Levator ani asymmetry and deviation in high-type anorectal malformation evaluated by magnetic resonance imaging.

INTRODUCTION: The levator ani (LA) complex in high-type imperforate anus (H-IA), low-type imperforate anus (L-IA), and Hirschsprung's disease (HD) patients as controls were documented using magnetic resonance imaging (MRI) and compared for symmetry. MATERIALS AND METHODS: Mean left:right LA thickness ratio (LA ratio), and deviation of the LA from the pubococcygeal line (PCL; LA angle) were calculated from thin-slice MRI images (axial 2 mm, coronal 2 mm, and sagittal 3 mm) of the puborectalis and pubococcygeus taken parallel to the PCL under sedation in H-IA (n=14), L-IA (n=16), and HD (n=9). RESULTS: MRI scans were performed between January 2018 and June 2021. LA were significantly thinner in H-IA (1.78±0.46 mm) compared with L-IA (2.97±0.55 mm) and controls (2.87±0.32 mm), p<0.0001. LA ratio was significantly lower in H-IA (0.71±0.15) compared with L-IA (0.93±0.04), and controls (0.91±0.06), p<0.0001. Mean LA-angle was significantly different in H-IA, 10.8° (range 6°-19°), versus L-IA and controls, both zero degrees (range 0°-5°), p<0.0001, respectively. CONCLUSIONS: LA was confirmed to be significantly asymmetric in H-IA. Because outcome of surgical repair involving a midline incision, such as posterior sagittal anorectoplasty could be impaired, pediatric surgeons are advised to plan surgical intervention for H-IA carefully and appropriately.

Efficacy and safety of prophylactic superselective embolization for angiomyolipoma at the renal hilum.

OBJECTIVE: This study investigated the efficacy and safety of superselective transcatheter arterial embolization for angiomyolipoma at the renal hilum. METHODS: Between August 2012 and January 2015, 13 patients with 16 angiomyolipomas at the renal hilum underwent initial, prophylactic, superselective transcatheter arterial embolization. The patients were followed by computed tomography or magnetic resonance imaging, and volume-reduction ratios after embolization were measured. RESULTS: The mean or median post-embolization volume reduction ratios were 23% (follow-up duration, 1-2 months), 55% (3-6 months), 55% (7-12 months), 66% (1-2 years), 67% (2-3 years), and 54% (>3 years). After initial embolization, none of the 16 tumors bled or required surgery; two (13%) tumors recurred; and three (19%) tumors received repeat embolization. Estimated glomerular filtration rates were not decreased at medians of 7 days (near the time of discharge) and 39 days (first clinical follow-up) post-procedure, compared with baseline. Except for post-embolization syndrome, no procedure-related complications occurred. CONCLUSIONS: Superselective embolization for renal hilar angiomyolipoma is safe and kidney-preserving, with good tumor volume reduction and bleeding prevention.

Evaluation of solid portions in non-small cell lung cancer-the solid part is not always measurable for clinical T factor.

BACKGROUND: Solid component size on thin-section computed tomography is used for T-staging according to the eighth edition of the Tumor Node Metastasis classification of lung cancer. However, the feasibility of using the solid component to measure clinical T-factor remains controversial. METHODS: We evaluated the feasibility of measuring the solid component in 859 tumours, which were suspected cases of primary lung cancers, requiring surgical resection regardless of the procedure or clinical stage. After excluding 126 pure ground-glass opacity tumours and 450 solid tumours, 283 part-solid tumours were analysed to determine the frequency of cases where the measurement of the solid portion was difficult along with the associated cause. Pathological invasiveness was also evaluated. RESULTS: The solid portion of 10 lesions in 283 part-solid nodules was difficult to measure due to an underlying lung disease (emphysema and pneumonitis). The solid portion of 62 lesions (21.9%) without emphysema and pneumonitis was difficult to measure due to imaging features of the tumours. Among the 62 patients, five had no malignancy and one with a tumour size of 33 mm had nodal metastasis. There were 56 lesions with a tumour size of ≤30 mm, wherein nodal metastases, vascular and/or lymphatic invasions were not observed. CONCLUSION: For one-fifth of the part-solid tumours, measurement of the solid component was difficult. Moreover, these lesions had low invasiveness, especially in T1. The measurement of the solid portion and the classification of T1 in 1-cm increments may be complex.

Verification of image quality and quantification in whole-body positron emission tomography with continuous bed motion.

OBJECTIVE: Whole-body dynamic imaging using positron emission tomography (PET) facilitates the quantification of tracer kinetics. It is potentially valuable for the differential diagnosis of tumors and for the evaluation of therapeutic efficacy. In whole-body dynamic PET with continuous bed motion (CBM) (WBDCBM-PET), the pass number and bed velocity are key considerations. In the present study, we aimed to investigate the effect of a combination of pass number and bed velocity on the quantitative accuracy and quality of WBDCBM-PET images. METHODS: In this study, WBDCBM-PET imaging was performed at a body phantom using seven bed velocity settings in combination with pass numbers. The resulting image quality was evaluated. For comparing different acquisition settings, the dynamic index (DI) was obtained using the following formula: [P/S], where P represents the pass number, and S represents the bed velocity (mm/s). The following physical parameters were evaluated: noise equivalent count at phantom (NECphantom), percent background variability (N10 mm), percent contrast of the 10 mm hot sphere (QH, 10 mm), the QH, 10 mm/N10 mm ratio, and the maximum standardized uptake value (SUVmax). Furthermore, visual evaluation was performed. RESULTS: The NECphantom was equivalent for the same DI settings regardless of the bed velocity. The N10 mm exhibited an inverse correlation (r < - 0.89) with the DI. QH,10 mm was not affected by DI, and a correlation between QH,10 mm/N10 mm ratio and DI was found at all the velocities (r > 0.93). The SUVmax of the spheres was not influenced by the DI. The coefficient of variations caused by bed velocity decreased in larger spheres. There was no significant difference between the bed velocities on visual evaluation. CONCLUSION: The quantitative accuracy and image quality achieved with WBDCBM-PET was comparable to that achieved with non-dynamic CBM, regardless of the pass number and bed velocity used during imaging for a given acquisition time.

Superselective Transcatheter Arterial Embolization for Large Unruptured Renal Angiomyolipoma in Lymphangioleiomyomatosis.

PURPOSE: To retrospectively evaluate therapeutic performance and complications of superselective transcatheter arterial embolization (TAE) for unruptured renal angiomyolipoma (AML) in patients with lymphangioleiomyomatosis (LAM) and to investigate the correlation between percentage reduction in tumor volume and intratumoral fat content. MATERIALS AND METHODS: Superselective TAE was performed in 14 consecutive patients with 15 large unruptured renal AMLs associated with LAM (mean age, 38 y; range, 21-57 y). Patients had renal AML with aneurysms ≥ 5 mm in diameter, tumor-related abdominal symptoms, or both. In all cases, embolization of 1 tumor was achieved in a single session by using multiporous gelatin sponge particles (GSPs) with additional metallic coils in all but 1 case. Tumor volume and fat content percentage were measured on CT or MR imaging before and after superselective TAE (median, 11 months; range, 6-14 months). RESULTS: Residual tumor staining declined by > 90% after all TAE sessions except 2, with embolization of all treated aneurysms. No nontarget embolization or severe complications were encountered. Mean percentage reduction in tumor volume after superselective TAE was 69% (range, 21%-95%). Percentage tumor volume reduction was negatively correlated with fat content before embolization (P < .01). CONCLUSIONS: Superselective TAE with multiporous GSPs and metallic coils for large unruptured renal AML in patients with LAM is useful for reducing tumor volume and treating intratumoral aneurysms without major pulmonary or renal complications. Extent of tumor reduction may be influenced by fat content before embolization.

A new two-step accurate CT-MRI fusion technique for post-implant prostate cancer.

PURPOSE: To develop an accurate method of fusing computed tomography (CT) with magnetic resonance imaging (MRI) for post-implant dosimetry after prostate seed implant brachytherapy. MATERIAL AND METHODS: Prostate cancer patients were scheduled to undergo CT and MRI after brachytherapy. We obtained the three MRI sequences on fat-suppressed T1-weighted imaging (FST1-WI), T2-weighted imaging (T2-WI), and T2*-weighted imaging (T2*-WI) in each patient. We compared the lengths and widths of 450 seed source images in the 10 study patients on CT, FST1-WI, T2-WI, and T2*-WI. After CT-MRI fusion using source positions by the least-squares method, we decided the center of each seed source and measured the distance of these centers between CT and MRI to estimate the fusion accuracy. RESULTS: The measured length and width of the seeds were 6.1 ± 0.5 mm (mean ± standard deviation) and 3.2 ± 0.2 mm on CT, 5.9 ± 0.4 mm, and 2.4 ± 0.2 mm on FST1-WI, 5.5 ± 0.5 mm and 1.8 ± 0.2 mm on T2-WI, and 7.8 ± 1.0 mm and 4.1 ± 0.7 mm on T2*-WI, respectively. The measured source location shifts on CT/FST1-WI and CT/T2-WI after image fusion in the 10 study patients were 0.9 ± 0.4 mm and 1.4 ± 0.2 mm, respectively. The shift on CT/FST1-WI was less than on CT/T2-WI (p = 0.005). CONCLUSIONS: For post-implant dosimetry after prostate seed implant brachytherapy, more accurate fusion of CT and T2-WI is achieved if CT and FST1-WI are fused first using the least-squares method and the center position of each source, followed by fusion of the FST1-WI and T2-WI images. This method is more accurate than direct image fusion.

Embolization of spontaneous intratumoral hemorrhage with the hemodynamic characteristics of arteriovenous fistula in renal angiomyolipoma.

Aneurysms within renal angiomyolipomas (AML) may rupture into the tumor or pararenal space. Transcatheter arterial embolization is the first-choice treatment to control bleeding. Here, we describe the use of coil embolization in two cases of spontaneous intratumoral hemorrhage with the hemodynamic characteristics of renal arteriovenous (AV) fistula in renal AML. In case 1, renal angiography showed several intratumoral aneurysms, one of which had ruptured into the tumor, resulting in the formation of an intratumoral hematoma. Blood flow within the hematoma was rapid and the blood was immediately returned to the systemic circulation through the left renal vein. In case 2, renal angiography showed that the rupture of an intratumoral aneurysm of a tumor-feeding artery had resulted in formation of an intratumoral hematoma and direct renal vein communication. No extratumoral hemorrhage was observed in either case. The hemodynamics of both hematomas resembled those of a high-flow renal AV fistula. The ruptured aneurysms were embolized with detachable and pushable coils (case 1) or pushable coils only (case 2). To our knowledge, this is the first report of successful embolization of AV fistula-like intratumoral hemorrhage in renal AML.

Reversed halo sign in tuberous sclerosis complex.

We describe a reversed halo sign in a teenage girl with tuberous sclerosis complex (TSC). Lung manifestations of TSC include lung cysts corresponding to lymphangioleiomyomatosis and small nodules indicating multifocal micronodular pneumocyte hyperplasia (MMPH). However, a reversed halo sign in TSC has never been reported. The lesion was microscopically consistent with MMPH. Immunohistological findings also supported the notion that the lesion is associated with TSC.