Live MR Angiographic Roadmapping for Uterine Artery Embolization: A Feasibility Study

PurposeTo assess the feasibility of live magnetic resonance (MR) angiography roadmapping guidance for uterine artery (UA) embolization (UAE) for fibroid tumors.Materials and MethodsTwenty patients underwent UAE with live MR angiographic roadmapping. The pre-acquired MR angiography scan was coregistered with the live intraprocedural fluoroscopy stream to create a visual roadmap to direct the microcatheter during UAE. Patient radiation dose, as measured by dose–area product (DAP), procedure time, contrast medium volume, and fluoroscopy time, was recorded. For the first 10 patients, an additional parameter of contrast medium volume needed to catheterize each UA was recorded.ResultsIn all 20 patients (40 UAs), the MR angiography overlay on live fluoroscopy was accurate and allowed for successful catheterization of the UA, resulting in a technical success rate of 100%. In the subset of the initial 20 UAs (ie, the first 10 patients) in which this data point was recorded, 17 (85%) were successfully catheterized with no iodinated contrast medium at all, by purely relying on the MR angiography roadmap. Mean procedure time was 45 minutes (range, 30–99 min), mean contrast agent dose was 75 mL (range, 46–199 mL), and mean DAP was 155 Gy·cm² (range, 37–501 Gy·cm²).ConclusionsLive MR angiographic roadmapping is feasible and accurate for catheter guidance during UAE.     

A Novel Resorbable Embolization Microsphere for Transient Uterine Artery Occlusion: A Comparative Study with Trisacryl-Gelatin Microspheres in the Sheep Model

PurposeTo evaluate angiographic recanalization, inflammatory reaction, and uterine damage after sheep uterine artery embolization (UAE) with a novel calibrated resorbable embolization microsphere (REM) and compare the results with control nonresorbable microspheres.Materials and MethodsSix hormonally artificially cycled sheep underwent bilateral UAE until stasis with either REM or trisacryl-gelatin microspheres (TGMS). At 7 days, control angiograms were obtained to assess the residual vascularization at arterial and parenchymal phases. The animals were then sacrificed for analysis of the presence of microspheres, inflammatory foreign body reaction, and surface areas of uterine damage.ResultsMean volume of microspheres injected per uterine artery (UA) or per animal did not differ between groups. At day 7, the flow was normal for six of six UAs that received embolization with REM versus only three of six UAs with TGMS (P = .0455, χ² test). Uterine parenchymography showed no defects in six UAs in the REM group versus five defects in six UAs in the TGMS group (P = .0060, χ² test). No REM or residual fragments of microspheres were observed on histologic analysis. TGMS were observed in tissues and accompanied by a mild inflammatory response. Necrosis rates were not significantly different between the two products, either in endometrium (REM 23.5% ± 28.8% [median 8.1%] vs TGMS 21.8% ± 23.7% [median 14.6%]) or in myometrium (REM 8.2% ± 22.7% [median 0.0%] vs TGMS 8.8% ± 20.8% [median 0.9%]). Endometrium alteration rate was lower with REM than with TGMS (39.7% ± 25.7% [median 34%] vs 60.6% ± 27.1% [median 71%]; P = .0060, Mann-Whitney test). Myometrium alteration rates were not significantly different between REM (45.7% ± 37.1% [median 63.0%]) and TGMS (37.8% ± 34.0% [median 19.1%]).ConclusionsAt 1 week after sheep UAE with REM, the recanalization was complete, the microspheres were completely degraded, and there was no remnant inflammatory response.     

Comparison of Polyvinyl Alcohol Microspheres and Tris-Acryl Gelatin Microspheres for Uterine Fibroid Embolization: Results of a Single-Center Randomized Study

PurposeTo assess the efficacy of two embolic agents in the treatment of symptomatic uterine leiomyomas.Materials and MethodsA randomized, prospective, single-center study enrolled 60 women with symptomatic uterine leiomyomas. Uterine artery embolization (UAE) with spherical polyvinyl alcohol (SPVA) microspheres (n = 30; 700–900 μm and 900–1,200 μm; near-stasis or stasis endpoint) and tris-acryl gelatin (TAG) microspheres (n = 30; 500–700 μm; “pruned-tree” endpoint) was performed. Infarction rates were calculated for the dominant tumor and for small (< 2 cm) and large (> 2 cm) nondominant tumors. The primary endpoint was tumor infarction at 24 hours measured by contrast-enhanced magnetic resonance imaging assessed by a blinded reviewer.ResultsBaseline characteristics were similar between groups. The primary endpoint was similar in both treatments (≥ 91% dominant tumor infarction; SPVA. 86.2%; TAG, 93.3%, P = .35). Complete infarction (100%) was also similar between arms at 24 hours and 3 months. Symptom severity was reduced and quality of life improved equally at 3 and 12 months in each treatment group. Complications were minor in both groups.ConclusionsUterine leiomyoma infarction at 24 hours and 3 months after treatment with SPVA or TAG microspheres was comparable when using near-stasis as a procedural endpoint with SPVA microspheres. Symptom relief was maintained for as long as 12 months for both embolic agents.     

Embolization of Angiographically Visible Type I and II Utero-ovarian Anastomoses during Uterine Artery Embolization for Fibroid Tumors: Impact on Symptom Recurrence and Permanent Amenorrhea

PurposeTo compare the incidences of symptom recurrence and permanent amenorrhea following uterine artery embolization (UAE) for symptomatic fibroid tumors in patients with type I and II utero-ovarian anastomoses (UOAs) with versus without ovarian artery embolization (OAE).Materials and MethodsA retrospective, institutional review board–approved study of 99 women who underwent UAE for symptomatic fibroid tumors from April 2005 to October 2010 was conducted to identify patients who had type I or II UOAs at the time of UAE. Based on the embolization technique, patients were categorized into standard (ie, UAE only), combined (ie, UAE and OAE), and control (patients without UOAs who underwent UAE) groups. Data collected included patient characteristics, procedural technique and findings, symptom recurrence, secondary interventions, and permanent amenorrhea. Statistical analysis was performed with the Fisher exact test, with significance reached at P < .05.ResultsTwenty patients (20.2%; mean age, 46.9 y ± 6.3) had type I (n = 3) or II (n = 17) UOAs. Thirteen (65%) underwent UAE only (standard group) and seven (35%) underwent UAE and OAE (combined group). There were no significant differences between groups in demographics or in the incidence of permanent amenorrhea after procedures (follow-up, 561 d ± 490). There was a significantly higher incidence of symptom recurrence in the standard group compared with the control group (P = .01), with no differences between combined and control groups (P = 1).ConclusionsThere were no statistical differences in permanent amenorrhea rates in the groups studied, with significantly higher symptom recurrence rates observed when OAE was not performed in the setting of UOA.     

The Effect of Uterine Artery Embolization on Premenstrual Symptoms in Patients with Symptomatic Fibroids or Adenomyosis

PurposeTo evaluate whether uterine artery embolization (UAE) can reduce the premenstrual symptoms in women undergoing UAE for fibroid tumors or adenomyosis.Materials and MethodsAmong 141 women who underwent UAE for symptomatic fibroid tumors or adenomyosis at a single institution between March 2011 and February 2013, 54 premenstrual symptoms in 39 patients were prospectively analyzed. Premenstrual symptoms were rated by the patient on a scale of 0 to 10, with 0 representing no symptom and 10 representing the baseline severity. The change in premenstrual symptom score was calculated by subtracting the baseline score from the post-UAE score. At 3–6 months after UAE, each woman also completed a symptom severity questionnaire to assess the severity of menstrual bleeding to compare the changes in premenstrual symptoms scores between women with and without menorrhagia.ResultsBack pain, headache, and gastrointestinal symptoms (eg, constipation, indigestion, lower abdominal pain) were significantly improved after UAE (P < .05). Muscle pain, fatigue, nervousness, breast tenderness, and systemic edema were also improved, but not significantly so. The mean premenstrual symptom score change in patients with menorrhagia was significantly greater than in those without menorrhagia (−6.4 vs −3.7; P = .044).There was no correlation between the degree of menorrhagia score change and the degree of premenstrual symptom score change (P = .186).ConclusionsUAE could be a method to alleviate some premenstrual symptoms in patients with uterine fibroid tumors or adenomyosis.     

Inferior Mesenteric Artery Collaterals to the Uterus during Uterine Artery Embolization: Prevalence,Risk Factors,and Clinical Outcomes

PurposeTo evaluate the prevalence of inferior mesenteric artery (IMA) collaterals to the uterus found during uterine artery embolization (UAE), associated risk factors, and clinical outcomes.Materials and MethodsThe records of 559 women who underwent UAE during the period 2008–2011 for uterine fibroids or adenomyosis found on magnetic resonance imaging were retrospectively analyzed. If IMA collaterals to the uterus were suspected on aortography performed after embolization, selective angiography was performed. Risk factors for IMA collaterals to the uterus were analyzed, including the presence of adenomyosis, baseline uterine volume, or prior pelvic surgery.ResultsCollaterals to the uterus were found from the ovarian artery (n = 21; 3.8%), IMA (n = 7; 1.3%), round ligament artery (n = 1; 0.2%), and internal pudendal artery (n = 1; 0.2%). IMA collaterals were found in seven patients. Of 185 patients, 6 (3.2%) had adenomyosis, with or without fibroids, which was significantly more frequent than the 1 (0.27%) of 374 patients who had fibroids only (P = .006). On multiple logistic regression analysis, the presence of adenomyosis (odds ratio, 19.556; P = .0168) and uterine volume (odds ratio, 1.003; P = .0069) were independent factors for the presence of IMA collaterals. Of the seven patients with IMA collaterals, embolization was not attempted in six, resulting in clinical failure in four. One patient who underwent IMA embolization with coils experienced clinical improvement.ConclusionsThe IMA was the second most common (1.3%) source of collaterals to the uterus. IMA collaterals were more frequent in patients with adenomyosis than in patients with fibroids only, resulting in high frequency of treatment failure.     

Safety and Therapeutic Efficacy of Complete or Near-Complete Ablation of Symptomatic Uterine Fibroid Tumors by MR Imaging–Guided High-Intensity Focused US Therapy

PurposeTo evaluate the safety and therapeutic efficacy of magnetic resonance (MR) imaging–guided high-intensity focused ultrasound (US) ablation of symptomatic uterine fibroid tumors with an immediate nonperfused volume (NPV) ratio of 80% or more.Materials and MethodsA total of 79 women with 117 uterine tumors were treated with MR-guided high-intensity focused US ablation. Immediate NPV, complications, and therapeutic efficacy (tumor volume reduction ratio and symptom severity score [SSS] decrease at 3-mo follow-up) were retrospectively assessed. Statistical comparisons of the frequency of complications and therapeutic efficacy were performed between patients with NPV ratios of at least 80% and less than 80%.ResultsTechnical success was achieved in 93.7% of cases (n = 74) of cases, and the immediate NPV ratio was 62.7% ± 25.5. Twenty-four patients exhibited an NPV ratio of at least 80% (89.7% ± 5.8), and 50 patients showed an NPV ratio of less than 80% (49.8% ± 20.7). All complications were minor in severity, and the incidences were not significantly different between groups (P > .05). The 3-month volume reduction ratio was significantly greater in patients with an NPV ratio of at least 80% (0.43 ± 0.17) than in those with an NPV ratio of less than 80% (0.20 ± 0.26; P = .002), although the decreases in SSS were not significantly different (20.9 ± 19.6 vs 12.1 ± 10.1; P = .097).ConclusionsIn MR-guided high-intensity focused US ablation of symptomatic uterine fibroid tumors, achievement of an immediate NPV ratio of at least 80% is safe, with greater tumor volume shrinkage compared with cases with a lower NPV ratio.     

Incidence of Additional Treatments in Women Treated with MR-Guided Focused US for Symptomatic Uterine Fibroids: Review of 138 Patients with an Average Follow-up of 2.8 Years

PurposeTo assess long-term outcomes of magnetic resonance (MR)–guided focused ultrasound (US) treatments of uterine fibroids.Materials and MethodsA retrospective follow-up of 138 patients treated at a single institution between March 2005 and November 2011 was conducted. The patients were not part of a clinical study and were followed through retrospective review of their medical records and telephone interviews to assess additional treatments for fibroid-related symptoms. Survival methods, including Cox proportional hazards models, were used to assess the association between incidence of additional treatments and patient data obtained during screening before treatment.ResultsThe average length of follow-up was 2.8 years (range, 1–7.2 y). The cumulative incidence of additional treatments at 36 months and 48 months after MR-guided focused US was 19% and 23%, respectively. Women who did not need additional treatment were older than women who did (46.3 y ± 5.6 vs 43.0 y ± 5.8; P = .006; hazard ratio, 0.855; 95% confidence interval, 0.789–0.925). Additionally, women with heterogeneous or bright fibroids on T2-weighted MR imaging were more likely to require additional treatment compared with women with homogeneously dark fibroids (hazard ratio, 5.185 or 5.937, respectively; 95% confidence interval, 1.845–14.569 or 1.401–25.166, respectively). Physician predictions of treatment success, recorded during the screening process, had significant predictive value (P = .018).ConclusionsThe long-term rates of additional interventions after MR-guided focused US of symptomatic uterine fibroids were found to be comparable with other uterine-sparing procedures, such as uterine artery embolization or myomectomy. Older patient age and homogeneously dark fibroids were associated with fewer additional treatments. Physician assessment of treatment success was found to be a valuable tool in patient screening.     

Long-term Outcomes of Coil Packing for Visceral Aneurysms: Correlation between Packing Density and Incidence of Coil Compaction or Recanalization

PurposeTo evaluate the correlation between packing density and the incidence of coil compaction or recanalization of visceral artery aneurysms (VAAs) after coil packing.Materials and MethodsBetween July 2004 and April 2012, coil packing was performed for 46 true visceral aneurysms (16 splenic, 11 pancreaticoduodenal, eight renal, six hepatic, three superior mesenteric, one right gastric, and one gastroepiploic) in 42 patients. The size and volume of the aneurysm, packing density, and the incidences of compaction and recanalization were evaluated retrospectively.ResultsThe mean follow-up period was 37 months ± 8 (range, 11–80 mo). The mean packing density was 19% ± 8 (range, 5%–42%), mean aneurysm size was 19 mm ± 8 (range, 5–40 mm), and mean volume was 4,108 mm³ ± 5,435 (range, 72–26,235 mm³). Compaction and recanalization occurred in two (4%) and 12 aneurysms (26%), respectively. The mean packing density was significantly lower in aneurysms with compaction or recanalization than in unaffected aneurysms (12% vs 22%; P = .00014). There was a significant difference in mean packing density between small (< 20 mm; 22%) and large (≥ 20 mm) aneurysms (15%; P = .0045). The mean size and volume were significantly larger for coil-compacted or recanalized aneurysms than for unaffected aneurysms (P < .05). In aneurysms with a packing density of at least 24%, no compaction or recanalization occurred.ConclusionsCoil compaction or recanalization after coil packing for VAAs more often occurs after insufficient embolization with low packing density and in patients with large aneurysms.     

Quantitative Assessment of Lipiodol Deposition after Chemoembolization: Comparison between Cone-Beam CT and Multidetector CT

PurposeTo evaluate the ability of cone-beam computed tomography (CBCT) performed directly after transarterial chemoembolization to assess ethiodized oil (Lipiodol) deposition in hepatocellular carcinoma (HCC) and compare it with unenhanced multidetector computed tomography (CT).Materials and MethodsConventional transarterial chemoembolization was used to treat 15 patients with HCC, and CBCT was performed to assess Lipiodol deposition directly after transarterial chemoembolization. Unenhanced multidetector CT was performed 24 hours after transarterial chemoembolization. Four patients were excluded because the margin of tumor or area of Lipiodol deposition was unclear. The image enhancement density of the entire tumor and liver parenchyma was measured by ImageJ software, and tumor-to-liver contrast (TLC) was calculated. In addition, volumetric measurement of tumor and Lipiodol was performed by semiautomatic three-dimensional volume segmentation and compared using linear regression to evaluate consistency between the two imaging modalities.ResultsThe mean value of TLC on CBCT was not significantly different from TLC on multidetector CT (337.7 HU ± 233.5 vs 283.0 HU ± 152.1, P = .103).The average volume of the whole tumor and of only the regions with Lipiodol deposition and the calculated average percentage of Lipiodol retention on CBCT were not significantly different compared with multidetector CT (tumor volume, 9.6 cm³ ± 11.8 vs 10.8 cm³ ± 14.2, P = .142; Lipiodol volume, 6.3 cm³ ± 7.7 vs 7.0 cm³ ± 8.1, P = .214; percentage of Lipiodol retention, 68.9% ± 24.0% vs 72.2% ± 23.1%, P = .578). Additionally, there was a high correlation in the volume of tumor and Lipiodol between CBCT and multidetector CT (R² = 0.919 and 0.903).ConclusionsThe quantitative image enhancement and volume analyses demonstrate that CBCT is similar to multidetector CT in assessing Lipiodol deposition in HCC after transarterial chemoembolization.     

Image Guidance for Endovascular Repair of Complex Aortic Aneurysms: Comparison of Two-dimensional and Three-dimensional Angiography and Image Fusion

PurposeTo evaluate the feasibility of image fusion (IF) of preprocedural arterial-phase computed tomography with intraprocedural fluoroscopy for roadmapping in endovascular repair of complex aortic aneurysms, and to compare this approach versus current roadmapping methods (ie, two-dimensional [2D] and three-dimensional [3D] angiography).Materials and MethodsThirty-seven consecutive patients with complex aortic aneurysms treated with endovascular techniques were retrospectively reviewed; these included aneurysms of digestive and/or renal arteries and pararenal and juxtarenal aortic aneurysms. All interventions were performed with the same angiographic system. According to the availability of different roadmapping software, patients were successively placed into three intraprocedural image guidance groups: (i) 2D angiography (n = 9), (ii) 3D rotational angiography (n = 14), and (iii) IF (n = 14). X-ray exposure (dose–area product [DAP]), injected contrast medium volume, and procedure time were recorded.ResultsPatient characteristics were similar among groups, with no statistically significant differences (P ≥ .05). There was no statistical difference in endograft deployment success between groups (2D angiography, eight of nine patients [89%]; 3D angiography and IF, 14 of 14 patients each [100%]). The IF group showed significant reduction (P < .0001) in injected contrast medium volume versus other groups (2D, 235 mL ± 145; 3D, 225 mL ± 119; IF, 65 mL ± 28). Mean DAP values showed no significant difference between groups (2D, 1,188 Gy·cm² ± 1,067; 3D, 984 Gy·cm² ± 581; IF, 655 Gy·cm² ± 457; P = .18); nor did procedure times (2D, 233 min ± 123; 3D, 181 min ± 53; IF, 189 min ± 60; P = .59).ConclusionsThe use of IF-based roadmapping is a feasible technique for endovascular complex aneurysm repair associated with significant reduction of injected contrast agent volume and similar x-ray exposure and procedure time.     

Respiration-induced Deformations of the Superior Mesenteric and Renal Arteries in Patients with Abdominal Aortic Aneurysms

PurposeTo quantify respiration-induced deformations of the superior mesenteric artery (SMA), left renal artery (LRA), and right renal artery (RRA) in patients with small abdominal aortic aneurysms (AAAs).Materials and MethodsSixteen men with AAAs (age 73 y ± 7) were imaged with contrast-enhanced magnetic resonance angiography during inspiratory and expiratory breath-holds. Centerline paths of the aorta and visceral arteries were acquired by geometric modeling and segmentation techniques. Vessel translations and changes in branching angle and curvature resulting from respiration were computed from centerline paths.ResultsWith expiration, the SMA, LRA, and RRA bifurcation points translated superiorly by 12.4 mm ± 9.5, 14.5 mm ± 8.8, and 12.7 mm ± 6.4 (P < .001), and posteriorly by 2.2 mm ± 2.7, 4.9 mm ± 4.2, and 5.6 mm ± 3.9 (P < .05), respectively, and the SMA translated rightward by 3.9 mm ± 4.9 (P < .01). With expiration, the SMA, LRA, and RRA angled upward by 9.7° ± 6.4, 7.5° ± 7.8, and 4.9° ± 5.3, respectively (P < .005). With expiration, mean curvature increased by 0.02 mm^?1 ± 0.01, 0.01 mm^?1 ± 0.01, and 0.01 mm^?1 ± 0.01 in the SMA, LRA, and RRA, respectively (P < .05). For inspiration and expiration, RRA curvature was greater than in other vessels (P < .025).ConclusionsWith expiration, the SMA, LRA, and RRA translated superiorly and posteriorly as a result of diaphragmatic motion, inducing upward angling of vessel branches and increased curvature. In addition, the SMA exhibited rightward translation with expiration. The RRA was significantly more tortuous, but deformed less than the other vessels during respiration.     

Feasibility of Time-Resolved MR Angiography for Detecting Recanalization of Pulmonary Arteriovenous Malformations Treated with Embolization with Platinum Coils

PurposeTo assess the feasibility of time-resolved magnetic resonance (MR) angiography as a follow-up method after embolization for pulmonary arteriovenous malformations (PAVMs).Materials and MethodsEvaluation of 28 PAVMs in 10 patients previously treated with embolization with platinum coils was performed. The mean observation period after embolization was 49 months. All patients underwent unenhanced chest computed tomography (CT) and time-resolved MR angiography followed by transcatheter digital subtraction angiography within 5 weeks for a definite diagnosis. Two radiologists reviewed the CT and time-resolved MR angiography findings using a blinded method. On CT, the draining veins of the PAVMs were measured before and after embolization, and shrinkage rates were calculated. On time-resolved MR angiography, recanalization was diagnosed when the draining vein or aneurysmal sac or both were enhanced in the pulmonary arterial phase. Correlations between recanalization, the shrinkage rate of the draining vein, and the diagnostic accuracies of CT and time-resolved MR angiography were assessed and compared with digital subtraction angiography.ResultsFive lesions could not be measured on CT because of metallic artifacts. The mean shrinkage rates of the draining vein for recanalized and occluded PAVMs were 23% ± 19 (SD) for recanalized PAVMs and 47% ± 21 for occluded PAVMs (P = .001). The sensitivity and specificity were 93% and 53%, respectively, when the shrinkage rate threshold was set to 50%. On time-resolved MR angiography, the sensitivity and specificity were 93% and 100%, respectively, for Reader 1 and 100% and 93%, respectively, for Reader 2. The κ coefficient was 0.86.ConclusionsTime-resolved MR angiography appears to be a feasible method for PAVM follow-up examinations and to provide a more accurate diagnosis of recanalization compared with unenhanced CT.     

Coils versus Gelatin Particles with or without Intraarterial Antibiotics for Partial Splenic Embolization: A Comparative Evaluation

PurposeTo compare the efficacy, complications, and inflammatory levels in partial splenic embolization (PSE) with coils or gelatin sponge (GS) particles with or without intraarterial antibiotic agents.Materials and MethodsForty-four patients with hypersplenism treated by PSE were assessed. GS particles were used in 31 patients, and coils were used in 13 patients. In 17 of the 31 patients who received GS, GS suspended in antibiotic solution was injected via the splenic artery. In the other 14 patients, antibiotic agents were not used. In all 13 coil group patients, an antibiotic solution was intraarterially injected before embolization. Platelet counts were compared between the GS and coil groups. Complications and serum C-reactive protein (CRP) levels were compared among the three groups.ResultsThere were no significant differences in platelet counts and platelet increased ratios at 6 months (10.0 × 10⁴/µL and 193% in the GS group vs 9.0 × 10⁴/µL and 221% in the coil group), and no significant differences in frequencies of complications. However, one splenic abscess occurred in a patient treated with GS without antibiotics, resulting in death. The mean serum CRP level in the GS with antibiotic group at 2 weeks was significantly lower than in the other two groups.ConclusionsThe efficacy of PSE is similar with the use of coils versus GS particles. Prophylactic intraarterial antibiotic treatment could be useful in preventing inflammatory reactions after PSE.     

Uterine Artery Embolization Using a Transradial Approach: Initial Experience and Technique

This study investigates the feasibility of performing uterine artery embolization (UAE) via transradial access (TRA). Growing evidence demonstrates significant benefits of TRA versus standard transfemoral access during percutaneous coronary intervention, now making it the preferred approach at many centers worldwide. At a single institution from March 2013 to October 2013, 29 consecutive patients were treated by transradial UAE. Technical success rate was 100%, with no immediate major or minor complications. The radial artery was patent at 1-month follow-up evaluation in all cases. These preliminary data suggest that transradial UAE is feasible and safe.     

Hypertrophic Cardiomyopathy (HCM): New insights into Coronary artery remodelling and ischemia from FFRCT

IntroductionAngina, myocardial ischemia, and coronary artery physiology in hypertrophic cardiomyopathy (HCM) are poorly understood. However, coronary computed tomography angiography (CCTA) with fractional flow reserve from CT (FFRCT) analysis offers a non-invasive method for evaluation of coronary artery volume to myocardial mass ratio (V/M) that may provide insight into such mechanisms. Thus, we sought to investigate changes in V/M in HCM.MethodsA retrospective analysis was performed on 37 HCM patients and 37 controls matched for age, sex, and cardiovascular risk factors; CCTA-derived coronary artery lumen volume (V) and myocardial mass (M) were used to determine V/M. FFR_CT values were calculated for the left anterior descending (LAD), left circumflex (LCx) and right coronary (RCA) arteries as well as the 3-vessel cumulative FFR_CT values.ResultsHCM patients had significantly increased myocardial mass (176 ± 84 vs. 119 ± 27 g, p < 0.0001) and total coronary artery luminal volume (4112 ± 1139 vs. 3290 ± 924 mm³, p < 0.0001) that resulted from increases in segmented luminal volumes of both the left and right coronary artery systems. However, HCM patients had significantly decreased V/M (23.8 ± 5.9 vs. 26.5 ± 5.3 mm³/g; p = 0.026) which was further decreased when restricting V/M analysis to those HCM patients with septal hypertrophy (22.4 mm³/g, p = 0.01) that was mild-moderately predictive of HCM (AUC = 0.68). HCM patients also showed significantly lower nadir FFR_CT values in the LCx (0.87 ± 0.06 vs. 0.91 ± 0.06, p = 0.02), and cumulative 3-vessel FFR_CT values (2.58 ± 0.18 vs. 2.63 ± 0.14, p = 0.006).ConclusionsHCM patients demonstrate significantly greater coronary volume. Despite this, HCM patients suffer from decreased V/M. Further prospective studies evaluating the relationship between V/M, angina, and heart failure in HCM are needed.     

Quantification of Tissue Shrinkage and Dehydration Caused by Microwave Ablation: Experimental Study in Kidneys for the Estimation of Effective Coagulation Volume

PurposeTo quantify the extent of tissue shrinkage and dehydration caused by microwave (MW) ablation in kidneys for estimation of effective coagulation volume.Materials and MethodsMW ablations were carried out in ex vivo porcine kidneys. Six study groups were defined: groups 1A, 2A, and 3A for MW ablation (90 W for 5 min, 7.5 min, or 10 min), and groups 1B, 2B, and 3B for control (without MW ablation). Pre- and postinterventional volume analyses were performed. Effective coagulation volumes (original tissue included in coagulation) were determined. Postinterventional dehydration analyses were performed with calculation of mean mass fractions of water.ResultsMean deployed energies were 21.6 kJ ± 1.1 for group 1A, 29.9 kJ ± 1.0 for group 2A, and 42.1 kJ ± 0.5 kJ for group 3A, and were significantly different (P < .0001). Differences between pre- and postinterventional volumes were ?3.8% ± 0.6 for group 1A, ?5.6% ± 0.9 for group 2A, and ?7.2% ± 0.4 for group 3A, and ?1.1% ± 0.3 for group 1B, ?1.8% ± 0.4 for group 2B, and ?1.1% ± 0.4 for group 3B. Postinterventional volumes were significantly smaller than preinterventional volumes for all groups (P < .01). Underestimations of effective coagulation volume from visualized coagulation volume were 26.1% ± 3.5 for group 1A, 35.2% ± 11.2 for group 2A, and 42.1% ± 4.9 for group 3A, which were significantly different (P < .01). Mean mass fractions of water were 64.2% ± 1.4 for group 1A, 63.2% ± 1.7 for group 2A, and 62.6% ± 1.8% for group 3A, with significant differences versus corresponding control groups (P < .01).ConclusionsFor MW ablation in kidneys, underestimation of effective coagulation volume based on visualized coagulation volume is significantly greater with greater deployed energy. Therefore, local dehydration with tissue shrinkage is a potential contributor.     

Localized Hyperthermia with Iron Oxide–Doped Yttrium Microparticles: Steps toward Image-Guided Thermoradiotherapy in Liver Cancer

PurposeTo test whether iron oxide (IO)–containing yttrium aluminosilicate (YAS) microparticles (MPs) can generate localized therapeutic hyperthermia (≥ 43°C) when injected intratumorally in an animal model of liver cancer and whether MP distributions could be visualized with magnetic resonance (MR) imaging.Materials and MethodsTwenty-one Sprague–Dawley rats implanted with N1-S1 liver tumors were assigned to alternating magnetic field (AMF) exposure following intratumoral injection with IO-YAS MPs (n = 7), sham surgery (n = 7), or baseline iron quantification (n = 7). Three fiberoptic probes allowed spatial and temporal monitoring of temperatures during 24 minutes of AMF exposure. T2-weighted turbo spin-echo MR imaging was performed within 1 hour after the procedure to detect signal voids caused by IO-YAS deposition. Hematoxylin and eosin–stained pathologic slides were also obtained, and the presence of IO-YAS was evaluated with inductively coupled plasma optical emission spectroscopy.ResultsFollowing AMF exposure, intratumoral temperatures after IO-YAS MP injection achieved therapeutic hyperthermia whereas those after sham surgery did not (46.6°C ± 1.3 vs 36.8°C ± 0.4; P < .0001). Within the treated group, the normal hepatic parenchyma (NHP) and rectal temperatures were 37.4°C ± 0.9 and 36.5°C ± 1.0 (P = .0809) at the conclusion of AMF exposure, respectively. A T2-weighted signal void at the tumor site was observed in all seven treated animals, and intratumoral IO-YAS was visualized on subsequent histopathologic examination in each case. The mean ratio of tumor:NHP Fe concentrations attributable to IO-YAS MPs was 108:1.ConclusionsAMF exposure of intratumoral IO-YAS MPs generates localized therapeutic hyperthermia in an animal model of liver cancer. MR detectability and potential for combination brachytherapy warrants further investigation for thermoradiotherapy in liver cancer.     

Transcatheter Arterial Chemoembolization with Doxorubicin-Eluting Superabsorbent Polymer Microspheres in the Treatment of Hepatocellular Carcinoma: Midterm Follow-up

PurposeTo investigate prospectively the safety, tolerability, and efficacy of transarterial chemoembolization using superabsorbent polymer (SAP) microspheres loaded with doxorubicin for the treatment of hepatocellular carcinoma (HCC).Materials and MethodsDuring the years 2006–2011, 64 patients underwent 144 transarterial chemoembolization with SAP microspheres procedures. Most of the patients were staged as Barcelona Clinic Liver Cancer class B (65%). The most frequent underlying liver diseases were hepatitis C (35%) and alcoholic liver disease (28%) resulting in Child-Pugh A (73.4%) or Child-Pugh B (17%) liver cirrhosis. Tumor response was assessed using modified Response Evaluation Criteria in Solid Tumors with magnetic resonance (MR) imaging performed 4–6 weeks after each procedure.ResultsSerious adverse events (n = 9) were ischemic or infectious in nature. Transarterial chemoembolization with SAP microspheres resulted in objective response rates of 67.5%, 44.5%, and 25% after first, second, and third sessions. There were 16 patients (25%) who underwent orthotopic liver transplantation after transarterial chemoembolization with SAP microspheres, of whom 2 experienced recurrent disease. During a median follow-up time of 14 months (range, 2–55 mo), 26 patients (40.5%) died. Median overall and transplant-free survivals were 20.5 months (95% confidence interval, 13.2–27.7) and 18 months (95% confidence interval, 14.2–21.8), respectively.ConclusionsTransarterial chemoembolization with SAP microspheres has an excellent safety profile in cirrhotic patients, even in the presence of advanced liver disease (Child-Pugh B) or advanced stages of HCC. This treatment produced meaningful tumor response rates as assessed by MR imaging.