Taiki Nozaki

Infarction of Uterine Fibroids After Embolization: Relationship Between Postprocedural Enhanced MRI Findings and Long-Term Clinical Outcomes

PurposeTo retrospectively evaluate the relationship between the degree of infarction of uterine fibroids on enhanced MRI after embolization and long-term clinical outcomes.MethodsDuring 92 months, 290 consecutive patients with symptomatic uterine fibroids were treated with embolization; 221 who underwent enhanced MRI before embolization and 1 week after embolization were included in this study. The infarction rates of all fibroid tissue were assessed using enhanced MRI after embolization. Patients were divided into three groups according to the infarction rates: group A (100% infarction, n = 142), group B (90–99% infarction, n = 74), group C (<90% infarction, n = 5). The cumulative rates of clinical outcomes were compared among groups using the Kaplan-Meier limited method.ResultsGroup A had a significantly higher rate of symptom control than groups B and C. The cumulative rates of symptom control at 5 years were 93%, 71%, and 60% in groups A, B, and C, respectively. Group A had a significantly lower rate of gynecologic intervention after embolization than groups B and C. The cumulative rates of additional gynecologic intervention at 5 years were 3%, 15%, and 20% in groups A, B, and C, respectively.ConclusionsThe degree of infarction of uterine fibroids after embolization on enhanced MRI was related to long-term clinical outcomes. Complete infarction of all fibroid tissue can induce a higher rate of symptom control, with a lower rate of additional gynecologic intervention in the long term compared with incomplete infarction of fibroid tissue.

Syndromes Associated with Vascular Tumors and Malformations: A Pictorial Review

Use of the International Society for the Study of Vascular Anomalies (ISSVA) classification system has been strongly recommended in recent years because of the need for separate therapeutic measures for patients with vascular tumors and malformations. In the ISSVA classification system, vascular tumors, which are neoplastic, are distinguished from vascular malformations, which are caused by vascular structural anomalies and are not neoplastic, on the basis of the presence or absence of neoplastic proliferation of vascular endothelial cells. It is important that radiologists be familiar with the development, diagnosis, and treatment of vascular tumors and malformations, especially the imaging features of low- and high-flow vascular malformations. Some vascular tumors and malformations develop in isolation, whereas others develop within the phenotype of a syndrome. Syndromes that are associated with vascular tumors include PHACE syndrome. Syndromes that are associated with vascular malformations include Sturge-Weber, Klippel-Trénaunay, Proteus, blue rubber bleb nevus, Maffucci, and Gorham-Stout syndromes, all of which demonstrate low flow, and Rendu-Osler-Weber, Cobb, Wyburn-Mason, and Parkes Weber syndromes, all of which demonstrate high flow. Because imaging findings may help identify such syndromes as systemic, it is important that radiologists familiarize themselves with these conditions.

Amenorrhea and resumption of menstruation after uterine artery embolization for fibroids

To determine whether women will experience permanent amenorrhea following uterine artery embolization for fibroids, and whether rates of onset differ in the long term according to age at the time of the procedure.

Quantification of Fatty Degeneration Within the Supraspinatus Muscle by Using a 2-Point Dixon Method on 3-T MRI

OBJECTIVE The objective of this study was to quantify fatty degeneration of the supraspinatus muscle by using a 2-point Dixon technique on 3-T MRI and to evaluate the correlation of muscular atrophy and fat fraction values among different severities of rotator cuff tears across differing ages and sexes. SUBJECTS AND METHODS Patients with shoulder pain (n = 359) were evaluated by shoulder MRI on a 3-T unit, including a 2-point Dixon sequence for quantification of muscle atrophy and fatty degeneration within the supraspinatus muscle. Two board-certified musculoskeletal radiologists evaluated the degree of rotator cuff tears in three groups: full-thickness tear (n = 63), partial tear (n = 54), and no tear (n = 242). In quantitative analysis, we measured signal intensity values of in-phase images (SIn) and fat images (SFat) within the supraspinatus muscle, and the fat fraction was calculated as SFat/SIn. The Thomazeau occupation ratio was used as a quantitative index of muscular atrophy. Fat fraction and muscle atrophy were evaluated among these groups. RESULTS Fat fraction values were changed with the degree of rotator cuff tears and were (mean ± SD) 0.258 ± 0.123 among patients with full-thickness tears, 0.166 ± 0.067 among patients with partial tears, and 0.128 ± 0.061 among patients with no tears, with statistically significant differences (p < 0.001). The values were higher in female than in male patients in all groups. The Pearson correlation coefficient was 0.348 between age and fat fraction value, and 0.664 between muscular atrophy rate and fat fraction value. CONCLUSION An increase in supraspinatus fatty degeneration was statistically significantly correlated with severity of supraspinatus tears and moderately correlated with muscular atrophy. Fatty degeneration tends to progress more rapidly than muscular atrophy in female patients, with statistically significant sex differences.

Imaging of vascular tumors with an emphasis on ISSVA classification

The International Society for the Study of Vascular Anomalies (ISSVA) classification is becoming the international standard classification system for vascular tumors and vascular malformations. The ISSVA classification strictly distinguishes vascular tumors (neoplastic lesions) from vascular malformations (non-neoplastic lesions) based on whether there is a proliferation of vascular endothelial cells present, and it is an extremely useful classification system for determining therapeutic measures. For vascular tumors, it is clinically significant in terms of discriminating infantile hemangioma and rapidly involuting congenital hemangioma, which are expected to spontaneously regress, from other vascular tumors requiring treatment. Needless to say, clinical courses are important for diagnosis, and it is also important for radiologists to understand imaging findings on vascular tumors because such tumors have unique findings on diagnostic images. In this paper, vascular tumors are classified based on the ISSVA classification, and clinical and imaging findings are reviewed.

T1rho mapping of entire femoral cartilage using depth- and angle-dependent analysis

AbstractObjectivesTo create and evaluate normalized T1rho profiles of the entire femoral cartilage in healthy subjects with three-dimensional (3D) angle- and depth-dependent analysis.MethodsT1rho images of the knee from 20 healthy volunteers were acquired on a 3.0-T unit. Cartilage segmentation of the entire femur was performed slice-by-slice by a board-certified radiologist. The T1rho depth/angle-dependent profile was investigated by partitioning cartilage into superficial and deep layers, and angular segmentation in increments of 4° over the length of segmented cartilage. Average T1rho values were calculated with normalized T1rho profiles. Surface maps and 3D graphs were created.ResultsT1rho profiles have regional and depth variations, with no significant magic angle effect. Average T1rho values in the superficial layer of the femoral cartilage were higher than those in the deep layer in most locations (p < 0.05). T1rho values in the deep layer of the weight-bearing portions of the medial and lateral condyles were lower than those of the corresponding non-weight-bearing portions (p < 0.05). Surface maps and 3D graphs demonstrated that cartilage T1rho values were not homogeneous over the entire femur.ConclusionsNormalized T1rho profiles from the entire femoral cartilage will be useful for diagnosing local or early T1rho abnormalities and osteoarthritis in clinical applications.Key Points• T1rho profiles are not homogeneous over the entire femur. • There is angle- and depth-dependent variation in T1rho profiles. • There is no influence of magic angle effect on T1rho profiles. • Maps/graphs might be useful if several difficulties are solved.

Normal T2 map profile of the entire femoral cartilage using an angle/layer‐dependent approach

To create standard T2 map profiles from the entire femoral cartilage of healthy volunteers in order to assess regional variations using an angular and layer‐dependent approach.

High-Resolution 3T MR Imaging of the Triangular Fibrocartilage Complex

This study is intended as a review of 3Tesla (T) magnetic resonance (MR) imaging of the triangular fibrocartilage complex (TFCC). The recent advances in MR imaging, which includes high field strength magnets, multi-channel coils, and isotropic 3-dimensional (3D) sequences have enabled the visualization of precise TFCC anatomy with high spatial and contrast resolution. In addition to the routine wrist protocol, there are specific techniques used to optimize 3T imaging of the wrist; including driven equilibrium sequence (DRIVE), parallel imaging, and 3D imaging. The coil choice for 3T imaging of the wrist depends on a number of variables, and the proper coil design selection is critical for high-resolution wrist imaging with high signal and contrast-to-noise ratio. The TFCC is a complex structure and is composed of the articular disc (disc proper), the triangular ligament, the dorsal and volar radioulnar ligaments, the meniscus homologue, the ulnar collateral ligament (UCL), the extensor carpi ulnaris (ECU) tendon sheath, and the ulnolunate and ulnotriquetral ligaments. The Palmer classification categorizes TFCC lesions as traumatic (type 1) or degenerative (type 2). In this review article, we present clinical high-resolution MR images of normal TFCC anatomy and TFCC injuries with this classification system.

Comparison of T1rho imaging between spoiled gradient echo (SPGR) and balanced steady state free precession (b-FFE) sequence of knee cartilage at 3 Tesla MRI

PURPOSE To investigate the difference in T1rho profiles of the entire femoral cartilage between SPGR and b-FFE sequences at 3.0T. MATERIALS AND METHODS 20 healthy volunteers were enrolled in this study. T1rho images of each subject were acquired with two types of pulse sequences: SPGR and b-FFE. Femoral cartilage segmentation was performed by two independent raters slice-by-slice using Matlab. Inter- and intra-observer reproducibility between the two imaging protocols was calculated. The relative signal intensity (SI) of cartilage, subchondral bone marrow, joint effusion, and the relative signal contrast between structures of the knee were quantitatively measured. The difference in T1rho values between SPGR and b-FFE sequences was statistically analyzed using the Wilcoxon signed-rank test. RESULTS The average T1rho value of the entire femoral cartilage with b-FFE was significantly higher compared to SPGR (p<0.05). The reproducibility of the segmented area and T1rho values was superior with SPGR compared to b-FFE. The inter-class correlation coefficient was 0.846 on SPGR and 0.824 on b-FFE. The intra-class correlation coefficient of T1rho values was 0.878 on SPGR and 0.836 on b-FFE. The two imaging techniques demonstrated different signal and contrast characteristics. The relative SI of fluid was significantly higher on SPGR, while the relative SI of subchondral bone was significantly higher on b-FFE (p<0.001). There were also significant differences in the relative contrast between fluid-cartilage, fluid-subchondral bone, and cartilage-subchondral bone between the two sequences (all p<0.001). CONCLUSION We need to pay attention to differences in T1rho values between SPGR and b-FFE in clinical applications.

Scurvy: From a Selective Diet in Children with Developmental Delay.

A 5-year-old boy with developmental delay presented with painful knees and difficulty walking for a month. He had been diagnosed with autism spectrum disorder and had a selective diet, only consuming bread, snacks, and water. Radiograph of the knee demonstrated a radiodense band at the chondroosseous junction and a translucent band in the metaphysis of the distal femora and the proximal tibiae (Figure, A), which raised a possibility of leukemic bands. However, the child’s complete blood count result was unremarkable. Prior to the scheduled bone marrow biopsy, magnetic resonance imaging (MRI) was obtained, which demonstrated ill-defined T2 hyperintensities in the metaphyses and juxtaosseous soft tissue (Figure, B). The diaphysis was spared. These findings led us to another possible diagnosis of scurvy. His serum vitamin C level was undetectable (<0.2 mg/dL).Vitamin supplementation improved his symptoms over the next 2 months. Scurvy or vitamin C deficiency is an ancient condition that has been known since the “Age of Discovery.” In modern developed countries, scurvy has become rare; however, it can still be seen in children with a very selective diet. In particular, children with developmental delay are at an increased risk for selective diet, both from the children’s choice and from the parents’ offering a limited variety of food. Affected children may have only musculoskeletal symptoms without classical hemorrhagic diathesis. Radiography may show only some of the classic signs of scurvy (generalized osteoporosis with Wimberger ring, Pelkan spur, Frankel line, and Trummerfeld zone). Recently, several reports about MRI findings of scurvy have been published. They recapitulate classic histologic features of scurvy at bone ends, such as disruption of the chondroosseous junction and metaphyseal reparative changes. Diaphyseal involvement is less common.MRI usually, but not always, enables clinicians to distinguish scurvy from other bone marrow infiltrative disorders, such as leukemia or metastatic neuroblastoma. Clinicians should be aware of scurvy as a differential diagnosis of children with painful limbs, particularly those with developmental delay and selective diet. ■