ObjectiveTo investigate imaging biomarkers of microperfusion in contrast-induced nephropathy (CIN) using contrast-enhanced ultrasound (CEUS).Materials and MethodsThe CIN model was fabricated by administering indomethacin (10 mg/kg), L-NAME (15 mg/kg), and iopamidol (10 mL/kg) to Sprague-Dawley rats. After 24 hours, CEUS was performed on CIN (n = 6) and control (n = 6) rats with sulphur hexafluoride microbubbles (SonoVue). From time-intensity curves obtained from the kidney arriving time (AT), acceleration time (AC), time to peak (TTP), and peak enhancement (PE) were measured and compared between the groups. After CEUS, the rats were sacrificed, and cell apoptosis markers were evaluated to confirm the development of CIN.ResultsAmong CEUS parameters, AT (7.8 ± 1.6 vs. 4.2 ± 0.5 s, p = 0.002), AC (4.7 ± 1.4 vs. 2.0 ± 0.4 s, p = 0.002), and TTP (12.5 ± 2.9 vs. 6.2 ± 0.6 s, p = 0.002) were significantly prolonged in the CIN group compared to controls. PE was significantly higher in the control group than in the CIN group (17.1 ± 1.9 vs. 12.2 ± 2.0 dB, p = 0.004). In kidney tissue, mRNA and protein levels of the apoptotic makers were significantly higher in the CIN group than in the control group (p = 0.003 and p = 0.002).ConclusionCEUS parameters can be used as imaging biomarkers for microperfusion in CIN. In rats with CIN, AT, AC, and TTP were significantly prolonged, while PE was significantly lower compared to controls.