The Role of Breast MRI in Detecting Asymptomatic Recurrence After Therapeutic Mastectomy.

OBJECTIVE. MRI is not routinely used to screen for cancer recurrence after therapeutic mastectomy; however, data on this topic are sparse. We performed this study to determine the utility of breast MRI in detecting asymptomatic locoregional recurrence after therapeutic mastectomy. MATERIALS AND METHODS. A retrospective record review identified all breast MRI studies performed in women who had undergone unilateral therapeutic mastectomy over a 6-year period (January 1, 2010, to January 1, 2016). A total of 402 studies were performed in 191 women between the ages of 26 and 78 years old, none of whom were experiencing symptoms on the mastectomy side. BI-RADS assessments for the mastectomy side were extracted from the radiology reports, and the electronic medical records were reviewed for surgical and oncologic history, clinical and imaging follow-up, and pathologic results. Malignancy was determined by pathologic results. Benignity was confirmed by at least one of the following: pathologic results, at least 12 months of documented disease-free clinical follow-up, or at least 12 months of documented disease-free imaging follow-up. Descriptive statistical and 2 × 2 contingency table analyses were performed. RESULTS. In all, 395 MR images (98.3%) were assessed as showing benign findings on the mastectomy side. Seven (1.7%) were interpreted as showing positive findings on the mastectomy side (BI-RADS category 4, suspicious for malignancy). Biopsy was performed in four of the seven positive interpretations. All four biopsies yielded malignancy for a positive predictive value of biopsy of 100%. The three remaining positive cases did not include biopsy; however, in each case, follow-up imaging showed improvement or resolution of the finding, yielding a positive predictive value of an abnormal examination of 57.1%. Two MRI studies were false-negative, with local recurrence within 12 months after MRI deemed to show benign findings, yielding a negative predictive value of 99.5%. Sensitivity and specificity were 66.7% and 99.2%, respectively. The cancer detection rate in the asymptomatic mastectomy side for all MRI examinations was 10 cancers per 1000 examinations. CONCLUSION. Our findings support inclusion of the mastectomy side in MRI examinations of the contralateral breast to screen for cancer recurrence after therapeutic mastectomy.

Superparamagnetic Iron Oxide Sentinel Node Tracer Injection: Effects on Breast MRI Quality.

OBJECTIVE: To evaluate the MRI artifact rendered by the typical injection of a ferromagnetic tracer now being intermittently used for intraoperative sentinel node (SN) identification at our institution, and to explore its impact on postoperative imaging and management. METHODS: This study was Institutional Review Board-approved and granted a waiver of consent. A database search tool was used to identify MRI exams performed on patients who had previously undergone breast-conserving surgery with use of a superparamagnetic iron oxide (SPIO) SN tracer between January 1, 2015, and May 1, 2020. MRI reports, images, and relevant demographic, oncologic, and surgical history were collected. The presence or absence of SPIO residue on breast MRI, as well as its impact on image quality, were extracted from the prospective reports. RESULTS: A total of 21 MRI exams were identified in 16 patients who had undergone breast-conservation therapy for cancer with use of SPIO SN tracer. Mean time from particle injection to baseline postoperative MRI exam was 10.8 months. All reports (21/21) noted evidence of SPIO residue. Of these, 5/21 were assessed as non-diagnostic; the remainder were assessed as limited. CONCLUSION: Radiologists should be aware of the use of superparamagnetic tracers for SN identification and the impact on the quality of future MRI examinations. Alternative injection approaches are being developed and sequence parameters adjusted to minimize artifact.

Congenital Oral Masses: An Anatomic Approach to Diagnosis.

Although congenital oral masses are rare, they are readily detectable during fetal US screening. Most congenital oral masses are benign, but some may cause mechanical airway obstruction, resulting in poor outcomes at delivery. The radiologist's ability to describe these abnormalities and their physiologic sequelae accurately can have a substantial effect on perinatal treatment. Furthermore, despite being rare, congenital oral lesions encountered at screening and at follow up fetal MRI provide the opportunity to make a specific diagnosis by following a simple anatomic approach. This article describes an anatomic algorithm as the framework for accurate diagnosis of congenital oral lesions. The imaging appearance of the most common congenital oral cavity neoplasms is outlined, including vascular anomalies, epulides, choristomas, congenital lingual thyroid anomalies, lingual hamartomas, and epignathi, and other conditions that mimic these at US. Also reviewed are perinatal management of masses that affect the fetal airway and the imaging features key to optimizing delivery outcomes. Online supplemental material is available for this article. ©RSNA, 2019.

Diffusion tensor MRI of the corpus callosum in amyotrophic lateral sclerosis.

PURPOSE: To determine if decline in corpus callosum (CC) white matter integrity in patients with amyotrophic lateral sclerosis (ALS) is localized to motor-related areas. MATERIALS AND METHODS: Twenty-one ALS patients and 21 controls participated. Diffusion tensor images (DTI) were acquired using 3 Tesla (T) MRI. Tract-based spatial statistics were used to examine whole-brain white matter damage. A segmentation schema was used to define CC volumes-of-interest (VOI). Fractional anisotropy (FA) and radial- and axial-diffusivity (RD, AD) were extracted from VOIs and compared between groups. DTI measurements in motor-related Area III were tested for correlation with symptoms and disease duration. RESULTS: Extracted FA values from CC VOIs were reduced in ALS patients (P≤0.0001), particularly in Areas II and III (P≤0.01). Reduced FA in Area III correlated with disease symptomology (P≤0.05) and duration (P≤0.02). Between-group whole-brain comparisons (P≤0.05, corrected) showed reduced FA and increased RD throughout white matter regions including the CC, corona radiata, and internal capsule. AD was increased in the left corona radiata and internal and external capsules. CONCLUSION: FA in motor-related regions of the CC is more affected than other CC areas in ALS patients. Microstructural pathology of transcallosal fiber tracts may represent a future component of an imaging biomarker for ALS.

The neurobiology of glucocerebrosidase-associated parkinsonism: a positron emission tomography study of dopamine synthesis and regional cerebral blood flow.

Mutations in GBA, the gene encoding glucocerebrosidase, the enzyme deficient in Gaucher disease, are common risk factors for Parkinson disease, as patients with Parkinson disease are over five times more likely to carry GBA mutations than healthy controls. Patients with GBA mutations generally have an earlier onset of Parkinson disease and more cognitive impairment than those without GBA mutations. We investigated whether GBA mutations alter the neurobiology of Parkinson disease, studying brain dopamine synthesis and resting regional cerebral blood flow in 107 subjects (38 women, 69 men). We measured dopamine synthesis with (18)F-fluorodopa positron emission tomography, and resting regional cerebral blood flow with H(2)(15)O positron emission tomography in the wakeful, resting state in four study groups: (i) patients with Parkinson disease and Gaucher disease (n = 7, average age = 56.6 ± 9.2 years); (ii) patients with Parkinson disease without GBA mutations (n = 11, 62.1 ± 7.1 years); (iii) patients with Gaucher disease without parkinsonism, but with a family history of Parkinson disease (n = 14, 52.6 ± 12.4 years); and (iv) healthy GBA-mutation carriers with a family history of Parkinson disease (n = 7, 50.1 ± 18 years). We compared each study group with a matched control group. Data were analysed with region of interest and voxel-based methods. Disease duration and Parkinson disease functional and staging scores were similar in the two groups with parkinsonism, as was striatal dopamine synthesis: both had greatest loss in the caudal striatum (putamen Ki loss: 44 and 42%, respectively), with less reduction in the caudate (20 and 18% loss). However, the group with both Parkinson and Gaucher diseases showed decreased resting regional cerebral blood flow in the lateral parieto-occipital association cortex and precuneus bilaterally. Furthermore, two subjects with Gaucher disease without parkinsonian manifestations showed diminished striatal dopamine. In conclusion, the pattern of dopamine loss in patients with both Parkinson and Gaucher disease was similar to sporadic Parkinson disease, indicating comparable damage in midbrain neurons. However, H(2)(15)O positron emission tomography studies indicated that these subjects have decreased resting activity in a pattern characteristic of diffuse Lewy body disease. These findings provide insight into the pathophysiology of GBA-associated parkinsonism.