Preemptive embolization of abdominal aortic aneurysm sac side branch arteries promotes early sac shrinkage after endovascular aneurysm repair1.

OBJECTIVES: The association between the occlusion rate of the side branch arteries branching from the abdominal aortic aneurysm sac and aneurysm sac shrinkage is unclear. We aimed to evaluate the efficacy of preemptive embolization of multiple side branch arteries branching from the abdominal aortic aneurysm sac in early aneurysm sac shrinkage after endovascular aneurysm repair. METHODS: Patients undergoing endovascular aneurysm repair of abdominal aortic aneurysms, with or without preemptive embolization of multiple side branch arteries, including the inferior mesenteric artery and lumbar arteries, between January 2016 and August 2021, were retrospectively evaluated. Preemptive embolization was introduced at our institution in January 2018 and has been performed in all patients who undergo endovascular aneurysm repair since then. We compared occlusion rates of the side branch arteries, frequency of type 2 endoleaks, changes in aneurysm sac size, percentage of aneurysm sac size decrease, and frequency of reduction in the aneurysm sac diameter by >5 mm. RESULTS: The study included 43 patients in the embolization group and 20 in the non-embolization group. Preemptive embolization was successfully performed without any ischemic complications. The total occlusion rate of side branch arteries was significantly higher in the embolization group than in the non-embolization group (70.2% vs. 29.3%, P<0.05). At 24 months of follow-up, the type 2 endoleak frequency was significantly lower in the embolization group than in the non-embolization group (6.9% vs. 31.6%, P<0.05). The frequency of reduction in the aneurysm sac diameter by >5 mm was significantly higher in the embolization group than in the non-embolization group at 24 months (62.1% vs. 31.6% P<0.05). The optimal cutoff value for the total occlusion rate of the side branch arteries to achieve reduction in the aneurysm sac diameter by >5 mm at 24 months, after endovascular aneurysm repair, was 66.7% in all patients (area under the curve=0.634; sensitivity=62.5%; specificity=70.8%). These findings suggest that occluding 66.7% or more of the side branch arteries may result in early aneurysmal shrinkage. CONCLUSION: Preemptive embolization of multiple side branch arteries, branching from the abdominal aortic aneurysm sac, may contribute to early aneurysm sac shrinkage; this may serve as a marker for fewer late complications after endovascular aneurysm repair.

Hepatic function markers as prognostic factors in patients with acute kidney injury undergoing continuous renal replacement therapy.

Acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT), secondary to cardiovascular disease and sepsis, is associated with high in-hospital mortality. Although studies have examined cardiovascular disease and sepsis in AKI, the association between AKI and hepatic functional impairment remains unclear. We hypothesized that hepatic function markers would predict mortality in patients undergoing CRRT. We included 1,899 CRRT patients from a multi-centre database. In Phase 1, participants were classified according to the total bilirubin (T-Bil) levels on the day of, and 3 days after, CRRT initiation: T-Bil < 1.2, 1.2 ≤ T-Bil < 2, and T-Bil ≥ 2 mg/dL. In Phase 2, propensity score matching (PSM) was performed to examine the effect of a T-Bil cutoff of 1.2 mg/dL (supported by the Sequential Organ Failure Assessment score); creating two groups based on a T-Bil cutoff of 1.2 mg/dL 3 days after CRRT initiation. The primary endpoint was total mortality 90 days after CRRT initiation, which was 34.7% (n = 571). In Phase 1, the T-Bil, aspartate transaminase (AST), alanine transaminase (ALT), and AST/ALT (De Ritis ratio) levels at CRRT initiation were not associated with the prognosis, while T-Bil, AST, and the De Ritis ratio 3 days after CRRT initiation were independent factors. In Phase 2, T-Bil ≥1.2 mg/dL on day 3 was a significant independent prognostic factor, even after PSM [hazard ratio: 2.41 (95% CI; 1.84-3.17), p < 0.001]. T-Bil ≥1.2 mg/dL 3 days after CRRT initiation predicted 90-day mortality. Changes in hepatic function markers in acute renal failure may enable stratification of high-risk patients.

Impact of System-F in Delivering Vascular Plugs for Aortic Side Branch Embolization During Endovascular Aneurysm Repair.

PURPOSE: This study aimed to illustrate the utility of our original system to deliver vascular plugs into aortic side branches during endovascular aneurysm repair (EVAR). TECHNIQUE: Our device, which we named "System-F," consists of a 14 Fr sheath, a 12 Fr long sheath with a side hole, a stiff guidewire as a shaft, and a parallelly-inserted delivery catheter navigated through the side hole into the aneurysm sac. Vertical motion and horizontal rotation of the side hole allow multidimensional movement of the delivery catheter within the aneurysm. This system was applied in 7 cases undergoing EVAR; 4 inferior mesenteric arteries and 14 lumbar arteries were embolized using vascular plugs. Type II endoleak (T2EL) was not observed in the follow-up survey of any case. Conclusion: The applicability of System-F for vascular plug placement in the side branches of abdominal aortic aneurysms has the potential to achieve high delivery capability and be widely applied for the prevention of T2EL. CLINICAL IMPACT: System-F has potential to change the strategies of pre-EVAR embolization.

Clinical utility of 67 Gallium-SPECT/CT for determining osteotomy indication in patients with lower-limb osteomyelitis.

Standard non-invasive methods for diagnosing and selecting the best treatment for osteomyelitis in patients with multiple chronic conditions remain to be established. We aimed to evaluate the ability of quantitative 67 Ga-citrate single-photon emission computed tomography (67 Ga-SPECT/CT) to determine the indication for either non-surgical treatment or osteotomy in patients with lower-limb osteomyelitis (LLOM) associated with diabetes mellitus and lower-extremity ischemia, based on monitoring of inflammatory activity in bone tissue. This single-centre prospective study conducted from January 2012 to July 2017 included 90 consecutive patients with suspected LLOM. Regions of interest were drawn on SPECT images during quantification of Ga accumulation. Subsequently, the inflammation-to-background ratio (IBR) was calculated by dividing the maximal accumulated lesion number by the mean number for the distal femur bone marrow of the unaffected side. Osteotomy was performed in 28 of 90 patients (31%). The osteotomy rate was higher for patients with IBR >8.4 (71.4%) than for those with IBR ≤8.4 (5.5%) (p < 0.001, sensitivity: 0.89, specificity: 0.84). In the multivariate Cox regression analysis, IBR >8.4 was an independent risk factor for osteotomy (hazard ratio [HR]: 19.0, 95% confident interval [CI]: 5.6-63.9, p < 0.001). Transcutaneous oxygen tension (TcPO2 ) was identified as an independent risk factor for lower-limb amputation (HR: 0.96, 95% CI: 0.92-0.99, p = 0.01). The current results indicate that quantitative 67 Ga-SPECT/CT is useful for distinguishing patients with LLOM likely to require osteotomy.

Comparison of Slow-Infusion Magnetic Resonance Angiography with Sequential K-Space Filling and Computed Tomography Angiography to Detect the Adamkiewicz Artery.

BACKGROUND: Radiographic detection of the Adamkiewicz artery (AKA) before aortic surgery helps to avoid spinal cord ischemia (SCI). We applied magnetic resonance angiography (MRA) using gadolinium enhancement (Gd-MRA) by means of the slow-infusion method with sequential k-space filling and compared AKA detectability with that of computed tomography angiography (CTA). METHODS: A total of 63 patients with thoracic or thoracoabdominal aortic disease (30 with aortic dissection [AD] and 33 with aortic aneurysm) who underwent both CTA and Gd-MRA to detect AKA were evaluated. The detectability of the AKA using Gd-MRA and CTA were compared among all patients and subgroups based on anatomical features. RESULTS: The detection rates of the AKAs using Gd-MRA and CTA were higher in all 63 patients (92.1% vs. 71.4%, P = 0.003). In AD cases, the detection rates using Gd-MRA and CTA were higher in all 30 patients (93.3% vs. 66.7%, P = 0.01) as well as in 7 patients whose AKA originated from false lumens (100% vs. 0%). In aneurysm cases, the detection rates using Gd-MRA and CTA were higher in 22 patients whose AKA originated from the nonaneurysmal parts (100% vs. 81.8%, P = 0.03). In clinical, SCI was observed in 1.8% of cases after open or endovascular repair. CONCLUSIONS: Despite the longer examination time and more complicated imaging techniques compared to those of CTA, the high spatial resolution of slow-infusion MRA may be preferable for detecting AKA before performing various thoracic and thoracoabdominal aortic surgeries.

Localization of Late Gadolinium Enhancement and Its Association with Ventricular Tachycardia in Patients with Cardiac Sarcoidosis.

Sustained ventricular tachycardia (sVT), leading to sudden cardiac death, is one of the common manifestations in cardiac sarcoidosis (CS). Although late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) has been reported to be associated with sVT, the relationships of its localization to sVT have not been fully evaluated.To evaluate the localization of LGE and its relationships to sVT in patients with CS, we reviewed medical record of consecutive 31 patients with CS who underwent CMR. The localization of LGE was divided into four categories: Left ventricular (LV) septum, LV free wall, right ventricular (RV) septum, and RV free wall. We investigated the association of sVT with localization of LGE and other parameters including serum biomarkers LV ejection fraction on echocardiography and Fluorine-18-fluorodeoxyglucose (FDG) accumulation on positron emission tomography (PET) -CT.Of the studied population, 8 patients (25.8%) were known to present with sVT among 31 CS patients. LGE was observed in the RV free wall in 6 patients with sVT, whereas it was in 5 patients without sVT (75.0% versus 21.7%, P = 0.022). Univariate analysis showed that only LGE in the RV free wall was associated with sVT (odds ratio [OR]: 10.80; 95% confidence interval [CI]: 1.64-70.93, P = 0.013).LGE in the RV free wall was associated with sVT in patients with CS.

Computed Tomography Attenuation Values of the High-Attenuating Crescent Sign Can Discriminate Between Rupture, Impending Rupture, and Non-Rupture of Aortic Aneurysms.

BACKGROUND: Although the high-attenuating crescent (HAC) sign can indicate aortic aneurysm (AA) impending rupture, the relation of its computed tomography (CT) value to the aneurysmal status remains unclear. This study compared the HAC sign CT-attenuation values among rupture, impending rupture, and non-rupture AA cases.Methods and Results:This included 76 patients (mean age: 77.0 years) diagnosed with HAC sign-associated AA between January 2005 and July 2015. The CT-attenuation values of the HAC sign (H) and aortic lumen (A) using region-of-interest methodology were measured and the H/A ratio was calculated. The study classified patients into the rupture group (R-G, n=36), impending rupture group (IR-G, n=16), and non-rupture group (NR-G, n=24); the H and the H/A ratio were compared among them. Additionally, the H and the H/A ratio cut-offs between the IR-G and NR-G groups were evaluated. The H and the H/A ratio were significantly higher in the R-G and IR-G than in the NR-G (both P<0.001); the H/A ratio was significantly higher in the R-G than in the IR-G (P=0.038). The optimal cut-off for H between the IR-G and NR-G was 50.3 Hounsfield units (area under the curve [AUC]=0.875; sensitivity=87.5%; specificity=87.5%), and that for the H/A ratio was 1.3 (AUC=0.909; sensitivity=91.7%; specificity=87.5%). CONCLUSIONS: Among patients with AA, the H and the H/A ratio were significantly higher in cases of rupture and impending rupture than in those of non-rupture.

A Comparison of Outcomes Based on Vessel Type (Native Artery vs. Bypass Graft) and Artery Location (Below-Knee Artery vs. Non-Below-Knee Artery) Using a Combination of Multiple Endovascular Techniques for Acute Lower Limb Ischemia.

BACKGROUND: To evaluate outcomes of endovascular treatment (EVT) using a combination of multiple endovascular techniques for acute lower limb ischemia (ALLI) and to compare outcomes based on vessel type and artery location. METHODS: A total of 95 consecutive patients with ALLI (mean age, 72.0 years; 65 males; 104 lower limbs) who received emergency EVT using a combination of multiple endovascular techniques including thrombolysis, aspiration thrombectomy, stenting, and balloon angioplasty with or without surgical thromboembolectomy, between January 2005 and December 2017 were included. Vessel type was classified into native artery occlusion (native occlusion) and bypass graft occlusion (graft occlusion), including prosthetic and vein graft. Additionally, native arteries were categorized into below-knee occlusion and non-below-knee occlusion. Technical success, perioperative death (POD), ALLI-related death, amputation, amputation-free survival (AFS), and complications were compared according to vessel type (native occlusion vs. graft occlusion) and artery location (below-knee occlusion vs. non-below-knee occlusion). RESULTS: Of all patients with ALLI, 16.8% underwent a single endovascular technique, whereas 83.2% underwent a combination of multiple endovascular techniques. The technicalsuccess, POD, and ALLI-related death rates in the total number of patients were 94.7%, 11.6%, and 4.2%, respectively. A total of 67 patients (75 limbs) and 28 patients (29 limbs) were classified as having native occlusion and graft occlusion (prosthetic, 24 limbs; vein, 5 limbs), respectively. No significant differences in technical success (native occlusion: 92.5% vs. graft occlusion: 100%), POD (14.9% vs. 3.6%), and ALLI-related death (6.0% vs. 0%) were noted between native occlusion and graft occlusion. However, the 30-day AFS rate of native occlusion was significantly lower than that of graft occlusion (75.2% vs. 96.3%, P=0.01). The amputation rate (P=0.03) and AFS rate (P=0.03) of below-knee occlusion were significantly worse for below-knee occlusion patients than for non-below-knee occlusion patients. CONCLUSIONS: EVT using multiple endovascular techniques for ALLI is effective and safe. A combination of multiple endovascular techniques is crucial for successful treatment. However, native occlusion may have a lower AFS rate than graft occlusion, and below-knee occlusion may have a higher risk of amputation than non-below-knee occlusion.

Multiparametric flow analysis using four-dimensional flow magnetic resonance imaging can detect cerebral hemodynamic impairment in patients with internal carotid artery stenosis.

PURPOSE: MRI-based risk stratification should be established to identify patients with internal carotid artery stenosis (ICS) who require further PET or SPECT evaluation. This study assessed whether multiparametric flow analysis using time-resolved 3D phase-contrast (4D flow) MRI can detect cerebral hemodynamic impairment in patients with ICS. METHODS: This retrospective study analyzed 26 consecutive patients with unilateral ICS (21 men; mean age, 71 years) who underwent 4D flow MRI and acetazolamide-stress brain perfusion SPECT. Collateral flow via the Willis ring was visually evaluated. Temporal mean flow volume rate (Net), pulsatile flow volume (ΔV), and pulsatility index (PI) at the middle cerebral artery were measured. Cerebral vascular reserve (CVR) was calculated from the SPECT dataset. Patients were assigned to the misery perfusion group if the CVR was < 10% and to the nonmisery perfusion group if the CVR was ≥ 10%. Parameters showing a significant difference in both groups were statistically evaluated. RESULTS: Affected side ΔV, ratio of affected to contralateral side Net (rNet), and ratio of affected to contralateral side ΔV were significantly correlated to CVR (p = 0.030, p = 0.010, p = 0.015, respectively). Absence of retrograde flow at the posterior communicating artery was observed in the misery perfusion group (p = 0.020). Combined cut-off values of the affected side ΔV (0.18 ml) and rNet (0.64) showed a sensitivity and specificity of 100% and 77.8%, respectively. CONCLUSION: Multiparametric flow analysis using 4D flow MRI can detect misery perfusion by comprehensively assessing blood flow data, including blood flow volume, pulsation, and collateral flow.

"Squid-Capture" Modified In Situ Stent-Graft Fenestration Technique for Recurrent Abdominal Aortic Occlusive Disease after Collapse of Balloon-Expandable Stent.

We present a case of an 85-year-old woman with bilateral limb-threatening ischemia caused by acute-on-chronic occlusion of the infrarenal aorta. The patient once underwent endovascular recanalization using nitinol and stainless-steel bare-metal stent implantation; however, the stainless-steel stent collapsed 3 months later. In the second endovascular therapy, "Squid-Capture" modified in situ stent-graft fenestration technique followed by stent-in-stent implantation with stent graft and bare-metal stent was successfully applied, and it can be regarded as a promising treatment option for the repair of abdominal aortic occlusive disease in some limited anatomical conditions.

An Extremely Rare Complication: Abdominal Aortic Aneurysm Rupture Caused by Migration of a Zenith Main Body Years After Repair of the Suprarenal Stent Separation.

PURPOSE: To report an unusual case of an abdominal aortic aneurysm (AAA) rupture caused by migration of a Zenith stent-graft main body years after its separation from the suprarenal stent. CASE REPORT: A 72-year-old man underwent endovascular aneurysm repair with a Zenith stent-graft for an infrarenal AAA in year 2000. At that time, a femorofemoral bypass was performed because the left external iliac and common femoral arteries were dissected during treatment. In 2013, follow-up computed tomography (CT) showed disconnection of the uncovered proximal stent, which led to a type Ia endoleak. An additional Zenith main body and Large Palmaz XL balloon-expandable stent were deployed; the endoleak disappeared. In 2016, the patient had abdominal pain, and emergency CT showed AAA rupture caused by migration of the first main body deployed in 2000 under the distal edge of the contralateral (left) leg of the additional main body from 2013, which led to a type IIIa endoleak between the 2 main bodies. A converter and iliac legs were deployed to successfully seal the type IIIa endoleak. The patient remains well 18 months after the second repair; CT scans document stable stent-grafts and no endoleak. CONCLUSION: Physicians should be aware of the potential risk for AAA rupture caused by late main body migration after treatment for suprarenal stent separation from a Zenith stent-graft.

Extracellular volume fraction assessed using cardiovascular magnetic resonance can predict improvement in left ventricular ejection fraction in patients with dilated cardiomyopathy.

T1 mapping using cardiac magnetic resonance (CMR) is useful for myocardial assessment. However, its prognostic value is not well defined. The aim of this study was to determine whether T1 mapping with CMR can predict reverse cardiac remodeling in patients with non-ischemic dilated cardiomyopathy (NIDCM). We also investigated the predictive prognostic value of T1 mapping with CMR in these patients. We included 33 patients with NIDCM admitted to Nippon Medical School Hospital between February 2012 and October 2015. All patients underwent CMR and echocardiography for clinical assessment within 1 month of admission (13 ± 16 days). Follow-up echocardiography was performed no sooner than 6 months after the initial echocardiogram (536 ± 304 days). We evaluated the correlations between native and post-contrast T1 values/extracellular volume fraction (ECV) and the difference in left ventricular ejection fraction (ΔLVEF) determined at baseline and follow-up echocardiography. No correlation was noted between ΔLVEF and native (p = 0.150, r = - 0.256) or post-contrast T1 values (p = 0.956, r = - 0.010). However, a significant and substantial correlation was found between ΔLVEF and ECV (p = 0.043, r = - 0.355). Four patients were hospitalized for heart failure (HF), but no cardiovascular-related deaths occurred over a median follow-up period of 34 months (interquartile range 25-49 months). Kaplan-Meier curves stratified by the median value of ECV were created. The higher ECV groups experienced a significantly higher incidence of HF-related hospitalization (p = 0.0159). ECV measured by CMR can predict improvements in LVEF in patients with NIDCM. In addition, ECV may be a predictive factor for HF-related hospitalization.

Novel treatment strategy for advanced hepatocellular carcinoma: combination of conventional transcatheter arterial chemoembolization and modified method with portal vein occlusion for cases with arterioportal shunt: a preliminary study.

Background A novel strategy to combine conventional transcatheter arterial chemoembolization (TACE) and TACE during portal vein occlusion (TACE-PVO) in the presence of high-flow arterioportal shunt (APS) has been developed to treat hepatocellular carcinoma (HCC) with portal invasion. Purpose To evaluate the efficacy of this strategy. Material and Methods Twenty-five cases of HCC with portal invasion, treated between April 2006 and December 2015, were evaluated. Balloon occlusion of the portal venous outlet was performed in eight cases of high-flow APS when performing TACE. Conventional TACE was performed in the other 17 cases. The primary endpoint was overall survival. Adverse events and deterioration of liver function were also evaluated. Results The median survival time (MST) was 12 months. One-, two-, and three-year survival rates were 48.0%, 39.3%, and 26.2%, respectively. Subgroup analysis and multivariate analysis revealed the CLIP score as prognostic factor. MST was 2.5 months in the subgroup with CLIP score ≥4 and 26.0 months in the subgroup with CLIP score ≤3 (hazard ratio = 7.7, 95% confidence interval = 2.3-25.8). Transient elevations of the levels of transaminase and bilirubin were observed; however, deterioration of liver function was infrequent; upgrading of Child-Pugh class in 9.1% of cases. Conclusion A novel strategy, combining conventional TACE and TACE-PVO, is effective for HCC with portal invasion. The CLIP score may be useful for considering treatment indication.

Haemodynamic changes in hepatocellular carcinoma and liver parenchyma under balloon occlusion of the hepatic artery.

OBJECTIVES: To investigate haemodynamic changes in hepatocellular carcinoma (HCC) and liver under hepatic artery occlusion. METHODS: Thirty-eight HCC nodules in 25 patients were included. Computed tomography (CT) during hepatic arteriography (CTHA) with and without balloon occlusion of the hepatic artery was performed. CT attenuation and enhancement volume of HCC and liver with and without balloon occlusion were measured on CTHA. Influence of balloon position (segmental or subsegmental branch) was evaluated based on differences in HCC-to-liver attenuation ratio (H/L ratio) and enhancement volume of HCC and liver. RESULTS: In the segmental group (n = 20), H/L ratio and enhancement volume of HCC and liver were significantly lower with balloon occlusion than without balloon occlusion. However, in the subsegmental group (n = 18), H/L ratio was significantly higher and liver enhancement volume was significantly lower with balloon occlusion; HCC enhancement volume was similar with and without balloon occlusion. Rate of change in H/L ratio and enhancement volume of HCC and liver were lower in the segmental group than in the subsegmental group. There were significantly more perfusion defects in HCC in the segmental group. CONCLUSIONS: Hepatic artery occlusion causes haemodynamic changes in HCC and liver, especially with segmental occlusion. KEY POINTS: • Hepatic artery occlusion causes haemodynamic changes in hepatocellular carcinoma and liver. • Segmental occlusion decreased rate of change in hepatocellular carcinoma-to-liver attenuation ratio. • Subsegmental occlusion increased rate of change in hepatocellular carcinoma-to-liver attenuation ratio. • Hepatic artery occlusion decreased enhancement volume of hepatocellular carcinoma and liver. • Hepatic artery occlusion causes perfusion defects in hepatocellular carcinoma.

The high matrix acquisition technique for imaging of atherosclerotic plaque inflammation in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography with time-of-flight: Phantom study.

BACKGROUND: Motion artifact and partial volume effect caused underestimation of coronary plaque inflammation. This study evaluated the high matrix acquisition technique using time-of-flight (TOF) positron emission tomography/computed tomography for imaging of atherosclerotic plaque inflammation with fluorine-18 fluorodeoxyglucose in small and moving phantoms. METHODS AND RESULTS: All images were reconstructed using a conventional algorithm without TOF (4 × 4 × 4 mm3 voxel size) and a high matrix algorithm with TOF (2 × 2 × 2 mm3 voxel size). Microsphere phantoms of 10, 7.9, 6.2, 5.0, and 4.0 mm diameters were acquired in 3-dimensional list-mode for 30 minutes. A heart phantom mimicking cardiac motion consisted of a hot spot simulating a plaque (φ 4 mm, φ 2 mm) on the outside of the left ventricle. In the microsphere and heart phantom study, visual discrimination, maximum activity, and target-to-background ratio using the high matrix algorithm with TOF were better than those using the conventional algorithm without TOF. CONCLUSION: The high matrix algorithm with TOF improves detection of small targets in phantoms.

Relationship of Nonseptal Late Gadolinium Enhancement to Ventricular Tachyarrhythmia in Hypertrophic Cardiomyopathy.

OBJECTIVE: This study aimed to determine the relationship between the extent and the location of late gadolinium enhancement (LGE) and ventricular tachyarrhythmia or implantable cardioverter defibrillator (ICD) in hypertrophic cardiomyopathy (HCM). METHODS: We enrolled 115 patients with HCM and LGE. The location of LGE was divided into septal and nonseptal segments. Clinical backgrounds and LGE were compared in patients between with and without the arrhythmia or consequent ICD installation. RESULTS: There were significant differences in the number of risk markers, left ventricular ejection fraction, extent of global LGE, and extent of nonseptal LGE between the groups (P < 0.01). Multivariate analysis revealed that the number of risk markers and extent of nonseptal LGE contributed to ventricular tachyarrhythmia or ICD installation (P < 0.01). CONCLUSIONS: The nonseptal LGE is related to ventricular tachyarrhythmia or ICD installation. We should be vigilant for nonseptal LGE when applying LGE to risk stratification for HCM.

Myocardial T2 Mapping in Patients With Hypertrophic Cardiomyopathy.

OBJECTIVE: The aim of this study was to evaluate the usefulness of T2 mapping for detecting myocardial injuries in patients with hypertrophic cardiomyopathy (HCM). METHODS: Twenty-one HCM patients and 7 healthy volunteers were examined. The T2 values were measured at hyperintense areas (high-T2 areas) identified with T2 mapping, at late gadolinium enhancement (LGE) areas, and in nullified myocardium of the HCM patients. The associations between T2 values and laboratory data or LGE areas were assessed. RESULTS: High-T2 areas had significantly greater T2 values than LGE areas (P < 0.05) and nullified areas (P < 0.01) of HCM and normal myocardium (P < 0.01). The presence of high-T2 areas was associated with an increase in troponin T levels (P = 0.02), and T2 values correlated with the levels of brain natriuretic peptide (P = 0.036, r = 0.86). CONCLUSIONS: T2 mapping identified myocardial injuries suggested by the laboratory data in HCM.

The reproducibility of time-of-flight PET and conventional PET for the quantification of myocardial blood flow and coronary flow reserve with (13)N-ammonia.

BACKGROUND: This study aimed to validate the reproducibility of quantitative analysis using time-of-flight (TOF) and conventional PET with (13)N-ammonia ((13)N-NH3). METHODS AND RESULTS: Phantom images were reconstructed with and without TOF, and recovery coefficients (RCs) and the percent contrast of each sphere over the percent background variability were assessed. In the clinical study, 21 subjects underwent dynamic (13)N-NH3 PET scanning under stress and rest conditions. The dynamic acquisition images and intra- and inter-observer reproducibility of myocardial blood flow (MBF) and coronary flow reserve (CFR) were compared between reconstructions (with and without TOF). In the phantom study, RCs and the percent contrast of each sphere over the percent background variability was improved with TOF. In the clinical study, the noise of blood pool and myocardial images with TOF was less than that without TOF. Territorial and global intra- and inter-observer reproducibility of MBF and CFR values was excellent. Although segmental intra- and inter-observer reproducibility was excellent, there were larger variations in apex and the segment near the right ventricle (RV) without TOF. These variations became inconspicuous with TOF. CONCLUSION: Visual image quality, RCs, and percent contrast over percent background variability with TOF were better than that without TOF. Excellent correlations and good agreements in quantitative values were observed. TOF improved the variation of segmental values.