Mimics of malignancy caused by concurrent imperforate hymen and transverse vaginal septum: an instructive case and review of the literature

The coexistence of imperforate hymen and vaginal septum is rare and their ability to mimic malignant manifestations have not been frequently reported. This current case report describes a 13-year-old girl that presented with cyclic abdominal pain for 6 months. She was found to have a huge mass via abdominal plain film X-ray and sonography, with inexplicably high levels of serum carcinoembryonic antigen, cancer antigen (CA)-19-9 and CA-125. Pelvic computed tomography imaging disclosed two huge cystic lesions in the uterine and upper vaginal cavities. Surgical intervention conformed the diagnosis of a concurrent imperforate hymen and transverse vaginal septum, echoing the imaging findings of haematocolpometra. Her tumour marker levels gradually returned to normal after surgery. This rare case of concomitant imperforate hymen and transverse vaginal septum highlights that haematocolpometra, a benign disease that might mimic malignancy, should be taken into consideration in any adolescent females with an abdominal mass and amenorrhoea to ensure an early diagnosis and timely appropriate management.     

Anomalous boron isotope effects on electronic structure and lattice dynamics of CuB2O4

Copper metaborate had a unique crystal structure and exhibited noteworthy magnetic phase transitions at 21 and 10 K. The electronic structure and lattice dynamics of copper metaborate Cu¹¹B₂O₄ single crystals were investigated and compared with the optical properties of CuB₂O₄, to assess the boron isotope effect. The optical absorption spectrum at room temperature revealed two charge-transfer bands at approximately 4.30 and 5.21 eV with an extrapolated direct optical band gap of 3.16 ± 0.07 eV. Compared with the data on CuB₂O₄, the electronic transitions were shifted to lower energies upon the replacement of a heavier boron isotope. The band gap was also determined to be lower in Cu¹¹B₂O₄. Anomalies in the temperature dependence of the optical band gap were observed below 21 K. Furthermore, 38 Raman-active phonon modes were identified in the room-temperature Raman scattering spectrum of Cu¹¹B₂O₄, which were also observed in CuB₂O₄ with a shift to lower frequencies. No broadening caused by isotopic changes was observed. As the temperature decreased, phonon frequencies shifted to higher wavenumbers and the linewidth decreased. Anomalous softening in the Raman peaks below 21 K was also revealed.

Copper metaborate had a unique crystal structure and exhibited noteworthy magnetic phase transitions at 21 and 10 K.     

Migration of a dislodged tip of an ultrasound lithotripter probe to the pulmonary artery: a rare complication of percutaneous nephrolithotomy

A 44-year-old man underwent percutaneous nephrolithotomy for a left renal staghorn stone. During the procedure, the tip of the ultrasound lithotripter dislodged from the probe rod when the renal stone was being disintegrated. The tip immediately disappeared from the field of nephroscopic vision. Despite a thorough search, the tip could not be found. Postoperative chest radiography revealed a foreign body, shaped like a lithotripter probe tip, located in the lingular branch of the left pulmonary artery. Eventually, left thoracotomy was performed to remove the foreign body. To our knowledge, this rare complication has never been reported before.     

Precise 3D/2D calibration between a RGB-D sensor and a C-arm fluoroscope

Purpose

Calibration and registration are the first steps for augmented reality and mixed reality applications. In the medical field, the calibration between an RGB-D camera and a C-arm fluoroscope is a new topic which introduces challenges.

Method

A convenient and efficient calibration phantom is designed by combining the traditional calibration object of X-ray images with a checkerboard plane. After the localization of the 2D marker points in the X-ray images and the corresponding 3D points from the RGB-D images, we calculate the projection matrix from the RGB-D sensor coordinates to the X-ray, instead of estimating the extrinsic and intrinsic parameters simultaneously.

Validation

In order to evaluate the effect of every step of our calibration process, we performed five experiments by combining different steps leading to the calibration. We also compared our calibration method to Tsai’s method to evaluate the advancement of our solution. At last, we simulated the process of estimating the rotation movement of the RGB-D camera using MATLAB and demonstrate that calculating the projection matrix can reduce the angle error of the rotation.

Results

A RMS reprojection error of 0.5 mm is achieved using our calibration method which is promising for surgical applications. Our calibration method is more accurate when compared to Tsai’s method. Lastly, the simulation result shows that using a projection matrix has a lower error than using intrinsic and extrinsic parameters in the rotation estimation.

Conclusions

We designed and evaluated a 3D/2D calibration method for the combination of a RGB-D camera and a C-arm fluoroscope.