Carola Brussaard

Introduction: Tuberous sclerosis complex (TSC) is a genetic disease caused by pathogenetic variants in either the TSC1 or TSC2 genes. Consequently, the mechanistic target of the rapamycin complex 1 (mTORC1) pathway, a regulator of cell growth, metabolism, and survival, becomes inappropriately activated, leading to the development of benign tumors in multiple organs. The role of mTORC1 in lipid metabolism and liver steatosis in TSC patients has not been well-studied, and clinical data on liver involvement in this population are scarce. Methods: We conducted a retrospective, cross-sectional study to compare liver steatosis in TSC patients with age-, sex-, BMI-, and diabetes status-matched controls. Participants with a definite diagnosis of TSC were recruited from the TSC clinic at UZ Brussel. Liver steatosis was quantified using the fat signal fraction from in-phase and out-of-phase MRI, with a threshold of ≥5% defining the presence of steatosis. We also evaluated the prevalence of liver angiomyolipomata in the TSC group and analyzed risk factors for both liver steatosis and angiomyolipomata. Results: The study included 59 TSC patients and 59 matched controls. The mean fat signal fraction was 4.0% in the TSC group and 3.9% in the controls, showing no significant difference (two-tailed Wilcoxon signed ranks test, p = 0.950). Liver steatosis was observed in 15.3% of TSC patients compared to 23.7% of the controls, which was not statistically significant (two-tailed McNemar test, p = 0.267). Liver angiomyolipomata were identified in 13.6% of the TSC cohort. Conclusions: Our study, describing in detail the liver phenotype of TSC patients, did not reveal a significant difference in the prevalence of MRI-assessed liver steatosis in a large cohort of TSC patients compared to a closely matched control group.

“Just Accepted” papers have undergone full peer review and have been accepted for publication in Radiology: Artificial Intelligence. This article will undergo copyediting, layout, and proof review ...

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.

Von Hippel-Lindau (VHL) disease is an autosomal dominantly inherited tumor syndrome. Affected patients develop central nervous system hemangioblastomas and abdominal tumors, among other lesions. Patients undergo an annual clinical screening program including separate magnetic resonance imaging (MRI) of the brain, whole spine and abdomen. Consequently, patients are repeatedly subjected to time-consuming and expensive MRI scans, performed with cumulative Gadolinium injections. We report our experience with a 35-min whole body MRI screening protocol, specifically designed for detection of VHL-associated lesions. We designed an MRI protocol dedicated to the typical characteristics of VHL-associated lesions in different imaging sequences, within the time frame of 35 min. Blank imaging of the abdomen is carried out first, followed by abdominal sequences with Gadolinium contrast. Next, the full spine is examined, followed by imaging of the brain. A single dose of contrast used for abdominal imaging is sufficient for further highlighting of spine- and brain lesions, thus limiting the Gadolinium dosage. We used 1.5 Tesla equipment, dealing with fewer artifacts compared to a 3 Tesla system for spine- and abdominal imaging, while preserving acceptable quality for central nervous system images. In addition, imaging on a 1.5 Tesla scanner is slightly faster. From January 2016 to November 2018, we performed 38 whole body screening MRIs in 18 VHL patients; looking for the most common types of VHL lesions in the abdomen, spine, and brain, both for new lesions and follow-up. The one-step approach MRI examinations lead to 6 surgical interventions for clinically significant or symptomatic hemangioblastomas in the brain and spine. One renal cell carcinoma was treated with radiofrequency ablation. In comparison with previous conventional MRI scans of the same patients, all lesions were visible with the focused protocol. Annual screening in VHL disease can be done in a rapid, safe and sensitive way by using a dedicated whole body MRI protocol; saving MRI examination time and limiting Gadolinium dose.

Background and Objectives: Lymphedema is caused by insufficient lymphatic drainage leading to abnormal accumulation of interstitial fluid within soft tissues. Lympho‐venous anastomosis (LVA), as a surgical option for selected patients, is widely applied. Through preoperative localization of functional lymphatics with indocyanine green, real time visualization of functioning lymphatic vessels is possible. This examination is time consuming and operator dependant and is not suitable to differentiate the ratio of fat hypertrophy to liquid edema.We investigated whether MR lymphangiography is accurate for imaging functional lymphatics and adjacent veins in arms. Furthermore, we investigated the accuracy and predictability of preoperative mapping for the feasibility of performing LVA and the preoperative decision making in lymphedema surgery.Methods: A prospective study was performed in which 25 patients suffering from lymphedema of the upper extremity were examined. MR lymphography with contrast agent injection in a deep dermal plane was performed.Results: Precise localization of lymphatic vessels crossing a vein was achieved in 18 of 25 arms. In 16 of the 18 patients in whom functional lymphatics were localized with an adjacent vein on MRI an LVA was performed successfully.Conclusions: MR lymphangiography is an accurate and reproducible method for imaging and mapping of lymphatic channels in the lymphedemateous limb.

Abdominal scars are no longer a contra-indication for abdominal perforator flap harvesting. Few research data exists about the regeneration potential of the abdominal wall's perforator system. Therefore, previous abdominoplasty with umbilical transposition is an absolute contra-indication for a DIEaP-flap (deep inferior epigastric artery perforator flap). A 50-year-old patient required a breast reconstruction of the right breast, 10 years after an abdominoplasty with undermining of the superior abdomen and umbilical transposition. The patient was scheduled for a free lumbar artery perforator (LaP) flap. The preoperative computed tomography-angiography mapping showed nice lumbar perforators and to our surprise a good-sized DIEa perforator in the peri-umbilical region. The DIEa perforator on the right hemi-abdomen, consisting of two veins and one artery, was pulsatile and found suitable in size. A classical flap harvest and transfer was further performed. This case report is the first in which a dominant perforator is found in the area of undermining after a full abdominoplasty with umbilical repositioning. Further investigations regarding the nature and timing of re-permeation or regeneration of perforators after abdominoplasty are to be done. Nevertheless, we are convinced that with appropriate perforator mapping and a suitable plan B, previous abdominoplasty is no longer an absolute but a relative contra-indication for performing DIEaP-flap.