Transcranial sonography in the critical patient.

Transcranial ultrasonography is a non-invasive, bedside technique that has become a widely implemented tool in the evaluation and management of neurocritically ill patients. It constitutes a technique in continuous growth whose fundamentals (and limitations) must be known by the intensivist. This review provides a practical approach for the intensivist, including the different sonographic windows and planes of insonation and its role in different conditions of the neurocritical patients and in critical care patients of other etiologies.

Using 3-D-Printed Structures to Evaluate the Potential Causes of the Color Doppler Twinkling Signature.

OBJECTIVE: The color Doppler twinkling artifact has been attributed to existing microbubbles or cavitation occurring on rough objects such as kidney stones, some breast biopsy clips, catheter guidewires and sandpaper. The objective was to investigate the correlation between the surface characteristics of helical constructs with different groove geometries and the occurrence of twinkling, as well as to identify locations conducive to bubble retention and/or cavitation. METHODS: Six half-cylinders were created with a microscale 3-D printer with 5 µm resolution to replicate the geometry of twinkling helical constructs resembling catheter guidewires. Four copies of each marker including a non-twinkling control were printed. The half-cylinders had pitch (peak-to-peak distance) values ranging from 87.5 to 343 µm and amplitude (groove depth) values ranging from 41.5 to 209 µm. The half-cylinders were submerged in degassed water and optically imaged before and after ultrasound insonification to visualize bubbles on the cylinders. The cylinders remained submerged while scanning with the color Doppler mode at frequencies from 3.1 to 6.3 MHz using a GE Logiq E9 scanner and 9L linear array transducer. RESULTS: Two markers exhibited twinkling: one with pitch-to-amplitude ratio of 174/210 µm/µm (0.8) that twinkled only with pre-existing bubbles on the marker; the other had a ratio of 87/87 µm/µm (1.00) that twinkled without pre-existing bubbles on the marker. CONCLUSION: This work provides strong evidence that both existing bubbles and either cavitation or ultrasound wave interactions with patterned or rough surfaces are significant factors in producing the twinkling signature.

Superb Microvascular Imaging in Pediatric Focal Nodular Hyperplasia.

OBJECTIVE: To investigate superb microvascular imaging (SMI), a novel Doppler ultrasound technique that can visualize low-velocity microvascular flow, for assessing pediatric focal nodular hyperplasia (FNH). PATIENTS AND METHODS: Nine FNH lesions in 6 patients were enrolled. On SMI and color Doppler imaging (CDI), intralesional vascularity was assessed visually and categorized as typical spoke-wheel pattern (central vessel radiating from the center to the periphery), multifocal spoke-wheel pattern, and nonspecific pattern. We compared the vascular features of the lesions between SMI and CDI and evaluated vascular patterns according to lesion size. RESULTS: In terms of vascularity pattern, the typical spoke-wheel pattern of FNH was noted more frequently on SMI (67%) than on CDI (11%; P < 0.05). In addition, a multifocal spoke-wheel pattern was noted in all remaining lesions (33%) on SMI. On the contrary, a nonspecific vascular pattern was detected in the majority (78%) of CDI. Regarding the lesion size and vascularity on SMI, the typical spoke-wheel pattern was seen more frequently in the small FNH group than in the large FNH group. The intralesional vascular signal was detected more frequently on SMI (100%) than on CDI (89%). CONCLUSION: SMI is feasible in evaluating FNH in children and has a greater ability to demonstrate the spoke-wheel pattern than CDI.

Investigation of alterations in retrobulbar hemodynamics and their correlation with choroidal thickness after strabismus surgery.

BACKGROUND: To evaluate the changes in retrobulbar circulation after strabismus surgery and to assess the relationship of these changes with choroidal thickness (CT). METHODS: This prospective study included 26 eyes of 26 patients who underwent strabismus surgery and 15 eyes of 15 healthy individuals as control group. The patients who had single horizontal muscle surgery were included in Group 1 (n = 14); and those who had surgery on both horizontal muscles were included in Group 2 (n = 12). Peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) of ophthalmic artery (OA), posterior ciliary artery (PCA), and central retinal artery (CRA) were measured using Color Doppler Ultrasonography. Subfoveal CT was measured via Optical Coherence Tomography. All measurements were obtained preoperatively, at 1st week and 1st month after surgery. RESULTS: There were no differences regarding preoperative blood flow velocity parameters among the groups. OA RI increased significantly at 1st week and 1st month after surgery in Group 1 and 2 (P = 0.029 and P = 0.045, respectively). There was a significant increase in PCA PSV at 1st week in Group 1 (P = 0.002). There was no difference between the mean preoperative and postoperative CT among the 3 groups. A negative correlation between the percentage changes of CT and CRA EDV was found in Group 2 (P = 0.011). CONCLUSION: Single and double horizontal rectus muscle surgery have a measurable effect on retrobulbar hemodynamics but these changes do not correlate with CT.

Correlation between choroidal vascularity and retrobulbar ocular blood flow changes and thyroid-associated ophthalmopathy activity: a cross-sectional study.

OBJECTIVE: To evaluate the alterations in retrobulbar color Doppler imaging (CDI) parameters and retinal/choroidal optical coherence tomography angiography (OCTA) parameters and their association with the clinical activity and severity in thyroid-associated orbitopathy (TAO) patients. METHODS: In this study, the retrobulbar flow parameters including resistance index (RI), Pulsatile Index(PI), peak systolic velocity (PSV) and end diastolic velocity (EDV) in posterior ciliary artery (PCA), central retinal artery (CRA) and ophthalmic artery (OA) were determined by CDI. Moreover, the retina and choroidal vascularity including the superficial vessel density (SVD), deep vessel density (DVD), choroidal thickness (ChT) and choroidal vascularity, including total choroidal area (TCA), luminal area (LA), stromal area (SA) and Choroidal Vascularity Index (CVI), were determined by OCTA. All patients grouped as active TAO and inactive TAO based on Clinical activity score (CAS). We picked the severe eye among the subjects and compared all parameters between two groups. We analyzed the correlations among those parameters. RESULTS: There was a significant difference in CAS score, proptosis value, ChT, LA, CVI between patients with active TAO and inactive TAO. In the active group, PSV and EDV of PCA were significantly higher than the inactive group. On logistic regression analysis, CAS was closely associated with PSV-PCA. On multiple linear regression, proptosis value was closely associated with ChT, LA, SA and CVI. CONCLUSION: Choroidal vascularization and retrobulbar blood flow were concurrently higher in active TAO patients and several variables in choroid circulation was closely related to TAO clinical features.

Deep-learning-based renal artery stenosis diagnosis via multimodal fusion.

PURPOSE: Diagnosing Renal artery stenosis (RAS) presents challenges. This research aimed to develop a deep learning model for the computer-aided diagnosis of RAS, utilizing multimodal fusion technology based on ultrasound scanning images, spectral waveforms, and clinical information. METHODS: A total of 1485 patients received renal artery ultrasonography from Peking Union Medical College Hospital were included and their color doppler sonography (CDS) images were classified according to anatomical site and left-right orientation. The RAS diagnosis was modeled as a process involving feature extraction and multimodal fusion. Three deep learning (DL) models (ResNeSt, ResNet, and XCiT) were trained on a multimodal dataset consisted of CDS images, spectrum waveform images, and individual basic information. Predicted performance of different models were compared with senior physician and evaluated on a test dataset (N = 117 patients) with renal artery angiography results. RESULTS: Sample sizes of training and validation datasets were 3292 and 169 respectively. On test data (N = 676 samples), predicted accuracies of three DL models were more than 80% and the ResNeSt achieved the accuracy 83.49% ± 0.45%, precision 81.89% ± 3.00%, and recall 76.97% ± 3.7%. There was no significant difference between the accuracy of ResNeSt and ResNet (82.84% ± 1.52%), and the ResNeSt was higher than the XCiT (80.71% ± 2.23%, p < 0.05). Compared to the gold standard, renal artery angiography, the accuracy of ResNest model was 78.25% ± 1.62%, which was inferior to the senior physician (90.09%). Besides, compared to the multimodal fusion model, the performance of single-modal model on spectrum waveform images was relatively lower. CONCLUSION: The DL multimodal fusion model shows promising results in assisting RAS diagnosis.

The value of quantitative contrast-enhanced ultrasonography analysis in evaluating central retinal artery microcirculation in patients with diabetes mellitus: comparison with colour Doppler imaging.

AIM: To compare the efficacy of quantitative contrast-enhanced ultrasonography (CEUS) analysis and colour Doppler ultrasound (CDU) in evaluating central retinal artery (CRA) microcirculation in patients with diabetes mellitus (DM). MATERIALS AND METHODS: In this prospective study, a total of 55 patients (98 eyes) with DM were enrolled as the study group. They were compared to 46 age-matched healthy volunteers (92 eyes) who were selected as the control group. Each patient underwent CDU and subsequent CEUS examination. CDU and quantitative CEUS parameters were evaluated. The diagnostic efficiency of the diagnostic performance of CEUS and CDU was evaluated and compared, and the scale thresholds of predictive indicators for the diagnosis of proliferative diabetic retinopathy (PDR) were evaluated using receiver operating characteristics (ROC) curve analyses. RESULTS: Group pairwise comparisons showed that the end diastolic velocity (EDV) and arrival time (AT) of CRA were significant predictors for PDR by CDU and by quantitative CEUS analysis, respectively (all p<0.05). The ROC curve analysis showed that the area under the curve value of AT was significantly higher than that of EDV (0.875 versus 0.634, p=0.0002). Accordingly, an AT cut-off value of 1.07 seconds resulted a sensitivity of 90.62 % and a specificity of 79.31 %. CONCLUSION: Quantitative CEUS analysis can improve the accuracy of clinical staging of diabetic retinopathy for the patients with DM, and the AT showed the best diagnostic efficiency.

The value of color doppler ultrasonography combined with computed tomography angiography and magnetic resonance angiography in the preoperative quantification and classification of carotid body tumors: a retrospective analysis.

BACKGROUND: Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) provide accurate vascular imaging information, but their use may be contraindicated. Color Doppler ultrasonography (CDU) provides simple, safe, noninvasive, and reproducible imaging. We therefore investigated the role of preoperative CDU combined with CTA and MRA in the quantification, typing, and diagnosis of carotid body tumors (CBTs). METHODS: We retrospectively analyzed patients with CBTs categorized into group A (type I [n = 1] and type II [n = 10]) or group B (type III [n = 56]) per the intraoperative Shamblin classification. CDU, CTA, and MRA characteristics of CBTs were observed, surgical results were correlated, and the diagnostic threshold of the CBT classification was calculated. RESULTS: CBTs were usually located at the common carotid artery bifurcation, encircling the carotid artery. An increased angle was found between the internal and external carotid arteries. On CDU, CBTs primarily presented as homogeneous hypoechoic masses with clear boundaries, rich flow signals, and a high-speed, low-resistance artery-like flow spectrum. CTA showed uniform or heterogeneous marked enhancement. MRA showed mixed T1 and slightly longer T2 signals and uniform or uneven obvious enhancement. With increases in the lesion size, amount of blood transfused, and operation time, the intraoperative classification level and possibility of skull-base invasion increased. When the maximum diameter of the lesion, the volume of the tumor, the distance between the upper margin of the tumor to the mastoid and the mandibular angle were 3.10 cm, 10.15 cm3, - 3.26 cm, and 0.57 cm, respectively, the largest Youden index was the best diagnostic boundary value for Shamblin type III tumors. CONCLUSIONS: CDU combined with CTA and MRA can accurately evaluate the size and classification of CBTs.

Value of micro-flow imaging and high-definition micro-flow imaging in differentiating malignant and benign breast lesions.

AIM: To evaluate the value of non-contrast micro-flow imaging (MFI) and high-definition micro-flow imaging (HD-MFI) in differentiating malignant and benign breast lesions. MATERIALS AND METHODS: One hundred and thirty-three patients with 138 breast lesions (80 benign and 58 malignant lesions) were examined using colour Doppler flow imaging (CDFI), MFI, and HD-MFI before biopsy, with blood flow signals graded into four types (grade 0, 1, 2, and 3) and penetrating vessels evaluated. The micro-vascular patterns of MFI and HD-MFI were evaluated and classified into five patterns: avascular, line-like, tree-like, root hair-like, and crab claw-like pattern. The diagnostic efficiency of micro-vascular patterns was analysed. Moreover, ultrasound Breast Imaging Reporting and Data System (BI-RADS) 4A lesions were also re-assessed according to the micro-vascular patterns of MFI or HD-MFI. RESULTS: The capability of detecting blood flow and penetrating vessels from high to low was HD-MFI, MFI, and CDFI, respectively (p<0.05). Rich blood flow signals, penetrating vessels, and root hair-like or crab claw-like pattern were more likely in malignant breast lesions, while few blood flow signals, tree-like pattern were mostly in benign lesions (p<0.05). The diagnostic efficiency of HD-MFI and MFI were higher than CDFI (p>0.05). MFI could reduce unnecessary biopsy of 52 US BI-RADS 4A lesions but with two malignancies missed, while 56 ultrasound BI-RADS 4A lesions could be downgraded by HD-MFI with none malignancies missed. CONCLUSIONS: MFI and HD-MFI can detect more blood flow in breast lesions than CDFI, and could help distinguish benign and malignant breast lesions. HD-MFI could reduce the unnecessary biopsy of US BI-RADS 4A lesions without missed malignancy.

Superb Microvascular Imaging Doppler Technique In The Evaluation Of Ovarian Stromal Vascularity In Women With Polycystic Ovary Syndrome.

OBJECTIVE: To compare the assessment of intra-ovarian stromal vascularity through transabdominal ultrasonography with colour Doppler imaging, power Doppler imaging, colour superb microvascular imaging and monochrome superb microvascular imaging in polycystic ovary syndrome cases. METHODS: The retrospective cross-sectional study was conducted at the Obstetrics and Gynaecology outpatient department of the Usak Training and Research Hospital, Turkey, from April 11 to June 18, 2018, and comprised grayscale colour Doppler imaging, power Doppler imaging, colour superb microvascular imaging and monochrome superb microvascular imaging of women with polycystic ovary syndrome. The recorded video images were evaluated by three radiologists and rated through consensus decision. Mean values for age, body mass index, follicle stimulating hormone and luteinizing hormone levels, luteinizing hormone-follicle stimulating hormone ratio, Ferriman Gallwey score, and mean ovarian volume of the subjects were evaluated. Data was analysed using Number Cruncher Statistical System. RESULTS: Of the 54 women evaluated, data of 42(77.8%) was included. There were a total of 83 ovaries, as the left ovary of 1(1.2%) patient was not visible. The mean age and body mass index were 24.02±5.8 years and 25.08±4.5kg/m2. Mean follicle stimulating hormone and luteinizing hormone levels were 5.51±1.91 and 7.91±6.13m IU/mL. Luteinizing hormone/follicle stimulating hormone ratio and Ferriman Gallwey score were 1.4±0.8 and 8.67 ±6.94, respectively. The mean ovarian volume was 12.2±3.43 cm3. The detection of vascularity was colour Doppler imaging 0.72±0.97, power Doppler imaging 0.96±1.08, colour superb microvascular imaging 2.47±1.25, and monochrome superb microvascular imaging 2.75±1.31. The techniques were significant for superb microvascular imaging Doppler than conventional Doppler (p<0.001). Hyper- ovarian stromal vascularity, like a 'stellate' sign, was detected in 17(20.5%) of the total 83 ovaries analysed. CONCLUSIONS: Transabdominal ultrasonography-colour superb microvascular imaging was found to be more effective in detecting ovarian vascularity than conventional Doppler technique in women with polycystic ovary syndrome.

Color Doppler Guided in Early Renal Allograft Biopsy: A Safer and Non-Inferior Technique.

BACKGROUND: This study compared a novel technique for renal allograft biopsy, color Doppler ultrasound-guided biopsy (CDUS-Bx), with routine ultrasound-guided biopsy (RUS-Bx). METHODS: A retrospective review was conducted on 111 patients, with 42 undergoing CDUS-Bx and 69 undergoing RUS-Bx. Urologists used an 18-gauge automatic spring-loaded biopsy needle for all procedures. CDUS-Bx tissue collection was guided by identifying renal vessels with color Doppler mode. RESULTS: Overall, the adequacy rate was 90.1%, with a higher number of glomeruli obtained in the CDUS-Bx group (25.6 ± 10.3 vs. 20.6 ± 11.3, P = .008). Acute tubular necrosis was the most frequent pathological diagnosis, with a higher prevalence in the CDUS-Bx group (69% vs 40.6%). T cell-mediated rejection had a lower incidence in the CDUS-Bx group (4.8% vs 21.7%), and antibody-mediated rejection was comparable between the 2 groups. The most common complication was microscopic hematuria, which was significantly less frequent in the CDUS-Bx group (48.7% vs 70.1%, P = .028), but there was no significant difference in the rate of gross hematuria between CDUS-Bx and RUS-Bx (11.9% vs 11.6%, P = .961). The number of cores was the only predictor of adequate biopsy, with a 93.2% adequacy rate after 3 cores of allograft biopsy. Multivariate analysis revealed that only the guiding type, CDUS-Bx, was associated with less microscopic hematuria (adjusted odds ratio 0.325, P = .018). CONCLUSIONS: Color Doppler ultrasound-guided biopsy had comparable tissue adequacy to RUS-Bx, with a lower incidence of microscopic hematuria. These findings suggest that CDUS-Bx may be a safe and effective alternative to RUS-Bx for allograft biopsy.

Utility of Color Doppler Ultrasonography in Monitoring of a Free Jejunal Flap.

OBJECTIVES: External color Doppler ultrasonography is reported to be a useful monitoring technique that is simple and noninvasive; however, details of imaging of the transferred free jejunal flap have not been reported. We reviewed our experience using external color Doppler ultrasonography to monitor a transferred free jejunal flap and examined its utility. STUDY DESIGN: Retrospective study. METHODS: Subjects were 43 patients who underwent total pharyngolaryngectomy, reconstruction with a free jejunal flap, and color Doppler ultrasonography before, during, and after surgery between September 2017 and December 2021. RESULTS: During surgery, arterial thrombosis was detected up to 100% with the loss of continuous color signals in the entire circumference. After surgery, the positive predictive value was 100% for each of wiggling movement, dynamic intestinal movement, and continuous color signals in the entire circumference on color Doppler ultrasonography for detecting flap viability. Their negative predictive value was 100%, 7.1%, and 50%, respectively. CONCLUSIONS: During surgery, the continuous color signals in the entire circumference sign were useful with 100% negative predictive value for detecting the arterial thrombosis. After surgery, the wiggling movement sign very was useful with 100% positive and negative predictive values, enabling salvage surgery to be performed soon after detection of flap failure. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:3361-3369, 2023.

Multimodal ultrasonography of male primary breast lymphoma.

① Gray scale ultrasound showed multiple hypoechoic masses of varying sizes in the right breast. The larger one was 1.8 × 0.7 cm (arrow), oval in shape, with clear boundaries, and lymphatic hilar-like structures. ② Color Doppler ultrasonography showed blood flow signals within the hypoechoic mass, and the larger (arrow) mass showed blood flow signals similar to lymphatic hilum. ③ Elastography showed the mass was soft and blue (short arrow) or green (long arrow) in texture, and the surrounding tissue was hard and red in texture. ④ Contrast-enhanced ultrasound showed that after 19 s of contrast agent injection, the whole breast showed a 'snowflake' high enhancement, but no enhancement was observed in local areas (arrow). ⑤ The ultrasound-guided puncture image clearly showed the puncture needle (arrow) insert into the hypoechoic mass for biopsy. ⑥ The arrow in the pathological image (HE, 20 × 10 times) showed tumor cells.

Traqueotomía percutánea guiada por ultrasonografía en tiempo real. Revisión de la literatura / Literature Review. Real-time ultrasonography-guided percutaneous tracheotomy

La traqueotomía percutánea por dilatación es un procedimiento que se realiza en las unidades de paciente crítico, implica la disección roma de los tejidos pretraqueales, seguida de la dilatación de la tráquea sobre la guía y la inserción de la cánula traqueal mediante la técnica de Seldinger. En las últimas décadas, la evidencia sugiere que, en manos de médicos capacitados, es al menos tan segura como la traqueotomía quirúrgica, con similar incidencia de complicaciones. La selección adecuada de pacientes y el uso de herramientas de seguridad complementarias, como broncoscopio o ultrasonido, disminuyen las tasas de falla y complicaciones. Siendo contraindicaciones absolutas para traqueotomía percutánea por dilatación una anatomía anormal, tumor maligno en el sitio de traqueostomía, coagulopatías o vía aérea difícil. La guía mediante broncoscopia permite la evaluación de la profundidad del tubo endotraqueal, confirma la posición de la aguja en el eje de la tráquea y la adecuada inserción del cable guía y dilatador. Entre sus desventajas destacan que, el sitio de punción está sujeto a sesgo y no puede guiar con precisión la aguja en la penetración de la tráquea. La traqueotomía percutánea guiada por ultrasonido es una alternativa validada en unidades, donde no se cuente con broncoscopia. Es un método rápido, seguro, que permite la identificación de estructuras anatómicas, vasculatura cervical, permite identificar el sitio de la punción y guía la inserción de la aguja en la tráquea. Esta técnica presenta altas tasas de éxito al primer intento, reduciendo significativamente el número de punciones.

Percutaneous dilation tracheostomy is a procedure performed in critical patient units. It involves blunt dissection of the pretracheal tissues followed by dilation of the trachea over the guidewire and insertion of the tracheal cannula using the Seldinger technique. In recent decades, evidence suggests that in the hands of trained physicians it is at least as safe as surgical tracheostomy, with a similar incidence of complications. The proper selection of patients and the use of complementary safety tools such as bronchoscope or ultrasound reduce failure rates and complications. Being absolute contraindications for PDT abnormal anatomy, malignant tumor at the tracheostomy site, coagulopathies, or difficult to treat airway. Bronchoscopy guidance allows evaluation of the depth of the endotracheal tube, confirms the position of the needle in the axis of the trachea and the proper insertion of the guide wire and dilator. Among its disadvantages are that the puncture site is subject to slant and cannot accurately guide the needle into the trachea. In addition, it requires Critical Patient Units with bronchoscope and trained personnel. Ultrasound-guided percutaneous tracheotomy is a validated alternative in units where bronchoscopy is not available. It is a fast, safe method that allows the identification of anatomical structures, cervical vasculature, identifies the puncture site and guides the insertion of the needle into the trachea. With high first-attempt success rates, significantly reducing the number of punctures.

Precise evaluation of blood flow patterns in human carotid bifurcation based on high-frame-rate vector flow imaging.

PURPOSE: To investigate the feasibility of high-frame-rate vector flow imaging (HiFR-VFI) compared to ultrasound color Doppler flow imaging (CDFI) for precisely evaluating flow characteristics in the carotid bifurcation (CB) of presumed healthy adults. METHODS: Forty-three volunteers were assessed for flow characteristics and their extensions using HiFR-VFI and CDFI in CBs. The flow patterns were classified according to the streamlines in HiFR-VFI and quantitatively measured using an innovative turbulence index (Tur-value). Interobserver agreement was also assessed. RESULTS: HiFR-VFI was consistent with CDFI in detecting laminar and nonlaminar flow in 81.4% of the cases; however, in 18.6% of the cases, only HiFR-VFI identified the nonlaminar flow. HiFR-VFI showed a larger extension of complex flow (0.37 ± 0.26 cm2 ) compared to CDFI (0.22 ± 0.21 cm2 ; p < 0.05). The flow patterns were classified into four types: 3 type-I (laminar flow), 35 type-II (rotational flow), 27 type-III (reversed flow), and 5 type-IV (complex flow). The Tur-value of type-IV (50.03 ± 14.97)% is larger than type-III (44.57 ± 8.89)%, type-II (16.30 ± 8.16)%, and type-I (1.48 ± 1.43)% (p < 0.05). Two radiologists demonstrated almost perfect interobserver agreement on recognizing the change of streamlines (κ = 0.81, p < 0.001). The intraclass correlation coefficient of the Tur-value was 0.98. CONCLUSION: HiFR-VFI can reliably characterize complex hemodynamics with quantitative turbulence measurement and may be an auxiliary diagnostic tool for assessing atherosclerotic arterial disease.

Evaluation of the transverse venous sinus with transcranial color-coded duplex.

BACKGROUND AND PURPOSE: Ultrasound-derived diagnosis of transverse venous sinus stenosis (TVSS) may have a promise given recent exploration of its role in pathophysiology of intracranial hypertension and availability of interventions like venous stenting. We investigated transverse venous sinus (TVS) insonation using transcranial color-coded duplex (TCCD) to establish normative values, inform on inherent physiological variability, and other measures to allow future studies on testing the construct validity of TCCD venous in diagnosing TVSS. METHODS: An institutional review board-approved prospective observational study evaluated 20 healthy volunteers to define TCCD-based measures for the TVS. Comparatively, the basal vein of Rosenthal, deep middle cerebral veins, and internal jugular veins were insonated. We report on physiological variability including the intrasubject, intersubject, and side-to-side variability; gradient of TVS velocities on each side from medial to lateral insonation; and the relationship between TVS and other insonated venous structures. RESULTS: Fifteen out of 20 subjects had the TVS insonated bilaterally, and five had unilaterally (four right, one left). TVS velocities had comparable intrasubject variability to other intracranial veins insonated and lower velocity-based variability than the pulsatility index. There was significant side-side variability in TVS-derived measures without discernible patterns. Insonating TVS from medial to lateral revealed a gradient with a bimodal peak in ultrasound-derived velocities. We did not find discernible relationships between TVS and other veins for TCCD-derived measures. CONCLUSIONS: These results can inform future studies validating the normative values in a larger sample and help explore the role of TCCD venous in the diagnosis of venous sinus stenosis.

Testicular torsion: an avascular testis at color Doppler ultrasound is not enough to prove the diagnosis.

INTRODUCTION: A Doppler ultrasound (US) of the scrotum is commonly used to improve the diagnostic confidence for testicular torsion in an emergency setting. However, the sensitivity of this investigation to identify torsion varies largely. This is due, in part, to a lack of guidelines on how-to perform the US and therefore training is necessary. EVIDENCE ACQUISITION: The Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology (ESUR-SPIWG) and the Section of Urological Imaging of the European Association of Urology (ESUI) established a joint panel of experts to standardize Doppler US investigation of patients with testicular torsion. The panel reviewed the available literature, identified accumulated knowledge and limitations, and released recommendations on how-to perform Doppler US in patients with acute scrotal pain. EVIDENCE SYNTHESIS: Diagnosis of testicular torsion is based on clinical evaluation and investigation of the cord, the testis, and the paratesticular structures. A preliminary clinical evaluation, including history and palpation, is necessary. Grey scale US, color Doppler US and spectral analysis must be performed by a sonologist with at least level 2 competence. Modern equipment with adequate grey-scale and Doppler capabilities are required. CONCLUSIONS: Standardization of Doppler US in suspicious testicular torsion is presented, with the aim to obtain comparable results among different centres, prevent unnecessary operations, and improve patient management.

A comparison between the superb microvascular imaging technique and conventional Doppler ultrasound in evaluating chronic allograft damage in renal transplant recipients

PURPOSE: The present study comparatively evaluates the performance of conventional Doppler ultrasound and superb microvascular imaging (SMI) in delineating the cortical microvessels of the transplanted kidney and compares the chronic allograft damage index (CADI) based on the examination of biopsy specimens with Doppler ultrasound and SMI findings. METHODS: Sixty-eight renal transplant recipients underwent kidney biopsy with the pre-diagnosis of rejection before undergoing renal Doppler ultrasound examination between January 2020 and October 2020. The distance between the kidney capsule and the vascular structure closest to the kidney capsule was measured at the level of the lower pole in the transplanted kidney using color Doppler ultrasound (CDUS), power Doppler ultrasound (PDUS), and the SMI technique. The kidney size, resistive index at the level of the arcuate artery in the lower pole of the kidney, and renal artery flow rates were also measured. RESULTS: The mean distance between the kidney capsule and the vessel was 2.44 ± 2.0 mm on CDUS, 1.34 ± 1.2 mm on PDUS, 0.99 ± 1.8 mm using the color SMI (cSMI) technique, and 0.86 ± 1.8 mm using the monochrome SMI (mSMI) technique. The study found that the SMI technique was superior to CDUS and PDUS in delineating the cortical microvasculature of the kidney. Both Doppler ultrasound examinations and the SMI technique proved effective in predicting the CADI (P = 0.006 for CDUS, P = 0.002 for PDUS, P = 0.018 for cSMI, and P = 0.027 for mSMI). Among conventional Doppler ultrasound examinations and the SMI technique, PDUS had the highest sensitivity, and cSMI had the highest specificity in differentiating high and low CADI values. Both the cSMI and mSMI techniques had similar sensitivity values, whereas only cSMI exhibited high specificity. CDUS had the lowest specificity value (P = 0.003 for CDUS, P = 0.002 for PDUS, P = 0.005 for cSMI, and P = 0.004 for mSMI). CONCLUSION: The present study is the first in the literature to demonstrate the utility of the distance between the kidney capsule and the vessels in predicting the CADI score and to compare the Doppler ultrasound examinations and SMI technique in doing so.

Application of B-flow imaging and its enhanced mode in perforator mapping.

AIM: To explore the value of B-flow (B-mode blood flow) imaging and its enhanced mode in perforator mapping. MATERIALS AND METHODS: Before surgery, B-flow imaging, enhanced B-flow imaging, colour Doppler flow imaging (CDFI), and contrast-enhanced ultrasound (CEUS) were used to detect the skin-perforating vessels and small vessels in the fat layer of the donor site. Taking the intra-operative results as the reference standard, the diagnostic consistency and efficiency of the four modes were compared. Statistical analysis was performed using the Friedman M-test, Cochran's Q-test, and the Z-test. RESULTS: Thirty flaps were excised, with 34 skin-perforating vessels and 25 non-skin-perforating vessels, as confirmed during surgery. In order of the number of skin-perforating vessels detected, the results showed that enhanced B-flow imaging detected more vessels than B-flow imaging and CDFI (all p<0.05), CEUS detected more vessels than B-flow imaging and CDFI (all p<0.05), B-flow imaging detected more vessels than CDFI (p<0.05). All four modes had remarkable and satisfactory diagnostic consistency and effectiveness, but B-flow imaging was the best (sensitivity 100%, specificity 92%, Youden index 0.92). In order of the number of small vessels in the fat layer detected, the results showed that enhanced B-flow imaging detected more vessels than CEUS, B-flow imaging, and CDFI (all p<0.05). CEUS detected more vessels than B-flow imaging and CDFI (all p<0.05). CONCLUSION: B-flow imaging is an alternative method for perforator mapping. Enhanced B-flow imaging can reveal the microcirculation of flaps.