T1-Weighted Sequences (with and without Fat Saturation)

Summary Aim: Minimally invasive resection of hyperfunctional parathyroid glands is an alternative to open surgery. However, it requires a precise preoperative localization. This study evaluated the diagnostic use of magnetic resonance (MR) imaging, parathyroid scintigraphy, and consecutive image fusion. Patients, methods: 17 patients (9 women, 8 men; age: 29-72 years; mean: 51.2 years) with primary hyperparathyroidism were included. Examination by MRI used unenhanced T1- and T2-weighted sequences as well as contrast-enhanced T1-weighted sequences. 99mTc-MIBI scintigraphy consisted of planar and SPECT (single photon emission tomography) imaging techniques. In order to improve the anatomical localization of a scintigraphic focus, SPECT-data were fused with the corresponding MR-data using a modified version of the Express 5.0 software (Advanced Visual Systems, Waltham, MA). Results of image fusion were then compared to histopathology. Results: In 14/17 patients, a single parathyroid adenoma was found. There were 3 cases with hyperplastic glands. MRI detected 10 (71%), scintigraphy 12 (86%) adenomas. Both modalities detected 1/3 patients with hyperplasia. Image fusion improved the anatomical assignment of the 13 scintigraphic foci in five patients and was helpful in the interpretation of inconclusive MR-findings in two patients. Conclusions: Both MRI and 99mTc-MIBI scintigraphy sensitively detect parathyroid adenomas but are less reliable in case of hyperplastic glands. In case of a scintigraphic focus, image fusion considerably improves its topographic assignment. Furthermore, it facilitates the evaluation of inconclusive MRI findings.

Download Full-text

Lumbosacral Lipoma: Gadolinium-Enhanced Fat Saturation T1 Weighted MR Image is Necessary?

Journal of the Korean Radiological Society ◽

10.3348/jkrs.1999.40.4.645 ◽

1999 ◽

Vol 40 (4) ◽

pp. 645

Author(s):

Man Won Yoon ◽

Hyun Chul Kim ◽

Tae Woong Chung ◽

Jeong Jin Seo ◽

Gwang Woo Chung ◽

...

Keyword(s):

Mr Image ◽

Fat Saturation ◽

Lumbosacral Lipoma

Download Full-text

Pituitary MRI characteristics in 297 acromegaly patients based on T2-weighted sequences

Endocrine Related Cancer ◽

10.1530/erc-14-0305 ◽

2015 ◽

Vol 22 (2) ◽

pp. 169-177 ◽

Cited By ~ 46

Author(s):

Iulia Potorac ◽

Patrick Petrossians ◽

Adrian F Daly ◽

Franck Schillo ◽

Claude Ben Slama ◽

...

Keyword(s):

Large Population ◽

Optic Chiasm ◽

Research Priority ◽

Maximal Diameter ◽

Magnetic Resonance Imaging Mri ◽

Multimodal Management ◽

Mri Characteristics ◽

Weighted Sequences ◽

The Relationship

Responses of GH-secreting adenomas to multimodal management of acromegaly vary widely between patients. Understanding the behavioral patterns of GH-secreting adenomas by identifying factors predictive of their evolution is a research priority. The aim of this study was to clarify the relationship between the T2-weighted adenoma signal on diagnostic magnetic resonance imaging (MRI) in acromegaly and clinical and biological features at diagnosis. An international, multicenter, retrospective analysis was performed using a large population of 297 acromegalic patients recently diagnosed with available diagnostic MRI evaluations. The study was conducted at ten endocrine tertiary referral centers. Clinical and biochemical characteristics, and MRI signal findings were evaluated. T2-hypointense adenomas represented 52.9% of the series, were smaller than their T2-hyperintense and isointense counterparts (P<0.0001), were associated with higher IGF1 levels (P=0.0001), invaded the cavernous sinus less frequently (P=0.0002), and rarely caused optic chiasm compression (P<0.0001). Acromegalic men tended to be younger at diagnosis than women (P=0.067) and presented higher IGF1 values (P=0.01). Although in total, adenomas had a predominantly inferior extension in 45.8% of cases, in men this was more frequent (P<0.0001), whereas in women optic chiasm compression of macroadenomas occurred more often (P=0.0067). Most adenomas (45.1%) measured between 11 and 20 mm in maximal diameter and bigger adenomas were diagnosed at younger ages (P=0.0001). The T2-weighted signal differentiates GH-secreting adenomas into subgroups with particular behaviors. This raises the question of whether the T2-weighted signal could represent a factor in the classification of acromegalic patients in future studies.

Download Full-text

Letter to the Editor: Craniopharyngiomas in the elderly: the crucial influence of tumor topography on surgical risk assessment

Neuroendocrinology ◽

10.1159/000516172 ◽

2021 ◽

Author(s):

José M. Pascual ◽

Ruth Prieto

Keyword(s):

Risk Assessment ◽

Elderly Patients ◽

Tumor Tissue ◽

Significant Proportion ◽

Wide Band ◽

The Elderly ◽

Surgical Risk ◽

Definition Of ◽

Weighted Sequences ◽

Tumor Topography

Classifying CPs within the overly vague, uninformative category “suprasellar” prevents gaining any true insight regarding the risks associated with the surgical procedure employed. Routine MRI obtained with conventional T1- and T2-weighted sequences along the midsagittal and coronal trans-infundibular planes allow an accurate and reliable preoperative definition of CP topography. CPs developing primarily within the infundibulum and/or tuberal region of the hypothalamus, as well as those wholly located within the 3V, should be distinguished preoperatively from those lesions originally expanding beneath the 3V floor (3VF), the true suprasellar tumors. Among adult patients, about 40% of CPs correspond to infundibulo-tuberal tumors expanding primarily within the 3VF, above an intact pituitary gland and stalk. This subgroup of CPs shows strong adherences to the surrounding hypothalamus, as they are embedded within a wide band of reactive gliotic tissue, usually infiltrated by microscopic finger-like solid cords of tumor tissue. In elderly patients, a significant proportion of CPs correspond to papillary tumors developing above an intact 3VF, usually showing small pedicle-like or sessile-like attachments to the infundibulum. With the current diagnostic MRI workup routinely employed for CPs, it is possible, for the majority of lesions, to preoperatively differentiate these topographical variants and predict the type of CP-hypothalamus relationship that will be found during surgery.

Download Full-text

Delayed post-hypoxic leukoencephalopathy: Case report

European Psychiatry ◽

10.1016/j.eurpsy.2017.01.1654 ◽

2017 ◽

Vol 41 (S1) ◽

pp. s839-s839 ◽

Cited By ~ 1

Author(s):

M. Solerdelcoll Arimany ◽

M. Garriga ◽

E. Parellada

Keyword(s):

Neuropsychiatric Symptoms ◽

Brain Mri ◽

Clinical History ◽

Good Prognosis ◽

Mri Findings ◽

The Mean ◽

Competing Interest ◽

Weighted Sequences ◽

Direct Toxicity ◽

Progressive Cognitive Impairment

IntroductionDelayed post-hypoxic leukoencephalopathy (DPHL) is an underrecognized syndrome of delayed demyelination, where patients manifest neuropsychiatric symptoms after a period of 2–40 days of apparent recovery from a cerebral hypo-oxygenation episode.ObjectivesWe report a case of a patient who successfully recovered from an overdose of heroin, but then suffered a delayed abrupt neurological deterioration.AimsTo improve assessment and recognition of DPHL.MethodsAn adequate retrospective collection of clinical data and nonsystematic review of the literature was performed.ResultsA 43-year-old male with schizoaffective disorder who attempted suicide with an overdose of heroin, was successfully revived and return to his previously mental status, but 3 weeks after, he abruptly developed progressive cognitive impairment with akinetic mutism and ataxia. He was admitted to our acute psychiatric unit after brain CT and chemistry analyses were unremarkable. Brain MRI showed diffusely symmetric hyperintensity in the white matter (WM), pronominally the periventricular WM, on FLAIR and T2 weighted sequences. At 16 weeks postoverdose, he presented improvement both cognitive and motor symptoms, lasting deficits in frontal-executive functions.DiscussionDPHL is characterized by similar clinical and neuroimaging features regardless of the initial insult. The mean lucid interval coincides with the replacement half-life for myelin related lipids and proteins. Prolonged mild-to-moderate hypo-oxygenation of WM is thought to disrupt myelin turnover. It appears probable that these were responsible for DPHL in our patient rather than a direct toxicity.ConclusionDPHL can be diagnosed when clinical history, laboratory assessments and MRI findings are concordant. DPHL requires extensive support care and carries a relatively good prognosis.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Download Full-text

Developing a Specific MRI Technology to Identify Complications Caused by Breast Implants

Applied Sciences ◽

10.3390/app11083434 ◽

2021 ◽

Vol 11 (8) ◽

pp. 3434

Author(s):

Ming-Fang Lin ◽

Lu-Han Lai ◽

Wen-Tien Hsiao ◽

Melissa Min-Szu Yao ◽

Wing-P Chan

Keyword(s):

Water Saturation ◽

Spin Echo ◽

Pulse Sequences ◽

Breast Implants ◽

Fast Spin Echo ◽

Silicone Implants ◽

Water Suppression ◽

Dynamic Contrast Enhancement ◽

Produce Water ◽

Fat Saturation

With advancements in aesthetic medicine, breast augmentation has become a popular plastic surgery worldwide, typically performed using either fine-needle injection or silicone implants. Both carry complication risks from rupture over time. In this study, we aimed to reduce misjudgments and increase diagnostic value by developing an MRI technique that can produce water- and silicone-specific images from MRI scans of phantoms (Natrelle® saline-filled breast implants) and human bodies. Pig oil, soybean oil, and normal saline were used to simulate human breast tissue, and two common types of breast implants, saline bags, and silicone bags, were selected as well, resulting in five materials scanned. Six pulse sequences were applied: T1W fast spin echo (FSE), T1W SPGR/60, T2W, T2W fat-saturation, STIR, and STIR water-saturation. Human body scans were additionally investigated using 3D SPGR fat-saturation dynamic contrast enhancement. Results show that the best way to enhance tissue contrast in images of silicone implants is to apply STIR combined with water suppression, and the best way to enhance saline bag implants is to apply T2W fat-saturation combined with fat suppression. Both offered very high sensitivity and specificity, rendering this method especially useful for distinguishing normal mammary glands from siliconoma.

Download Full-text

MR Imaging–Pathologic Correlation of Uveal Melanomas Undergoing Secondary Enucleation after Proton Beam Radiotherapy

Applied Sciences ◽

10.3390/app11094310 ◽

2021 ◽

Vol 11 (9) ◽

pp. 4310

Author(s):

Pietro Valerio Foti ◽

Corrado Inì ◽

Mario Travali ◽

Renato Farina ◽

Stefano Palmucci ◽

...

Keyword(s):

Mr Imaging ◽

Proton Beam ◽

Uveal Melanoma ◽

Vitreous Hemorrhage ◽

Nerve Degeneration ◽

Proton Beam Radiotherapy ◽

Iris Neovascularization ◽

Weighted Sequences ◽

Histopathologic Findings ◽

Optic Nerve Degeneration

Background: Currently, radiotherapy represents the most widely employed therapeutic option in patients with uveal melanoma. Although the effects of proton beam radiotherapy on uveal melanoma end ocular tissues have been histologically documented, their appearance at MR imaging is still poorly understood. The purpose of our study was to elucidate the magnetic resonance (MR) semiotics of radiotherapy-induced changes to neoplastic tissues and ocular structures in patients with uveal melanoma undergoing secondary enucleation after proton beam radiotherapy. Methods: Nine patients with uveal melanoma who had undergone proton beam radiotherapy, MR imaging, and subsequent secondary enucleation were retrospectively selected. The histopathologic findings evaluated for irradiated tumors were necrosis, fibrosis, and viable tumor, while the histopathologic findings evaluated for extratumoral ocular/periocular tissues were radiation-related intraocular inflammation, vitreous hemorrhage, optic nerve degeneration, iris neovascularization, and periocular fibrotic adhesions. On MR images, the appearance of the abovementioned histologic features was assessed on conventional and diffusion-weighted sequences. Results: T2-weighted sequences performed better in detecting radiation-induced necrosis, fibrosis, optic nerve degeneration, and periocular fibrotic adhesions. T1-weighted sequences were preferable for identifying cataracts, vitreous hemorrhage, and inflammatory complications. Contrast-enhanced T1-weighted sequences were irreplaceable in assessing iris neovascularization, and in confirming inflammatory complications. Conclusions: In the light of their increasing role in the multidisciplinary management of patients with uveal melanoma, radiologists should be aware of the MR appearance of the effects of radiotherapy on neoplastic and ocular tissue, in order to improve the accuracy of follow-up MR examinations.

Download Full-text