Pain type and neuropathic pain components in acute herpes zoster.

OBJECTIVES: The aim of this study was to investigate the pain type (nociceptive or neuropathic) and neuropathic pain components in patients with acute herpes zoster (HZ). METHODS: Patients with acute HZ referred to the outpatient Dermatology and Venereology clinic between January 2021 and January 2022 were retrospectively detected. The demographic data including gender and age, rash localization, pain severity, and neuropathic pain components were recorded. Pain severity and neuropathic pain components were evaluated using a Visual Analog Scale (VAS) and Douleur Neuropathique 4 (DN4), respectively. RESULTS: The study included a total of 58 patients, comprising 33 females and 25 males. Of these patients, 35 (60.3%) were found to have neuropathic pain. Itching, burning, pins and needles, and tingling were the most frequently reported neuropathic pain signs and symptoms. The proportion of female patients with neuropathic pain was found to be significantly higher than that of male patients (p=0.021). No significant differences were observed in the distribution of pain across different body sites or in the age of patients with neuropathic pain (p>0.05). Itching was significantly more common in younger patients (p=0.02). CONCLUSION: In conclusion, the study found that over half of the patients with acute HZ experienced neuropathic pain, and this was more frequently observed in female patients. Analysis of different components of neuropathic pain showed significant differences in age, gender, and site distribution. The findings of this study may have important implications for the manage-ment and treatment of acute HZ.

The relationship between disability and depression, anxiety, and sleep quality in patients with coccydynia.

OBJECTIVES: In this study, our aim was to investigate the relationship between sleep quality, anxiety, depression, and disability in patients with coccydynia. METHODS: This prospective cross-sectional study evaluated 60 patients diagnosed with coccydynia. Clinical and demographic characteristics of the patients were recorded. Outcome measures included the Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), and Pittsburgh Sleep Quality Index (PSQI), which were analyzed. RESULTS: Depressive symptoms and anxiety were detected in 47 (78.3%) and 49 (81.6%) of the 60 patients, respectively. Additionally, 46 (76.7%) patients were identified as poor sleepers. Our results demonstrated a statistically significant positive correlation between the quality of sleep and anxiety and depressive symptoms scores (p<0.001); there was also a statistically weak positive correlation with disability index values. CONCLUSION: Depressive symptoms, anxiety, and poor sleep quality are exacerbated by disability in coccydynia. While coccydynia has been previously associated with neurotic disorders, the mechanisms underlying poor sleep quality remain unclear.

A Randomized Comparison Between Interscalene and Combined Interscalene-Suprascapular Blocks for Arthroscopic Shoulder Surgery: A Prospective Clinical Study.

Background: To compare the analgesic effect of ISB with a combination of ISB-SSNB and patients who were given opioids with PCA without block in adult patients undergoing shoulder surgery, as measured by opioid consumption and pain intensity in the first 24 hours postoperatively. Methods: Ninety patients who underwent shoulder surgery were randomly divided into three groups. Group I in which ISB was performed and patient-controlled analgesia (PCA) was inserted, Group II with; ISB and SSNB combined, and PCA was inserted, and Group III where; only PCA was used. Visual analog scale (VAS) pain scores at the second, fourth, sixth, 12th, and 24th hours, morphine consumption, additional analgesic requirement, and patient satisfaction were evaluated. Results: Compared with Group III, the VAS pain score was significantly lower in Group I and Group II at 2, 4, 6, 12, and 24 hours postoperatively. In Group I, the VAS score at rest at the 6th hour was found to be higher than in Group II. The 24-hour total morphine consumption was higher in the control group than in Group I and Group II. The satisfaction score of the control group was lower than Group I and Group II. Conclusion: The combined application of ISB and SSNB block is beneficial in shoulder surgery to provide both intraoperative and postoperative analgesia and opioid consumption. Level of Evidence: Level I; Randomized Controlled Trial; Treatment Study.

Cardiac PET Myocardial Blood Flow Quantification Assessment of Early Cardiac Allograft Vasculopathy.

BACKGROUND: Positron emission tomography (PET) has demonstrated utility for diagnostic and prognostic assessment of cardiac allograft vasculopathy (CAV) but has not been evaluated in the first year after transplant. OBJECTIVES: The authors sought to evaluate CAV at 1 year by PET myocardial blood flow (MBF) quantification. METHODS: Adults at 2 institutions enrolled between January 2018 and March 2021 underwent prospective 3-month (baseline) and 12-month (follow-up) post-transplant PET, endomyocardial biopsy, and intravascular ultrasound examination. Epicardial CAV was assessed by intravascular ultrasound percent intimal volume (PIV) and microvascular CAV by endomyocardial biopsy. RESULTS: A total of 136 PET studies from 74 patients were analyzed. At 12 months, median PIV increased 5.6% (95% CI: 3.6%-7.1%) with no change in microvascular CAV incidence (baseline: 31% vs follow-up: 38%; P = 0.406) and persistent microvascular disease in 13% of patients. Median capillary density increased 30 capillaries/mm2 (95% CI: -6 to 79 capillaries/mm2). PET myocardial flow reserve (2.5 ± 0.7 vs 2.9 ± 0.8; P = 0.001) and stress MBF (2.7 ± 0.6 vs 2.9 ± 0.6; P = 0.008) increased, and coronary vascular resistance (CVR) (49 ± 13 vs 47 ± 11; P = 0.214) was unchanged. At 12 months, PET and PIV had modest correlation (stress MBF: r = -0.35; CVR: r = 0.33), with lower stress MBF and higher CVR across increasing PIV tertiles (all P < 0.05). Receiver-operating characteristic curves for CAV defined by upper-tertile PIV showed areas under the curve of 0.74 for stress MBF and 0.73 for CVR. CONCLUSIONS: The 1-year post-transplant PET MBF is associated with epicardial CAV, supporting potential use for early noninvasive CAV assessment. (Early Post Transplant Cardiac Allograft Vasculopahty [ECAV]; NCT03217786).

Isolated Subclinical Right Ventricle Systolic Dysfunction in Patients after Liver Transplantation.

Although hemodynamic alterations in end-stage liver disease (ESLD) and its association with porto-pulmonary hypertension have been well-established, the long-term effects of ESLD on RV systolic function in patients without porto-pulmonary hypertension remain disregarded. Here we aimed to assess the long-term effect of ESLD on RV function and its relationship with the use of NSBBs and clinical, laboratory and imaging parameters in end-stage liver disease. The use of NSBBs is still controversial due to concerns about reduced cardiac contractility and the possibility of increased mortality. Thirty-four liver transplant recipients were included. Demographic characteristics, laboratory and baseline echocardiography measures were obtained. Patients were recalled for transthoracic echocardiographic evaluation after transplantation. Right ventricle dysfunction was identified by having at least one value below the reference levels of RV S', or TAPSE. Isolated subclinical RV dysfunction was observed at 20.6% of the sample population. The present study demonstrates hemodynamic circulation in cirrhosis and increased preload and afterload might have long-term effects on RV function, even the lack of porto-pulmonary hypertension. These findings underline the significance of cardiac function follow-up in cirrhotic patients after transplantation. In this study, patients treated with propranolol seemed to have better RV function and less gastrointestinal bleeding. We speculated that preoperative propranolol treatment might help preserve RV function by providing RAS suppression, improving endothelial function and hyperdynamic circulation seen in ESLD. This potential protective relationship between the use of propranolol and RV function might improve mortality or graft-failure during OLT and after liver transplantation in patients with cirrhosis.

Acquisition, Processing, and Interpretation of PET 18F-FDG Viability and Inflammation Studies.

PURPOSE OF REVIEW: This article reviews the acquisition protocols and image interpretation for 18F-fluorodeoxyglucose (18F-FDG) imaging with positron emission tomography (PET) applied to the evaluation of myocardial viability and inflammation. RECENT FINDINGS: Cardiac PET with 18F-FDG provides essential information for the assessment of myocardial viability and inflammation and is usually combined with PET perfusion imaging using 82Rb or 13N-ammonia. Viable myocardium maintains glucose metabolism which can be detected via the uptake of 18F-FDG by PET imaging. The patient is prepared for viability imaging by shifting the metabolism of the heart to maximize the uptake of glucose and hence of 18F-FDG. Comparison of the 18F-FDG and myocardial perfusion images allows distinction between regions of the myocardium that are hibernating and thus may recover function with intervention, from those that are infarcted. Increased glucose utilization in the inflammatory cells also makes 18F-FDG a useful imaging technique in conditions such as cardiac sarcoidosis. Here, suppression of normal myocardial uptake is essential for accurate image interpretation. 18F-FDG PET broadens the scope of information potentially available through a cardiac PET study. With careful patient preparation, it provides valuable insights into myocardial viability and inflammatory processes such as sarcoidosis.

Effectiveness of point-of-care oral ivabradine for cardiac computed tomography.

BACKGROUND: Coronary CT angiography (CCTA) is increasing seen as a first line investigation in patients with suspected coronary artery disease. Heart-rate control improves the image quality and diagnostic accuracy of CCTA. Typically, beta-blockers are administered to induce sinus bradycardia. Sinus bradycardia may also be induced by ivabradine. We hypothesized that in a real-world population ivabradine would be an effective alternative to metoprolol at heart rate lowering for CCTA. METHODS: This was a retrospective analysis of consecutive patients who were exposed to an ivabradine-based (IB) versus a metoprolol-only (MO) protocol to achieve a target heart rate 65 and received heart-rate lowering medication: 1958 patients had MO, and 718 received IB protocol. Target heart rate of

Atrial Arrhythmias in Clinically Manifest Cardiac Sarcoidosis: Incidence, Burden, Predictors, and Outcomes.

Background Recent data have suggested a substantial incidence of atrial arrhythmias (AAs) in cardiac sarcoidosis (CS). Our study aims were to first assess how often AAs are the presenting feature of previously undiagnosed CS. Second, we used prospective follow-up data from implanted devices to investigate AA incidence, burden, predictors, and response to immunosuppression. Methods and Results This project is a substudy of the CHASM-CS (Cardiac Sarcoidosis Multicenter Prospective Cohort Study; NCT01477359). Inclusion criteria were presentation with clinically manifest cardiac sarcoidosis, treatment-naive status, and implanted with a device that reported accurate AA burden. Data were collected at each device interrogation visit for all patients and all potential episodes of AA were adjudicated. For each intervisit period, the total AA burden was obtained. A total of 33 patients met the inclusion criteria (aged 56.1±7.7 years, 45.5% women). Only 1 patient had important AAs as a part of the initial CS presentation. During a median follow-up of 49.1 months, 11 of 33 patients (33.3%) had device-detected AAs, and only 2 (6.1%) had a clinically significant AA burden. Both patients had reduced burden after CS was successfully treated and there was no residual fluorodeoxyglucose uptake on positron emission tomography scan. Conclusions First, we found that AAs are a rare presenting feature of clinically manifest cardiac sarcoidosis. Second, AAs occurred in a minority of patients at follow-up; the burden was very low in most patients. Only 2 patients had clinically significant AA burden, and both had a reduction after CS was treated. Registration URL: https://www.clini​caltr​ials.gov; unique identifier NCT01477359.

The Future of Cardiac Molecular Imaging.

Molecular imaging with positron emission tomography (PET) and single-photon emission computed tomography (SPECT) serves numerous applications in clinical cardiology and research. Similar to other medical imaging technologies, this area has undergone and continues to experience rapid changes resulting from technological and medical advances. These have immediate impacts on diagnosis, treatment planning, and patient care, as well as supplying innovative tools for fundamental and translational research. A broad shift toward hybrid PET systems and incorporation of advanced computational tools has been accompanied by mechanism-specific, targeted radiopharmaceuticals that seek to address long-standing limitations in cardiac imaging. While this review addresses some of the still-emerging clinical uses of established radiopharmaceuticals, it too highlights newer imaging probes, applications, and imaging techniques and instrumentation on the horizon. We highlight molecular imaging advances in inflammatory and infiltrative myocardial conditions, heart metabolism, vascular and valvular diseases, neurohormonal dysregulation, and transformational technical advances such as the rise of artificial intelligence and theranostic approaches to cardiovascular disease.

PET and SPECT Tracers for Myocardial Perfusion Imaging.

Coronary artery disease has been the leading cause of death since the 1960s, which has motivated the research and development of myocardial perfusion imaging (MPI) agents for early diagnosis and to guide treatment. MPI with SPECT has been the clinical workhorse for MPI, but over the past two decades PET MPI is experiencing growth due to enhanced image quality that results in superior diagnostic accuracy over SPECT. Furthermore, dynamic PET imaging of the tracer distribution process from time of tracer administration to tracer accumulation in the myocardium has enabled routine quantification of myocardial blood flow (MBF) and myocardial flow reserve (MFR) in absolute units. MBF and MFR incrementally improve diagnostic and prognostic accuracy over MPI alone. In some cases (eg, rubidium PET imaging with pharmacologic stress) MPI, MBF, and MFR can be acquired simultaneously without incremental cost, radiation exposure, or significant processing time. Nuclear cardiology clinics have been looking to incorporate MBF quantification into clinical routine, but traditional SPECT and MPI tracers are inadequate for this challenge. Cardiac dedicated SPECT scanners can also perform dynamic imaging and have stimulated research into MBF quantification using SPECT tracers. New perfusion tracers must be tailored for emerging clinical needs (including MBF quantification), technical capabilities of imaging instrumentation, market constraints, and supply chain feasibility. Because these conditions have been evolving, tracers previously considered inferior may be reconsidered for future applications and some recently developed tracers may be suboptimal. This article reviews current, clinically-available tracers and those under development showing greatest potential. It discusses for each tracer the rationale for development, physiological mechanism of uptake by the myocardium, published evaluation results and development state. Finally, it gauges the suitability of each tracer for clinical application. The article demonstrates an acceleration in the pace of perfusion radiotracer development due to better understanding of the relevant physiology, better chemistry tools and small animal imaging. Consequently, bad tracers may fail faster and with less wasted investment, and good tracers may translate more efficiently from bench to bedside.

Decreased left atrial global longitudinal strain predicts the risk of atrial fibrillation recurrence after cryoablation in paroxysmal atrial fibrillation.

PURPOSE: We aimed to investigate the association of atrial fibrillation (AF) recurrence with left atrial (LA) strain in nonvalvular paroxysmal AF patients after cryoablation. METHODS: We included 190 patients who underwent successful cryoablation due to paroxysmal AF. In addition to classical echocardiographic data, LA apical 2-chamber (A2C) strain, LA apical 4-chamber (A4C) strain, and LA global longitudinal strain (LA-GLS) values were calculated by speckle tracking echocardiography. Forty-eight-hour Holter monitoring was performed to all patients no later than 6 months after ablation. RESULTS: AF recurrence was detected in 42 patients (22.1%). End-systolic diameter, LA end-systolic diameter, LA-volume, LA-volume index, interatrial septum thickness, coronary sinus diameter, epicardial fat thickness (EFT), and septal E/E` ratio were significantly higher, LV-EF, IVRT, septal S and A` wave, lateral S wave, LA-A2C strain, LA-A4C strain, and LA-GLS were significantly lower in patients with AF recurrence. LA-GLS, LA-volume index, and EFT were found to be independent parameters for predicting AF recurrence. CONCLUSIONS: LA-GLS and LAVI should be included in routine evaluations to determine long-term AF recurrence preoperatively.

Relationship between erythrocyte sedimentation rate and choroidal and retinal thickness in Behçet's disease / A relação entre a taxa de sedimentação eritrocitária, espessuras de coroide e retina na doença de Behçet

ABSTRACT Purpose: To compare retinal and choroidal thickness in patients with Behçet's disease with and without ocular involvement as well as to evaluate the correlation between erythrocyte sedimentation rate and choroidal thickness among patients with Behçet's disease. Methods: This was a prospective interventional study investigating erythrocyte sedimentation as well as choroidal and retinal thickness among patients with Behçet's disease. Patients who were diagnosed based on The International Criteria for Behçet's Disease with (Group A) or without (Group B) ocular involvement and a matched control group (Group C) participated in the study. Optical coherence tomography measurements and blood tests were performed on the same day. Retinal and choroidal thickness were measured using spectral-domain optical coherence tomography (Spectralis, Heidelberg Engineering, Heidelberg, Germany), and central macular thickness, central subfoveal choroidal thickness, and retinal nerve fiber layer thickness were measured using optical coherence tomography. Results: Average erythrocyte sedimenta­tion values were 9.89 mm/h in Group A, 16.21 mm/h in Group B, and 3.89 mm/h in Group C; average central subfoveal choroidal thickness values were 350.66, 331.74, and 325.95 mm, respectively. Average central macular thickness and retinal nerve fiber layer thickness values of patients in Groups A, B and C were 226.39 and 225.97mm; 234.11 and 92.00 mm; and 97.58 and 99.84 mm, respectively. No significant difference was seen between Group A and B patients in central subfoveal choroidal thickness, central macular thickness, or retinal nerve fiber layer thickness values. Central macular thickness was statistically significantly thinner in Groups A and B than in Group C (p=0.016). Group A had thinning in the nasal quadrant of the retinal and general retinal nerve fiber layers when compared with those in Group C (p=0.010 and 0.041, respectively). A connection could not be established between the erythrocyte sedimentation, central subfoveal cho­roidal thickness, central macular thickness, and retinal nerve fiber layer thickness in the patients with Behçet's disease. Conclusion: The erythrocyte sedimentation rate is typically used to test for activation of Behçet's disease and assess treatment response. In our study, we could not establish a connection between the erythrocyte sedimentation rate and central subfoveal choroidal thickness, central macular thickness, and retinal nerve fiber layer thickness in patients with systematically active Behçet's disease without ocular involvement.

RESUMO Objetivos: Comparar a espessura da retina e da coroide em pacientes com doença de Behçet, com e sem acometimento ocular e avaliar a correlação entre a taxa de sedimentação de eritrócitos e a espessura da coroide em pacientes com doença de Behçet. Métodos: Estudo prospectivo intervencional que investigou a sedimentação de eritrócitos, espessura de coroide e da retina em pacientes com doença de Behçet. Os pacientes que foram diagnosticados com base nos Critérios Internacionais para a Doença de Behçet com (Grupo A) ou sem (Grupo B) envolvimento ocular e um grupo controle correspondente (Grupo C) participaram do estudo. Medidas de tomografia de coerência óptica e exames de sangue foram realizados no mesmo dia. As espessuras da retina e da coroide foram medidas utilizando tomografia de coerência óptica de domínio espectral (Spectralis, Heidelberg Engineering, Hidelberg, Germany) e a espessura macular central, a espessura coroidal subfoveal central e a espessura da camada de fibra nervosa da retina foram medidas usando tomografia de coerência óptica. Resultados: Os valores médios de sedimentação de eritrócitos foram de 9,89 mm/h no Grupo A, 16,21 mm/h no Grupo B e 3,89 mm/h no Grupo C; os valores médios da espessura da coroide subfoveal central foram 350,66, 331,74 e 325,95 mm respectivamente. Os valores médios da espessura macular central e da espessura da camada de fibra nervosa da retina dos pacientes nos grupos A, B e C foram de 226,39, 225,97, 234,11 mm e 92,00, 97,58, 99,84 mm respectivamente. Não houve diferença significativa entre pacientes do Grupo A e B na espessura da coroide subfoveal central, espessura macular central ou valores da espessura da camada de fibra nervosa da retina. A espessura macular central foi estatisticamente significativamente mais fina nos Grupos A e B do que no Grupo C (p=0,016). O Grupo A apresentou afinamento na porção nasal das camadas retiniana e geral da fibra nervosa da retina quando comparado com o Grupo C (p=0,010, p=0,041, respectivamente). Não foi possível estabelecer uma conexão entre a sedimentação dos eritrócitos, a espessura subfoveal central da coroide, a espessura macular central e espessura da camada de fibras nervosas da retina nos pacientes com doença de Behçet. Conclusão: A taxa de sedimentação de eritrócitos é comumente utilizada para testar a ativação da doença de Behçet e avaliar a resposta ao tratamento. Em nosso estudo, não foi possível estabelecer uma conexão entre a taxa de sedimentação de eritrócitos e a espessura da coroide subfoveal central, espessura macular central e espessura da camada de fibras nervosas da retina em pacientes com doença de Behçet sistematicamente ativa sem envolvimento ocular.

Relationship between erythrocyte sedimentation rate and choroidal and retinal thickness in Behçet's disease.

PURPOSE: To compare retinal and choroidal thickness in patients with Behçet's disease with and without ocular involvement as well as to evaluate the correlation between erythrocyte sedimentation rate and choroidal thickness among patients with Behçet's disease. METHODS: This was a prospective interventional study investigating erythrocyte sedimentation as well as choroidal and retinal thickness among patients with Behçet's disease. Patients who were diagnosed based on The International Criteria for Behçet's Disease with (Group A) or without (Group B) ocular involvement and a matched control group (Group C) participated in the study. Optical coherence tomography measurements and blood tests were performed on the same day. Retinal and choroidal thickness were measured using spectral-domain optical coherence tomography (Spectralis, Heidelberg Engineering, Heidelberg, Germany), and central macular thickness, central subfoveal choroidal thickness, and retinal nerve fiber layer thickness were measured using optical coherence tomography. RESULTS: Average erythrocyte sedimenta-tion values were 9.89 mm/h in Group A, 16.21 mm/h in Group B, and 3.89 mm/h in Group C; average central subfoveal choroidal thickness values were 350.66, 331.74, and 325.95 mm, respectively. Average central macular thickness and retinal nerve fiber layer thickness values of patients in Groups A, B and C were 226.39 and 225.97mm; 234.11 and 92.00 mm; and 97.58 and 99.84 mm, respectively. No significant difference was seen between Group A and B patients in central subfoveal choroidal thickness, central macular thickness, or retinal nerve fiber layer thickness values. Central macular thickness was statistically significantly thinner in Groups A and B than in Group C (p=0.016). Group A had thinning in the nasal quadrant of the retinal and general retinal nerve fiber layers when compared with those in Group C (p=0.010 and 0.041, respectively). A connection could not be established between the erythrocyte sedimentation, central subfoveal cho-roidal thickness, central macular thickness, and retinal nerve fiber layer thickness in the patients with Behçet's disease. CONCLUSION: The erythrocyte sedimentation rate is typically used to test for activation of Behçet's disease and assess treatment response. In our study, we could not establish a connection between the erythrocyte sedimentation rate and central subfoveal choroidal thickness, central macular thickness, and retinal nerve fiber layer thickness in patients with systematically active Behçet's disease without ocular involvement.

Morning blood pressure surge is associated independently with orthostatic hypotension in hypertensive patients under treatment.

OBJECTIVE: Morning blood pressure surge (MBPS) and orthostatic hypotension (OH) play a role in the occurrence of cardiovascular events. We aimed to investigate the association between MBPS and OH in hypertensive patients under treatment. PATIENTS AND METHODS: We prospectively included 297 patients (mean age: 53.8±10.7 years, male/female: 101/196) with essential hypertension. Tilt table testing was performed for the diagnosis of OH. OH was classified into three groups as initial OH (0-15 s), classical OH (15 s to 3 min), and delayed OH (3-30 min). Patients were categorized into two main groups: patient with OH or without OH. We used sleep-through MBPS. The MBPS was calculated as the difference between the average blood pressure (BP) during the 2 h after awakening and the lowest night-time BP. RESULTS: We detected initial OH in two patients, classic OH in seven patients, delayed OH in 20 patients, and delayed OH with syncope in two patients. MBPS, thiazide diuretic, and α-blocker treatments were found to be associated independently with the occurrence of OH. Every 10 mmHg increase in MBPS was found to increase the rate of development of OH by 29.6%. The cut-off value of MBPS obtained by the receiver operator characteristic curve analysis was 35 mmHg for the prediction of OH occurrence (sensitivity: 58.0%, specificity: 68.0%). The area under the curve was 0.657 (95% confidence interval: 0.553-0.771, P=0.004). CONCLUSION: OH is a major problem in hypertensive patients. Increased MBPS, which can be detected easily by 24-h ambulatory BP monitor, predicts the occurrence of OH independently.

Incremental value of live/real time three-dimensional transesophageal echocardiography in the assessment of ventricular septal rupture following acute myocardial infarction.

Ventricular septal rupture is a serious complication following acute myocardial infarctions and is associated with a significant mortality rate. Classically, two-dimensional transthoracic echocardiography has been used to diagnose this complication and visualize its location. Two-dimensional transesophageal echocardiography has supplemented the transthoracic approach by providing more accurate assessment of the defect size and in guiding closure both percutaneously and intraoperatively. This modality, however, is limited to two-dimensional views only, and a greater breadth of information is instead available through the use of three-dimensional transesophageal echocardiography. We present a series of 11 patients in which live/real time three-dimensional transesophageal echocardiography offered incremental benefits over two-dimensional imaging alone.