The active papillary muscle sign in 18F-FDG PET/CT cardiac sarcoidosis exams and its relationship with myocardial suppression.

OBJECTIVE: Papillary muscle (PM) activity may demonstrate true active cardiac sarcoidosis (CS) or mimic CS in 18FDG-PET/CT if adequate myocardial suppression (MS) is not achieved. We aim to examine whether PM uptake can be used as a marker of failed MS and measure the rate of PM activity presence in active CS with different dietary preparations. MATERIALS AND METHODS: We retrospectively reviewed PET/CTs obtained with three different dietary preparations. Diet-A: 24-h ketogenic diet with overnight fasting (n = 94); Diet-B: 18-h fasting (n = 44); and Diet-C: 72-h daytime ketogenic diet with 3-day overnight fasting (n = 98). Each case was evaluated regarding CS diagnosis (negative, positive, and indeterminant) and presence of PM activity. MaxSUV was measured from bloodpool, liver, and the most suppressed normal myocardium. Linear mixed-effects models were used to compare these factors between those with PM activity and those without. RESULTS: PM activity was markedly lower in the Diet-C group compared with others: Diet-C: 6 (6.1%), Diet-A: 36 (38.3%), and Diet-B: 26 (59.1%) (p < 0.001). MyocardiumMaxSUV was higher, and MyocardiummaxSUV/BloodpoolmaxSUV, MyocardiummaxSUV/LivermaxSUV ratios were significantly higher in the cases with PM activity (p < 0.001). Among cases that used Diet-C and had PM activity, 66.7% were positive and 16.7% were indeterminate. If Diet-A or Diet-B was used, those with PM activity had a higher proportion of indeterminate cases (Diet-A: 61.1%, Diet-B: 61.5%) than positive cases (Diet-A: 36.1%, Diet-B: 38.5%). CONCLUSION: Lack of PM activity can be a sign of appropriate MS. PM activity is less common with a specific dietary preparation (72-h daytime ketogenic diet with 3-day overnight fasting), and if it is present with this particular preparation, the likelihood that the case being true active CS might be higher than the other traditional dietary preparations.

Use of a Commercial 7-T MRI Scanner for Clinical Brain Imaging: Indications, Protocols, Challenges, and Solutions-A Single-Center Experience.

The first commercially available 7-T MRI scanner (Magnetom Terra) was approved by the FDA in 2017 for clinical imaging of the brain and knee. After initial protocol development and sequence optimization efforts in volunteers, the 7-T system, in combination with an FDA-approved 1-channel transmit/32-channel receive array head coil, can now be routinely used for clinical brain MRI examinations. The ultrahigh field strength of 7-T MRI has the advantages of improved spatial resolution, increased SNR, and increased CNR but also introduces an array of new technical challenges. The purpose of this article is to describe an institutional experience with the use of the commercially available 7-T MRI scanner for routine clinical brain imaging. Specific clinical indications for which 7-T MRI may be useful for brain imaging include brain tumor evaluation with possible perfusion imaging and/or spectroscopy, radiotherapy planning; evaluation of multiple sclerosis and other demyelinating diseases, evaluation of Parkinson disease and guidance of deep brain stimulator placement, high-detail intracranial MRA and vessel wall imaging, evaluation of pituitary pathology, and evaluation of epilepsy. Detailed protocols, including sequence parameters, for these various indications are presented, and implementation challenges (including artifacts, safety, and side effects) and potential solutions are explored.

Probabilistic tractography of the extracranial branches of the trigeminal nerve using diffusion tensor imaging.

PURPOSE: The peripheral course of the trigeminal nerves is complex and spans multiple bony foramen and tissue compartments throughout the face. Diffusion tensor imaging of these nerves is difficult due to the complex tissue interfaces and relatively low MR signal. The purpose of this work is to develop a method for reliable diffusion tensor imaging-based fiber tracking of the peripheral branches of the trigeminal nerve. METHODS: We prospectively acquired imaging data from six healthy adult participants with a 3.0-Tesla system, including T2-weighted short tau inversion recovery with variable flip angle (T2-STIR-SPACE) and readout segmented echo planar diffusion weighted imaging sequences. Probabilistic tractography of the ophthalmic, infraorbital, lingual, and inferior alveolar nerves was performed manually and assessed by two observers who determined whether the fiber tracts reached defined anatomical landmarks using the T2-STIR-SPACE volume. RESULTS: All nerves in all subjects were tracked beyond the trigeminal ganglion. Tracts in the inferior alveolar and ophthalmic nerve exhibited the strongest signal and most consistently reached the most distal landmark (58% and 67%, respectively). All tracts of the inferior alveolar and ophthalmic nerve extended beyond their respective third benchmarks. Tracts of the infraorbital nerve and lingual nerve were comparably lower-signal and did not consistently reach the furthest benchmarks (9% and 17%, respectively). CONCLUSION: This work demonstrates a method for consistently identifying and tracking the major nerve branches of the trigeminal nerve with diffusion tensor imaging.

Case report: Delayed posttraumatic cortical laminar necrosis secondary to spreading depolarization induced spreading ischemia from old subarachnoid hemorrhage.

Cortical laminar necrosis usually occurs secondary to infarcts or hypoxia, however other causes, including hypoglycemia, status epilepticus and immunosuppressive therapy have been reported. To our knowledge, CLN is not a phenomenon expected in the case of trauma. We report a unique case of delayed post-traumatic CLN which occurred 30 days after the initial trauma, without any proven cause apart from possible spreading depolarization induced spreading ischemia from adjacent subarachnoid hemorrhage with distinct radiologic features.

Torcular pseudomass in newborns and its association with delivery: follow up or leave it alone?

PURPOSE: The cranial epidural space (ES) is a potential space and is not generally recognized unless there is underlying pathology. With MRI in newborns, we have frequently observed T2 hyperintense thickening of the ES posterior to the confluence of sinuses, also referred to as "torcular pseudomass" (TP). We aim to identify the frequency of TP and possible associations with delivery. METHODS: Retrospectively, brain MRIs of 194 neonates obtained within the first 2 weeks of life were evaluated. If TP was present, imaging characteristics and thickness were assessed by two observers, using fat-suppressed T2WI/FLAIR, T1WI, and SWI. Exclusion criteria were motion artifact, lack of sagittal T2WI, and lack of clinical data. Medical records were evaluated for demographic and clinical data. Follow-up exams were evaluated if available. Patients with TP and without were compared using Student t and chi-square tests. RESULTS: TP was present in 64/158 (40%). No difference was found between the groups regarding sex, gestational age, birth weight, delivery type, fetal presentation during delivery, birth difficulty, and neurological sequelae (p > 0.05). Eight patients with TP underwent follow-up imaging, and in 6/8, TP completely resolved. Two patients showed persistent TP, improving from 3.2 to 1 mm in one child and from 3.2 to 2.8 mm in the other within a week. CONCLUSION: TP frequently occurs in early newborns. TP does not appear to be associated with factors related to delivery, shows complete resolution in most cases with a follow-up, and is likely of no clinical importance.

Stability of serial platelet and urine protein measurements in patients receiving nusinersen for spinal muscular atrophy.

INTRODUCTION/AIMS: Patients undergoing nusinersen treatment for spinal muscular atrophy are subject to measurements of platelet count and urine protein before each injection due to concern for platelet depletion and renal dysfunction according to the prescribing information. These tests may be uncomfortable or inconvenient and may cause delays in treatment. However, it is still unclear whether these values have been significantly affected by nusinersen treatment. Our aim in this study was to determine whether these measurements ever reached critical values that necessitated withholding treatment at our center. METHODS: Records from 57 patients treated with nusinersen at our institution between 2017 and 2020 were retrospectively analyzed. Laboratory values for platelet count, random urine protein, and total urine protein:creatinine ratio were collected from all patients before each procedure. RESULTS: Mean patient age was 28.9 years (range, 2-76 years). Mean platelet count was 307 × 109 /L (range, 96-755 × 109 /L; normal lab limits, 150-450 × 109 /L), mean random urine protein was 0.164 g/L (range, <0.05-0.73 g/L), and mean total urine protein:creatinine ratio was 0.885 g per gram creatinine (range, 0.12-9.71 g per gram creatinine). No laboratory values precluded continuing treatment for any patient. DISCUSSION: Although further study on a larger cohort is warranted for more definitive conclusions, it may not be necessary to measure platelet count and urine protein before each nusinersen treatment, particularly in the maintenance phase.

GammaTile® brachytherapy in the treatment of recurrent glioblastomas.

BACKGROUND: GammaTile® (GT) is a recent U.S. Food and Drug Administration (FDA) cleared brachytherapy platform. Here, we report clinical outcomes for recurrent glioblastoma patients after GT treatment following maximal safe resection. METHODS: We prospectively followed twenty-two consecutive Isocitrate Dehydrogenase (IDH) wild-type glioblastoma patients (6 O6-Methylguanine-DNA methyltransferase methylated (MGMTm); sixteen MGMT unmethylated (MGMTu)) who underwent maximal safe resection of recurrent tumor followed by GT placement. RESULTS: The cohort consisted of 14 second and eight third recurrences. In terms of procedural safety, there was one 30-day re-admission (4.5%) for an incisional cerebrospinal fluid leak, which resolved with lumbar drainage. No other wound complications were observed. Six patients (27.2%) declined in Karnofsky Performance Score (KPS) after surgery due to worsening existing deficits. One patient suffered a new-onset seizure postsurgery (4.5%). There was one (4.5%) 30-day mortality from intracranial hemorrhage secondary to heparinization for an ischemic limb. The mean follow-up was 733 days (range 279-1775) from the time of initial diagnosis. Six-month local control (LC6) and twelve-month local control (LC12) were 86 and 81%, respectively. Median progression-free survival (PFS) was comparable for MGMTu and MGMTm patients (~8.0 months). Median overall survival (OS) was 20.0 months for the MGMTu patients and 37.4 months for MGMTm patients. These outcomes compared favorably to data in the published literature and an independent glioblastoma cohort of comparable patients without GT treatment. CONCLUSIONS: This clinical experience supports GT brachytherapy as a treatment option in a multi-modality treatment strategy for recurrent glioblastomas.

A common yet undescribed MRI finding in newborns: posterior epidural space edema of the cervical and upper thoracic spine.

PURPOSE: Posterior spinal epidural space (PSES) is a fat-containing space. We noted numerous spinal MRIs demonstrating T2-hyperintense thickening of the cervical/thoracic PSES in early newborns, resembling epidural edema. Our aim is to describe the appearance/frequency of this finding and explore any associations with delivery. METHODS: Retrospectively, 202 spinal/cranial MRIs, belonging to newborns within the first 2 weeks of life, were evaluated using sagittal fat-suppressed T2, T1-FLAIR, and STIR. Exclusion criteria were motion, incomplete spine imaging, lack of sagittal T2/STIR, and inadequate clinical data. Ninety-three patients were included in the final analysis. We reviewed all cases for T2 hyperintense thickened PSES and, if present, accompanying abnormal T1 signal. The spinal canal and PSES thickness were measured. Clinical and demographic data were collected. Follow-up exams were evaluated, if available. Cases with thickened PSES and without were compared. RESULTS: T2-hyperintense thickened PSES was present in 60/93 (64.5%). Mean PSES thickness was 2.3 mm (0.7-4.6). The mean PSES thickness/spinal canal diameter ratio was 0.2 (0.1-0.5). No cord compression was identified. One had a hyperintense T1 PSES signal, compatible with epidural hemorrhage. No difference was found between those with thickened PSES and without, regarding sex, gestational age, birth weight, birth method, difficult delivery, fetal position, or neurologic status (p>0.05). Follow-up imaging was available in 10, with complete resolution of T2 hyperintense PSES thickening. CONCLUSION: T2 hyperintense PSES thickening is common in imaged newborns and reversible at follow-up. No significant neurologic outcomes were found related to its presence; thus, follow-up does not appear necessary.

Lymphadenopathy after the third Covid-19 vaccine.

Axillary lymphadenopathy ipsilateral to the vaccination site has been clinically and radiologically reported after administration of COVID-19 vaccines. This can be an important diagnostic dilemma, particularly in cancer patients who are being staged or re-staged, as this benign entity may mimic metastasis, cause unnecessary biopsies and changes in therapy. Here we present a breast cancer patient and a patient with squamous cell carcinoma of the head and neck, who had already received the first two doses of mRNA type COVID-19 vaccines before, now presenting with new hypermetabolic reactive lymphadenopathy on FDG PET/CT after the third booster dose.

Impact of 18-French Rectal Tube Placement on Image Quality of Multiparametric Prostate MRI.

This study compared prostate multiparametric MRI (mpMRI) performed using an 18-French rectal tube in place throughout the examination after initial placement by a technologist (n = 97) with mpMRI performed without rectal tube placement (n = 99). Acquisition parameters were otherwise identical. Two radiologists scored subjective image quality and measured rectal diameter. For both readers, rectal tube placement was associated (p < .001) with improved ADC map quality, decreased DWI distortion, decreased rectal gas, and decreased rectal diameter. Findings support routine rectal tube placement for prostate mpMRI.

COMPARISON OF THE EFFECT OF THREE DIFFERENT DIETARY MODIFICATIONS ON MYOCARDIAL SUPPRESSION IN 18F-FDG PET/CT EVALUATION OF PATIENTS FOR SUSPECTED CARDIAC SARCOIDOSIS.

Rationale: A definitive dietary preparation recommendation is not possible based on literature in achievement of myocardial suppression for diagnosis of cardiac sarcoidosis (CS) with 18F-FDG PET/CT. Our goal is to compare three different dietary preparations in achievement of the best myocardial suppression and CS diagnosis. Methods: We retrospectively reviewed and compared three dietary preparations used at our institution. Three different diets were applied from 03/2014 to 12/2019. 24-h ketogenic diet with overnight fasting (n = 94); 18h-fasting (n = 44); 72-h daytime ketogenic diet with 3-day overnight fasting (n = 98). The interpretation of initial reports was recorded, and an independent radiologist (observer) retrospectively re-evaluated each case regarding CS diagnosis (Negative, Positive, Indeterminant) and myocardial suppression (Complete, Failed, Partial). Interobserver agreement was analyzed. We measured MaxSUV from bloodpool, liver, and the most suppressed normal myocardium. Results: We identified superior myocardial suppression with the 72-h preparation indicated by a higher bloodpool/myocardium and liver/myocardium ratios (P<0.001). Myocardial suppression rates for 72-h ketogenic diet, 24-h ketogenic diet and 18-h fasting preparations are as follows; Complete myocardial suppression: 96.9%/68.1%/52.3%, Failed myocardial suppression: 0%/23.4%/25%, Partial myocardial suppression: 3.1%/8.5%/22.7%) (P<0.001). The 72-hour preparation had significantly fewer "indeterminant" and "positive" exams. CS diagnosis rates for 72-h ketogenic diet, 24-h ketogenic diet and 18-h fasting preparations are as follows; Negative: 82.7%/52.1%/27.3%, Indeterminant: 2.0%/24.5%/40.9%, Positive: 15.3%/23.4%/31.8% (P<0.001). High agreement was present with the observer and the report (κ=0.88) Conclusion: A 72-h daytime ketogenic diet with 3-day overnight fasting, achieved substantially superior myocardial suppression versus 24-h ketogenic diet with overnight fasting and 18h-fasting using 18F-FDG PET/CT. This 72-h preparation results in significantly fewer "indeterminant" and potentially "false positive" CS results.

Lymphadenopathy in COVID-19 Vaccine Recipients: Diagnostic Dilemma in Oncologic Patients.

Five cases of axillary lymphadenopathy are presented, which occurred after COVID-19 vaccination and mimicked metastasis in a vulnerable oncologic patient group. Initial radiologic diagnosis raised concerns for metastasis. However, further investigation revealed that patients received COVID-19 vaccinations in the ipsilateral arm prior to imaging. In two cases, lymph node biopsy results confirmed vaccination-related reactive lymphadenopathy. Ipsilateral axillary swelling or lymphadenopathy was reported based on symptoms and physical examination in COVID-19 vaccine trials. Knowledge of the potential for COVID-19 vaccine-related ipsilateral adenopathy is necessary to avoid unnecessary biopsy and change in therapy. © RSNA, 2021.

Not a pearl necklace: synchronous papillary carcinoma of thyroglossal duct cyst and thyroid gland.

We report an unusual case of synchronous papillary carcinoma of thyroglossal duct cyst (TGDC) and thyroid gland. Here, the radiology findings, surgical approach and subsequent management, and pathology of an synchronous papillary carcinoma of TGDC and thyroid gland are described.

The Role of Dual-Phase FDG PET/CT in the Diagnosis and Follow-Up of Brain Tumors.

OBJECTIVE. FDG PET/CT of brain tumors is limited by background activity. Dual-phase FDG PET/CT can eliminate this limitation and allow discernment of viable tumors. Our aim was to assess the diagnostic capability of dual-phase FDG PET/CT qualitatively and quantitatively and to determine cutoff values for dual-phase FDG PET/CT in brain tumor imaging. MATERIALS AND METHODS. Retrospectively, 51 malignant brain tumors were evaluated with dual-phase FDG PET/CT in 32 patients. Acquisitions were performed 30 minutes (time 1) and 3 hours (time 2) after administration of 10 mCi (370 MBq) FDG and 6 hours of fasting. Two observers independently and qualitatively evaluated lesions. A weighted Cohen kappa was used to calculate interrater reliability and accuracy. Quantitatively, maximum standardized uptake value (SUVmax) was measured in the lesions, contralateral white matter (CWM), contralateral caudate nucleus head, and ipsilateral cerebellar cortex (CC). Lesion-to-CWM SUVmax, lesion-to-contralateral caudate nucleus head SUVmax, and lesion-to-ipsilateral CC SUVmax ratios at time 1 and time 2 were calculated. ROC analysis was used to determine optimum cutoff values, and AUC ratios were compared among quantitative parameters. Lesion outcome was determined by pathologic results (available in 15 lesions), lesion stability on serial MRI examinations (representing nonviable tumor), or decreased tumor size on serial MRI examinations after new treatment (representing viable tumor). RESULTS. Thirty-seven viable and 14 nonviable lesions were evaluated. Qualitatively, the diagnostic accuracy (first observer: κ = 0.45 to κ = 0.59; second observer: κ = 0.41 to κ = 0.66) and interrater reliability (at time 1: κ = 0.51; at time 2: κ = 0.83) improved with delayed imaging. AUC and ROC analysis showed comparably high sensitivity, specificity, and accuracy profiles for early and delayed dual-phase FDG PET/CT. Some of the proposed cutoff values were as follows: lesion SUVmax at time 1, 7.20 (sensitivity, 89.2%; specificity, 85.7%); lesion SUVmax at time 2, 7.80 (sensitivity, 97.3%; specificity, 71.4%); lesion-to-CWM SUVmax at time 1, 2.05 (sensitivity, 78.4%; specificity, 92.9%); and lesion-to-CWM SUVmax at time 2, 2.36 (sensitivity, 81.1%; specificity, 85.7%). CONCLUSION. Dual-phase FDG PET/CT improves lesion detection and diagnostic accuracy in malignant brain tumors.

Nusinersen injections in adults and children with spinal muscular atrophy: a single-center experience.

PURPOSE: Nusinersen is a drug approved in December 2016 for treatment of spinal muscular atrophy (SMA). We want to share our initial experience with image-guided, non-image-guided, and port-delivered nusinersen injections in a large single-center SMA patient cohort, treating both pediatric and adult patients with focus on technical considerations and other patient concerns from a combined perspective of patient, neurologist, and radiologist. METHODS: All nusinersen injections between February 2017 and September 2018 were retrospectively reviewed. We obtained age, sex, SMA type and technical details of the injections and postprocedure complications for each procedure. RESULTS: A total of 52 patients (24 women [46%]; 4 patients with SMA-1 [7.6%]; 30 patients with SMA-2 [57.8%]; 18 patients with SMA-3 [34.6%]; mean age, 25.5 years [7 months to 62 years]) with a total of 265 injections were included. Of the 265 injections, 206 (77.9%) were performed with local anesthetic, 25 (9.4%) with moderate sedation, and 23 (8.6%) under general anesthesia. We performed 65 CT-guided transforaminal injections in 13 patients, 106 fluoroscopy-guided lumbar punctures in 24 patients and 83 lumbar punctures in 16 patients using conventional technique. Only 6 of 265 injections (2.2%) ended up with a post-lumbar puncture headache (PLPH) requiring medical treatment. None required an epidural blood patch. Fourteen PLPH (5.2%) occurred and resolved at the same day without any treatment. After 6 of 265 injections (2.2%), patients reported soreness at the injection site which resolved spontaneously. Three elected to have an intrathecal reservoir placement (2 lumbar, 1 intraventricular) with a total of 11 injections. One patient with lumbar catheter developed infection after surgery with subsequent meningitis and treatment delay. After the resolution of meningitis, a new intraventricular reservoir was placed without any complication in the following injections. CONCLUSION: With the introduction of nusinersen treatment, neurologists and radiologists play an important role in treatment of SMA patients and therefore should be familiar with different techniques and complications of drug administration. Using good technique, it is possible to have very low complication rates even in this complex patient population, and various image-guided procedures can be a safe alternative to surgical approach, even in the most difficult cases.