Jerry W. Froelich

ACR Guidance Document for Safe MR Practices: 2007

E. Kanal is a consultant for, is a member of the speakers bureau of, and provides research support for Bracco Diagnostics and GE Healthcare; is a member of the speakers bureau of and provides research support for Siemens Medical Solutions; and provides research support for Berlex and Medtronic. T. Gilk is a consultant for Mednovus, Inc. J. R. Gimbel provides research support for St. Jude Medical, Medtronic, and Biotronik. J. Nyenhuis is a consultant for and provides research support to Medtronics. J. Weinreb is a consultant and member of the speakers bureau for GE Healthcare.

ACR guidance document on MR safe practices: 2013

Because there are many potential risks in the MR environment and reports of adverse incidents involving patients, equipment and personnel, the need for a guidance document on MR safe practices emerged. Initially published in 2002, the ACR MR Safe Practices Guidelines established de facto industry standards for safe and responsible practices in clinical and research MR environments. As the MR industry changes the document is reviewed, modified and updated. The most recent version will reflect these changes. J. Magn. Reson. Imaging 2013;37:501–530.

Eigenimage filtering in MR imaging.

This article presents the technical aspects of a linear filter, referred to as eigenimage filtering, and its applications in magnetic resonance (MR) imaging. The technique is used to obtain a single composite image depicting a particular feature of interest while suppressing one or more interfering features. The appropriate weighting components to be used in the linear filter are determined on the criterion that the desired feature is enhanced while the interfering features are suppressed. The criterion is expressed mathematically as a ratio. By applying Rayleighs principle, the ratio is maximized by finding the eigenvector associated with the maximum eigenvalue of the corresponding generalized eigenvalue problem. The appropriate weighting factors for the linear filter are the elements of the eigenvector which maximize the ratio. The utilization of the technique is demonstrated in its application to a simulated MR image sequence as well as to acquired MR image sequences of a normal and an abnormal brain. Index Terms: Magnetic resonance imaging, physics and instrumentation—Magnetic resonance imaging, techniques—Eigenimage filtering.

Imaging of inflammatory processes with labeled cells

Radionuclide techniques for localizing inflammatory processes had relied heavily upon 67Ga-citrate until McAfee and Thakur described the technique for the radiolabeling of leukocytes with 111In-oxine. Since their initial description in 1976 there has been continued development of the radiopharmaceutical, as well as clinical efficacy. At present 111In-labeled leukocytes continue to be handled as an investigational new drug but this has not greatly limited its clinical availability. Indium-111 leukocytes are the agent of choice for evaluation of patients with fever of unknown origin, osteomyelitis, and prosthetic graft infections; and preliminary data shows great promise in the area of detecting reoccurrence of inflammatory bowel disease. This article attempts to review currently accepted uses of 111In leukocytes as well as potential areas of application.

Detection of gastrointestinal bleeding with 99mTc-labeled red blood cells

Using a modified in vivo Tc-99M red cell labeling technique, gastrointestinal bleeding scintigraphy was performed in 100 patients with GI bleeding. Sixty-two patients with melena or bright red blood per rectum had positive scintiscans. In comparison to results of angiography, endoscopy, surgery and contrast radiography, radionuclide scintigraphy correctly located the site of bleeding in 83% of patients. The procedures could be performed over a 24 hr period which increased the sensitivity of the test since 85% of the scintiscans were positive at one hr or greater after the onset of imaging. The procedure was more sensitive than angiography in detecting sources of GI bleeding. We conclude that GI bleeding scintigraphy 99mTc-red cells in an accurate and effective method to detect upper and lower GI bleeding in patients with acute intermittent gastrointestinal bleeding.

Positron emission tomography scanning in the setting of post‐transplant lymphoproliferative disorders

Abstract:  Background:  Post‐transplant lymphoproliferative disorder (PTLD) is a serious complication of transplantation. We examined the role of positron emission tomography (PET) scanning in PTLD.

Water-fat MRI for assessing changes in bone marrow composition due to radiation and chemotherapy in gynecologic cancer patients.

To assess the feasibility of using fat‐fraction imaging for measuring marrow composition changes over large regions in patients undergoing cancer therapy.

2017 HRS expert consensus statement on magnetic resonance imaging and radiation exposure in patients with cardiovascular implantable electronic devices

Julia H. Indik, MD, PhD, FHRS, FACC, FAHA (Chair), J. Rod Gimbel, MD (Vice-Chair), Haruhiko Abe, MD,* Ricardo Alkmim-Teixeira, MD, PhD, Ulrika Birgersdotter-Green, MD, FHRS, Geoffrey D. Clarke, PhD, FACR, FAAPM,6,x Timm-Michael L. Dickfeld, MD, PhD, Jerry W. Froelich, MD, FACR,8,{ Jonathan Grant, MD, David L. Hayes, MD, FHRS, Hein Heidbuchel, MD, PhD, FESC,** Salim F. Idriss, MD, PhD, FHRS, FACC, Emanuel Kanal, MD, FACR, FISMRM, MRMD, Rachel Lampert, MD, FHRS, Christian E. Machado, MD, FHRS, CCDS, John M. Mandrola, MD, Saman Nazarian, MD, PhD, FHRS, Kristen K. Patton, MD, Marc A. Rozner, PhD, MD, CCDS, Robert J. Russo, MD, PhD, FACC, Win-Kuang Shen, MD, FHRS,21,xx Jerold S. Shinbane, MD, FHRS, Wee Siong Teo, MBBS (NUS), FRCP (Edin), FHRS,23,{{ William Uribe, MD, FHRS, Atul Verma, MD, FRCPC, FHRS, Bruce L. Wilkoff, MD, FHRS, CCDS, Pamela K. Woodard, MD, FACR, FAHA***

The appended curve technique for deconvolutional analysis method and validation

Deconvolutional analysis (DCA) is useful in correction of organ time activity curves (response function) for variations in blood activity (input function). Despite enthusiastic reports of applications of DCA in renal and cardiac scintigraphy, routine use has awaited an easily implemented algorithm which is insensitive to statistical noise. The matrix method suffers from the propagation of errors in early data points through the entire curve. Curve fitting or constraint methods require prior knowledge of the expected form of the results. DCA by Fourier transforms (FT) is less influenced by single data points but often suffers from high frequency artifacts which result from the abrupt termination of data acquisition at a nonzero value.To reduce this artifact, we extend the input (i) and response curves to three to five times the initial period of data acquisition (P) by appending a smooth low frequency curve with a gradual taper to zero. Satisfactory results have been obtained using a half cosine curve of length 2-3P. The FTs of the input and response I and R, are computed and R/I determined. The inverse FT is performed and the curve segment corresponding to the initial period of acquisition (P) is retained. We have validated this technique in a dog model by comparing the mean renal transit times of 131I-iodohippuran by direct renal artery injection to that calculated by deconvolution of an intravenous injection. The correlation was excellent (r=0.97, P0.005).The extension of the data curves by appending a low frequency “tail” before DCA reduces the data termination artifact. This method is rapid, simple, and easily implemented on a microcomputer. Excellent results have been obtained with clinical data.

Longitudinal assessment of bone loss from diagnostic computed tomography scans in gynecologic cancer patients treated with chemotherapy and radiation

OBJECTIVE The objective of the study was to measure the volumetric bone mineral density (vBMD) using diagnostic computed tomography scans in gynecologic oncology patients. STUDY DESIGN In a retrospective study, spine and femoral neck (FN) vBMD was measured for 1 year in 40 patients receiving chemotherapy or radiation. RESULTS There is significant bone loss after chemotherapy, radiation, and a combination of radiation and chemotherapy (P = .0211). In 1 year, the percent reduction in vBMD (±SE) at L1-L2 spine and the FN was a 15.9% (±5.67) and 10.4% (±4.06) in chemotherapy; 11% (±5.68) and 15.8% (±2.56) in radiation; and 21.0% (±7.03) and 3.6% (±3.3.7) in the combined therapy group. Bone loss was evident immediately after treatment and persisted or worsened in most women. CONCLUSION Gynecologic cancer patients treated with chemotherapy or radiation experience immediate and prolonged bone loss; thus, pre- and posttreatment monitoring of bone loss is important in these patients.