Intramedullary Insetting of Silicone Implant for Lateral Stability in Distal Interphalangeal Joint Arthroplasty.

Silicone implant arthroplasty is an alternative surgical intervention for painful and deformed osteoarthritis of the distal interphalangeal (DIP) joints. DIP joint stability is essential for hand function; however, it carries a potential risk of postoperative joint instability. To address this concern, an intramedullary implant insetting method was used to maintain joint stability by minimum resection of the head of the middle phalanx and preserving the collateral ligament. In the new method, the length of the bone excision was limited to maintain the lateral cortical bone with the insertion of the collateral ligament, and the medullary cavity of the middle phalanx was partially removed to intentionally set the hinge part of the silicone implant in the medullary canal. Between 20 digits of the conventional approach and 23 digits of the intramedullary insetting method, there were no significant differences in patient demographics (ie, age, affected hand, and finger), and clinical characteristics (ie, active DIP joint arc, DIP joint extension loss, grip strength, visual analog scale, and Quick Disabilities of the Arms, Shoulder and Hand questionnaire score) before and over 6 months after surgery. However, postoperative joint instability was significantly lower with the intramedullary insetting method, with a significantly shorter length of bone excision of the middle phalanx. This new approach is more beneficial than the conventional approach for preventing postoperative joint instability.

Dynamic External Fixator as Treatment for Congenital Little Finger Contracture.

The surgical soft tissue release of extension contracture at metacarpophalangeal (MP) joint is technically easy; however, the preventive hand therapy after surgery is really difficult in clinical practice. Congenital MP joint contracture, especially little finger, is also difficult to spread its limited range of motion (ROM). Here, we present a patient with a congenital MP joint contracture of the little finger managed with dynamic external fixator (DEF). A 21-year-old male irritated from limited ROM associated with pain of the right little finger of more than 1 year. The symptom started after trauma on his hand while playing lacrosse. Further examination revealed that his MP joint was congenitally contracted. To address this pathology, DEF followed by orthotic therapy was done. Two years after the procedure and therapy, the MP joint ROM of the finger surpassed that of the contralateral unaffected digit without pain and recurrence. The patient was able to return to his sports of lacrosse.

Diagnostic efficacy of the magnetic resonance T1w/T2w ratio for the middle cerebellar peduncle in multiple system atrophy and spinocerebellar ataxia: A preliminary study.

BACKGROUND: The standardized T1-weighted/T2-weighted (sT1w/T2w) ratio for the middle cerebellar peduncle (MCP) has been reported to be sensitive for detecting degenerative changes in the cerebellar subtype of multiple system atrophy (MSA-C), even in the early stages. We aimed to investigate the diagnostic value of the MCP sT1w/T2w ratio for differentiating between MSA-C and spinocerebellar ataxia (SCA). METHODS: We included 32 MSA-C, 8 SCA type 3 (SCA3), 16 SCA type 6 (SCA6) patients, and 17 controls, and the MCP sT1w/T2w ratio was analyzed using a region-of-interest approach. The diagnostic performance of the MCP sT1w/T2w ratio in discriminating among MSA-C, SCA3, and SCA6 was assessed and compared with diagnosis based on visual interpretation of MCP hyperintensities and the "hot cross bun" (HCB) sign. RESULTS: MCP sT1w/T2w ratio values were markedly lower in patients with MSA-C than in those with SCA3, those with SCA6, and controls (p < 0.001). The MCP sT1w/T2w ratio showed high diagnostic accuracy for distinguishing MSA-C from SCA3 (area under curve = 0.934), SCA6 (area under curve = 0.965), and controls (area under curve = 0.980). The diagnostic accuracy of the MCP sT1w/T2w ratio for differentiating MSA-C from SCA3 or SCA6 (90.0% for MSA-C vs. SCA3, and 91.7% for MSA-C vs. SCA6) was comparable to or superior than that of visual interpretation of MCP hyperintensities (80.0-87.5% in MSA-C vs. SCA3 and 87.6-97.9% in MSA-C vs. SCA6) or the HCB sign (72.5-80.0% in MSA-C vs. SCA3 and 77.1-93.8% in MSA-C vs. SCA6). CONCLUSIONS: The MCP sT1w/T2w ratio might be a sensitive imaging-based marker for detecting MSA-C-related changes and differentiating MSA-C from SCA3 or SCA6.

DRD2 Taq1A Polymorphism-Related Brain Volume Changes in Parkinson's Disease: Voxel-Based Morphometry.

Taq1A polymorphism is a DRD2 gene variant located in an exon of the ANKK1 gene and has an important role in the brain's dopaminergic functions. Some studies have indicated that A1 carriers have an increased risk of developing Parkinson's disease (PD) and show poorer clinical performance than A2 homo carriers. Previous studies have suggested that A1 carriers had fewer dopamine D2 receptors in the caudate and increased cortical activity as a compensatory mechanism. However, there is little information about morphological changes associated with this polymorphism in patients with PD. The study's aim was to investigate the relationship between brain volume and Taq1A polymorphism in PD using voxel-based morphometry (VBM). Based on Taq1A polymorphism, 103 patients with PD were divided into two groups: A1 carriers (A1/A1 and A1/A2) and A2 homo carriers (A2/A2). The volume of the left prefrontal cortex (PFC) was significantly decreased in A2 homo carriers compared to A1 carriers. This finding supports the association between Taq1A polymorphism and brain volume in PD and may explain the compensation of cortical function in A1 carriers with PD.

Band-like hyperintensity along the ventral surface of the brain stem on FLAIR and DWI in leptomeningeal carcinomatosis of lung adenocarcinoma.

Since leptomeningeal carcinomatosis is rarely observed before diagnosis of the primary cancer, its detection is often delayed. We report the case of a 60-year-old woman who presented with lung adenocarcinoma with leptomeningeal carcinomatosis. Magnetic resonance imaging showed the characteristic abnormal hyperintensity along the ventral surface of the brain stem on fluid-attenuated inversion recovery and diffusion weighted imaging. It had no contrast uptake. Based on these findings, we were able to make an early diagnosis of leptomeningeal carcinomatosis of lung adenocarcinoma. This condition was resolved after treatment with a tyrosine kinase inhibitor.

Conversion to Extension Contracture as a Means of Correction of Severe Flexion Contracture of the PIP Joint Using a Modified Dynamic External Fixator.

Background: This is a retrospective case series investigating the outcomes using a dynamic external fixator (DEF) for treatment on severe flexion contractures at the proximal interphalangeal (PIP) joint. Severe flexion contractures of the PIP joint occurring after multiple operations and neglected over a long period of time are difficult to treat. The recurrence of contracture, even after successful treatment, is inevitable in patients with severe cases. In this study, we defined the severity of PIP joint contracture based on the active range of motion (ROM), soft tissue condition, and duration of the contracture. We also illustrated the strategy, results, and complications of using a DEF with rubber bands in these severe cases. Methods: We studied 11 fingers of 10 patients with PIP joint contracture treated by DEF. These were fixed at a small arc and neglected for an average 4.1 years (range, 1-9 years). The temporal Kirshner wire (K-wire) fixation after achieving an extension via DEF was maintained for 9.1 weeks on average. We retrospectively reviewed the results of these patients with an average 2-year follow-up. Results: Our method yielded favorable results upon retrospective evaluation. The average active ROM of the affected PIP joint improved from 90/96° to 34/83° with a functional arc and good patient satisfaction. The elastic force induced by strong rubber bands was safe and effective. The first step of joint space widening was the key to obtaining a successful joint extension afterwards. Serious progression of osteoarthritis at the PIP joint and pin-site fracture were a complication in each one case. Conclusions: In this study, we evaluate the surgical strategy of using DEFs powered by elastic torque from rubber bands to treat severe cases of flexion contractures of fingers. We first created extension contracture intentionally, followed by promoting flexion movement during follow-up in this group of patients.

Multidimensional Deep Learning Reduces False-Positives in the Automated Detection of Cerebral Aneurysms on Time-Of-Flight Magnetic Resonance Angiography: A Multi-Center Study.

Current deep learning-based cerebral aneurysm detection demonstrates high sensitivity, but produces numerous false-positives (FPs), which hampers clinical application of automated detection systems for time-of-flight magnetic resonance angiography. To reduce FPs while maintaining high sensitivity, we developed a multidimensional convolutional neural network (MD-CNN) designed to unite planar and stereoscopic information about aneurysms. This retrospective study enrolled time-of-flight magnetic resonance angiography images of cerebral aneurysms from three institutions from June 2006 to April 2019. In the internal test, 80% of the entire data set was used for model training and 20% for the test, while for the external tests, data from different pairs of the three institutions were used for training and the remaining one for testing. Images containing aneurysms > 15 mm and images without aneurysms were excluded. Three deep learning models [planar information-only (2D-CNN), stereoscopic information-only (3D-CNN), and multidimensional information (MD-CNN)] were trained to classify whether the voxels contained aneurysms, and they were evaluated on each test. The performance of each model was assessed using free-response operating characteristic curves. In total, 732 aneurysms (5.9 ± 2.5 mm) of 559 cases (327, 120, and 112 from institutes A, B, and C; 469 and 263 for 1.5T and 3.0T MRI) were included in this study. In the internal test, the highest sensitivities were 80.4, 87.4, and 82.5%, and the FPs were 6.1, 7.1, and 5.0 FPs/case at a fixed sensitivity of 80% for the 2D-CNN, 3D-CNN, and MD-CNN, respectively. In the external test, the highest sensitivities were 82.1, 86.5, and 89.1%, and 5.9, 7.4, and 4.2 FPs/cases for them, respectively. MD-CNN was a new approach to maintain sensitivity and reduce the FPs simultaneously.

Clinical feasibility of single-shot fluid-attenuated inversion recovery with wide inversion recovery pulse designed to reduce cerebrospinal fluid and motion artifacts for evaluation of uncooperative patients in acute stroke protocol.

Fluid-attenuated inversion recovery (FLAIR) imaging is a key sequence for stroke assessment. Motion artifact reduction with short acquisition time is still challenging, but necessary in the magnetic resonance (MR) stroke protocol, especially for uncooperative patients suspected of stroke. The aim of this study is to investigate the feasibility of modified single-shot FLAIR with wide inversion recovery pulses for use in stroke patients. This is a prospective study, which included 30 patients clinically suspected of stroke who were examined by MR stroke protocol from January 2018 to September 2018. A 1.5 T, multi-shot-turbo spin-echo (TSE) conventional FLAIR, and single-shot-TSE-FLAIR with wide inversion recovery pulse were used. Modified single-shot FLAIR was obtained for 30 patients with suspected stroke who moved during conventional FLAIR scan. Motion artifacts were randomly and independently scored using a 5-grade scale by three radiologists in blinded fashion. Whether the FLAIR vessel hyperintensity sign was present was visually evaluated. Statistical tests included Wilcoxon-signed rank test and weighted Cohen's kappa statistics. The motion artifact score was significantly lower in single-shot FLAIR than in conventional FLAIR (0.37 ± 0.56 vs. 1.83 ± 1.18; p < 0.05. The vessel hyperintensity sign was visualized in 6 and 5 patients on single-shot and conventional FLAIR images, respectively. This study demonstrates the value of single-shot FLAIR for stroke assessment. Single-shot FLAIR reduced motion artifact and visualized vessel hyperintensity sign more than conventional FLAIR. LEVEL OF EVIDENCE: 2. TECHNICAL EFFICACY STAGE: 2.

[Imaging Findings of Sarcoidosis in Neurology].

Sarcoidosis is a systemic granulomatous inflammation of unknown etiology that is reported in all age groups but with a higher prevalence in young adults. Sarcoidosis frequently involves the lungs, eyes, lymph nodes and skin. The involvement of the central nervous system (CNS) is reported with other sarcoidosis forms. Although only nervous system involvement presenting as CNS lesions are seen in 1% of cases, autopsy studies have confirmed CNS lesions in up to 25% of the cases. The nervous system including the brain, spinal cord, cerebral meninges, cranial nerves, pituitary gland, peripheral nerves, and muscles are reported to be affected. Although imaging findings of the nodules in sarcoidosis are nonspecific and atypical in 25-30% of cases, familiarity with the relevant clinical symptoms is helpful in recognizing sarcoidosis presence. The histopathological biopsy results of the organ affected by sarcoidosis help identify the characteristic noncaseating granuloma and its aggregation, and together with the imaging findings often reflecting such microstructure aid in sarcoidosis confirmation. This section describes the characteristic features seen in each image along with the image findings for each site.

Computed tomography findings of early-stage TAFRO syndrome and associated adrenal abnormalities.

OBJECTIVES: To compare CT findings of early (within 3 weeks post-onset)- and later (within 1 month before or after diagnostic criteria were satisfied, and later than 3 weeks post-onset) stage thrombocytopenia, anasarca, fever, reticulin fibrosis, renal dysfunction, and organomegaly (TAFRO) syndrome. METHODS: Between 2014 and 2019, 13 patients with TAFRO syndrome (8 men and 5 women; mean age, 54.9 years) from nine hospitals were enrolled. The number of the following CT findings (CT factors) was recorded: the presence of anasarca, organomegaly, adrenal ischaemia, anterior mediastinal lesion, bony lesion, and lymphadenopathy. Records of adrenal disorders (adrenomegaly, ischaemia, and haemorrhage) throughout the disease course were also collected. Differences in CT factors at each stage were statistically compared between remission and deceased groups. RESULTS: Para-aortic oedema and mild lymphadenopathy were observed in all patients, whereas pleural effusion, ascites, and subcutaneous oedema were found in 5/13, 7/13, and 7/13 cases, respectively, at the early stage. CT factors at the early stage were significantly higher in the deceased than in the remission group (mean, 11 vs 6.5; p = 0.04), while they were nonsignificant at the later stage. Adrenal disorders were present in 7/13 cases throughout the course including 6 of adrenomegaly and 4 of ischaemia at the early stage. CONCLUSIONS: Para-aortic oedema and mild lymphadenopathy are most common at the early stage. Anasarca, organomegaly, lymphadenopathy, and adrenal disorders on early-stage CT are useful for unfavourable prognosis prediction. Moreover, adrenal disorders are frequent even at the early stage and are useful for early diagnosis of TAFRO syndrome. KEY POINTS: • CT findings facilitate early diagnosis and prognosis prediction in TAFRO syndrome. • Adrenal disorders are frequently observed in TAFRO syndrome. • Adrenal disorders are useful for differential diagnosis of TAFRO syndrome.

Ultrasound Evaluation of Dermal Sinuses/Fistulas in Pediatric Patients.

A dermal sinus/fistula is a common condition; the relevant department should be consulted for appropriate treatment. It is important for radiologists to have adequate knowledge of these conditions to provide the correct diagnosis and recommend subsequent management. This review describes the following lesions: preauricular sinus, midline sinus of the upper lip, nasal dermoid sinus cyst, cheek fistula, first branchial cleft anomaly/sublingual branchial cleft anomaly, thyroglossal duct cyst/fistula, lateral cervical sinus/fistula, congenital dermal sinus/fistula of the anterior chest region, congenital skin sinus/fistula with a sternal cleft, and congenital prepubic sinus. On the basis of the skin orifice location and ultrasound images, radiologists can provide useful information to physicians.

Ultrasound imaging of the anorectal malformation during the neonatal period: a comprehensive review.

Anorectal malformation (ARM) is classified as low, intermediate, or high; accurate diagnosis of the type during the early neonatal period is important to determine the appropriate initial surgical approach. This review assesses the role of ultrasound examination in the classification of ARM during the neonatal period, with a focus on landmarks on the sonogram, the approach used for sonography, and the optimal examination timing. The following three factors on the sonogram are used for the classification: location of the fistula, the distance between the distal rectal pouch and the anal dimple (perineum) (P-P distance), and the relationship between the puborectalis muscle and the distal rectal pouch. Three approaches can be used to evaluate ARM by ultrasonography, namely, suprapubic, perineal, and infracoccygeal approaches. Each approach has its own advantages and disadvantages. Optimal timing of the ultrasound examination is also important with respect to each factor to classify ARM. We have described the pitfalls of ultrasound in diagnosis of cases, namely ARM with Down syndrome (which tends to be without fistula), ARM with low birth weight, ARM with unusual location of fistula, ARM with opened fistula (where the P-P distance is unreliable), and cloacal malformation (variation of the high-type ARM).

Primary hepatic choriocarcinoma in an 83-year-old woman.

We present a case of primary hepatic choriocarcinoma in an 83-year-old Japanese woman with gastric wall and lymph node metastases and a splenic vein tumor thrombus. Multiple irregular hepatic tumors with massive necrosis and hemorrhage were observed during autopsy. Syncytiotrophoblast-like and mononucleated cytotrophoblast-like cell morphology with focal hepatocellular carcinoma (HCC)-like trabecular structures was observed. In immunohistochemical analyses, the tumor cells expressed human chorionic gonadotropin (hCG) and cytokeratins (AE1/AE3, CK7, CK19) but were negative for alpha-fetoprotein (AFP), glypican-3, and vimentin. Immunohistochemical findings did not reveal evidence of HCC or angiosarcoma. We concluded the liver tumor was primary hepatic choriocarcinoma.

Fluctuations in chemical gelation.

We study a chemical gelation model in two dimensions which includes both monomer aggregations and bond fluctuations. Our numerical simulation shows that a sol-gel transition occurs when an initial monomer concentration is above a critical concentration. Fractal aggregates grow until the sol-gel transition occurs. After the gelation, however, bond fluctuations break the fractal structure and an interesting inhomogeneous gel fiber network appears instead. A pore size distribution of the inhomogeneous structure shows the existence of hierarchical structures in the gel phase. It is also found that slow dynamics appear near the critical concentration.