Dual-energy computed tomography (DECT)-derived quantification of iodine concentration (IC) is increasingly used in oncologic imaging to characterize lesions and evaluate treatment response. However, only limited data are available on intraindividual consistency of IC and its variation. This study investigates the longitudinal reproducibility of IC in organs, vessels, and lymph nodes in a large cohort of healthy patients who underwent repetitive DECT imaging.

A total of 159 patients, who underwent a total of 469 repetitive (range, 2-4), clinically indicated portal-venous phase DECT examinations of the chest and abdomen, were retrospectively included. At time of imaging, macroscopic tumor burden was excluded by follow-up imaging (≥3 months). Iodine concentration was measured region of interest-based (N = 43) in parenchymatous organs, vessels, lymph nodes, and connective tissue. Normalization of IC to the aorta and to the trigger delay as obtained from bolus tracking was performed. For statistical analysis, ion protocol.

Our study confirms intraindividual, longitudinal variation of DECT-derived IC, which varies among vessels, lymph nodes, organs, and connective tissue, following different perfusion characteristics; normalizing to the aorta seems to improve reproducibility when using a constant contrast media injection protocol.

Distinguishing benign from malignant orbital lesions remains challenging both clinically and with imaging, leading to risky biopsies. The objective was to differentiate benign from malignant orbital lesions using radiomics on 3 T magnetic resonance imaging (MRI) examinations.

This institutional review board-approved prospective single-center study enrolled consecutive patients presenting with an orbital lesion undergoing a 3 T MRI prior to surgery from December 2015 to July 2019. Radiomics features were extracted from 6 MRI sequences (T1-weighted images [WIs], DIXON-T2-WI, diffusion-WI, postcontrast DIXON-T1-WI) using the Pyradiomics software. Features were selected based on their intraobserver and interobserver reproducibility, nonredundancy, and with a sequential step forward feature selection method. Selected features were used to train and optimize a Random Forest algorithm on the training set (75%) with 5-fold cross-validation. Performance metrics were computed on a held-out test set (25%) with boots CI, 0.615-0.751), and 0.935 (95% CI, 0.905-0.961). The radiomics model outperformed all reader groups, including expert neuroradiologists (P < 0.01). DIRECT RED 80 Adding clinical and categorizable imaging data did not significantly impact the algorithm performance (P = 0.49).

An MRI radiomics signature is helpful in differentiating benign from malignant orbital lesions and may outperform expert radiologists.

An MRI radiomics signature is helpful in differentiating benign from malignant orbital lesions and may outperform expert radiologists.A 14-year-old girl presented with bilateral keratoconus (KC). Maximum keratometry was 63.9 diopters (D) in the right eye and 63.7 D in the left eye. Minimum corneal thickness was 371 μm in the right eye and 370 μm in the left eye. The right eye underwent epithelium-off accelerated corneal crosslinking (CXL) using hypotonic dextran-free 0.1% riboflavin solution and a riboflavin-soaked ultraviolet-barrier-free soft contact lens to increase thickness to more than 400 μm. The same procedure was followed for the left eye 4 months later, when 2 riboflavin-soaked soft contact lenses were applied in piggyback fashion. At 19 months postopertively, in the right eye, visual acuity, maximum keratometry, mean keratometry, and topographical indices were improved. In the left eye, visual acuity, mean keratometry, and central KC index were improved. Accelerated CXL and piggyback modification was a safe and an effective treatment in this pediatric case with KC with thin cornea.A 62-year-old woman was referred for evaluation of a nonhealing epithelial defect of the left eye. Examination also revealed left upper lid ptosis, cicatricial lagophthalmos, and palpable lid masses. With probing, the patient admitted to recent history of lobular carcinoma and remote history of ductal carcinoma of the breast. Imaging showed abnormal tissue in the left extraconal orbit involving the lacrimal gland. After orbitotomy and biopsy of the mass, pathology specimens returned consistent with metastatic carcinoma of the left orbit with breast as the site of the primary tumor. The patient completed palliative radiation therapy and chemotherapy. Amniotic membranes were placed to promote healing of the persistent epithelial defect with good response. Unfortunately, the patient died approximately 1 year after her initial presentation secondary to her oligometastatic disease. There is a wide spectrum of clinical manifestations associated with orbital metastasis. Careful consideration must be given to cancer patients with ophthalmologic complaints.

To assess the utility of a femtosecond laser-assisted stromal channel to assist the creation of a big bubble (BB) for deep anterior lamellar keratoplasty (DALK) surgery in cadaveric corneas.

L V Prasad Eye Institute, Hyderabad, India.

Experimental study.

An attempt to create a BB was made on 10 donor pairs of human cadaveric corneoscleral tissues. The 20 corneas were split into 2 groups group A underwent femtosecond laser pretreatment and group B had conventional manual deep lamellar technique. Laser pretreatment was performed using the VisuMax femtosecond laser system to create a stromal channel using the intracorneal ring segment treatment module for direct insertion of the 27-gauge air cannula for pneumodissection at a predetermined depth.

A type 1 BB was achieved in 9 of 10 corneas in group A and in 7 of 10 corneas in Group B. One cornea from group A had a combined type 1 and 2 BB while no BB was achieved in 1 cornea.

Creation of an intrastromal channel using a femtosecond laser at a predetermined depth appeared to be a promising option to increase the chances of achieving a BB when compared with the conventional air injection technique of BB DALK.

Creation of an intrastromal channel using a femtosecond laser at a predetermined depth appeared to be a promising option to increase the chances of achieving a BB when compared with the conventional air injection technique of BB DALK.