Miliary meningeal tuberculosis - an unusual imaging presentation for an early definitive diagnosis.

PURPOSE: Tuberculous meningitis (TBM) causes significant morbidity and mortality in young children. Early treatment can be initiated with magnetic resonance (MR) imaging diagnosis. We present MR-detectable miliary meningeal TB in two patients. CASE 1: A 9-year-old girl developed fevers, cough, lethargy, and seizures. Brain MRI demonstrated multiple, small, T2-dark, rim-enhancing lesions, associated with cranial nerve and leptomeningeal enhancement. CSF showed pleocytosis, low glucose, and high protein. Chest CT showed mediastinal lymphadenopathy, multiple small interstitial lung nodules, and a splenic hypo enhancing lesion. Serial bronchoalveolar lavage studies were Xpert MTB/RIF and acid-fast negative. Endobronchial US-guided biopsy of a subcarinal lymph node was positive for Xpert MTB PCR. She was started on a 4-drug treatment for TBM and dexamethasone. Contact tracing revealed a remote positive contact with pulmonary tuberculosis. CASE 2: A 17-year-old female with Crohn's disease on adalimumab developed refractory ear infections despite multiple courses of antibiotics. She underwent myringotomy, with negative aerobic ear fluid culture. Brain MRI, obtained due to persistent otorrhea, showed multiple, small, round, T2-dark lesions. CSF studies were normal. CT chest, abdomen, and pelvis to assess for disseminated disease showed left upper lobe tree-in-bud nodules, hypoattenuating splenic lesions and a left obturator internus abscess with adjacent osteomyelitis. She underwent CT-guided aspiration of the obturator muscle collection, bronchoscopy with bronchoalveolar lavage, biopsy of two preexisting chronic skin lesions, and ear fluid aspiration. QuantiFERON Gold was positive. Ear fluid was Xpert MTB/RIF assay and acid-fast stain positive. Cultures from the ear fluid, skin tissue, muscle tissue, and alveolar lavage showed growth of acid-fast bacilli. She was started on 4-drug therapy and prednisone. CONCLUSION: Our cases highlight that TBM in many cases remains a diagnostic dilemma - both our patients presented in a prolonged atypical manner. The term miliary TB not only refers to a pattern of interstitial nodules on chest radiographs but also indicates the hematogenous spread of the disease and concurrent pulmonary and extrapulmonary involvement with high risk of TB meningitis. We promote the use of the term miliary meningeal TB - in both cases, the neuroimaging diagnosis of TB preceded both chest imaging and laboratory confirmation of the disease. Miliary meningeal nodules on MRI may have characteristic T2 low signal and may be more conspicuous in children and immunocompromised individuals where background basal meningeal enhancement is less prominent.

Imaging features of soft-tissue infections.

Skin and soft tissues are among the most common sites of infections. Infections can involve the superficial epidermis to deep muscles and bones. Most infections spread through contiguous structures, although hematogenous spread can occur in the setting of an immunocompromised state and with atypical infections. While clinical diagnosis of infections is possible, it often lacks specificity, necessitating the use of imaging for confirmation. Cross-sectional imaging with US, CT, and MRI is frequently performed not just for diagnosis, but to delineate the extent of infection and to aid in management. Nonetheless, the imaging features have considerable overlap, and as such, it is essential to integrate imaging features with clinical features for managing soft tissue infections. Radiologists must be aware of the imaging features of different infections and their mimics, as well as the pros and cons of each imaging technique to properly use them for appropriate clinical situations. In this review, we summarize the most recent evidence-based features of key soft tissue infections.

Metabolic topography of autoimmune non-paraneoplastic encephalitis.

PURPOSE: F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) is emerging to be a useful tool in supporting the diagnosis of AIE. In this study, we describe the metabolic patterns on F-18 FDG PET imaging in AIE. METHODS: Twenty-four antibody-positive patients (anti-NMDA-15, anti-VGKC/LGI1-6, and anti-GAD-3), 14 females and 10 males, with an age range of 2-83 years were included in this study. Each PET study was evaluated visually for the presence of hypometabolism or hypermetabolism and semiquantitatively using Cortex ID (GE) and Scenium (Siemens) by measuring regional Z-scores. These patterns were correlated with corresponding antibody positivity once available. RESULTS: Visually, a pattern of hypometabolism, hypermetabolism, or both in various spatial distributions was appreciated in all 24 patients. On quantitative analysis using scenium parietal and occipital lobes showed significant hypometabolism with median Z-score of -3.8 (R) and -3.7 (L) and -2.2 (R) and -2.5 (L) respectively. Two-thirds (16/24) showed significant hypermetabolism involving the basal ganglia with median Z-score of 2.4 (R) and 3.0 (L). Similarly on Cortex ID, the median Z-score for hypometabolism in parietal and occipital lobes was -2.2 (R) and -2.4 (L) and -2.6 (R) and -2.4 (L) respectively, while subcortical regions were not evaluated. MRI showed signal alterations in only 11 of these patients. CONCLUSION: There is heterogeneity in metabolic topography of AIE which is characterized by hypometabolism most commonly involving the parietal and occipital cortices and hypermetabolism most commonly involving the basal ganglia. Scenium analysis using regional Z-scores can complement visual evaluation for demonstration of these metabolic patterns on FDG PET.

Update of the role of PET/CT and PET/MRI in the management of patients with cervical cancer.

In cervical cancer (CC), fluorine18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) has been proven to be beneficial for patient management. Positron emission tomography/CT is useful in pretreatment evaluation due to the ability to evaluate disease extent and to assess regional lymph nodes as well as distant sites for metastases. Positron emission tomography/CT has an impact on treatment planning as well as it is incorporated in radiation therapy planning, resulting in more appropriate and effective treatment with less cost and radiation dose to normal tissues. Positron emission tomography/CT is used to predict early treatment response and to assess treatment response after completion of concurrent chemoradiation therapy. Positron emission tomography/CT has been used for surveillance after treatment as well as for restaging in suspected recurrent or metastatic disease. Qualitative PET/CT imaging findings as well as quantitative parameters such as maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) are useful to predict prognosis and clinical outcome. Moreover, PET imaging using other radiotracers to detect and quantify hypoxia may help to identify aggressive tumors and predict treatment outcome even though it is not widely clinical used. Positron emission tomography/magnetic resonance imaging (PET/MRI) instruments are now available, which may potentially improve evaluation of primary tumors and metastatic sites given the improved soft tissue contrast resolution of MRI relative to CT. This article reviews the role of 18F-FDG PET/CT, hypoxia agent PET/CT, and 18F-FDG PET/MRI in the management of patients with CC.

Transcending Language Barriers: Can ChatGPT Be the Key to Enhancing Multilingual Accessibility in Healthcare?

OBJECTIVE: To explore the capabilities of ChatGPT for the purpose of simplifying and translating radiology reports into Spanish, Hindi, and Russian languages, with comparisons to its performance in simplifying to the English language. METHODS: 50 deidentified abdomen-pelvis CT reports were fed to ChatGPT (4.0), instructing it to simplify and translate the report. The processed reports were rated on factual correctness (I), potential harmful errors (II), completeness (III), and explanation of medical terms (IV). The translated versions were also rated on the quality of translation (V). The scores in each category were compared between the translated versions and each translated version was compared with the English version in the first four categories. The original reports and the simplified English reports were rated on the Flesch Reading Ease Score (FRES) and the Flesch Kincaid Grade Level (FKRL). RESULTS: The Spanish translation outperformed the Hindi and Russian version significantly in categories I and III (p<0.05). All translated versions performed significantly worse compared to the English version in category IV (p<0.001). Notably, the Hindi translated version performed significantly worse in all 4 categories (p<0.05). The Russian translated version was also significantly worse in category III (p<0.05). In the first three categories, the Spanish translation, and the Russian translation in the first two categories demonstrated no statistically significant difference from the English version. No statistically significant difference was observed in the FRES and FKRL of the simplified English reports. Typographical errors in the original reports negatively affected the translation. CONCLUSION: ChatGPT demonstrates potential ability in translating reports and communicating pertinent clinical information with limited errors. More training and tailoring are required for languages that are not as commonly used in medical literature. LLMs can be used for translating and simplifying radiology reports, potentially improving access to healthcare, and helping reduce healthcare costs.

The Emerging Role of FDG PET/CT in Diagnosing Endocarditis and Cardiac Device Infection.

Infective endocarditis and cardiac implantable electronic device infection (CIEDI) have witnessed an increasing incidence in clinical practice and associated with increasing health care expenditure. Expanding indications of CIED in various cardiovascular conditions have also contributed to the surge of these infections. Early diagnosis of these infections is associated with a favorable prognosis. Given the lack of a single definitive diagnostic method and the limitations of echocardiography, which is considered a central diagnostic imaging modality, additional imaging modalities are required. Recent studies have highlighted the diagnostic utility of FDG PET and CT. In this review article, we discuss the existing limitations of echocardiography, acquisition protocols of PET/CT, and indications of these advanced imaging modalities in infective endocarditis and CIEDI diagnosis.

Mesenteric Tuberculosis Masquerading as Carcinoid Tumor on Conventional Imaging and DOTANOC Positron Emission Tomography/Computed Tomography: Uncommon Presentation of a Common Disease.

Carcinoid tumor of the mesentery has a classical imaging morphology. A specific diagnosis can often be provided on the basis of clinical history, elevated serum neuroendocrine markers, and uptake on somatostatin receptor-based radiotracer studies. Although a number of inflammatory and neoplastic conditions may mimic carcinoid tumor on many of these modalities, uptake on 68Ga-DOTANOC positron emission tomography/computed tomography (PET/CT) is considered specific. We report a case of a 28-year-old male presenting with a mesenteric mass along with elevated serum neuroendocrine markers and uptake on DOTANOC PET/CT, all suggestive of carcinoid tumor. However, the histopathologic examination after surgical resection revealed necrotizing granulomas consistent with tuberculosis (TB). This case highlights the great masquerader that TB can be and stresses the importance of keeping a high index of suspicion for TB, especially in endemic areas.

Ewing's Sarcoma of Scapula: a Rare Case Report.

Neoplasms arising from scapula are rare. We herein, present a rare case of Ewing's sarcoma of scapula in a 9-year-old male child. Extensive literature search reveals that less than 20 similar cases have been reported so far. The index case had been treated with multimodal therapies-chemotherapy, surgery, and radiotherapy. This case is reported to highlight the rarity of the case and discuss the review of literature comprehensively.

A Rare Case of Synchronous Papillary Microcarcinoma and Metastatic Neuroendocrine Tumor of Unknown Primary.

Thyroid papillary microcarcinomas (PMCs) usually follow a very benign clinical course and are rarely metastatic. Any case of PMC presenting with distant metastases without any rising thyroglobulin level should be suspected to have any other primary apart from the thyroid and a meticulous clinical and diagnostic approach should be considered to identify the second primary. We hereby present a case of 52-year-old female treated as PMC with metastatic liver lesion, which was initially thought to be of thyroidal origin. Later, it was diagnosed as a metastatic neuroendocrine tumor of unknown primary.

Active Leprosy Neuritis Detected on FDG PET/CT.

Uses of FDG PET/CT have been previously documented in multiple series in peripheral nerve pathologies, including neurolymphomatosis, peripheral nerve sheath tumor, and plexopathies. We present the case of a 24-year-old man with leprosy neuritis who underwent FDG PET/CT. We suggest that FDG PET/CT can be used as an adjunct tool to monitor neuritis in leprosy patients.

Simple Predictor of Minute Ventilation: Holliday-Segar Revisited.

BACKGROUND: Minute ventilation (MV) and calorific requirement (CR) are both functions of metabolic demand. The Holliday-Segar formula is a weight-based tool for predicting CR. This study was performed to derive an equation, based on the Holliday-Segar formula, for calculating resting MV from body-weight (BW), which is applicable for all age groups. METHODS: MV for BW (obtained from Radford normogram) was plotted against CR for BW (as per Holliday-Segar formula), for BWs ranging from neonates to adults. From the scatter plot thus obtained, best-fit line, with the origin as intercept, was drawn. Linear regression analysis was used to obtain R2 coefficient and P value. RESULTS: The plot of MV against CR yields a straight line passing through the origin with a slope = 46.87. R2 value is 0.98886, P < 0.001. CONCLUSION: MV can be easily and reliably estimated for all age groups from the equation: MV (mL/min) = 47 × CR (kcal/h).

FDG-PET/CT in Skeletal Muscle: Pitfalls and Pathologies.

FDG-PET/CT is an integral part of modern-day practice of medicine. By detecting increased cellular metabolism, FDG-PET/CT can help us detect infection, inflammatory disorders, or tumors, and also help us in prognostication of patients. However, one of the most important challenges is to correctly differentiate the abnormal uptake that is potentially pathologic from the physiological uptake. So while interpreting a PET/CT, one must be aware of normal biodistribution and different physiological variants of FDG uptake. Skeletal muscles constitute a large part of our body mass and one of the major users of glucose. Naturally, they are often the site of increased FDG uptake in a PET study. We as a nuclear medicine physician must be aware of all the pitfalls of increased skeletal muscle uptake to differentiate between physiological and pathologic causes. In this review, we have discussed the different causes and patterns of physiological FDG uptake in skeletal muscles. This knowledge of normal physiological variants of FDG uptake in the skeletal muscles is essential for differentiating pathologic uptake from the physiological ones. Also, we reviewed the role of FDG-PET/CT in various benign and malignant diseases involving skeletal muscle.

Detection of Thymoma on 99mTc MIBI Scintigraphy: Revisiting the Past.

Although thymoma is a rare tumor, it is the most common anterior mediastinal tumor, usually affecting the adults in their fifth and sixth decade. We present a case of 68-year-old man with history of myocardial infarction, who presented to the cardiology OPD with recent onset of exertional dyspnea. On 99mTc MIBI myocardial perfusion SPECT, there was an extra cardiac accumulation of radiotracer in the anterior mediastinum just above the heart, which later was diagnosed as thymoma on histopathology.

18-F-FDG PET-CT in Monitoring of Chemotherapeutic Effect in a Case of Metastatic Hepatic Epithelioid Hemangioendothelioma.

Hepatic epithelioid hemangioendothelioma is a rare variant of mesenchymal tumor. Surgical resection or partial hepatectomy is the treatment of choice in the case of localized disease. However, in metastatic cases, chemotherapeutic drugs targeting the tyrosine kinase are being used. We hereby present 18-F-fludeoxyglucose positron emission tomography-computed tomography findings in a case of a 35-year old woman with metastatic HEHE showing significant response to Sorafenib therapy after 6 months.

Ictal PET in Ohtahara Syndrome With Hemimegalencephaly.

Ohtahara syndrome is one of the causes of infantile epilepsies, which presents with refractory seizures and characteristic EEG changes. It is often associated with structural anomalies in the brain. We report a case of 5-month-old girl with Ohtahara syndrome with hemimegalencephaly who presented with refractory seizures and ictal FDG PET/CT helped in localizing the seizure focus.

Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Disseminated Cryptococcosis.

Disseminated cryptococcosis without pulmonary involvement is a very rare phenomenon. Patterns of organ involvement in cryptococcosis resemble various other infective conditions as well as malignant conditions on fluorodeoxyglucose positron emission tomography-computed tomography. We present a case of a 43-year-old male patient who had disseminated cryptococcosis. The rarity of the case being noninvolvement of lungs and meninges and resembling more like lymphoma due to the diffuse involvement of the lymph nodes on both sides of the diaphragm.

In Vivo Demonstration of PSMA Expression in Adenocarcinoma Urinary Bladder Using 68Ga-PSMA 11 PET/CT.

In vitro and in vivo studies have demonstrated prostate-specific membrane antigen (PSMA) expression in various malignant and benign tumors. Based on the recent immunohistochemical study showing PSMA expression in adenocarcinoma of urinary bladder, we hypothesized that PSMA expression in adenocarcinoma of urinary bladder can be demonstrated in vivo using Ga-PSMA 11 PET/CT. We present a man with exstrophy bladder, presenting with adenocarcinoma urinary bladder referred for staging PET/CT. Both F-FDG and Ga-PSMA-11 PET/CT were done, which showed PSMA expression in the primary tumor as well as metastatic lymph nodes.

Peritoneal Super Scan on 18F - FDG PET-CT in a Patient of Burkitt's Lymphoma.

Peritoneal lymphomatosis is seen less frequently, but when seen, it is mostly associated with aggressive variants of malignancies. FDG uptake has been reported in peritoneal lymphomatosis both in DLBCL and Burkitt's lymphoma. We report a case of Burkitt's lymphoma with involvement of entire peritoneum, which looks like a "peritoneal super scan" on FDG PET-CT.

Incidentally Detected Penile Metastases in a Patient of Carcinoma Urinary Bladder on Follow-up FDG PET/CT.

Penis is an extremely uncommon site for metastases to occur and is often associated with very grave prognosis. Most of the secondary tumors originating in the penis have primaries from prostate, urinary bladder, and gastrointestinal tract. We hereby report a 65-year-old man, known case of carcinoma urinary bladder, who came for FDG PET/CT for metastatic workup. PET/CT study revealed FDG-avid mass lesion in the root and shaft of the penis, making it suggestive of metastases, which was confirmed later by MRI correlation.

Osteomyelitis due to multiple rare infections in a patient with idiopathic CD4 lymphocytopenia.

A 26-year-old male patient presented with features suggestive of osteomyelitis involving the entire left femur, hip joint and knee joint. Culture from the debrided tissue grew Acinetobacter spp. and he was treated with sensitivity based antibiotics but the symptoms did not resolve. The synovial biopsy showed multinucleated giant cells and acid fast bacilli on Ziehl Neelsen stain. Cartridge based nucleic acid amplification test (GeneXpert) was negative. The Mycobacteria growth indicator tube culture was found to be positive for Mycobacterium abscessus. The patient was started on imipenem, amikacin and macrolide based therapy. There was partial response initially but the patient worsened again. A girdle stone arthroplasty with cemented nail (with tobramycin) insertion after debridement of the infected tissue was done. Potassium hydroxide (KOH) mount from the debridement sample was found to be positive for aseptate hyphae suggestive of mucormycosis. He was treated with liposomal amphotericin B. He was evaluated for immunodeficiency in view of multiple atypical infections and was found to have a low CD4 count. The patient was discharged on amikacin, azithromycin, trimethoprim-sulfamethoxazole and posaconazole. Follow up showed considerable resolution both clinically and radiologically. To our knowledge, this is the first reported case of osteomyelitis with co-infection of Acinetobacter spp., M. abscessus and mucormycetes. We report this case to highlight the possibility of multiple rare infections in patients with immunodeficiency. Also, atypical complicated bone infections, such as Mycobacterium abscessus and mucormycetes might require combined medical and surgical treatment.