Reliability of respiratory-gated real-time two-dimensional cine incorporating deep learning reconstruction for the assessment of ventricular function in an adult population.

This study aimed to assess the image quality and accuracy of respiratory-gated real-time two-dimensional (2D) cine incorporating deep learning reconstruction (DLR) for the quantification of biventricular volumes and function compared with those of the standard reference, that is, breath-hold 2D balanced steady-state free precession (bSSFP) cine, in an adult population. Twenty-four patients (15 men, mean age 50.7 ± 16.5 years) underwent cardiac magnetic resonance for clinical indications, and 2D DLR and bSSFP cine were acquired on the short-axis view. The image quality scores were based on three main criteria: blood-to-myocardial contrast, endocardial edge delineation, and presence of motion artifacts throughout the cardiac cycle. Biventricular end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and left ventricular mass (LVM) were analyzed. The 2D DLR cine had significantly shorter scan time than bSSFP (41.0 ± 11.3 s vs. 327.6 ± 65.8 s; p < 0.0001). Despite an analysis of endocardial edge definition and motion artifacts showed significant impairment using DLR cine compared with bSSFP (p < 0.01), the two sequences demonstrated no significant difference in terms of biventricular EDV, ESV, SV, and EF (p > 0.05). Moreover, the linear regression yielded good agreement between the two techniques (r ≥ 0.76). However, the LVM was underestimated for DLR cine (109.8 ± 34.6 g) compared with that for bSSFP (116.2 ± 40.2 g; p = 0.0291). Respiratory-gated 2D DLR cine is a reliable technique that could be used in the evaluation of biventricular volumes and function in an adult population.

Reliability of respiratory-triggered two-dimensional cine k-adaptive-t-autocalibrating reconstruction for Cartesian sampling for the assessment of biventricular volume and function in patients with repaired tetralogy of Fallot.

OBJECTIVE: To compare left ventricular (LV) and right ventricular (RV) volume, function, and image quality of a respiratory-triggered two-dimensional (2D)-cine k-adaptive-t-autocalibrating reconstruction for Cartesian sampling (2D kat-ARC) with those of the standard reference, namely, breath-hold 2D balanced steady-state free precession (2D SSFP), in patients with repaired tetralogy of Fallot (TOF). METHODS: 30 patients (14 males, mean age 32.2 ± 13.9 years) underwent cardiac magnetic resonance, and 2D kat-ARC and 2D SSFP images were acquired on short-axis view. Biventricular end-diastolic volume (EDV) and end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and LV mass (LVM) were analysed. RESULTS: The 2D kat-ARC had significantly shorter scan time (35.2 ± 9.1 s vs 80.4 ± 16.7 s; p < 0.0001). Despite an analysis of image quality showed significant impairment using 2D kat-ARC compared to 2D SSFP cine (p < 0.0001), the two sequences demonstrated no significant difference in terms of biventricular EDV, LVESV, LVSV, LVEF, and LVM. However, the RVESV was overestimated for 2D kat-ARC compared with that for 2D SSFP (73.8 ± 43.2 ml vs 70.3 ± 44.5 ml, p = 0.0002) and the RVSV and RVEF were underestimated (RVSV = 46.2±20.5 ml vs 49.4 ± 20.4 ml, p = 0.0024; RVEF = 40.2±12.7% vs. 43.5±14.0%, p = 0.0002). CONCLUSION: Respiratory-triggered 2D kat-ARC cine is a reliable technique that could be used in the evaluation of LV volumes and function. ADVANCES IN KNOWLEDGE: 2D cine kat-ARC is a reliable technique for the assessment LV volume and function in patients with repaired TOF.

Systematic evaluation of collateral pathways to the artery of Adamkiewicz using computed tomography.

OBJECTIVES: Preoperative identification of the artery of Adamkiewicz can help prevent postoperative spinal cord injury in patients undergoing thoracic and thoraco-abdominal aortic aneurysm repair. Although several studies have shown the feasibility of evaluating the artery of Adamkiewicz using multidetector row computed tomography (MDCT), no detailed investigations regarding the collateral circulation to the artery of Adamkiewicz have been performed. The purpose of this study was to investigate the collateral circulation to the artery of Adamkiewicz using MDCT in patients with thoracic and thoraco-abdominal aortic aneurysms. METHODS: Our institutional review board approved this study. Sixty-four patients with descending thoracic and thoraco-abdominal aortic aneurysms associated with the occlusion of the segmental artery from which the artery of Adamkiewicz originated were scanned using 64- or 320-detector row computed tomography. Two independent observers evaluated the MDCT images based on the degree of visualization of the artery of Adamkiewicz and its collateral circulation using a 4-point scale. RESULTS: The average visualization score was 2.8 ± 0.6. In 53 of the 64 (83%) patients, image quality was judged to be diagnostic. MDCT demonstrated 75 collateral pathways to the artery of Adamkiewicz in these 53 patients. Sixty-four of the 75 (85%) pathways were collaterals around the spinal column, and the remaining 11 (15%) pathways were collateral arteries in the thoracic wall. CONCLUSIONS: MDCT revealed the collateral pathways to the artery of Adamkiewicz around the spinal column and in the thoracic wall in 83% of our patients with thoracic and thoraco-abdominal aortic aneurysms.

Diagnostic accuracy of a modified subtraction coronary CT angiography method with short breath-holding time: a feasibility study.

OBJECTIVE: To explore the feasibility and diagnostic accuracy of modified subtraction coronary CT angiography (CCTA) with short breath-holding time in patients who have limited breath-hold capability and severe coronary artery calcification. METHODS: 11 patients with a coronary calcium score >400 underwent CCTA using a modified subtraction protocol. All patients were unable to hold their breath for more than 20 s. Subjective image quality using a four-point scale and the presence of significant (>50%) luminal stenosis were assessed for each calcified or stented segment on both conventional CCTA and modified subtraction CCTA images and compared with invasive coronary angiography (ICA) as the gold standard. RESULTS: The mean breath-holding time was 13.0 ± 0.9 s. A total of 35 calcified or stented coronary segments were evaluated. The average image quality was increased from 2.1 ± 0.9 with conventional CCTA to 3.1 ± 0.7 with subtraction CCTA (p < 0.001). The segment-based diagnostic accuracy for detecting significant stenosis according to ICA revealed an area under the receiver-operating characteristic curve of 0.722 for conventional CCTA and 0.892 for subtraction CCTA (p = 0.036). CONCLUSION: Modified subtraction CCTA allows the breath-holding time to be shortened to <15 s. As compared with conventional CCTA, modified subtraction CCTA showed improvement in image quality and diagnostic accuracy in patients with limited breath-hold capability and severe calcification. ADVANCES IN KNOWLEDGE: Modified subtraction CCTA can improve the diagnostic accuracy in patients with a high calcium score and patients who are unable to perform long breath-holds.

Modified Subtraction Coronary CT Angiography Method for Patients Unable to Perform Long Breath-Holds: A Preliminary Study.

RATIONALE AND OBJECTIVES: Severe calcifications of the coronary arteries are still a major challenge in coronary computed tomography (CT) angiography (CCTA). Subtraction CCTA using a 320-detector row CT scanner has recently been introduced for patients with severe calcifications. However, the conventional subtraction CCTA method requires a long breath-holding time of approximately 20-40 seconds. This is a major problem in clinical practice because many patients may not be able to perform such a long breath-hold. We explored a modified subtraction CCTA method with a short breath-holding time to overcome this problem. MATERIALS AND METHODS: This study was approved by our institutional review board, and all patients gave written informed consent. A total of 12 patients with a coronary calcium score of >400 were enrolled in this study. All patients were unable to hold their breath for more than 20 seconds. Modified subtraction CCTA was performed using the bolus-tracking method. The acquisition protocol was adjusted so that the mask scan was acquired 10 seconds after the postcontrast scan during a single breath-hold. The subtraction image was obtained by subtracting the mask image data from the postcontrast image data. The breath-holding times were recorded. Enhancement of the coronary arteries in the subtraction images was assessed. Subjective image quality was evaluated in a total of 32 segments using a 4-point scale. RESULTS: The mean breath-holding time was 12.8 ± 0.8 seconds (range, 12-14 seconds). The average CT number in the coronary arteries was 288.6 ± 80.5 Hounsfield units (HU) in the subtraction images. Average image quality was significantly increased from 2.1 ± 0.9 with conventional CCTA to 3.1 ± 0.7 with subtraction CCTA (P < 0.001). With subtraction CCTA, the number of non-diagnostic segments was significantly reduced from 53% to 19% (P = 0.001). CONCLUSIONS: This preliminary study has shown that our modified subtraction CCTA method allows the breath-holding time to be shortened to <15 seconds. This may substantially improve the success rate of subtraction CCTA by reducing artifacts and allowing this technique to be applied to patients who are unable to perform a long breath-hold.

Structural Difference in Superconductive and Nonsuperconductive Bi-S Planes within Bi4O4Bi2S4 Blocks.

The relationship between the structure and superconductivity of Bi4O4S3 powders synthesized by heating under ambient and high pressures was investigated using synchrotron X-ray diffraction, Raman spectroscopy, and transmission electron microscopy (TEM) observation. The Bi4O4S3 powders synthesized under ambient pressure exhibited a strong superconductivity (diamagnetic) signal and zero resistivity below ∼4.5 K, while the Bi4O4S3 powder synthesized by the high-pressure method exhibited a low-intensity signal down to 2 K. Further annealing of the latter Bi4O4S3 powder under ambient pressure led to the development of a strong signal and zero resistivity. The crystal structures of all Bi4O4S3 phases consisted of Bi4O4Bi2S4 blocks including a Bi-S layer and anion(s) sandwiched between Bi4O4Bi2S4 blocks, but minor structural differences were detected. A comparison of the structures of the superconductive and nonsuperconductive Bi4O4S3 samples suggested that the superconductive Bi4O4S3 phases had slightly smaller lattice parameters. The average structures of the superconductive Bi4O4S3 phases were characterized by a slightly shorter and less bent Bi-S plane. Raman spectroscopy detected vibration of the S-O bonds, which can be attributed to sandwiched anion(s) such as SO4(2-). TEM observation showed stacking faults in the superconductive Bi4O4S3 phases, which indicated local fluctuation of the average structures. The observed superconductivity of Bi4O4S3 was discussed based on impurity phases, enhanced hybridization of the px and py orbitals of the Bi-S plane within Bi4O4Bi2S4 blocks, local fluctuation of the average structures, compositional deviation related to suspicious anion(s) sandwiched between Bi4O4Bi2S4 blocks, and the possibility of suppression of the charge-density-wave state by enriched carrier concentrations.

Subtraction coronary CT angiography using second-generation 320-detector row CT.

The purpose of this study was to explore the feasibility of subtraction coronary computed tomography angiography (CCTA) by second-generation 320-detector row CT in patients with severe coronary artery calcification using invasive coronary angiography (ICA) as the gold standard. This study was approved by the institutional board, and all subjects provided written consent. Twenty patients with calcium scores of >400 underwent conventional CCTA and subtraction CCTA followed by ICA. A total of 82 segments were evaluated for image quality using a 4-point scale and the presence of significant (>50 %) luminal stenosis by two independent readers. The average image quality was 2.3 ± 0.8 with conventional CCTA and 3.2 ± 0.6 with subtraction CCTA (P < 0.001). The percentage of segments with non-diagnostic image quality was 43.9 % on conventional CCTA versus 8.5 % on subtraction CCTA (P = 0.004). The segment-based diagnostic accuracy for detecting significant stenosis according to ICA revealed an area under the receiver operating characteristics curve of 0.824 (95 % confidence interval [CI], 0.750-0.899) for conventional CCTA and 0.936 (95 % CI 0.889-0.936) for subtraction CCTA (P = 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value for conventional CCTA were 88.2, 62.5, 62.5, and 88.2 %, respectively, and for subtraction CCTA they were 94.1, 85.4, 82.1, and 95.3 %, respectively. As compared to conventional, subtraction CCTA using a second-generation 320-detector row CT showed improvement in diagnostic accuracy at segment base analysis in patients with severe calcifications.

[Gemcitabine and cisplatin therapy in advanced or metastatic urothelial cancer: comparison of side effect with MVAC (methotrexate, vinblastine, doxorubicin, and cisplatin)].

OBJECTIVE: Cisplatin-based combination chemotherapy has been considered as standard therapy for advanced or metastatic urothelial carcinoma. A recent study has, however, revealed that gemcitabine may have the potential to act synergistically with cisplatin. Therefore, the side effects of gemcitabine plus cisplatin (GC) therapy were compared with those of methotrexate, vinblastine, doxorubicin and cisplatin (MVAC) therapy in patients with advanced or metastatic urothelial carcinoma. PATIENTS AND METHODS: Twenty-two patients received GC therapy. Gemcitabine (1000 mg/m2) was administered on days 1, 8 and 15 of each 28-day cycle. Cisplatin (70 mg/m2) was administered on day 2 of each cycle. As a control group, 24 patients received MVAC therapy (methotrexate at 30 mg/m2 on days 1, 15, 22, vinblastine at 3 mg/m2 on days 2, 15, 22, doxorubicin at 30 mg/m2 on day 2, and cisplatin at 70 mg/m2 on day 2 of each 28-day cycle. RESULTS: In the group of patients which received GC therapy, the overall response rates based on independent radiologic reviews of the 20 patients with measurable disease were 55%, with 20% CR and 35% PR. Fewer GC patients as compared with MVAC patients had grade 3/4 anorexia (4.5% vs. 75%, respectively), stomatitis (9.0% vs. 66.7%, respectively), and alopecia (27.3% vs. 100%, respectively). On the other hand, there were no significant differences in the incidence or pattern of hematologic toxicities between the group receiving GC therapy and that receiving MVAC therapy. Fatal neutropenic sepsis occurred in one patient receiving MVAC therapy. CONCLUSION: GC therapy is effective for the treatment of advanced or metastatic urothelial carcinoma, with an acceptable clinical safety profile. This study also indicates that GC therapy may be better tolerated and safer than MVAC therapy.

[Lateral radiography of the knee with single-leg standing].

The purpose of this investigation was to accomplish reproducible radiography of single-leg standing lateral radiography of the knee by adjusting lateral rotation using a ruler to measure foot position. After preliminary assessment of three-dimensional CT of the knees of normal volunteers, the best adjustment of external rotation was estimated. A ruler was made for use in adjusting the angle of knee rotation by measuring foot rotation. Based on the foot rotation measured by this ruler, the positioning of radiography was adjusted to correct rotation. Rotation was estimated by the distance between the posterior edges of the lateral and medial femoral condyles. Fifteen-degree and 17.5-degree rotations were used for correction. Correction of rotation was 17 degrees on average. This helped not only to correct external rotation in the initial radiography but also to correct rotation for repeat radiography. Our method is quantitative and highly reproducible, and it increases the success rate of lateral knee radiography.