Correlation between normally aerated lung and respiratory system compliance at clinical high positive end-expiratory pressure in patients with COVID-19.

Normally aerated lung tissue on computed tomography (CT) is correlated with static respiratory system compliance (Crs) at zero end-expiratory pressure. In clinical practice, however, patients with acute respiratory failure are often managed using elevated PEEP levels. No study has validated the relationship between lung volume and tissue and Crs at the applied positive end-expiratory pressure (PEEP). Therefore, this study aimed to demonstrate the relationship between lung volume and tissue on CT and Crs during the application of PEEP for the clinical management of patients with acute respiratory distress syndrome due to COVID-19. Additionally, as a secondary outcome, the study aimed to evaluate the relationship between CT characteristics and Crs, considering recruitability using the recruitment-to-inflation ratio (R/I ratio). We analyzed the CT and respiratory mechanics data of 30 patients with COVID-19 who were mechanically ventilated. The CT images were acquired during mechanical ventilation at PEEP level of 15 cmH2O and were quantitatively analyzed using Synapse Vincent system version 6.4 (Fujifilm Corporation, Tokyo, Japan). Recruitability was stratified into two groups, high and low recruitability, based on the median R/I ratio of our study population. Thirty patients were included in the analysis with the median R/I ratio of 0.71. A significant correlation was observed between Crs at the applied PEEP (median 15 [interquartile range (IQR) 12.2, 15.8]) and the normally aerated lung volume (r = 0.70 [95% CI 0.46-0.85], P < 0.001) and tissue (r = 0.70 [95% CI 0.46-0.85], P < 0.001). Multivariable linear regression revealed that recruitability (Coefficient = - 390.9 [95% CI - 725.0 to - 56.8], P = 0.024) and Crs (Coefficient = 48.9 [95% CI 32.6-65.2], P < 0.001) were significantly associated with normally aerated lung volume (R-squared: 0.58). In this study, Crs at the applied PEEP was significantly correlated with normally aerated lung volume and tissue on CT. Moreover, recruitability indicated by the R/I ratio and Crs were significantly associated with the normally aerated lung volume. This research underscores the significance of Crs at the applied PEEP as a bedside-measurable parameter and sheds new light on the link between recruitability and normally aerated lung.

Adverse plasma branched-chain amino acid profile mirrors fatty muscle degeneration in diabetic heart failure patients.

AIMS: Elevated plasma branched-chain amino acids (BCAAs) are tightly linked to incident diabetes and its complications, while lower BCAAs are associated with adverse outcomes in the elderly and heart failure (HF) patients. The interplay between body compositions and plasma BCAAs, especially under the influence of co-morbid diabetes in HF patients, is not well understood. Here, we examined the impact of diabetes on the prognostic value of plasma BCAA and its association with body compositions in HF patients. METHODS AND RESULTS: We retrospectively examined 301 HF patients (70 ± 15 years old; 59% male), among which 36% had diabetes. Blood samples for plasma BCAA measurements were collected in a fasting state after stabilization of HF and analysed using ultraperformance liquid chromatography. A dual-energy X-ray absorptiometry scan assessed regional body compositions, and muscle wasting was defined as appendicular skeletal muscle mass index (ASMI) < 7.00 and <5.40 kg/m2 for males and females, respectively, according to the criteria of the Asian Working Group for Sarcopenia. Although analyses of covariance revealed that plasma BCAAs were significantly higher in diabetic patients, low valine (<222.1 nmol/mL) similarly predicted adverse events defined by HF hospitalization, lethal arrhythmia, or all-cause death in both diabetic and non-diabetic patients independently of age, sex, and NT-proBNP (adjusted hazard ratio [HR] 3.1, 95% confidence interval [CI] of 1.1-8.6 and adjusted HR 2.67, 95% CI 1.1-6.5, respectively; P for interaction 0.88). In multivariate linear regression analyses comprising age, sex, and regional body compositions as explanatory variables, plasma BCAAs were positively correlated with visceral adipose tissue area in non-diabetic patients (standardized ß coefficients [ß] = 0.44, P < 0.001). In contrast, in diabetic patients, plasma BCAAs were correlated positively with ASMI (ß = 0.49, P = 0.001) and negatively with appendicular fat mass index (AFMI; ß = -0.42, P = 0.004). Co-morbid diabetes was independently associated with muscle wasting (adjusted odds ratio 2.1, 95% CI 1.1-4.0) and significantly higher plasma 3-methylhistidine level, a marker of myofibrillar degradation. In diabetic patients, ASMI uniquely showed a J-shaped relationship with AFMI, and in a subgroup of HF patients with muscle wasting, diabetic patients showed 12% higher AFMI than non-diabetic patients despite comparable ASMI reductions. CONCLUSIONS: Despite higher plasma BCAA levels in HF patients with diabetes, the prognostic value of low valine remained consistent regardless of diabetes status. However, low BCAAs were distinctly associated with fatty muscle degeneration in the extremities in diabetic patients, suggesting the importance of targeted interventions to prevent such tissue remodelling in this population.

Partial arch replacement of type A aortic dissection after thoracic endovascular aortic repair for type B dissection.

BACKGROUND: Stent graft-induced new entry (SINE), defined as the stent graft-induced formation of a new entry point for blood to enter an area, is increasingly being observed after thoracic endovascular aortic repair (TEVAR) for Stanford type B aortic dissection worldwide. We herein describe a case of Stanford type A aortic dissection due to proximal SINE after TEVAR for Stanford type B dissection. CASE PRESENTATION: This case involved a 58-year-old man with type A aortic dissection due to SINE. Six years previously, he had developed severe back pain and was diagnosed with type B aortic dissection after computed tomography examination. Because the primary entry was positioned at the descending aorta, we conducted TEVAR for exclusion of the entry with a GORE TAG conformable thoracic aortic graft. He was thereafter followed by our hospital. Six years later, he developed jaw pain and was examined at another hospital. He was transferred to our hospital because of the possibility of type A dissection. Computed tomography revealed type A aortic dissection with proximal site SINE. Emergency partial arch replacement was conducted, and he was discharged on postoperative day 27. Because the entry was at the lesser curve of the arch, we excluded the entry and conducted partial arch replacement. CONCLUSIONS: In this case, proximal SINE occurred 6 years after TEVAR. Because SINE may occur even in the long term after TEVAR, careful follow-up is necessary.

A Case of a Giant Hemangioma of a Primary Cardiac Tumor.

We report a case of a 71-year-old female with a primary cardiac tumor. The patient had undergone surgery for uterine cancer 10 years ago and presented to a nearby clinic complaining of dyspnea on exertion. Chest X-ray revealed cardiac enlargement, prompting further investigations, which revealed a massive tumor protruding into the left atrium and extending toward the outer wall of the left ventricle. The patient was referred to a cardiac surgery department for myocardial biopsy. The tumor biopsy confirmed a diagnosis of a vascular tumor. Due to the tumor's large size and the difficulty in achieving complete resection, a conservative approach was chosen as the patient expressed a preference for non-surgical treatment. This is an extremely rare case of a large primary cardiac tumor, and we report it accordingly.

Initial Outcomes of Physician-Modified Inner Branched Endovascular Repair in High-Surgical-Risk Patients.

PURPOSE: To report the initial outcomes of physician-modified inner branched endovascular repair (PMiBEVAR) for pararenal aneurysms (PRAs), thoracoabdominal aortic aneurysms (TAAAs), and aortic arch aneurysms in high-surgical-risk patients. MATERIALS AND METHODS: A total of 10 patients (6 men; median age, 83.0 years) treated using PMiBEVAR were enrolled in this retrospective, single-center study. All patients were at high surgical risk because of severe comorbidities (American Society of Anesthesiologists physical status score≥3 or emergency repair). End points were defined as technical success per patient and per vessel (successful deployment), clinical success (no endoleaks postoperatively), in-hospital death, and major adverse events. RESULTS: There were 3 PRAs, 4 TAAAs, and 3 aortic arch aneurysms with 12 renal-mesenteric arteries and 3 left subclavian arteries incorporated by inner branches. The technical success rate was 90.0% (9/10) per patient and 93.3% (14/15) per vessel. The clinical success rate was 90% (9/10). There were 2 in-hospital deaths, unrelated to aneurysms. Paraplegia and shower emboli occurred separately in 2 patients. Three patients experienced prolonged ventilation for 3 days after surgery. Aneurysm sac shrinkage occurred in 4 patients, and aneurysm size stabilized in 1 patient during follow-up, more than 6 months later. None of the patients required intervention. CONCLUSION: PMiBEVAR is a feasible approach for treating complex aneurysms in high-surgical-risk patients. This technology may complement the existing technology in terms of improved anatomical adaptability, no time delay and practicability in many countries. However, long-term durability remains undetermined. Further large-scale and long-term studies are needed. CLINICAL IMPACT: This is the first clinical study to investigate outcomes of physician-modified inner branched endovascular repair (PMiBEVAR). PMiBEVAR for treating pararenal aneurysm, thoracoabdominal aortic aneurysm, or aortic arch aneurysm is a feasible procedure. This technology is likely to complement existing technology in terms of improved anatomical adaptability (compared to off-the-shelf devices), no time delay (compared to custom-made devices), and the potential to be performed in many countries. On the other hand, surgery time varied greatly depending on the case, suggesting a learning curve and the need for technological innovation to perform more consistent surgeries.

A suicide attempt by intramuscular injection of pentobarbital sodium into rectus abdominis suggested by computed tomography.

Suicide attempts in humans due to injections of the veterinary drug pentobarbital sodium have been rarely reported. Herein, we present a case of a suicide attempt by intramuscular injection of pentobarbital sodium into the rectus abdominis muscle, which was suggested by computed tomography (CT). A 73-year-old man was brought to the emergency department with GCS 3 (E1V1M1) and an incised wound on the right side of the neck. A bottle of Somnopentyl® (pentobarbital sodium, 64.8 mg/ml), a 20-ml empty syringe with an 18-mm needle, and no. 10 scalpel were present at the scene. At the emergency department, the patient was intubated and was admitted to the intensive care unit. A urine drug screen test by SIGNIFY® ER was positive for benzodiazepines and barbiturates, and continuous veno-venous hemofiltration (CHF) was initiated. The route of drug administration was initially unknown; however, a CT scan revealed swelling of the left rectus abdominis muscle with a wound suggestive of a needle puncture, and the CT analysis suggested 38.16 ml as the maximum dose of pentobarbital sodium. On day 3, the patient's consciousness improved, and he was weaned off CHF and mechanical ventilation. There have been several reports of postmortem CT yielding information on the site of administration of intoxicants, but there have been none for surviving intoxicated patients. This is the first report of the usefulness of CT to identify the site of administration of the causative agent of intoxication while the patient is still alive.

Correlation between the hysteresis of the pressure-volume curve and the recruitment-to-inflation ratio in patients with coronavirus disease 2019.

BACKGROUND: Since the response to lung recruitment varies greatly among patients receiving mechanical ventilation, lung recruitability should be assessed before recruitment maneuvers. The pressure-volume curve (PV curve) and recruitment-to-inflation ratio (R/I ratio) can be used bedside for evaluating lung recruitability and individualing positive end-expiratory pressure (PEEP). Lung tissue recruitment on computed tomography has been correlated with normalized maximal distance (NMD) of the quasi-static PV curve. NMD is the maximal distance between the inspiratory and expiratory limb of the PV curve normalized to the maximal volume. However, the relationship between the different parameters of hysteresis of the quasi-static PV curve and R/I ratio for recruitability is unknown. METHODS: We analyzed the data of 33 patients with severe coronavirus disease 2019 (COVID-19) who received invasive mechanical ventilation. Respiratory waveform data were collected from the ventilator using proprietary acquisition software. We examined the relationship of the R/I ratio, quasi-static PV curve items such as NMD, and respiratory system compliance (Crs). RESULTS: The median R/I ratio was 0.90 [interquartile range (IQR), 0.70-1.15] and median NMD was 41.0 [IQR, 37.1-44.1]. The NMD correlated significantly with the R/I ratio (rho = 0.74, P < 0.001). Sub-analysis showed that the NMD and R/I ratio did not correlate with Crs at lower PEEP (- 0.057, P = 0.75; and rho = 0.15, P = 0.41, respectively). On the contrary, the ratio of Crs at higher PEEP to Crs at lower PEEP (Crs ratio (higher/lower)) moderately correlated with NMD and R/I ratio (rho = 0.64, P < 0.001; and rho = 0.67, P < 0.001, respectively). CONCLUSIONS: NMD of the quasi-static PV curve and R/I ratio for recruitability assessment are highly correlated. In addition, NMD and R/I ratio correlated with the Crs ratio (higher/lower). Therefore, NMD and R/I ratio could be potential indicators of recruitability that can be performed at the bedside.

Pulmonary vessels and bronchus anatomy of the left upper lobe.

PURPOSES: The bronchopulmonary vascular bifurcation patterns in the upper lobe of the left lung are diverse. Therefore, it is important for general thoracic surgeons to understand the detailed anatomy of the pulmonary segments when performing thoracoscopic anatomical pulmonary resection. This study aimed to analyze the bronchovascular patterns of the left upper lobe and summarize the anatomical information associated with pulmonary anatomical pulmonary resection. METHODS: We reviewed the anatomical patterns of pulmonary vessels and the left lung bronchus of 539 patients using computed tomography imaging data including those obtained using three-dimensional computed tomography. We herein report the anatomic structure in the left upper lobe. RESULTS: Regarding the superior division bronchi, a pattern of trifurcation into B1+2, B3, lingular division bronchus was observed in nine patients (1.7%). A pattern of proximal bifurcation of B4 was found in eight patients (1.5%). Regarding the lingular veins (LV), patterns of LV drainage into the left lower pulmonary vein were observed in 22 patients (4.1%). Regarding the pulmonary artery, mediastinal lingular arteries (MLA) were found in 161 patients (29.9%). CONCLUSION: The bifurcation patterns of the bronchovascular region in the upper lobe of the left lung were clarified. These results should be carefully noted when performing anatomical pulmonary resection.

Anatomy of the left subsuperior segment for segmentectomy.

PURPOSE: The subsuperior segmental bronchi (B*) forms the subsuperior segment (S*) between the superior (S6) and basal segment (S7, S8, S9, S10) of the lung. However, the anatomical planes of S* remains undefined. The present study clarified the anatomical features of S*. METHODS: We reviewed the anatomical patterns of pulmonary vessels and the left lung bronchus in 539 patients using three-dimensional computed tomography. We report the anatomic structure in S*. RESULTS: A total of 537 patients were analyzed. B* was observed in 129 (24.0%) patients. The intersegmental vein between S6 and S* was complete in all cases. The absence of intersegmental veins of S* was observed in 77 (14.3%) patients, reaching 59.7% of B* cases. Twenty-two (4.1%) cases of B* diverged from the trunk of the basal bronchus, and about half of the B* branched to the dorsolateral (n = 77, 14.3%) or dorsal (n = 2, 0.37%) direction. CONCLUSION: Our study revealed the branching patterns of B* and anatomical intersegmental veins of S*. Our results provide useful information regarding anatomical segmentectomy including or adjusting to the left S*.

Atrial flutter after surgeries of congenitally corrected transposition of great arteries in total visceral inversion.

A 51-year-old man, who had a history of open heart surgery for corrected transposition of great arteries, presented with palpitation due to atrial tachycardia. A propagation map using three-dimensional electroanatomical mapping (CARTO3) showed atrial flutter and underwent linear ablation successfully. This case highlights the difficulty of diagnosis before mapping following a complicated cardiac operation and the usefulness of three-dimensional mapping.

CT reconstruction with thick slices not only underestimates lymph node size but also reduces data reproducibility in colorectal cancer.

BACKGROUND: Reliable size measurement of lymph node (LN) metastases is important for the evaluation of cancer treatment. However, image analyses without proper settings may result in inappropriate diagnoses and staging. PURPOSE: To investigate whether reconstruction slice thickness in computed tomography (CT) affects measurements of LN size and reproducibility. MATERIAL AND METHODS: We analyzed 48 patients with histological diagnoses of sigmoid colon and rectal cancer who underwent contrast-enhanced CT colonography as part of a surgical treatment preparation. A board-certified radiologist selected 106 LNs whose short-axis diameter was ≥5 mm on 1-mm-thick images; the short-axis diameters were measured on 1- and 5-mm-thick images by the radiologist and residents and compared using Wilcoxon matched-pairs signed rank test. Data variation and reproducibility were evaluated using the F test and Bland-Altman analysis. P<0.05 was considered significant. RESULTS: Short-axis diameters measured on 5-mm-thick images were significantly lower than those measured on 1-mm-thick images (P<0.01), even in the LNs whose short-axis diameters were over twice the slice thickness (P<0.05). Of the 106 LNs, 57 showed short-axis diameter <5 mm on 5-mm-thick images; the maximum short-axis diameter was 6.7 mm on a 1-mm thick image. Data variation was significantly larger on 5-mm thick images than 1-mm-thick images in small LNs (P<0.05) and reproducibility on 5-mm-thick images was inferior to that on 1-mm-thick images. CONCLUSION: Thick reconstruction slices in CT can result in an underestimation of LN size and reduce data reproducibility. When measuring LN size, a thin reconstruction slice would be recommended based on targeted LN size.

Lateral Position With Gantry Tilt Further Improves Computed Tomography Image Quality Reconstructed Using Single-Energy Metal Artifact Reduction Algorithm in the Oral Cavity.

OBJECTIVE: To assess the limitations of single-energy metal artifact reduction algorithm in the oral cavity and evaluate the availability of a solution by setting the patient in a lateral position (LP) with the use of a gantry tilt (GT). METHODS: We analyzed 88 patients with dental metals retrospectively in study 1, and 74 patients prospectively in study 2. Patients were classified: metal I with dental metals in 1 region, metal II in 2 regions, and metal III in 3 regions. Patients underwent neck computed tomography examinations in a supine position (SP) in study 1, and 2 positions, an LP with a GT and an SP, in study 2. All images were reconstructed with this algorithm. Image quality was scored using a 4-point scale: 1 = severe artifact, 2 = moderate artifact, 3 = slight artifact, 4 = no artifact. The scores were compared between metal I, metal II, and metal III using the Mann-Whitney U test in study 1, and between an LP with a GT and an SP using the Wilcoxon signed ranks test in study 2. RESULTS: The scores outside the dental arch were significantly higher in metal I than in metal II and metal III (3.0 ± 0.6 vs 2.3 ± 0.5 vs 2.2 ± 0.4; P < 0.0001 for metal I vs metal II and for metal I vs metal III) and significantly higher in an LP with a GT than an SP (3.2 ± 0.4 vs 2.3 ± 0.4; P < 0.0001). CONCLUSIONS: Single-energy metal artifact reduction algorithm could reduce metal artifacts adequately in patients with dental metals in 1 region, but not in 2 or more regions. However, even for the latter, combination of this algorithm and an LP with a GT could further improve the image quality.

Pulmonary vessels and bronchial anatomy of the left lower lobe.

PURPOSE: To identify and clarify the comprehensive anatomic patterns in the left lower lobe (LLL). METHODS: Using computed tomography (CT) imaging data, including that obtained using three-dimensional CT, we reviewed the anatomic patterns of the pulmonary vessels and bronchi in the left lungs of 539 patients, focusing on the LLL. RESULTS: The two-stem type in A6 was observed in 131 (24.7%) patients and the three-stem type in A6 was observed in 11 (2.1%) patients. The independent two-stem type in B6 was observed in four (0.75%) patients. The B7 with independent branching from the basal bronchi was observed in 42 (7.9%) patients. B* was observed in 129 (24.0%) patients and B* was accompanied by A* in all patients. An extrapericardial common trunk of the left pulmonary veins was identified in five patients (0.93%). CONCLUSION: We identified various bronchovascular patterns in the LLL of a large number of patients. Our results provide useful information for anatomic pulmonary resection, especially segmentectomy.

[Assessment of Left Ventricular Systolic and Diastolic Function with Retrospective Electrocardiogram Triggered 320-row Area Detector Computed Tomography: A Comparison with Ultrasound Echocardiography].

BACKGROUND: The 320-row area detector computed tomography (ADCT) for the evaluation of left ventricular (LV) systolic function has been reported, but reporting of ADCT for the evaluation of LV diastolic function (LVDF) cannot be found. The purpose of this study was to examine the usefulness of ADCT in the assessment of LV systolic and diastolic function compared to ultrasound echocardiography (Echo) as the standard of reference. MATERIALS AND METHODS: We evaluated 60 consecutive patients (mean age 62.4 ± 13.2 years, male/female 36/24) who underwent ADCT (retrospective electrocardiogram triggered) and Echo. All patients were classified into three groups (A, B, C) according to LVDF evaluated by Echo. We examined peak filling rate (PFR) and time to peak filling (TPF) as indicator of LVDF using ADCT. RESULTS: Good correlations between ADCT and Echo were demonstrated for the assessment of LVSF. PFR of group B (mild diastolic dysfunction) patients (1.92 ± 0.69) and group C (moderate severe diastolic dysfunction) patients (1.90 ± 0.75) were significantly lower than that of group A (normal diastolic function) patients (2.50 ± 0.43). TPF of group B (191.6 ± 54.4 ms) and group C patients (197.5 ± 64.0 ms) were significantly higher than that of group A patients (149.5±34.1 ms). CONCLUSIONS: ADCT is useful method for the evaluation of LVSF and LV diastolic dysfunction.

[Influence of heart rhythm, breathing and arm position during computed tomography scanning on the registration accuracy of electro anatomical map (EAM) images, left atrium three-dimensional computed tomography angiography images, and fluoroscopy time during ablation to treat atrial fibrillation].

BACKGROUND: In CARTOMERGE(®) for treatment of atrial fibrillation (AF) by ablation, by integrating electro anatomical map (EAM) and left atrium three-dimensional computed tomography angiography (3D-CTA) images, identification of the ablation points is simplified and the procedure can be made carried out more rapidly. However, the influence that heart rhythm, breathing and arm position during CT scanning have on registration accuracy and fluoroscopy time is not clear. PURPOSE: To clarify the influence on registration accuracy and fluoroscopy time of heart rhythm, breathing and arm position during CT scanning. METHODS: The patients were CT-scanned during both sinus rhythm (SR) and AF in each study subject. We evaluated the registration accuracy of images reconstructed between the cardiac cycle and assessed the registration accuracy and fluoroscopy time of images obtained during inspiratory breath-hold, expiratory breath-hold and up and down position of the arm. RESULTS: Although the registration accuracy of the EAM image and left atrium 3D-CTA image showed a significant difference during SR, no significant difference was seen during AF. Expiratory breath-hold and down position of the arm resulted in the highest registration accuracy and the shortest fluoroscopy time. However, arm position had no significant effect on registration accuracy. CONCLUSIONS: Heart rhythm and breathing during CT scanning have a significant effect on the registration accuracy of EAM images, left atrium 3D-CTA images, and fluoroscopy time.

Total thoracoscopic lung segmentectomy of anterior basal segment of the right lower lobe (RS8) for NSCLC stage IA (case report).

A 69-year-old woman with a pulmonary nodule in anterior basal segment of the right lower lobe (RS8) was referred to our department. The diameter of the tumor was 12 mm, and it had increased over a few months. First, video-assisted thoracoscopic lung surgery (VATS) biopsy of the pulmonary nodule was carried out. Frozen section examination of this nodule confirmed the diagnosis of bronchioloalveolar carcinoma (BAC). Segmentectomy of RS8 with lower mediastinal node dissection (ND2a-1) was performed. The intersegmental plane was identified using the intersegmental veins as landmarks and the demarcation between the resected (inflated) and preserved (collapsed) lungs. Electrocautery at 70 watts was used to divide the intersegmental plane. A vessel sealing system was used to seal and cut the pulmonary arteries. Postoperative histopathological examination revealed that the tumor was T1aN0M0 BAC, and the minimal distance between the surgical margin and the tumor edge was 15 mm. The patient was discharged from hospital on postoperative day 5 without any complications.

[Evaluation of three-dimensional enhanced brain surface imaging using CT (3D surface CT angiography) and magnetic resonance imaging (3D surface MR angiography)].

The optimal imaging conditions for 3D brain surface imaging by magnetic resonance imaging (MRI) and multi-slice CT were investigated. Visualization of the sulci, gyri, and veins on the brain's surface was also compared between 3D surface images acquired using multi-slice CT and conventional single-slice CT and MRI. Various imaging parameters, including slice thickness, dose, and matrix size, were evaluated using our original brain surface phantom and longitudinal direction evaluation phantom as well as images obtained from healthy volunteers. Subjects of the clinical study were patients with arteriovenous malformations and brain tumors who underwent CT-angiography at the same time as MR-angiography. The quality of 3D images of the brain surface is most strongly influenced by partial volume effects related to slice thickness. In multi-slice CT, a slice thickness of 0.5 mm can be employed to minimize the partial volume effect, providing results that are far superior to those that can be achieved by conventional single-slice 3D-CT. In addition, the excellent S/N of multi-slice CT permits the veins on the brain's surface to be clearly visualized without the use of contrast medium. With regard to visualization of the sulci and gyri, although some problems remain to be overcome, multi-slice CT was found to be equivalent to 3D surface imaging using MRI.