Inneke Willekens

Background: The detection of suspicious microcalcifications on mammography represents one of the earliest signs of a malignant breast tumor. Assessing microcalcifications’ characteristics based on their appearance on 2D breast imaging modalities is in many cases challenging for radiologists. The aims of this study were to: (a) analyse the association of shape and texture properties of breast microcalcifications (extracted by scanning breast tissue with a high resolution 3D scanner) with malignancy, (b) evaluate microcalcifications’ potential to diagnose benign/malignant patients. Methods: Biopsy samples of 94 female patients with suspicious microcalcifications detected during a mammography, were scanned using a micro-CT scanner at a resolution of 9 μm. Several preprocessing techniques were applied on 3504 extracted microcalcifications. A high amount of radiomic features were extracted in an attempt to capture differences among microcalcifications occurring in benign and malignant lesions. Machine learning algorithms were used to diagnose: (a) individual microcalcifications, (b) samples. For the samples, several methodologies to combine individual microcalcification results into sample results were evaluated. Results: We could classify individual microcalcifications with 77.32% accuracy, 61.15% sensitivity and 89.76% specificity. At the sample level diagnosis, we achieved an accuracy of 84.04%, sensitivity of 86.27% and specificity of 81.39%. Conclusions: By studying microcalcifications’ characteristics at a level of details beyond what is currently possible by using conventional breast imaging modalities, our classification results demonstrated a strong association between breast microcalcifications and malignancies. Microcalcification’s texture features extracted in transform domains, have higher discriminating power to classify benign/malignant individual microcalcifications and samples compared to pure shape-features.

Introduction: No standard protocol for surveillance for melanoma patients is established. Whole-body magnetic resonance imaging (whole-body MRI) is a safe and sensitive technique that avoids exposure to X-rays and contrast agents. This prospective study explores the use of whole-body MRI for the early detection of recurrences. Material and Methods: Patients with American Joint Committee on Cancer Staging Manual (seventh edition; AJCC-7) stages IIIb/c or -IV melanoma who were disease-free following resection of macrometastases (cohort A), or obtained a durable complete response (CR) or partial response (PR) following systemic therapy (cohort B), were included. All patients underwent whole-body MRI, including T1, Short Tau Inversion Recovery, and diffusion-weighted imaging, every 4 months the first 3 years of follow-up and every 6 months in the following 2 years. A total body skin examination was performed every 6 months. Results: From November 2014 to November 2019, 111 patients were included (four screen failures, cohort A: 68 patients; cohort B: 39 patients). The median follow-up was 32 months. Twenty-six patients were diagnosed with suspected lesions. Of these, 15 patients were diagnosed with a recurrence on MRI. Eleven suspected lesions were considered to be of non-neoplastic origin. In addition, nine patients detected a solitary subcutaneous metastasis during self-examination, and two patients presented in between MRIs with recurrences. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were, respectively, 58%, 98%, 58%, 98%, and 98%. Sensitivity and specificity for the detection of distant metastases was respectively 88% and 98%. No patient experienced a clinically meaningful (>grade 1) adverse event. Conclusions: Whole-body MRI for the surveillance of melanoma patients is a safe and sensitive technique sparing patients′ cumulative exposure to X-rays and contrast media.

Objective: The aim of this study was to investigate the prevalence of TMJ chondrocalcinosis on head CT scans in patients with chondrocalcinosis of the knee or wrist. Methods and materials: 227 patients with radiological evidence of calcifications on knee or wrist radiographs had a head CT scan obtained for unrelated purposes. CT scans were retrospectively reviewed for the presence of temporomandibular crystal deposition. Prevalence, bilaterality, age and gender distribution were determined. Results: 41 of 227 (18%) of patients had TMJ chondrocalcinosis. TMJ chondrocalcinosis was more common in females (17%) than males (1%). It was more commonly unilateral (68%) than bilateral (32%). Conclusion: In patients with peripheral calcific disease, the TMJ is more commonly involved than previously reported and this is more common in females compared to males.

To assess normal distribution of fluid in the tendon sheaths of the ankle.

This study aimed at studying the MR imaging appearance of the tibiotalar ligament in asymptomatic volunteers.

The study objective is to investigate the impact of a wide range of contrast media (CM) iodine concentrations on CT enhancement at constant total iodine dose (TID) and iodine delivery rate (IDR). Seven injection protocols, based on different iodine concentrations ranging from 120 to 370 mg I/mL, were assessed on 4 minipigs at a constant TID of 320 mg I/kg and IDR of 0.64 g I/s. Dynamic images were acquired on a clinical 64-slice MDCT scanner for 120 s with the abdominal aorta, vena cava inferior and liver parenchyma in the field-of-view. Maximal enhancement, time-to-peak and peak width were assessed. The enhancement curve characteristics were correlated with CM iodine concentration. In particular, CM with lower iodine concentrations yielded a significant increased maximal enhancement and peak width compared to the standard-of-care concentrations: e.g. in the aorta, 245 HU maximal enhancement and 9.2 s peak width with the 320 mg I/mL iodine concentration increased to 291 HU and 16.1 s with 160 mg I/mL. When maintaining a constant TID and IDR, by compensating injection rate and volume, injection of a CM with reduced iodine concentration results in a diagnostically beneficial higher maximal enhancement and longer enhancement peak duration.

Microcalcifications (MCs) are small calcium deposits which are often present in breast tissue. Although they may be an early indicator of breast cancer, they are often present in healthy women. Judging on the malignancy of MCs based on their appearance on mammograms is a challenging task for radiologists as mammography projects a 3D object onto a 2D plane, as a consequence, superposition of tissue may alter their appearance. Although Computer Aided Detection and Diagnosis (CAD) systems have been developed to assist radiologists in detecting and characterizing MCs, they mainly focus on analyzing MCs' spatial configuration rather than their individual characteristics. In this study, we propose a CAD system for the characterization of individual MCs, whose shape is visualized in 3D by scanning breast tissue with micro-CT, a high resolution 3D imaging modality. By calculating a large amount of radiomic features we are able to classify MCs as benign or malignant with 75.88% accuracy, 62.13% sensitivity and 86.39% specificity, outperforming the state of the art and proving that there is a difference regarding the shape and the texture of individual MCs. Although this methodology is not applicable in vivo, its potential for use in intra operative imaging is high, as it can reduce the waiting time between tissue extraction and result of the anatomopathological investigation, facilitating and accelerating the procedure.

Erythromelalgia is a rare condition characterized by attacks of intensely painful, red and warm feet and/or hands. Symptoms typically are triggered by heat and relieved by cooling of the extremities. Primary cases are due to mutations in the gene for a sodium channel expressed in nociceptive and sympathetic ganglion neurons; secondary causes include blood disorders, infections, drugs, connective tissue diseases, neuropathic diseases, including diabetic neuropathy, and malignancies. We present bone scan findings in a case of erythromelalgia in an 18 years old student, in whom the symptoms developed suddenly. No underlying disease could be demonstrated and the patient fully recovered. The scan findings were strikingly similar to those of reflex sympathetic dystrophy.