Quantitative SPECT/CT parameters of myocardial 99mTechnetium-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) uptake in suspected cardiac transthyretin amyloidosis.

BACKGROUND: 99mTc-labelled bisphosphonates are used for imaging assessment of patients with transthyretin cardiac amyloidosis (ATTR). Present study evaluates whether quantitative SPECT/CT measurement of absolute myocardial 99mTc-labelled 3,3-diphosphono-1,2-propanodicarboxylic acid (Tc-DPD) uptake can diagnose patients with suspected ATTR. METHODS: Twenty-eight patients (25 male, age 80.03 ± 6.99 years) with suspected ATTR referred for Tc-DPD imaging had planar and SPECT/CT imaging of the chest. Three operators independently obtained Tc-DPD myocardial SUVmax and SUVmean above threshold (SMaT) (20, 40 and 60% of SUVmax), using a semi-automated threshold segmentation method. Results were compared to visual grading (0-3) of cardiac uptake. RESULTS: Twenty-two patients (78%) had cardiac uptake (2 grade 1, 15 grade 2, 5 grade 3). SUVmax and SMaT segmentation thresholds enabled separating grades 2/3 from 0/1 with excellent inter- and intra-reader correlation. Cut-off values 6.0, 2.5, 3 and 4 for SUVmax, SMaT20,40,60, respectively, separated between grades 2/3 and 0 /1 with PPV and NPV of 100%. SMaT20,40,60(cardiac)/SUVmean (liver) and SMaT20,40,60(cardiac)/SUVmean(liver/lung) separated grades 2 and 3. CONCLUSION: Quantitative SPECT/CT parameters of cardiac Tc-DPD uptake are robust, enabling separation of patients with grades 2 and 3 cardiac uptake from grades 0 and 1. Larger patient cohorts will determine the incremental value of SPECT/CT quantification for ATTR management.

Postoperative changes after surgical mesh hernia repair: a pitfall in interpretation of 18F-FDG PET-CT.

OBJECTIVE: A number of case reports have demonstrated FDG uptake around mesh prostheses after hernia repair surgery. This study characterizes FDG PET-CT findings after hernia repair with synthetic mesh in a series of cancer patients. MATERIALS AND METHODS: FDG PET-CT studies were reviewed for increased FDG uptake consistent with CT appearances of post-surgical hernia repair in cancer patients. The findings were correlated with clinical data and follow-up studies. RESULTS: 53 PET-CT studies in 22 patients (18 males, 31-79 years) were identified. Surgery for repair of inguinal (n = 14), ventral (n = 5) or umbilical (n = 3) hernia was performed, 4-204 months prior to PET-CT. FDG avidity was focal or linear in the region of the anterior abdominal or pelvic wall (mean SUV max 4.0 ± 2.3). Corresponding nonspecific CT findings included soft tissue thickening (n = 18), fat infiltration (n = 20) and fluid collection (n = 19) in the region of the omentum, adjacent to or in the inner abdominal or pelvic wall at the surgical site. Linear hyper-dense structures (n = 9) or metallic clips (n = 8) seen on CT suggested benign postoperative changes. In 10/12 (83.3%) patients with repeat PET-CT, FDG uptake remained unchanged, one showed more diffuse uptake and another showed reduced uptake on follow-up. There was neither significant change in CT appearance at the surgical site in these 12 patients, nor in 3 additional patients with only CT follow-up. Another 3 patients had previous CT demonstrating hernia at the same location. CONCLUSION: With increasing use of synthetic mesh, awareness of variations in FDG PET-CT appearance is important to avoid false interpretation in cancer patients.

PET/CT detects abdominal wall and port site metastases of colorectal carcinoma.

Abdominal wall metastases from colorectal cancer (CRC) may be resected with curative results. Such lesions, often indicators of additional intra-abdominal lesions, may appear in surgical scars, stomas and port site metastases after laparoscope-assisted surgery (LAS). Post-operative changes, primarily surgical scars, alter local physical findings making early detection of small lesions challenging. The purpose of this study was to retrospectively evaluate the contribution of PET/CT to the diagnosis of recurrent colorectal cancer in the post-operative abdominal wall. 120 patients were referred for PET/CT with suspected recurrent CRC based on clinical, radiological or laboratory findings. All underwent whole body PET/CT imaging. 12 of these 120 (10%), were found to have abdominal wall lesions. A total of 16 abdominal wall lesions were detected, located to surgical scars, stomas, drain and laparoscope ports. Additional findings on PET/CT in this group included liver metastases, intra-abdominal lesions and retroperitoneal lymph node involvement. In general, the patients in this small group were young with high grade tumours presenting in advanced stages. In conclusion, PET/CT appears to be a sensitive tool for the diagnosis of abdominal wall recurrence of CRC. The accuracy of localization afforded by the fused functional and anatomic images makes PET/CT a likely tool for diagnosing abdominal wall lesions, including port site metastases of other aetiologies.

PET/CT in the evaluation of response to treatment of liver metastases from colorectal cancer with bevacizumab and irinotecan.

The present approach at our institution for the treatment of patients with colorectal (CRC) cancer and with liver metastases planned for metastasectomy is the neoadjuvant administration of Bevacizumab with Irinotecan based therapy. Metabolic imaging of tumor viability with 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET), and simultaneous anatomic localization provided by low-dose non-enhanced computed tomography (CT), can be obtained in a combined modality FDG-PET/CT scan. The purpose of this study was to evaluate the possible contribution of FDG-PET/CT as a surrogate marker to evaluate treatment response of liver metastases in vivo. This is a retrospective evaluation of 18F-FDG PET and CT findings in the first seven consecutive patients. FDG-PET/CT scans were performed before the start of the neoadjuvant and after four cycles of therapy, just prior to surgery. Results were compared to concurrent contrast-enhanced CT, when required, and pathology. Response to treatment was determined according to RECIST size criteria obtained from data from thin (3-5mm) slice CT, and changes in uptake of 18F-FDG uptake on PET. A total of 20 liver lesions were evaluated in seven patients. Overall, 6/7 patients had favorable response to treatment, and only one had progression of disease. One patient was found to be inoperable at surgery. Biopsy was obtained in 1/4 lesions in this patient, while pathology was unable for the remaining three lesions. As such, pathologic validation of findings was available for 17/20 lesions. Complete response (CR) was evident on FDG-PET in 10/17 (58%) lesions, whereas only 4/17(23%) were deemed CR by CT. Similarly, only 1/17 (6%) lesion appeared stable by FDG-PET criteria, whereas three (18%) were termed stable disease (SD) according to size on CT. FDG-PET findings correlated better than CT with pathology, and were more indicative of pathology. Overall PET/CT correctly predicted necrosis at pathology in 70% vs. 35% by CT. Our results suggest that 18F-FDG PET may be instrumental for predicting the pathologic response to Bevacizumab based therapy.

PET/CT in the evaluation of patients with squamous cell cancer of the head and neck.

The purpose of this study was to compare the findings of positron emission tomography (PET) with fused PET and computed tomography (CT) in patients with suspected locoregional and distant head and neck cancer and to evaluate the impact of those findings on clinical management. Studies of 25 patients were retrospectively evaluated. PET findings were classified as malignant, benign or equivocal. PET/CT findings were then similarly classified and the PET-only results were amended accordingly. Comparison of findings was done on lesion and patient levels. A total of 45 foci of increased 18F-fluorodeoxyglucose (FDG) uptake were noted in 18 patients. PET/CT imaging defined anatomic localization of 41/45 lesions and clarified 6/10 equivocal PET findings. Additional information was provided by PET/CT regarding 9/45 (20%) of the lesions. PET/CT significantly affected patient management in 3/25 patients (12%) by limiting the extent of disease in one and excluding viable disease in two others. The accuracy of PET/CT was 88%, the sensitivity 100% and the specificity was 77%. The negative predictive value was 100% in this combined group of patients with locoregional and distant head and neck cancer. PET/CT is highly contributory for initial staging and in the evaluation of patients with suspected recurrent SCC of the head and neck, in whom anatomic imaging is inconclusive due to the locoregional distortions rendered by surgery and radiotherapy.

Relaxation dynamics of a single DNA molecule.

The relaxation of a single DNA molecule is studied. The experimental system consists of optical tweezers and a micron-sized bead that is tethered to the bottom of the sample by a single double-stranded DNA molecule. The bead slows down the DNA relaxation from a strongly stretched configuration such that it is passing through stretched equilibrium states. This allows for a theoretical description of the relaxation trajectory, which is in good agreement with experiment.

The role of gamma-PET in the evaluation of patients with recurrent squamous cell cancer of the head and neck.

Squamous cell carcinoma (SCC) is the most common cancer of the head and neck (HNC). Advanced HNC warrants extensive ablative and reconstructive procedures, significantly altering locoregional anatomy, while radiation treatment further adds to the distortion. Anatomic imaging is therefore often inconclusive in suspected recurrent HNC. Functional imaging with fluorodeoxyglucose-positron emission tomography (FDG-PET) has been reported contributory in the evaluation of patients with SCC. While most reports are from dedicated PET systems, full ring PET is of limited availability and gamma-PET may offer a suitable compromise. The therapeutic impact of gamma-PET in patients with suspected recurrent HNC was retrospectively evaluated. Seventeen patients were evaluated. All had undergone surgery for HNC, 16 also received radiotherapy. gamma-PET scans were compared to anatomic imaging, histopathology and clinical follow-up. The impact of the FDG-PET scan on patient management was then evaluated. Eleven positive findings were confirmed. Two false positives were due to radiation changes, a recognized pitfall. There were no false negatives. Overall accuracy of the 18F-FDG gamma-PET scans was 88% with considerable effect on patient management. Gamma-PET with FDG appears valuable in the evaluation of suspected recurrent HNC, and may provide a suitable alternative when dedicated PET is unavailable.

The clinical impact of 18F-FDG gamma PET in patients with recurrent well differentiated thyroid carcinoma.

The therapeutic approach to recurrent well-differentiated thyroid cancer is based on the detection of active disease. While a measured increase of thyroglobulin level in an ablated patient is highly suggestive of recurrence, localization of the tumour is necessary for adequate treatment planning. A whole body scan with 131I yields false negative results in the presence of non-iodophyllic foci of disease. Hypermetabolic foci of differentiated thyroid carcinoma can be detected by gamma PET with 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG). This study retrospectively evaluated the therapeutic impact of the 18F-FDG scan in patients with suspected recurrent thyroid carcinoma in whom the iodine scan was negative. Twenty patients (five male, 15 female) aged 19-77 years, were suspected of having recurrent thyroid carcinoma due to elevated thyroglobulin levels and/or palpable neck findings. All whole body iodine scans obtained with diagnostic doses (74-148 MBq (2-4 mCi) of 131I), were reported normal, i.e., no iodophyllic foci were detected. Whole body gamma positron emission tomography (PET) imaging was performed in fasting patients following i.v. administration of 370 MBq (10 mCi) 18F-FDG, with a strict 1 h immobilization post-injection. Gamma PET results were validated either by anatomical imaging, repeat iodine scanning after administration of a therapeutic dose (at least 3,700 MBq (100 mCi) of 131I) or surgery. The impact of the FDG scan on patient management was evaluated by the referring physicians. Positive gamma PET results confirmed the presence of active disease in 14/15 patients. One false positive finding (fibrosis) and one false negative (carcinoid) were reported. Localization of hypermetabolic foci supported treatment decisions in 10 patients, and significantly altered therapeutic management in six others. Treatment was withheld in four patients with negative findings. The clinical impact of the scan in this patient group is similar to that reported in the literature and justifies its future implementation.

Fatal liver infarction after transjugular intrahepatic portosystemic shunt procedure.

Hepatic infarction is a rare disease. We describe here a cirrhotic patient with end-stage renal failure and recurrent tense ascites with fatal hepatic infarction after transjugular intrahepatic portosystemic shunt (TIPS) procedure. Abdominal ultrasound, radionuclide liver scan, abdominal computed tomography scan, and finally liver biopsy established the diagnosis. The mechanism causing the infarct is not clear. However, as the infarct appeared after the patient had an episode of shock and disseminated intravascular coagulation, it could well be that the concomitant hepatic arterial insufficiency contributed to the infarct. Physicians should be aware of this possible catastrophic complication.

Synoviorthesis with radioactive Yttrium in haemophilia: Israel experience.

Radioactive Yttrium-90 (90Y) was injected into 163 joints. Of these patients 115 were persons with haemophilia and they suffered from recurrent haemarthroses. The median age at the time of the initial exposure to 90Y was between 11 and 15 years and the median follow-up period 11 years. Over 80% of the patients with haemophilia reported a decrease in the number of haemarthroses and 15% stopped bleeding altogether in the treated articulation. The safety of this modality of management has been reported and hence the patients age should not be regarded as a criteria.

Bilateral accessory iliac horns: pathognomonic findings in Nail-patella syndrome. Scintigraphic evidence on bone scan.

Nail-patella syndrome is a rare hereditary (autosomal dominant) disorder, also called hereditary osteo-onychodysplasia and Fong's syndrome. Its incidence is 4.5 per million population in the United States. Patients have a characteristic tetrad of pathologic symptoms including fingernail dysplasia, hypoplastic or absent patellas, radial head dislocation, and iliac horns. Soft-tissue changes and renal dysplasia have also been associated with the syndrome. Iliac horns are bilateral accessory outgrowths consisting of cortex and medulla continuous with the iliac bone. They are located at the site of attachment of the gluteus medius muscles and project posterolaterally. These smooth bony outgrowths are asymptomatic, frequently palpable, and, because they have no effect on gait, they need not be treated. Iliac horns are the pathognomonic feature of Nail-patella syndrome; that is, they occur in approximately 80% of cases and are observed only in this condition. Four patients (two female, two male) with Nail-patella syndrome have been examined in the authors' department: three family members, including a 37-year-old woman, her 18-year-old son, and her 15-year-old daughter, and an unrelated 26-year-old man. All patients, regardless of age or sex, had similar pelvic findings on their bone scans. Although whole-body scans were obtained in all patients, significant scintigraphic findings were observed only in the pelvis in all the patients examined. This is most likely the result of the mild nature of the related deformities, which do not yield scintigraphically detectable osteoblastic changes. A representative image showing these independent ossification on a Tc-99m MDP bone scan is presented. A conventional pelvic radiographic image of the same patient's pelvis is presented for comparison.

Evidence for striatal modulation in the presence of fixed cortical injury in obsessive-compulsive disorder (OCD).

A patient with obsessive-compulsive disorder (OCD) onset resulting from a traumatic head injury underwent longitudinal brain imaging evaluation. Structural and functional brain imaging studies were repeatedly performed before and after treatment. Computerized tomography (CT) demonstrated bilateral prefrontal contusions immediately following the trauma and prior to the onset of OCD. Magnetic resonance imaging (MRI) demonstrated bilateral cortical abnormalities in the prefrontal and anterior-temporal regions a few months following the onset of OCD. Almost concurrently, single photon emission computerised tomography (SPECT) demonstrated bilateral perfusion deficits in fronto-temporal regions, and asymmetric increased perfusion in the anterior striatum. Six months later, after clinical improvement, a second SPECT study demonstrated improvement of brain perfusion, mostly in the striatum. The reflection of these results on a possible model of brain pathogenesis in OCD, and the role of brain imaging in neuropsychiatric evaluation, are demonstrated.

Non-union of undisplaced radial neck fracture in a rheumatoid patient.

Non-union of an undisplaced fracture of the radial neck in a rheumatoid patient is presented. Possible causes are discussed, and the literature reviewed.

Parkinsonian syndrome complicating systemic lupus erythematosus.

Two girls with florid extrapyramidal parkinsonism complicating systemic lupus erythematosus (SLE) are reported. One patient (15 years old) presented with extreme rigidity, irritability, and mutism initially diagnosed as acute psychosis. Examination revealed severe extrapyramidal akinetic mutism, along with marked restlessness. CT and MRI imaging of the brain were unremarkable. EEG revealed moderate generalized disturbance of background activity. 99mTc-HmPAO SPECT cerebral scanning detected decreased regional cerebral blood flow at the basal ganglia. Dopamine-agonist drugs led to complete recovery after 3 months, along with normalization of EEG and SPECT alterations. The second patient (16 years old) was assessed for progressive bradykinesia and apathy impeding her active daily activities, and she was suspected to have developed depression. Neurologic assessment revealed a parkinsonian syndrome that was less severe than that of the first patient. The EEG showed mild disturbance of background activity, and 99mTc-HmPAO SPECT demonstrated impaired regional cerebral blood flow over the basal ganglia. A parkinsonian extrapyramidal syndrome complicating SLE should therefore be taken into account in any patient with SLE presenting with marked behavioral alterations, rigidity, or akinetic mutism.

[Massive pulmonary embolism--summary of experiences with 13 patients].

Pulmonary embolism is a common event in hospitalized patients. In some cases it presents with hemodynamic collapse, indicating massive obliteration of the pulmonary vasculature and has a very grim prognosis; 2/3 of such patients die within 2 hours of onset of symptoms. We describe our experience in 13 patients with massive pulmonary embolism. An aggressive diagnostic and therapeutic approach, utilizing sophisticated imaging techniques, thrombolytic therapy and surgery, led to the survival of 8 of the patients. Our experience supports an aggressive approach in these seriously ill patients.

Littoral cell angioma: a vascular tumor mimicking a solid tumor on a Tc-99m-red blood cell spleen scan.

A splenic space occupying lesion, in a 45-year-old woman, was negative in a Tc-99m-RBC spleen scan. A diagnostic splenectomy was performed and the lesion was found to be a vascular tumor, lately identified as littoral cell angioma. The histological and immunohistochemical findings are discussed in correlation with the imaging results.

[Multidisciplinary approach to the treatment of musculo-skeletal tumors].

Tumors of the musculoskeletal system are relatively rare. They occur mostly in the young, while in older age groups metastases and myeloma are more prevalent. Treatment has undergone major change in the past 20 years with the introduction of neoadjuvant treatment protocols. According to recent reports 5-year survival rates have increased from 20% to 60-70%. These new protocols involve the use of modern imaging modalities, immunohistochemical pathological analysis and improved surgical technics. This has required establishment of multidisciplinary teams of experts to escort the patient through all the steps of current treatment.

Bilateral femoral stress fractures in a child due to in-line (roller) skating.

We report a child who presented with a limp following 6 weeks of strenuous roller skating. Directed X-rays on admission were normal but a 99mTc-methylene diphosphanate bone scan demonstrated increased uptake in the mid-thirds of the femurs compatible with grade IV stress fracture. Immediate abstention from roller skating for 5 weeks resulted in a complete cure. The "new" side effect of this increasingly popular sport is discussed with regard to paediatric stress fractures and to other roller skating-associated injuries.