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Basidiobolomycosis is a rare curable fungal infection caused by the saprophytic fungus Basidiobolus ranarum. It often causes skin infections but rarely infects visceral tissues in humans. Gastrointestinal basidiobolomycosis is an emerging form, which is rare but is increasingly reported. Due to its ability to mimic more common diagnoses such as chronic inflammatory disorders and malignancies, Basidiobolomycosis imposes a diagnostic challenge on most physicians. Therefore, a timely and correct diagnosis by laboratory tests and careful review of images along with proper medical management can save patients from invasive treatments and reduce both morbidity and mortality. Here, we present a rare case of an 8-year-old boy with basidiobolomycosis initially misdiagnosed as rhabdomyosarcoma. We aim to highlight basidiobolomycosis as a potential differential from masses on imaging under the right clinical circumstances and to provide radiologists with key imaging details to help recognize this infectious etiology and reduce its associated morbidity.

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Primary CNS vasculitis is an inflammatory brain disease commonly misdiagnosed affecting the medium and small vessels of the CNS. Due to its broad and non-specific clinical and radiological manifestations; Its diagnosis remains challenging. New diagnostic tools and biomarkers which increase specificity and facilitate the diagnosis for patients with suspected vasculitis are highly desirable to enable physicians to start therapy that can alter its potential aggressive course like immunosuppressant. This case report highlights the potential role of 18F-choline PET/MRI as a novel imaging tool that might help in the right clinical scenario in the diagnosis of this disease. Furthermore, it speculates on its secondary role in monitoring the response to immunosuppressant therapy.

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BACKGROUND: There is variable cardiac uptake observed on oncological ¹8F-fludeoxyglucose ([¹8F]FDG) positron emission/computed tomography (PET/CT). The main purpose of this study is to evaluate patterns of overnight fasting myocardial [¹8F]FDG uptake in oncological PET/CT and analyse the relationship between myocardial [¹8F]FDG uptake and myocardial ischaemia on stress single-photon emission CT (SPECT) myocardial perfusion imaging (MPI). MATERIAL AND METHODS: A total of 362 subjects underwent both oncological PET/CT and stress SPECT MPI within 3 months of each other. Subjects with focal-mass-like [¹8F]FDG myocardial uptake raising the suspicion of cardiac metastasis and subjects with coronary artery disease (CAD) were excluded. The myocardial [18F]FDG uptake was classified into four patterns. RESULTS: Abnormal SPECT MPI was noted in 91 (25%) patients; 220 (61%) patients had completely absent [18F]FDG uptake, 80 (22%) had diffuse [¹8F]FDG uptake, 39 (11%) had focal on diffuse [¹8F]FDG uptake, and 23 (6%) had focal or regional myocardial [¹8F]FDG uptake, the regional [¹8F]FDG myocardial uptake was the most predictive of myocardial ischaemia on SPECT MPI, and there were positive associations between age, sex, hypertension, tobacco smoking, hypercholesterolemia, and left ventricular ejection, a fair agreement was noted between the focal or regional FDG uptake and presence of ischaemia on SPECT, K = 0.394 (95% CI 0.164 to 0.189). CONCLUSIONS: Based on the presented findings, the physiological myocardial [¹8F]FDG uptake in fasting oncology patients is variable. The regional myocardial [¹8F]FDG uptake pattern is the most frequent pattern associated with myocardial ischaemia on stress SPECT MPI, however, the agreement between regional FDG uptake and presence of ischaemia on SPECT is fair.

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The most prevalent primary malignancy of the liver is hepatocellular carcinoma (HCC); its poor prognosis is mainly related to intrahepatic recurrence and extrahepatic metastases. However, survival from HCC has improved due to better control of the primary tumor, the development of newer treatment modalities, including liver transplant, together with advances in imaging techniques. Therefore, the significance of patient management as corresponds with distant metastases has increased; since the proper evaluation and detection of extrahepatic metastases is crucial to optimize potential therapy for patients. Conventional imaging like CT, MRI play crucial rule in patient's diagnosis and qualifying for a certain type of therapy. More recently, a molecular imaging tool with radiolabeled deoxyglucose and fluorocholine has proved its promising value as a complementary tool to conventional studies. In this review, the frequent sites of metastases and HCC spread are discussed as well as the imaging findings as seen by both conventional imaging techniques and by molecular imaging tools, namely 18F-Choline PET/CT, and FDG PET. The implications of guiding treatment planning have also been discussed.

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A 69-year-old male patient who had a history of well-differentiated hepatocellular carcinoma (HCC) post right hepatectomy presented a year later with iron-deficiency anemia. His anemia work-up included upper endoscopy that revealed multiple gastric polyp a biopsy from the largest demonstrated metastatic hepatocellular carcinoma. His magnetic resonance imaging (MRI) showed a gastric "polyp" without evidence of local HCC recurrence within the liver. His subsequent dual imaging with Choline/fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) confirmed the gastric metastases and in addition revealed other sites of unexpected metastatic disease in the right adrenal and the bone that was asymptomatic. Patient was started on sorafenib and currently he is alive one-and-half-year postdetection of his metastatic disease under palliative care. This case showed that the possibility of gastric metastases should be kept in mind when confronted with anemia in HCC patient and also highlight the complementary role of molecular imaging modality along with MRI in the metastatic work-up for hepatocellular carcinoma postcurative resection.

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OBJECTIVE/BACKGROUND: To evaluate the efficacy and outcome of adding low-dose fractionated radiotherapy (LDFRT) to induction chemotherapy plus concurrent chemoradiation in locally advanced nasopharyngeal carcinoma (LANPC). METHODS: A single-institute, phase II-III, prospectively controlled randomized clinical trial was performed at King Faisal Specialist Hospital and Research Centre. Patients aged 18-70 years with WHO type II and III, stage III-IVB nasopharyngeal carcinoma, Eastern Cooperative Oncology Group performance score of 0-2, with adequate hematological, renal, and hepatic function were eligible. In total, 108 patients were enrolled in this trial. All patients received two cycles of induction docetaxel and cisplatin (75 mg/m2 each) chemotherapy on Days 1 and 22, followed by concurrent chemoradiation therapy. Radiation therapy consisted of 70 Gy in 33 fractions, with concurrent cisplatin 25 mg/m2 for 4 days on Days 43 and 64. Patients were randomly assigned to either adding LDFRT (0.5 Gy twice daily 6 hours apart for 2 days) to induction chemotherapy in the experimental arm (54 patients) or induction chemotherapy alone in the control arm (54 patients). RESULTS: There was no significant difference in the post-induction response rates (RRs) or in toxicity between the two treatment arms. The 3-year overall survival (OS), locoregional control (LRC), and distant metastases-free survival (DMFS) rates for experimental arm and control arm were 94% versus 93% (p = .8), 84.8% versus 87.5% (p = .58), and 84.1% versus 91.6% (p = .25), respectively. CONCLUSION: The results showed no benefit from adding LDFRT to induction chemotherapy in terms of RR, OS, LRC, and DMFS.

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Whole-body 18F-fluorodeoxyglucose positron emission tomography (PET) has been used extensively in the last decade for the primary staging and restaging and to assess response to therapy in these patients. We aim to discuss the diagnostic performance of PET/computed tomography in the initial staging of breast carcinoma including the locally advanced disease and to illustrate its role in restaging the disease and in the assessment of response to therapy, particularly after the neoadjuvant chemotherapy. Causes of common pitfalls during image interpretations will be also discussed.

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A 35-year-old man presented with significant weight loss of 30 kg over the previous 6 months, with newly diagnosed diabetes. Routine laboratory tests were normal, except for markedly elevated blood glucose. Computed tomography (CT) of the abdomen revealed a large severely enhanced mass replacing most of the pancreas and liver metastatic nodules and multiple paraaortic lymph node metastases, 18F-fluorodeoxygluocse positron emission tomography/computed tomography (18F-FDG PET/CT) was performed and revealed mild FDG uptake in the pancreatic mass, as well as mild uptake in the liver and lymph node metastases. A biopsy of the liver metastasis was consistent glucagonoma that was confirmed with markedly elevated serum glucagon level. Subsequently, 68Ga-DOTATATE PET/CT was performed for better tumor characterization and for assessment of the tumors' response to therapy, 68Ga-DOTATATE scan revealed intense uptake in the pancreatic mass, liver metastases, and paraaortic lymph node metastases. The patient responded well to peptide receptor radionuclide therapy. This case highlights the role of both 68Ga-DOTATATE and 18FDG-PET/CT in the diagnosis and management of a glucagonoma. 68Ga-DOTATATE is the tracer of choice for well-differentiated glucagonoma and offers very high diagnostic accuracy as compared with that of cross-sectional and other functional imaging and enables correct patient selection for peptide receptor radionuclide therapy.

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Rapidly progressive interstitial lung disease is typically associated with clinically amyopathic dermatomyositis and the anti-melanoma differentiation associated gene 5 antibody, a condition with high mortality and resistance to classic immunosuppression. Recent reports have described the efficacy of the Janus kinase inhibitor tofacitinib in the treatment of rapidly progressive interstitial lung disease in anti-melanoma differentiation associated gene 5 antibody-positive clinically amyopathic dermatomyositis. It is uncertain, however, whether tofacitinib alters the course of rapidly progressive interstitial lung disease in other variants of dermatomyositis that are unrelated to the anti-melanoma differentiation associated gene 5 antibody and whether the early addition of the anti-fibrotic tyrosine kinase inhibitor nintedanib interferes with the development of fibrosis. To answer these questions, we present and discuss the case of an elderly woman who presented with a flare of dermatomyositis sine myositis. Based upon the detection of anti-Jo-1 antibodies and the absence of anti-melanoma differentiation associated gene 5 antibodies, anti-synthetase syndrome was diagnosed. While the cutaneous manifestations quickly resolved with prednisone, azathioprine and tacrolimus, the respiratory function paradoxically and rapidly deteriorated, and invoked the use of tofacitinib. Markedly raised ferritin levels and a severe numerical deficiency of circulating natural killer cells paralleled the acute lung inflammation, which was reflected by 18F-fluorodeoxyglucose hypermetabolism on positron emission tomography/CT. Tofacitinib lead to a prompt clinical recovery, with a reduction in oxygen requirement, correction of hyperferritinemia, reversal of the natural killer cell deficiency, and a decrease in 18F-fluorodeoxyglucose uptake in the affected lung segments. Subsequently, nintedanib was added at a point in time when inflammation subsided. Apart from cytomegalovirus reactivation no adverse events occurred. In conclusion, tofacitinib reversed the pronounced inflammatory component of anti-Jo-1 antibody-positive, anti-melanoma differentiation associated gene 5 antibody-negative rapidly progressive interstitial lung disease, confirming that Janus kinase signaling pathways are critically involved in the pathogenesis of rapidly progressive interstitial lung disease, apparently independently of the targeted autoantigen. Although some improvement in pulmonary function was observed, it seems premature to conclusively judge on reversibility or prevention of pulmonary fibrosis by pairing both kinase inhibitors for which an extended follow-up and ideally, prospective and controlled studies are needed.

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There have been little and conflicting data regarding the relationship between coronary artery calcification score (CACS) and myocardial ischemia on positron emission tomography myocardial perfusion imaging (PET MPI). The aims of this study were to investigate the relationship between myocardial ischemia on PET MPI and CACS, the frequency and severity of CACS in patients with normal PET MPI, and to determine the optimal CACS cutoff point for abnormal PET. This retrospective study included 363 patients who underwent same-setting stress PET perfusion imaging and CACS scan because of clinically suspected coronary artery disease (CAD). Fifty-five (55%) of the 363 patients had abnormal PET perfusion. There was an association between sex, diabetes mellitus (DM), smoking, and CACS and PET perfusion abnormities with P = 0.003, 0.05, 0.005, and 0.001, respectively. However, there was no association between PET perfusion abnormalities with age, body mass index, hypertension, and hypercholesterolemia. There was association between CACS and age, sex, and DM with P = 0.000, 0.014, and 0.052, respectively, and stepwise increase in the frequency of myocardial ischemia and CACS groups. Receiver-operating characteristic analysis showed that a CACS ≥304 is the optimal cutoff for predicting perfusion abnormalities with sensitivity of 64% and specificity of 69%. In conclusion, the frequency of CAC in patients with normal PET MPI is 49%, it is highly recommended to combine CACS with PET MPI in patients without a history of CAD. PET MPI identifies myocardial ischemia and defines the need for coronary revascularization, but CAC reflects the anatomic burden of coronary atherosclerosis. Combining CACS to PET MPI allows better risk stratification and identifies high-risk patients with PET, and it may change future follow-up recommendations. CACS scan is readily available and easily acquired with modern PET-computed tomography (CT) and single-photon emission CT (SPECT)-CT with modest radiation exposure.

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Gastrointestinal Bleeding Scintigraphy (GIBS) of 99mTc-labelled red blood cells is a relatively simple examination to perform, with high diagnostic accuracy and a relatively lower radiation dose. A positive scan can either suggest surgery without further investigation or can indicate angiography, a more targeted procedure. Whipple pancreatoduodenectomy is most often performed for tumors of the head of the pancreas. Pancreatoduodenectomy has 30%-40% morbidity and mortality, and while post-pancreatoduodenectomy hemorrhage is seen in less than 10% of patients, it accounts for 11%-38% mortality. The role of imaging in patients to detect relative hemodynamic stability is essential. Computed tomography angiography (CTA) shows the cause, site, and nature of bleeding, while digital subtraction angiography (DSA) has a diagnostic as well as a therapeutic role. We present a patient who presented with active gastrointestinal bleeding (GI) bleeding after undergoing a Whipple procedure, to highlight the role of GIBS in the successful localization of a bleeding site and the guidance of digital DSA in the embolization and control of the active bleeding.

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Fluorodeoxyglucose (FDG)-positron emission tomography-computed tomography (PET-CT) has been playing a pivotal role in tumor imaging for the past 20 years. Head and neck (HN) cancers are a good example that can illustrate such unique role of FDG imaging contributing to the patient's management. In this review article, we will describe the normal physiological distribution of FDG within HN structures focusing on its limitations and pitfalls. In addition, we will be also describing its role in the initial staging and restaging of the disease, particularly with regard to therapy response assessment. Furthermore, its role in the evaluation of patients with malignant cervical adenopathy from an unknown primary will be described. In 2016, the Royal College of Radiologists in its third edition published evidence-based guidelines for PET-CT use in HN cancer emphasizing its rule in all these clinical scenarios that are being described in this review. Finally, we will be highlighting future directions in the field of molecular imaging of HN tumors with a special emphasis on the new PET tracers.

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PURPOSE: Although the overall incidence of bone metastasis is not known, over one-half of the people who die of cancer in the USA every year are thought to have bone involvement. In this study we have developed a method to quantify the metabolic and anatomic changes induced by different types of bone metastases in cancer patients using PET/CT images. PATIENTS AND MATERIALS: Seventy-three cancer patients with no previous history of chemotherapy or radiotherapy who had definite bone metastases documented by PET/CT and other conventional modalities were selected for this study. PET and computed tomography (CT) images were resampled to the same pixel size. Thereafter, the bone structure was segmented using thresholding. The 50% of the maximum standardized uptake value within the bone mask was used to identify bone lesions in each slice. Using the final regions of interest defined at 70% of the maximum, the lesion characteristics including the mean Hounsfield Units were computed from the PET/CT images. The lesions were subjected to visual confirmation by an experienced physician who also categorized them on the basis of the appearances in CT as lytic, sclerotic, mixed, or no-change type. The lesion characteristics were compared using statistical methods. RESULTS: In all, 340 bony lesions in 73 patients with different cancer types were analyzed. The lesions were further categorized into four groups on the basis of their anatomical location. The spine hosts the largest number of lesions. The lumbar bones are the most preferential sites within the spine. Statistical comparison of CT values indicated that the difference between no-change and lytic types was significant. Uptake period did not seem to have a significant impact on no-change and sclerotic types. Quantitatively, maximum standardized uptake value for lytic, no change, mixed, and sclerotic lesions were 7.4, 6.1, 8.2, and 7.2, respectively. CONCLUSION: A quantitative method provides a convenient way that may serve as a useful tool in monitoring and assessing the response to therapy.

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PURPOSE: The aim of this study was to evaluate the efficacy of fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) compared with bone scan in detecting bone metastases in patients with head and neck cancer. MATERIALS AND METHODS: A total of 319 patients with head and neck cancer were identified in our database who had undergone F-FDG PET/CT, from January 2006 until June 2007. Of them 156 patients (age range 15-100 years) met our inclusion criteria - namely, biopsy-proven head and neck cancer, and bone scan and F-FDG PET/CT within 30 days. Comparison was made on a lesion-by-lesion analysis. MRI, multidetector CT, and the clinical course of the patients were our references. RESULTS: F-FDG PET/CT identified (n=213) bone lesions in 18 patients, in addition to distant metastases in solid organs such as the liver and lung, lymphadenopathy above and below the diaphragm, and adrenal glands in 12 patients. However, bone scan identified (n=198) 16 patients. Bone scan missed two patients with confirmed bone metastases by means of biopsy in one patient and radiologically in the second. F-FDG PET/CT showed true-positive results in 18 patients, whereas bone scan showed true-positive results in 16 patients. F-FDG PET/CT showed true-negative results in 138 patients, whereas bone scan showed true-negative results in 134 patients. F-FDG PET/CT showed no false-positive or false-negative results. However, bone scan had two false-positive and two false-negative results. The overall sensitivity, specificity, and accuracy was 100% for F-FDG PET/CT and 88, 98, and 96%, respectively, for bone scan. CONCLUSION: F-FDG PET/CT is superior to Tc-methylene diphosphonate bone scan in detecting bone metastases in head and neck cancer.

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BACKGROUND AND OBJECTIVES: 18F-FDG PET yields physiologic information that allows for identifying cancer based on altered tissue metabolism. The aim of this study was to prospectively validate the predictive value of positron emission tomography (PET) in squamous cell carcinoma (SCC) of the esophagus treated by pre-operative chemotherapy followed by esophagectomy. DESIGN AND SETTING: Prospective efficacy and toxicity study of patients enrolled between January 1999 and September 2003. PATIENTS AND METHODS: Twenty-one patients with SCC of the esophagus who were potentially resectable underwent 18F-FDG PET imaging before the first cycle of neoadjuvant chemotherapy and at least 14 days after the third cycle. A patient was classified as a metabolic responder when the metabolic activity of the primary tumor as measured by the maximum standardized uptake values had decreased by 50% or more at the time of the second 18F-FDG PET. RESULTS: The median age of the study cohort was 60 years with a range of 39-70 years; 12 patients were males and 9 were females. 18F-FDG PET had increased activity in the primary tumor in all patients. Metabolic response occurred in 14/21 patients (66%), while 7/21 (33%) patients did not show a metabolic response. Metabolic responders had a high clinical response rate (92%), a median progression free survival (PFS) of 16.4 months and a median overall survival (OS) of 35.3 months. In contrast, prognosis was poor for metabolic non-responders with a clinical response rate of 42% (P=.025), a median PFS of 7.13 months (P=.032) and median OS of 12 months (P=.038). CONCLUSION: Our results demonstrate that changes in tumor metabolic activity after neoadjuvant chemotherapy predicts PFS and OS in esophageal SCC patients.

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OBJECTIVES: The objective of the study was to compare F-18-fluorodeoxyglucose position emission tomography (FDG-PET) with diagnostic whole body scanning (DxWBS) and post-ablation radioiodine whole body scanning (TxWBS) and to assess its prognostic value in newly diagnosed differentiated thyroid cancer (DTC) patients, hypothesizing that FDG-PET is more likely to disclose locoregional and distant metastases. PATIENTS AND METHODS: DxWBS and FDG-PET scanning were performed in 26 newly diagnosed DTC patients who underwent thyroidectomy and TxWBS in 24 cases who had radioactive iodine ablation. The results of the FDG-PET scans were correlated with the stage of the disease and the long-term outcome of DTC. RESULTS: Overall, 18 FDG-PET scans (69.2%) were positive showing a total of 40 foci while 8 scans (30.8%) were negative. The corresponding 26 DxWBS were all positive and showed a total of 47 foci. DxWBS and TxWBS showed similar foci in the 24 patients who had ablation therapy. In contrast to the FDG-PET scans that showed uptake of 26 foci (65%) outside the thyroid bed, 45 foci (95.7%) on DxWBS were in the thyroid bed while 2 foci (4.3%) were in cervical lymph nodes and no focus was seen outside the neck area (P=0.000). There was a clear correlation between the FDG-PET results, the stage of the disease and long-term outcome; seven of the eight negative FDG-PET scans were in stage 1, while all patients with disease higher than stage 1 (six patients) had positive scans. Over a median of 30 months (10-48), seven out of eight patients (87.5%) with negative FDG-PET scans were in remission compared with only eight patients (44.4%) with positive FDG-PET (P=0.04). CONCLUSIONS: In the postoperative evaluation of DTC, compared with DxWBS and TxWBS, FDG-PET scans are more likely to reveal uptake outside the thyroid bed and to correlate with the stage of the disease and long-term outcome.

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