Systemic and Neurosarcoidosis With Rare Involvement of the Extremities' Peripheral Nerves.

ABSTRACT: We present a case of sarcoidosis with a rare presentation of involvement of peripheral nerves of the lower limbs and subcutaneous nodules detected on 18 F-FDG PET/CT. The patient also had involvement of the spinal nerves and dura, histologically proven to be sarcoidosis. There were other manifestations of systemic sarcoidosis like metabolically active cervical and mediastinal lymphadenopathy. This case highlights the role of 18 F-FDG PET/CT in evaluating the uncommon sites of sarcoid involvement. Although many cases of sarcoid involvement of central nervous system have been reported, peripheral nerves involvement in the extremities was not found on a literature search.

Prostate-Specific Membrane Antigen PET/CT Detection of Prostate Cancer Metastasis to Thyroid and Cricoid Cartilages.

ABSTRACT: Prostate-specific membrane antigen (PSMA) PET/CT has revolutionized the imaging of prostate cancer. Historically, prostate cancer metastasis to thyroid and cricoid cartilages was thought to be exceedingly rare, with only a few reported cases in the literature. Prostate cancer metastasis to the laryngeal cartilages was detected in 4 of 221 patients who underwent imaging with 18 F-PSMA (Pylarify) or 68 Ga-PSMA (Illuccix) PET/CT for initial staging of high-risk prostate cancer or restaging evaluation in the setting of biochemical recurrence from April 2022 through October 2023. The increased sensitivity and specificity of PSMA PET/CT allow for the detection of previously occult metastatic disease.

Scintigraphic Detection of Abdominal Pseudocyst: A Complication of Ventriculoperitoneal Shunt.

We report a case of a large abdominal pseudocyst detected on scintigraphy in a patient with a history of ventriculoperitoneal shunt placement who presented with headache and suspected shunt malfunction.

Synchronous Ectopic Thyroid Gland and Ectopic Parathyroid Adenoma on 99mTc-Sestamibi Scintigraphy and Correlative Imaging.

99mTc-sestamibi scintigraphy localizes parathyroid adenoma as a persistent focus of uptake on delayed images, whereas thyroid glands in normal or ectopic locations are seen on only early images and wash out on delayed images. We report a case of absence of eutopic neck thyroid activity and synchronous ectopic lingual thyroid and mediastinal parathyroid adenoma on scintigraphy confirmed with CT.

Multimodality Imaging for Diagnosing Transthyretin Cardiac Amyloidosis.

Amyloidosis is the result of the extracellular deposition of amyloid in various organs. Common types are light-chain and transthyretin amyloidosis. Cardiac amyloidosis (CA) is a restrictive cardiomyopathy caused by amyloid infiltration in cardiac tissues. The detection of CA is increasing with the advent of easily accessible imaging modalities. Early diagnosis ensures a better prognosis. We present a case of cardiac amyloidosis, diagnosed from specific imaging findings on cardiac magnetic resonance imaging and more precisely as transthyretin type based on findings on nuclear scintigraphy.

Evaluation of Hepatopulmonary Syndrome with Technetium-99m Macroaggregated Albumin Scintigraphy.

Hepatopulmonary syndrome (HPS) is characterized by intrapulmonary vascular dilatation causing hypoxemia in patients with liver disease. Technetium-99m macroaggregated albumin (99mTc-MAA) scintigraphy have diagnostic value in suspected HPS by detecting clinically significant right to left shunt. In presence of cirrhosis, MAA scan with extra-pulmonary organs visualization is specific of intrapulmonary shunting. MAA scintigraphy also provides added value of quantification of the shunt.

Gallium-68 Prostate-Specific Membrane Antigen Positron Emission Tomography: A Practical Guide for Radiologists and Clinicians.

Prostate cancer (PCa) is the third most common form of cancer and the most common cancer diagnosis in men in the United States. It is known that prostate-specific membrane antigen (PSMA) is overexpressed in PCa. PSMA is a type II transmembrane glycoprotein expressed in several benign and malignant tissues. In December 2020, FDA approved Gallium-68 (68Ga) PSMA, which is a PSMA-targeted positron emission tomography (PET) imaging agent. Molecular imaging targeting PSMA has shown substantial advancement in PCa imaging. In this article, we discuss the radiopharmaceutical, indications to do PSMA PET, technical aspects of PSMA PET imaging, normal biodistribution of PSMA, other benign and malignant conditions that can take up PSMA, staging of prostate cancer, and how to report PSMA PET.

Diffuse Hepatic Accumulation of 99mTc-Macroaggregated Albumin Suggesting Synchronous Superior and Inferior Vena Cava Obstruction.

We report a rare case of incidental diffuse hot liver on 99mTc-macroaggregated albumin lung perfusion scanning done to exclude pulmonary embolism. This scintigraphic finding suggested synchronous obstruction of the superior and inferior venae cavae, later confirmed on CT angiography. Although many cases of focal hepatic uptake have been reported, reports of diffuse uptake because of vena cava obstruction are scarce in the literature.

18F-FDG PET/CT Unveiling of Implant Rupture and Clinically Unsuspected Silicone Granuloma in Treated Breast Cancer.

18F-FDG uptake in enlarged lymph nodes is always suspicious, especially in cancer patients. We report a case of hypermetabolic internal mammary lymphadenopathy in a breast cancer patient who was previously treated with bilateral mastectomy and implants. The abnormal nodal uptake turned out to be due to foreign body-induced inflammation, as confirmed histopathologically. Vigilant PET interpretation is required in breast cancer patients who have evidence of breast implant rupture.

Pediatric Skeletal Scintigraphy: What a General Radiologist Needs to Know.

Pediatric skeletal scintigraphy is a noninvasive imaging modality which aids in functional as well as anatomic evaluation of bone. Bone scintigraphy plays a major role in diagnosis and evaluation of various benign, primary malignant and metastatic pediatric bone pathologies. The advantage of bone scan is that it becomes positive well before the bone pathology is evident on radiographs and specifically the entire skeleton can be imaged in a single examination. Pediatric bone scintigraphy evaluation can be challenging to the general radiologist not routinely exposed to the study, as the growing skeleton is quite different from a mature skeleton especially at or near the growth plates. Though nonspecific, bone scintigraphy is a very sensitive modality. Correlation with a good history and other imaging modalities like radiographs, computed tomography and magnetic resonance imaging helps in diagnosis.

Looking beyond the indication: Bone scan for trauma providing unsuspected initial diagnosis of acute critical lower limb arterial compromise.

We report a case of rare incidental initial detection of unsuspected arterial supply compromise to the right lower extremity on a bone scan done to rule out fracture in a patient with right hip pain following a fall. Follow up CT angiogram confirmed near complete occlusion of right lower extremity arteries for which patient underwent above knee amputation.

Evaluation of tumor-induced osteomalacia with 111In-pentetreotide scintigraphy.

In cases of nonhereditary osteomalacia associated with hypophosphatemia and inadequate response to vitamin D supplementation, one should consider the possibility of tumor-induced osteomalacia, a paraneoplastic syndrome caused by small mesenchymal tumors often found in obscure locations. We present a case of tumor-induced osteomalacia in which (111)In-pentetreotide scintigraphy aided in accurate localization of the culprit brachial plexus tumor and cure after resection.

Primary hyperparathyroidism-related brown tumors mimicking other giant cell-containing skeletal tumors: role of correlative imaging in diagnosis.

A patient initially suspected of having a giant cell granuloma was subsequently found-through additional imaging with (99m)Tc-sestamibi and ultrasound-to have osteolytic brown tumors caused by a parathyroid adenoma. Brown tumors that relate to primary hyperparathyroidism may mimic other skeletal tumors that contain giant cells, presenting difficulty with accurate diagnosis. Correlative imaging can have a valuable role in such cases, potentially avoiding the extensive work-up usually done for suspected bone metastases.