Metallic Artifact Reduction of Multiacquisition With Variable Resonance Image Combination Selective-Short Tau Inversion Recovery for Postoperative Cervical Spine With Artificial Disk Replacement: A Preliminary Study.

OBJECTIVE: This study aimed to evaluate multiacquisition with variable resonance image combination selective short tau inversion recovery (MAVRIC SL STIR) for metallic artifact reduction in magnetic resonance imaging (MRI) of postoperative cervical spine with artificial disk replacement. METHODS: A porcine cervical spine with artificial disk replacement was subject to 3 T MRI with variable fat-suppressed fluid-sensitive sequences. Five volunteers underwent MRI with MAVRIC SL STIR and STIR. Quantitative and qualitative analyses were performed for metallic artifact reduction. RESULTS: MAVRIC SL STIR showed the least signal void areas in the tissue phantom and volunteer study. In the tissue phantom study, MAVRIC SL STIR showed the best visualization of anatomic structure, least distortion, and signal pile-up. However, it ranked last for the homogeneity of fat suppression among sequences. In the volunteer study, MAVRIC SL STIR showed better visualization of anatomic structure and lesser distortion, but showed worse image quality of the spinal cord than STIR in the sagittal plane (P < 0.05). CONCLUSIONS: MAVRIC SL STIR might be useful for visualization of anatomy by reduction of signal void areas and distortion in the operated site but should be used as a complement to STIR for evaluation of the spinal cord signal change.

Ectopic vascularization of the right kidney arising from contralateral common iliac artery.

BACKGROUND: Variant renal arteries have been reported in 20~30% of the entire population. The anatomic variations among advanced patients should be investigated when performing surgery or interventional procedures on the kidney. Most variant renal arteries originated from various level of the abdominal aorta. Very rarely, this case shows renal artery originated from the contralateral common iliac artery with other accessory arteries. CASE PRESENTATION: MDCT angiography revealed several anatomical variants of the right kidney. There were four right renal arteries. The main renal artery originated from the left proximal common iliac artery and other renal artery originated from the aortic bifurcation. The other two renal arteries arose from the abdominal aorta, lower thoracic T12 level and lower lumbar L4 level. The right kidney was located at the level of the third to fifth lumbar vertebra. And renal pelvis of the right kidney was laterally rotated. CONCLUSION: This case documented a rare anatomic variant, involving multiple accessory renal arteries, including the main artery originating from the contralateral iliac artery, caused by a specific renal embryological condition. These variants should be analysed to effectively perform surgical and interventional procedures.

Eyes of beautiful women and femme fatales depicted in Western portraits.

This study aimed to compare the eyes of beautiful women and femme fatales depicted in Western portraits. A total of 37 samples were collected; 19 beautiful women and 18 femme fatales. Nine aspects were measured in reference to the corneal horizontal diameter. The estimated corneal vertical diameter was calculated by a corneal horizontal diameter multiply constant, 1.11.The double-fold was observed in 89% (17 of 19) of the beautiful women and 83% (15 of 18) of the femme fatales. The eye-width ratio was 2.42 (SD, 0.28) in the beautiful women and 2.31 (SD, 0.34) in the femme fatales. The eye-height ratio was 0.91 (SD, 0.18) in the beautiful women and 0.84 (SD, 0.10) in the femme fatales. Eyebrow-to-upper lid distance was 0.92 (SD, 0.35) in the beautiful women and 0.89 (SD, 0.23) in the femme fatales. The interpupillary distance was 5.00 (SD, 0.46) in the beautiful women and 5.00 (SD, 0.71) in the femme fatales. The intercanthal distance was 2.72 (SD, 0.42) in the beautiful women and 2.78 (SD, 0.73) in the femme fatales The outer canthal distance was 7.32 (SD, 0.64) in the beautiful women and 7.20 (SD, 1.01) in the femme fatales. The ptosis amount was -0.01 (SD, 0.18) in the beautiful women and 0.06 (SD, 0.01) in the femme fatales. For the above 7 measurements, there were no significant differences between the 2 groups (P > 0.05, t test).It is noteworthy that the beautiful women and femme fatales have the same interpupillary distance (5.00). Also, the ptosis ratio was almost zero in both groups (-0.01 [SD, 0.18] in the beautiful women and 0.06 [SD, 0.01] in the femme fatales). The results of this study might be of some reference in performing eyelid surgeries especially in brow lifts or canthoplasties.

[Pathophysiology and MRI Findings of Infectious Spondylitis and the Differential Diagnosis]. / 감염성 척추염과 감별질환의 병태생리와 MRI 소견.

On MRI, abnormal signals of the intervertebral disc, destruction of the upper and lower vertebral body endplate around the disc, and bone marrow edema around the endplate are considered typical findings of infectious spondylitis. These findings can also appear in various non-infectious spinal diseases, such as degenerative changes, acute Schmorl's node, spondyloarthropathy, synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO), chronic recurrent multifocal osteomyelitis, and calcium pyrophosphate dihydrate crystal deposition disease. The imaging findings of infectious spondylitis that can be differentiated from these non-infectious spinal diseases on MRI are high signal intensity and abscess of the disc space, an abscess in the paraspinal soft tissue, and the loss of the linear low signal intensity on T1-weighted images of the bony endplate. However, these differentiation points do not always apply since there are many similarities in the imaging findings of infectious and non-infectious diseases. Therefore, for an accurate diagnosis, it is important to know the imaging characteristics related to the pathophysiology of not only infectious spondylitis but also non-infectious spinal diseases, which requires differentiation from infection.

Characteristics, trend, and methodological quality of systematic reviews and meta-analyses in nuclear medicine: A bibliometric analysis of studies published between 2005 and 2016.

To evaluate the characteristics, trend, and quality of systematic reviews and meta-analyses in nuclear medicine.We performed a PubMed search to identify systematic reviews and meta-analyses published between 2005 and 2016 in the field of nuclear medicine. The following data were extracted: journal name, impact factor, type of study, topics with cancer type, imaging modalities, authors (number, country, affiliation, presence of nuclear medicine specialists and statisticians, discordance between the first and corresponding authors), funding, methodological quality, methods used for quality assessment, and statistical methods.We included 185 nuclear medicine articles. Meta-analyses (n = 164; 88.6%) were published about 7 times more frequently than systematic reviews. Oncology was the most commonly studied topic (n = 125, 67.6%). The first authors were most frequently located in China (n = 73; 39.5%). PET was the most commonly used modality (n = 150; 81.1%). Both the number of authors and the ratio of discordance between the first and corresponding authors tended to progressively increase over time.The mean AMSTAR score increased over time (5.77 in 2005-2008, 6.71 in 2009-2012, and 7.44 in 2013-2016). The proportion of articles with quality assessment increased significantly (20/26 in 2005-2008, 54/65 in 2009-2012, and 79/94 in 2013-2016). The most commonly used assessment tool was quality assessment of diagnostic accuracy studies (n = 85; 54.9%).The number and quality of systematic reviews and meta-analyses in nuclear medicine have significantly increased over the review period; however, the quality of these articles varies. Efforts to overcome specific weaknesses of the methodologies can provide opportunities for quality improvement.