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Letter from the Editors: Radionuclide Imaging in Acute Care
Volume 43, Number 2
] 2013
Letter from the Editors: Radionuclide Imaging in Acute Care
I
t has been a decade since we last devoted an issue of Seminars to the subject of the role of Nuclear Medicine in acute care.1 Many of the clinical areas discussed then remain relatively similar but they have benefited from enhanced knowledge and experience. It is important to keep in mind that several of these areas of acute care radionuclide procedures represent a considerable portion of our daily routine practice and have evolved into standard of care studies. These include hepatobiliary scintigraphy for acute cholecystitis, gastrointestinal bleeding studies, ventilation-perfusion lung imaging for pulmonary embolism and radionuclide confirmation of brain death. One area that has achieved enhanced usage during the past decade is resting myocardial perfusion studies to triage patients with chest pain and determine if they may have acute coronary syndrome requiring hospital admission. Conversely it makes possible a safe discharge of those with negative results. Dr Bob Hendel and his colleagues at the University of Miami have been strong proponents of this methodology and make an excellent case for its efficacy.2 Commitment to this program requires 24/7 availability of physicians, nurses, and technologists. The relative roles of ventilation-perfusion (V/Q) scintigraphy and computed tomographic pulmonary angiography (CTPA) in diagnosing pulmonary embolism (PE) have long been a controversial area for us. There is general agreement as well as a burgeoning number of articles and editorials citing the over diagnosis and over treatment of PE.3,4 It is clear that small PEs, in particular, are managed differently in the U.S. as compared to other countries. Almost all positive CTPA or V/Q studies in the U.S. will be followed by anticoagulant therapy whereas this is not necessarily the case elsewhere where small PEs in low-risk patients will be monitored without aggressive treatment. Associated with this over diagnosis issue is the concern about radiation exposure from CTPA; particularly to the female breast.5 At Montefiore Medical Center, we have conclusively shown that the V/Q study is associated with a very similar false-negative rate to CTPA.6 For the past 6 years, we have followed an
0001-2998/12/$ - see front matter & 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1053/j.semnuclmed.2012.12.002
algorithm whereby a negative chest x-ray is followed by V/Q while a positive chest x-ray is sent for a CTPA. This practice of ‘‘outcome’’ rather than ‘‘accuracy’’ medicine has served us well. Drs Onyedika, Glaser, and Freeman review this experience.7 The use of brain scintigraphy for confirming brain death has evolved from using nonlipophilic blood-brain barrier radiotracers, such as 99mTc-DTPA to lipophilic agents that cross the blood-brain barrier, eg 99mTc-HMPAO and 99mTcECD. These latter agents allow one to evaluate blood flow distribution within the brain rather than the flow only studied with the nonlipophilic agents. Drs Zuckier and Sogbein review the current state of these brain perfusion studies.8 Many of the adult procedures referred to have applicability to children, as well. Several other areas of clinical concern, such as bleeding Meckel diverticulum and focal or diffuse functional renal cortical damage occur more frequently in the pediatric population. Dr Martin Charron and his colleagues at the Toronto Hospital for Sick Children provide us with a detailed discussion of how nuclear medicine facilitates diagnosis of these acute care problems in children.9 Completing this acute care issue are excellent reviews of radionuclide methodology in infection by our colleagues Drs Charito Love and Chris Palestro,10 acute GI disorders by Drs Allen and Tulckinsky,11 and renal transplants and obstruction by the father-daughter physician team of George and Efrosyni Sfakianakis.12 Hopefully our readers will benefit from these articles as they may use the information in their own practices. Leonard M. Freeman, MD M. Donald Blaufox, MD, PhD
References 1. Emergency nuclear medicine procedures. Semin Nucl Med 2003;33(4) 2. Ghutak A, Hendel RC: Role of imaging for acute chest pain syndromes 2013;43;71–81. 3. Burge AJ, Freeman KD, Klapper PJ, et al: Increased diagnosis of pulmonary embolism without a corresponding decline in mortality during the CT era. Clin Radiol 2008;63:381-386
69
70 4. Hoffman JR, Cooper RJ: Over diagnosis of disease: A modern epidemic. Arch Intern Med 2012;172:1123 5. Parker MD, Hui FK, Comacho MA: Female breast radiation-exposure during CT pulmonary angiography. AJR Am J Roentgenol 2005;185: 1228-1231 6. Stein EG, Haramati LB, Chamarthy M, et al: Success of a safe and simple algorithm to reduce use of CT angiography in the emergency department. AJR Am J Roentgenol 2010;194:392-397 7. Onyedika C, Glaser J, Freeman LM: Pulmonary embolism: Role of ventilation-perfusion scintigraphy. Semin Nucl Med 2013;43:82-87
L.M. Freeman and M. Donald Blaufox 8. Zuckier LS, Sogbein BO: Brain perfusion studies in the evaluation of acute neurologic abnormalities. Semin Nucl Med 2013;43:129-138 9. Shammas A, Vali R, Charron M: Pediatric nuclear medicine in acute care. Semin Nucl Med 2013;43:139-156 10. Love C, Palestro CJ: Radionuclide imaging of inflammation and infection in the acute care setting. Semin Nucl Med 2013;43:102-113 11. Sfakianakis E, Sfakianakis G: Renal scintigraphy in the acute care setting. Semin Nucl Med 2013;43:114-128 12. Allen TW, Tulckinsky M: Nuclear medicine tests for acute gastrointestinal conditions. Semin Nucl Med 2013;43:88-101
] 2013
Letter from the Editors: Radionuclide Imaging in Acute Care
I
t has been a decade since we last devoted an issue of Seminars to the subject of the role of Nuclear Medicine in acute care.1 Many of the clinical areas discussed then remain relatively similar but they have benefited from enhanced knowledge and experience. It is important to keep in mind that several of these areas of acute care radionuclide procedures represent a considerable portion of our daily routine practice and have evolved into standard of care studies. These include hepatobiliary scintigraphy for acute cholecystitis, gastrointestinal bleeding studies, ventilation-perfusion lung imaging for pulmonary embolism and radionuclide confirmation of brain death. One area that has achieved enhanced usage during the past decade is resting myocardial perfusion studies to triage patients with chest pain and determine if they may have acute coronary syndrome requiring hospital admission. Conversely it makes possible a safe discharge of those with negative results. Dr Bob Hendel and his colleagues at the University of Miami have been strong proponents of this methodology and make an excellent case for its efficacy.2 Commitment to this program requires 24/7 availability of physicians, nurses, and technologists. The relative roles of ventilation-perfusion (V/Q) scintigraphy and computed tomographic pulmonary angiography (CTPA) in diagnosing pulmonary embolism (PE) have long been a controversial area for us. There is general agreement as well as a burgeoning number of articles and editorials citing the over diagnosis and over treatment of PE.3,4 It is clear that small PEs, in particular, are managed differently in the U.S. as compared to other countries. Almost all positive CTPA or V/Q studies in the U.S. will be followed by anticoagulant therapy whereas this is not necessarily the case elsewhere where small PEs in low-risk patients will be monitored without aggressive treatment. Associated with this over diagnosis issue is the concern about radiation exposure from CTPA; particularly to the female breast.5 At Montefiore Medical Center, we have conclusively shown that the V/Q study is associated with a very similar false-negative rate to CTPA.6 For the past 6 years, we have followed an
0001-2998/12/$ - see front matter & 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1053/j.semnuclmed.2012.12.002
algorithm whereby a negative chest x-ray is followed by V/Q while a positive chest x-ray is sent for a CTPA. This practice of ‘‘outcome’’ rather than ‘‘accuracy’’ medicine has served us well. Drs Onyedika, Glaser, and Freeman review this experience.7 The use of brain scintigraphy for confirming brain death has evolved from using nonlipophilic blood-brain barrier radiotracers, such as 99mTc-DTPA to lipophilic agents that cross the blood-brain barrier, eg 99mTc-HMPAO and 99mTcECD. These latter agents allow one to evaluate blood flow distribution within the brain rather than the flow only studied with the nonlipophilic agents. Drs Zuckier and Sogbein review the current state of these brain perfusion studies.8 Many of the adult procedures referred to have applicability to children, as well. Several other areas of clinical concern, such as bleeding Meckel diverticulum and focal or diffuse functional renal cortical damage occur more frequently in the pediatric population. Dr Martin Charron and his colleagues at the Toronto Hospital for Sick Children provide us with a detailed discussion of how nuclear medicine facilitates diagnosis of these acute care problems in children.9 Completing this acute care issue are excellent reviews of radionuclide methodology in infection by our colleagues Drs Charito Love and Chris Palestro,10 acute GI disorders by Drs Allen and Tulckinsky,11 and renal transplants and obstruction by the father-daughter physician team of George and Efrosyni Sfakianakis.12 Hopefully our readers will benefit from these articles as they may use the information in their own practices. Leonard M. Freeman, MD M. Donald Blaufox, MD, PhD
References 1. Emergency nuclear medicine procedures. Semin Nucl Med 2003;33(4) 2. Ghutak A, Hendel RC: Role of imaging for acute chest pain syndromes 2013;43;71–81. 3. Burge AJ, Freeman KD, Klapper PJ, et al: Increased diagnosis of pulmonary embolism without a corresponding decline in mortality during the CT era. Clin Radiol 2008;63:381-386
69
70 4. Hoffman JR, Cooper RJ: Over diagnosis of disease: A modern epidemic. Arch Intern Med 2012;172:1123 5. Parker MD, Hui FK, Comacho MA: Female breast radiation-exposure during CT pulmonary angiography. AJR Am J Roentgenol 2005;185: 1228-1231 6. Stein EG, Haramati LB, Chamarthy M, et al: Success of a safe and simple algorithm to reduce use of CT angiography in the emergency department. AJR Am J Roentgenol 2010;194:392-397 7. Onyedika C, Glaser J, Freeman LM: Pulmonary embolism: Role of ventilation-perfusion scintigraphy. Semin Nucl Med 2013;43:82-87
L.M. Freeman and M. Donald Blaufox 8. Zuckier LS, Sogbein BO: Brain perfusion studies in the evaluation of acute neurologic abnormalities. Semin Nucl Med 2013;43:129-138 9. Shammas A, Vali R, Charron M: Pediatric nuclear medicine in acute care. Semin Nucl Med 2013;43:139-156 10. Love C, Palestro CJ: Radionuclide imaging of inflammation and infection in the acute care setting. Semin Nucl Med 2013;43:102-113 11. Sfakianakis E, Sfakianakis G: Renal scintigraphy in the acute care setting. Semin Nucl Med 2013;43:114-128 12. Allen TW, Tulckinsky M: Nuclear medicine tests for acute gastrointestinal conditions. Semin Nucl Med 2013;43:88-101