Cerebellar Ataxia With Neuropathy and Vestibular Areflexia Syndrome Due to Replication Factor C Subunit 1 Gene Repeat Expansion.

ABSTRACT: A 56-year-old man was born to consanguineous parents. He experienced slow-progressing sensory disturbances in the upper extremities. T1-weighted images showed cerebellar atrophy. 123I-IMP SPECT revealed reduced cerebral blood flow in the cerebellum. 123I-FP-CIT SPECT showed low uptake of dopamine transporter in the bilateral tail of the striatum. 123I-MIBG scintigraphy shows a decreased heart-to-mediastinum ratio. Flanking polymerase chain reaction suggested biallelic repeat expansion in intron 2 of RFC1, and subsequent repeat-primed polymerase chain reaction revealed ACAGG repeat expansion. Thus, he was diagnosed as cerebellar ataxia with neuropathy and vestibular areflexia syndrome.

MRI-based radiomics analysis for differentiating phyllodes tumors of the breast from fibroadenomas.

OBJECTIVES: To evaluate the diagnostic performance of MRI-based radiomics model for differentiating phyllodes tumors of the breast from fibroadenomas. METHODS: This retrospective study included 88 patients (32 with phyllodes tumors and 56 with fibroadenomas) who underwent MRI. Radiomic features were extracted from T2-weighted image, pre-contrast T1-weighted image, and the first-phase and late-phase dynamic contrast-enhanced MRIs. To create stable machine learning models and balanced classes, data augmentation was performed. A least absolute shrinkage and selection operator (LASSO) regression was performed to select features and build the radiomics model. A radiological model was constructed from conventional MRI features evaluated by radiologists. A combined model was constructed using both radiomics features and radiological features. Machine learning classifications were done using support vector machine, extreme gradient boosting, and random forest. The area under the receiver operating characteristic (ROC) curve (AUC) was computed to assess the performance of each model. RESULTS: Among 1070 features, the LASSO logistic regression selected 35 features. Among three machine learning classifiers, support vector machine had the best performance. Compared to the radiological model (AUC: 0.77 ± 0.11), the radiomics model (AUC: 0.96 ± 0.04) and combined model (0.97 ± 0.03) had significantly improved AUC values (both p < 0.01) in the validation set. The combined model had a relatively higher AUC than that of the radiomics model in the validation set, but this was not significantly different (p = 0.391). CONCLUSIONS: Radiomics analysis based on MRI showed promise for discriminating phyllodes tumors from fibroadenomas. KEY POINTS: • The radiomics model and the combined model were superior to the radiological model for differentiating phyllodes tumors from fibroadenomas. • The SVM classifier performed best in the current study. • MRI-based radiomics model could help accurately differentiate phyllodes tumors from fibroadenomas.

Temporal subtraction of low-dose and relatively thick-slice CT images with large deformation diffeomorphic metric mapping and adaptive voxel matching for detection of bone metastases: A STARD-compliant article.

To evaluate the improvement of radiologist performance in detecting bone metastases at follow up low-dose computed tomography (CT) by using a temporal subtraction (TS) technique based on an advanced nonrigid image registration algorithm.Twelve patients with bone metastases (males, 5; females, 7; mean age, 64.8 ±â€Š7.6 years; range 51-81 years) and 12 control patients without bone metastases (males, 5; females, 7; mean age, 64.8 ±â€Š7.6 years; 51-81 years) were included, who underwent initial and follow-up CT examinations between December 2005 and July 2016. Initial CT images were registered to follow-up CT images by the algorithm, and TS images were created. Three radiologists independently assessed the bone metastases with and without the TS images. The reader averaged jackknife alternative free-response receiver operating characteristics figure of merit was used to compare the diagnostic accuracy.The reader-averaged values of the jackknife alternative free-response receiver operating characteristics figures of merit (θ) significantly improved from 0.687 for the readout without TS and 0.803 for the readout with TS (P value = .031. F statistic = 5.24). The changes in the absolute value of CT attenuations in true-positive lesions were significantly larger than those in false-negative lesions (P < .001). Using TS, segment-based sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the readout with TS were 66.7%, 98.9%, 94.4%, 90.9%, and 94.8%, respectively.The TS images can significantly improve the radiologist's performance in the detection of bone metastases on low-dose and relatively thick-slice CT.

Correction to: Sudden fatal bleeding from a uretero-arterial fistula combined with pre-existing uretero-colic and uretero-vaginal fistulas 7 years after a cervical cancer surgery: a case report.

In the original publication of this article [1], the family name of an author is wrong.

Sudden fatal bleeding from a uretero-arterial fistula combined with pre-existing uretero-colic and uretero-vaginal fistulas 7 years after a cervical cancer surgery: a case report.

BACKGROUND: Uretero-arterial fistulas (UAFs) are a rare cause of hematuria and could be fatal often due to a diagnostic delay despite recent advances in the treatment modalities. CASE PRESENTATION: A 52-year-old woman with a history of advanced cervical cancer developed a fever and was diagnosed with a left uretero-colic fistula. She also had a uretero-vaginal fistula and suffered from repeated urinary tract infections over 6 years. While waiting for an elective colostomy, she developed sudden perineal bleeding and died 14 h after the onset. The autopsy findings revealed that bleeding from a newly developed UAF spreads out to the extracorporeal space through the pre-existing fistulas. CONCLUSIONS: Bleeding from a UAF complicated by other uretero-genital and/or uretero-enteric fistulas could proceed rapidly resulting in a fatal outcome because of a lack of a tamponade effect. Early recognition of a UAF in high-risk patients is crucial for a prompt diagnosis, which might lead to a treatment success.

Mesenchymal chondrosarcoma of the orbit: imaging features of CT and MRI.

OBJECTIVE:: Mesenchymal chondrosarcoma (MCS) of the orbit is a rare and aggressive form of chondrosarcoma. The purpose of this study was to retrospectively identify the imaging features of mesenchymal chondrosarcoma of the orbit. METHODS:: This study included five patients with histologically confirmed MCS of the orbit who had undergone either CT, MRI, or both. Images were evaluated for the following: location, size, margin, CT density and presence or absence of calcification and/or ossification, MRI findings including dynamic contrast-enhancement and time-intensity curves. RESULTS:: CT was performed in four of the five patients, and all four (100%) demonstrated calcification and ossification of the mass. MRI was performed in all five patients. In two patients (40%), the mass demonstrated areas of hyperintensity on T1 weighted images. CONCLUSION:: The presence of a well-defined, orbital mass with calcification and ossification on CT and, marked heterogenous enhancement and a rapid-washout pattern on dynamic MRI indicate a high probability of MCS of the orbit. In addition, MCS of the orbit can demonstrate areas of hyperintensity on T1 weighted images, representing bone marrow fat tissue of ossification. ADVANCES IN KNOWLEDGE:: MCS of the orbit is a highly malignant tumor, and early diagnosis by imaging is important. Radiologists should be aware of the imaging features of MCS of the orbit.

18F-FDG PET/CT Findings of Mesenchymal Chondrosarcoma of the Orbit.

Mesenchymal chondrosarcoma of the orbit is an extremely rare and aggressive tumor. We report image findings of F-fluorodeoxyglucose (FDG) positron emission/computed tomography (PET/CT) in 2 cases, one primary case and one recurrent case. The F-FDG PET/CT images revealed high uptake with an SUVmax of 6.7 and 11.7, respectively. In both cases, the HEY1-CoA2 gene fusion was positive. The high uptake of F-FDG in mesenchymal chondrosarcoma of the orbit well suggests the malignancy of this tumor.