Michelle Browne MBBCh, Presenter: Nothing to Disclose

Carmel G. Cronin MBBCh, MRCPI, Abstract Co-Author: Nothing to Disclose

Collette English MBBCh, MMedSc, Abstract Co-Author: Nothing to Disclose

Jennifer NiMhuircheartaigh MBBCh, Abstract Co-Author: Nothing to Disclose

Joseph M. Murphy MBBCh, Abstract Co-Author: Nothing to Disclose

John Francis Bruzzi MBBCh, Abstract Co-Author: Nothing to Disclose

To prospectively evaluate the diagnostic usefulness of thin-slice reconstructions of the pulmonary arteries in routine staging or restaging CT scans in oncology patients for the purpose of detection of clinically unsuspected pulmonary emboli.

In consecutive oncology patients undergoing routine contrast-enhanced CT scans of the thorax for staging or restaging,contiguous thin slice(1mm) reformatted images of the pulmonary arteries were prospectively acquired in addition to routine 5 mm-thick slices.All scans were performed on a 64-slice multidetector CT scanner using a bolus tracking technique that initiated the scan at the phase of optimal pulmonary arterial enhancement.Each study was prospectively analyzed by 2 diagnosic radiologists who noted the presence,number and location of incidental pulmonary emboli.Clinical information regarding cancer type,chemotherapy status,stage of disease and other relevant clinical findings were recorded.A retrospective 6 month radiological follow-up was also performed.

279 patients were included (mean age, 60; age range, 16-88),125 males(45%) and 154 females(55.2%).Cancer types imaged included breast(79), colorectal(37), lymphoma(36), lung (15),ovarian(14), renal cell(13), TCC of bladder(13),melanoma(13),testicular(10),metastatic disease of unknown primary(7) squamous cell carcinoma(7), oesophageal(6) and cervical(6) along with smaller numbers of prostate,pancreatic, laryngeal and thyroid cancer.Clinically unsuspected pulmonary emboli were detected in 15 patients(5.4%).In 6 of these patients(2.1%),the pulmonary emboli were only identifiable on the thin-slice reconstructions and not on the routine 5 mm thick slices.The cancer types in these 15 patients were colorectal cancer (4),transitional cell carcinoma of the bladder(2), metastatic disease of unknown primary (2),oesophageal cancer (2),pancreatic cancer(1)and malignant melanoma(1),ovarian cancer(1),lymphoma(1) and renal cell carcinoma(1).Follow-up CT scans showed that a failure to initiate anticoagulation was associated with recurrent pulmonary emboli.

Thin-slice reconstructions of routine CT thorax, abdomen and pelvis can detect PE's that are not identifiable on standard slice thickness of 5mm.

Clinically unsuspected pulmonary emboli occur in oncology patients undergoing routine staging or restaging CT scans and their detection often requires the acquisition of thin-slice CT images.

Browne, M, Cronin, C, English, C, NiMhuircheartaigh, J, Murphy, J, Bruzzi, J, Detection of Clinically Unsuspected Pulmonary Emboli in Oncology Patients: Diagnostic Usefulness of Systematic Thin-Slice Reconstructions of the Pulmonary Arteries during Routine Staging and Restaging CT.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6008177.html