Jerry Stern

Lung scintigraphy in pulmonary capillary hemangiomatosis. A rare disorder causing primary pulmonary hypertension.

The authors report the results of lung scintigraphy in two patients with primary pulmonary hypertension caused by pulmonary capillary hemangiomatosis, a rare disorder resulting from the proliferation of histologically normal capillaries in the lung. Perfusion studies revealed a non-homogeneous pattern with some focal defects, similar to that seen with some other histologic types of primary pulmonary hypertension. The mechanisms underlying this perfusion pattern are unknown.

Atypical bisphosphonate-associated subtrochanteric and femoral shaft stress fractures: diagnostic features on bone scan.

A 69-year-old woman presented with a spontaneous right subtrochanteric hip fracture. Pan-imaging following orthopedic repair failed to identify a primary malignancy to explain the presumed pathologic basis for this fracture. The patient then underwent bone scintigraphy and SPECT/CT which showed mild uptake in multifocal endosteal thickening of the lateral left femoral diaphysis, diagnostic of bisphosphonate-associated femoral shaft stress fractures, but no evidence of metastatic bone disease. Atypical bisphosphonate-associated subtrochanteric and femoral shaft stress fractures have a fairly specific appearance on bone scintigraphy, and nuclear medicine physicians should be aware of this relatively infrequent emerging pathology.

Spectrum of malignant renal and urinary bladder tumors on 18F-FDG PET/CT: a pictorial essay☆

A wide variety of malignant renal and urinary bladder diseases can be detected on (18)F-FDG PET/CT. Although the PET/CT findings are often nonspecific, the aim of this atlas was to demonstrate that the spectrum of renal and urinary bladder malignancy that can be evaluated with PET/CT is much broader than current medical literature would suggest. PET/CT readers and oncologists should be aware of the variety of urological tumor types that can be detected on PET/CT and some of the patterns of (18)F-FDG uptake that can be observed in these cases.

Spectrum of Malignant Pleural and Pericardial Disease on FDG PET/CT

OBJECTIVE The purpose of this article is to illustrate a wide spectrum of malignant primary and secondary pleural and pericardial diseases imaged with (18)F-FDG PET/CT. CONCLUSION A wide variety of malignant pleural and pericardial diseases can be detected, staged, and monitored by FDG PET/CT. Although the PET/CT findings are often nonspecific, the aim of this atlas is to show that the spectrum of pleural and pericardial disease that can be evaluated with PET/CT is much broader than current literature would suggest. PET/CT readers and oncologists should be aware of the wide variety of malignancies that can affect the pleura and pericardium and some of the patterns of FDG uptake that can be observed in these cases.

Chronic vascular graft infection with fistula to bone causing vertebral osteomyelitis, imaged with F-18 FDG PET/CT.

Vascular grafts have an infection rate ranging from 1% to 3%. While early infections occur within 4 months after surgery and are associated with virulent organisms, late infections can occur after months to years of surgery and are often caused by low virulence organisms that survive in an adherent biofilm. Host defense recognition of bacterial biofilm can result in perigraft abscesses, aorto-enteric fistulas, and very rarely, fistulas into adjacent bone. We present a case of an 83-year-old man, who had an F-18 FDG PET/CT scan for workup of a solitary pulmonary nodule, and was incidentally diagnosed with chronic multifocal infection of an aorto-iliac vascular graft, with an infected fistula tract into adjacent bone causing chronic vertebral osteomyelitis, which was confirmed with a contrast-enhanced CT. The patient was asymptomatic and not a surgical candidate, and was treated conservatively with a course of antibiotics. This case highlights the utility of F-18 FDG PET/CT in the imaging of chronically infected vascular grafts and in identifying potentially lethal complications such as fistulas into adjacent structures.

Tuberculous synovitis of the hip joint diagnosed by FDG PET-CT.

A 61-year-old woman with a history of lupus had a Positron emission tomography-computed tomography (PET-CT) scan as part of a malignancy workup for new cerebellar lesions. She had presented with new onset headaches. A CT scan of the thorax, abdomen, and pelvis, done 2 months earlier, had only shown an asymptomatic left hip joint effusion that was attributed to a nonerosive synovitis, possibly caused by her lupus. The PET-CT now showed extensive left acetabular and femoral head destructive bone lesions that had progressed significantly in 2 months, with associated intense 18F-fluoro-2-deoxy-glucose (FDG) uptake (maximal SUV 8.7). The left hip joint effusion also had intense FDG uptake. The hip joint was aspirated following the PET scan, and the synovial fluid grew mycobacterium tuberculosis. The PET-CT also showed an enlarged left iliopsoas bursa, which did not have FDG uptake and was therefore probably not infected.

Hepatitis C-Related Primary Effusion Lymphoma of the Pleura and Peritoneum, Imaged With F-18 FDG PET/CT

Primary Effusion Lymphoma (PEL) is a rare form of Non-Hodgkin lymphoma that involves serous body cavities (pleural, pericardial, or peritoneal) with lymphomatous effusions in the absence of lymphadenopathy or organomegaly. Although it was seen mostly in HIV-positive patients, it has recently been reported in HIV-negative patients with chronic Hepatitis B or C infections. PEL is associated with human herpes virus type-8 infection, often presents with rapidly progressive effusions and generally has a poor prognosis. This is a case of a 65-year-old HIV-negative man with Hepatitis C cirrhosis, who presented with abdominal pain. An F-18 FDG PET/CT showed marked ascites and pleural effusions with increased F-18 FDG uptake in the pleura and peritoneum on the left side. Analysis of the cells in the peritoneal fluid revealed a human herpes virus 8-positive PEL of the peritoneum. As a result the patient was no longer considered a liver transplant candidate and died 2 weeks after the diagnosis.

Incidental Early Stage Endometrial Adenocarcinoma Diagnosed by F-18 FDG PET-CT, Which Was Negative on Ultrasound and Nonspecific on MRI

A 65-year-old woman with a history of gastric adenocarcinoma was referred for a follow-up F-18 FDG PET-CT scan. Although there was no evidence of recurrence of her gastric malignancy, there was an incidental finding of mild focal FDG uptake in the mid uterus. This was considered suspicious, especially in a postmenopausal woman, and she was referred for further imaging. Ultrasound did not find any abnormalities, and MRI re- ported a nonspecific focus of mild endometrial thickening. Extensive his- topathological sampling of the endometrium revealed a focus of intramucosal endometrial adenocarcinoma; the patient was diagnosed with Stage IA disease and treated surgically. This case demonstrates the importance of alerting referring physicians to even mildly FDG-avid focal abnormalities of the endometrium of postmenopausal women, despite normal or nonspecific correlative diagnostic imaging results. (Clin Nucl Med 2010;35: 265-266)

False positive high probability V/Q scan due to malignant obstruction of both pulmonary vein and artery.

A 64-year-old woman with known extensive metastatic breast cancer had a V/Q scan for suspicion of pulmonary embolism. The scan was interpreted as high probability. Due to the discordant clinical status and significant presumed clot burden, the patient underwent a pulmonary CT angiogram (CTA). No arterial embolus was seen and the perfusion defects were found to be caused by malignant obstruction of the left lower lobe pulmonary vein and right pulmonary artery. This high probability ventilation and perfusion (V/Q) scan was therefore a false positive scan for the detection of pulmonary embolus. (Clin Nucl Med 2009;34: 367–370) REFERENCES 1. Mallin WH, Silberstein EB, Shipley RT, et al. Fibrosing mediastinitis causing nonvisualization of one lung on pulmonary scintigraphy. Clin Nucl Med. 1993;18:594–596. 2. Park HM, Jay SJ, Brandt MJ, et al. Pulmonary scintigraphy in fibrosing mediastinitis due to histoplasmosis. J Nucl Med. 1981;22:349–351. 3. Bailey CL, Channick RN, Auger WR, et al. “High probability” perfusion lung scans in pulmonary venoocclusive disease. Am J Respir Crit Care Med. 2000;162:1974–1978. 4. PIOPED investigators. Value of the Ventilation/Perfusion scan in Acute Pulmonary Embolism. JAMA. 1990;263:2753–2759. 5. van Strijen MJ, de Monye W, Kieft GJ, et al. Diagnosis of pulmonary embolism with spiral CT as a second procedure following scintigraphy. Eur Radiol. 2003;13:1501–1507. 6. Mendelson S, Train J, Goldstein S, et al. Ventilation-Perfusion mismatch due to obstruction of pulmonary vein. J Nucl Med. 1981;22:1062–1063. 7. Stanley DC, Cho SR, Tisnado J, et al. Pulmonary arteriography in patients with hilar or mediastinal masses and lung scans suggesting pulmonary embolism. South Med J. 1981;74:960–964, 967. 8. Shields JJ, Cho KJ, Geisinger KR. Pulmonary artery constriction by mediastinal lymphoma simulating pulmonary embolus. AJR. 1980;135:147–150. Received for publication November 12, 2008; revision accepted February 18, 2009. From the Departments of *Nuclear Medicine, and †Radiology, Jewish General Hospital, Montréal, Québec, Canada. Reprints: Gad Abikhzer, MDCM, Department of Nuclear Medicine, Jewish General Hospital, 3755 Côte-Sainte-Catherine Road, Montréal, Québec, Canada H3T 1E2. E-mail: gad101@hotmail.com. Copyright

Observations on Tc-99m-erythrocyte venography in normal subjects and in patients with deep vein thrombosis

Blood pool imaging of the lower limbs with Tc-99m-erythrocytes demonstrates the deep venous channels of the leg. The radionuclide image of deep vein thrombosis, by this method, appears sufficiently distinctive to suggest that Tc-99m-erythrocyte venography may be a useful screening examination for deep vein patency.