Niall Sheehy

Clinical, Radiographic, and Biochemical Characterization of Multiple Myeloma Patients with Osteonecrosis of the Jaw

Purpose: Osteonecrosis of the jaw (ONJ) has been reported in patients with a history of aminobisphosphonate use. This study was conducted in order to define ONJ clinically and radiographically and gain insights into its pathophysiology. Experimental Design: Eleven multiple myeloma (MM) patients with ONJ were included in the study. Patients underwent clinical, biochemical, radiographic, and molecular profiling. Ten MM patients on aminobisphosphonates without ONJ and five healthy volunteers were used as controls for biochemical and molecular studies. Results: MM patients with ONJ were treated with either pamidronate (n = 3), zoledronate (n = 4), or both agents sequentially (n = 4) for a mean of 38.7 months. Radiographic studies showed bone sclerosis and fragmentation on plain films and computerized tomography. Quantitative regional analysis of NaF-PET and FDG-PET scans confirmed an increased standardized uptake value (SUVmax) in areas of ONJ. The target to background ratio of SUVmax was significantly greater for NaF-PET compared with FDG-PET scan. Biochemical bone marker data and transcriptional profiling studies showed that genes and proteins involved in osteoblast and osteoclast signaling cascades were significantly down-regulated in patients with ONJ. Conclusions: ONJ was associated with a mean duration of 38.7 months of aminobisphosphonate exposure. Radiographic and functional imaging confirmed sites of clinically established ONJ. Gene and protein studies are consistent with altered bone remodeling, evidenced by suppression of both bone resorption and formation.

Dental panoramic radiographic evaluation in bisphosphonate-associated osteonecrosis of the jaws

OBJECTIVES To determine the extent to which clinical and radiographic features of bisphosphonate-associated osteonecrosis of the jaw (BONJ) are correlated. DESIGN Retrospective case review. METHODS The records of 39 patients diagnosed with BONJ and examined by panoramic radiography were retrospectively evaluated. The arches were divided into sextants (n = 234) and evaluated for the following signs: sclerosis, surface irregularity, sockets, fragmentation and lysis. MAIN OUTCOME MEASURES The McNemar, Kruskall-Wallis and equivalency tests were performed to analyze the association between clinical and radiographic signs and BONJ severity. RESULTS Sixty-two out of 234 sextants were abnormal by clinical criteria and 61 out of 234 sextants demonstrated at least one radiographic abnormality. There was agreement between clinical and radiographic detection in 41 sextants. The data showed equivalency between BONJ diagnosis and both sclerosis and surface irregularity. The correlation between number of clinical sites and any radiographic finding was significant in the maxilla (P < 0.001) but not in the mandible (P = 0.178). The total number of radiographic signs per patient increased with BONJ stage. CONCLUSION Focal panoramic radiographic findings of sclerosis and surface irregularity correlate with clinical sites of BONJ. This may be a useful and reliable tool to detect early changes of BONJ or to confirm a clinical diagnosis.

Positron emission tomography/computed tomography imaging in Merkel cell carcinoma: A study of 270 scans in 97 patients at the Dana-Farber/Brigham and Women's Cancer Center

BACKGROUND Merkel cell carcinoma (MCC) is a rare and lethal cutaneous neuroendocrine carcinoma. Imaging is crucial for accurate staging, which remains a strong predictor of survival, as well as earlier detection of recurrence and progression, which are common despite aggressive management. There is no consensus on the role of initial and subsequent imaging for MCC. OBJECTIVE We sought to evaluate the use of 2-fluoro-[(18)F]-deoxy-2-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in the management of MCC. METHODS In all, 270 FDG-PET/CT studies were performed in 97 patients with pathology-proven MCC at the Dana-Farber/Brigham and Womens Cancer Center, Boston, Mass, from August 2003 to December 2010. RESULTS FDG-PET/CT scans were obtained as part of the initial (61 scans in 61 patients) and subsequent (209 scans in 79 patients) treatment strategies. MCCs were FDG-avid with a mean maximum standardized uptake value of primary lesions of 6.5 (range 1.3-12.9) and a mean maximum standardized uptake value of regional and distant metastases of 7.2 (range 1.5-9.9). FDG-PET/CT upstaged 16% of patients who underwent baseline scans. FDG-PET/CT studies showed that bone and bone-marrow metastases were more common than previously reported, and were often undetected by CT. LIMITATIONS Our study is limited by its retrospective design, and potential referral bias associated with a tertiary care center. CONCLUSIONS FDG-PET/CT performed as part of the initial management strategy tended to upstage patients with more advanced disease. FDG-PET/CT performed as part of the subsequent treatment strategy identified metastatic disease, particularly in bone/bone marrow, which was not seen on CT. FDG-PET/CT imaging is a valuable staging and restaging tool in MCC management.

Pediatric 99mTc-MDP Bone SPECT with Ordered Subset Expectation Maximization Iterative Reconstruction with Isotropic 3D Resolution Recovery

PURPOSE To perform a preliminary evaluation of the image quality of pediatric technetium 99m ((99m)Tc) methylene diphosphonate (MDP) bone single photon emission computed tomography (SPECT) by using iterative reconstruction-ordered subset expectation maximization with three-dimensional resolution recovery (OSEM-3D)-and to assess whether any improvements with use of this technique could lead to a reduction in patient dose or a shortening in imaging time. MATERIALS AND METHODS Institutional advisory board approval was obtained for this investigation. Fifty (99m)Tc-MDP SPECT studies of the spine were evaluated (36 female and 14 male patients; mean age, 15.5 years). Each study was acquired by using a dual-detector camera, with each detector rotating 360°. By using filtered back projection (FBP) and OSEM-3D, images were reconstructed from data generated by both detectors. Likewise, OSEM-3D was used to reconstruct data from a single detector simulating half the administered radiopharmaceutical activity. Two nuclear medicine physicians, blinded to the patient data, reviewed the images for image quality in four different categories by using a four-point scale: artifacts (category 1), lesions (category 2), noise (category 3), and image sharpness (category 4). RESULTS Compared with FBP, images reconstructed by using OSEM-3D with one or two detectors showed significant improvement in image quality with regard to lesion detection, noise level, and image sharpness (P < .02, .01, and .001, respectively). With OSEM-3D, no significant differences were observed when either one or two detectors were used. CONCLUSION Improved image quality of skeletal SPECT with either a 50% reduction in radiation dose or a 50% reduction in acquisition time or combination of the two can be achieved by using OSEM-3D.

Statins and neuroprotection

The beneficial effect of β-hydroxy-β-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) in primary prevention of coronary artery disease in those with hypercholesterolaemia and in secondary prevention in those with established coronary vascular disease are now well known. A growing body of evidence suggests that statins also possess important additional clinical benefits, such as stroke risk reduction. In this article we review the evidence that statins may be neuroprotective, especially in the brain parenchyma during stroke. We also review the observational data that statins may prevent the onset of dementia.

Hodgkins disease presenting with granulomatous angiitis of the central nervous system.

Sirs: A 52-year-old non-smoking man with a background of non-insulin dependent diabetes mellitus (NIDDM) was admitted to hospital after a witnessed generalized tonicclonic convulsion. He had been feeling unwell for several months and his family reported that his personality had changed and he had become very withdrawn. His general practitioner had started him on venlafaxine for this one week prior to admission. He had been diagnosed with NIDDM five years previously which was well controlled with metformin. He did not have documented nephropathy, neuropathy, retinopathy or symptomatic vascular disease. He was on no other medications except aspirin. On admission he was confused and was noted to have an enlarged right supraclavicular lymph node. Otherwise neurological examination was normal. In the first few days following admission he had two witnessed events in which he went suddenly pale and stared into the distance for about two minutes with smacking movements of his lips. These complex partial seizures were controlled with carbamazepine. His confusion persisted after admission, the mental status examination revealing abnormalities in attention and concentration. Routine haematology and biochemistry were normal. The ESR and CRP were raised at 21 mm/hr and 2.8 mg/dl respectively. An autoantibody screen was negative. His CSF showed a lymphocytic pleocytosis, elevated protein and a normal glucose, CSF cytology showed mature lymphocytes and PCR for herpes simplex was negative. He was HIV negative. Lymph node biopsy revealed nodular sclerosing Hodgkin’s disease. Computed tomography (CT) showed bulky nodes in his mediastinum and retroperitoneum. Bone marrow examination was normal. Magnetic resonance imaging of his brain showed extensive confluent white matter changes. There was no enhancement with contrast. It was felt that the patient might have a chronic atypical infectious process such as progressive multifocal Leucencephalopathy which might be exacerbated by immunosuppressive chemotherapy. Open wedge brain biopsy of the right frontal lobe was performed and revealed granulomatous angiitis in the gray and white matter and the meninges. The patient was initiated on a chemotherapeutic regimen involving high doses of steroids. He has had no further seizures and his confusion has resolved. Repeat CT of his thorax and abdomen have shown partial resolution of his lymphadenopathy. Granulomatous angiitis of the CNS (GANS), first reported in 1957, involves the small and medium vessels of the brain or spinal cord. The aetiology is unknown but it has been associated with herpes zoster, HIV, sarcoid, non-Hodgkin’s lymphoma and Hodgkin’s disease. The clinical presentation of GANS is diverse and can include encephalopathy, seizures, headache, malaise, stroke and haemorrhage. Systemic symptoms are usually absent. The diagnosis of GANS is difficult. Findings LETTER TO THE EDITORS

Ultrasonographically guided percutaneous embolization of a pulmonary pseudoaneurysm.

Pulmonary pseudoaneurysms have been described as an unusual complication of Swan-Ganz catheter placement, tuberculosis, bronchiectasis, aspergillomas, and pulmonary hypertension. Untreated, they may lead to life-threatening hemorrhage. Coil embolization to occlude the pseudoaneurysms is the treatment of choice. This report describes a case in which a pulmonary pseudoaneurysm that likely resulted from the previous use of a Swan-Ganz catheter was identified but in which angiography failed to demonstrate a feeding vessel. The pseudoaneurysm was visible by transthoracic ultrasonography because it was surrounded by consolidated lung, possibly related to hemorrhage. Ultrasonography was used to guide puncture of the pseudoaneurysm, and percutaneous coil embolization was performed subsequently. Subsequent angiography and computed tomography demonstrated successful occlusion of the aneurysm. This case illustrates the utility of percutaneous management of pulmonary pseudoaneurysms in certain cases.

Imaging features of extrapulmonary small cell carcinoma

Small cell carcinoma accounts for approximately 20% of lung cancers; however, it rarely occurs at other sites. Extrapulmonary small cell carcinoma (EPSCC) is notoriously aggressive with a strong propensity for both regional and distant spread. The majority of the literature on these uncommon tumours is from a clinicopathological viewpoint with a relative paucity of detail regarding the radiological findings. This review will focus on the imaging features of EPSCC in its predominant sites of origin: the gastrointestinal tract, genitourinary tract, head, neck, and breast. We will also discuss the role of positron-emission tomography (PET)/computed tomography (CT) in the staging of EPSCC.

Contrast-enhanced MR angiography of subclavian steal syndrome: value of the 2D time-of-flight "localizer" sign.

OBJECTIVE Our objective was to determine if direction of flow within the vertebral artery could be reliably determined by evaluation of flow-sensitive, low-resolution 2D time-of-flight (TOF) localizer images taken before 3D contrast-enhanced MR angiography (3D CEMRA) sequences in patients with unsuspected subclavian steal syndrome. CONCLUSION Vertebral artery patency on 3D CEMRA in cases in which the vessel is absent on the TOF localizer in association with ipsilateral subclavian artery stenosis indicates reversal of flow in the vertebral artery and confirms the subclavian steal phenomenon. The combination of anatomic imaging with 3D CEMRA with functional information provided by the low-resolution TOF localizer confirms the diagnosis of subclavian steal without additional imaging.

Neurosyphilis presenting with unusual hippocampal abnormalities on magnetic resonance imaging and positron emission tomography scans: a case report

IntroductionThe incidence of neurosyphilis has declined markedly since the introduction of penicillin therapy. While there are a number of case reports in the literature of neurosyphilis causing focal decreased 18F-fluorodeoxyglucose uptake on positron emission tomography/computed tomography scans, to the best of our knowledge this is the first published report of neurosyphilis presenting with intensely increased 18F-fluorodeoxyglucose uptake in the hippocampus.Case presentationA 55-year-old Caucasian man presented to our facility with acute collapse against a background of memory difficulties over the previous six months. The results of his initial physical examination were normal. He scored 24 out of 30 on the Montreal Cognitive Assessment test. A magnetic resonance imaging scan of his brain revealed high T2 signal intensity and atrophy within the right frontal area in addition to high T2 signal intensity in the bilateral mesial temporal areas. Blood and cerebrospinal fluid analysis revealed an active syphilis infection. An 18F-fluorodeoxyglucose positron emission tomography brain scan showed intensely increased 18F-fluorodeoxyglucose uptake limited to the head of the right hippocampus. He responded to penicillin treatment with an improvement in his cognition, which was further reflected in a complete resolution of the findings previously seen on magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography scans.ConclusionsDiagnosis of neurosyphilis can be difficult, as many patients are either asymptomatic or present with non-specific symptoms such as memory disturbance or seizures. This report highlights the importance of considering neurosyphilis in the differential diagnosis when mesiotemporal changes are seen on magnetic resonance imaging or 18F-fluorodeoxyglucose positron emission tomography scans.