Imaging

The use of imaging techniques other than x-ray is not nearly as widespread for psoriatic arthritis as it is for rheumatoid arthritis, and there are no guidelines on their use in this disease, according to Dr. Philip G. Conaghan, professor of musculoskeletal medicine at the University of Leeds in England. “For the vast majority of clinicians, x-rays are still the first line of investigation.”

In part, the imaging approach is dictated by the subtype of psoriatic arthritis (PsA). For example, in the spondylitic subtype with axial involvement, the work-up would be similar to that for a patient with inflammatory back pain: x-rays of the sacroiliac joints, followed by MRI if necessary.

For peripheral PsA, x-rays of the hand joints would be performed first to detect erosions and evidence of new bone formation. “In the clear-cut patient, who's got a dactylitic digit, often imaging won't be required. You'll make a clinical diagnosis in those patients, especially if there's a history of psoriasis or nail pitting or other features that lead you to think this is a psoriatic arthritis,” he said.

There are considerably fewer data on MRI and ultrasound in PsA than in rheumatoid arthritis (RA), but “before there's any bone damage, there's soft tissue inflammation,” said Dr. Conaghan, cochair of the OMERACT (Outcome Measures in Rheumatology) MRI Inflammatory Arthritis Task Force. Imaging modalities like MRI and ultrasound that pick up soft tissue abnormalities earlier than x-ray may be more useful.

“What we see with PsA—being typically seronegative—is that a lot of that inflammation is more than just intra-articular synovitis, as we see in RA. You see a lot of extra-articular inflammation. So you find more tenosynovitis, more subcutaneous edema, and sometimes enthesitis,” said Dr. Conaghan, who contributed to the OMERACT rheumatoid arthritis MRI reference image atlas. “Both ultrasound and MRI have a role to play in managing this disease, depending on their availability at your center.” Both techniques are useful for identifying tenosynovitis and synovitis. Ultrasound allows physicians to pick up subcutaneous edema at lower levels than would be possible on a physical examination.

For MRI, sequences that pick up inflammation—gadolinium-enhanced or STIR sequences—are the most useful, said Dr. Conaghan. “For peripheral joint PsA, you could use patient-friendly extremity MRI. [Magnet strength] anywhere from 0.2 T up to 3 T could be used.”

Ultrasound and MRI are both sensitive to inflammation, but “the link between inflammation and joint damage has not been as strongly made for PsA as for RA,” Dr. Conaghan noted. Several groups are looking at clarifying this link. “Once that has been achieved, there will be more rationale for stamping out inflammation.” Researchers will need to do large randomized trials to see if the suppression of inflammation can slow structural disease progression, as it does in RA.

There are no guidelines for using MRI or ultrasound to diagnose and follow patients with PsA at the moment; current clinical practice relies on clinical markers. However, OMERACT is developing a scoring system for peripheral PsA. The largest challenge that the group faces is that “we just don't have a lot of MR data sets [on PsA] available for us to look at,” said Dr. Conaghan. “We welcome hearing from groups with such MRI sets.”

Several groups are working on scoring systems for enthesitis using both ultrasound and MRI. Some of this work will be updated at the European League Against Rheumatism congress this summer. Work on evaluating MRI for the assessment of PsA is also ongoing, but these large imaging datasets are at least 1-2 years down the road. The OMERACT scoring system may be ready for validation in the next year.

Another problem with developing imaging guidelines for PsA is that disease involvement may be much more sporadic. “So you have fewer joints to evaluate per person, meaning that you might need larger datasets to show change.”

Ultrasound and MRI are likely to be used in the future in the drug development process to show effectiveness of investigational drugs over time.

MRI with gadolinium contrast reveals dactylitis in the toe of this patient. Courtesy Dr. Philip Helliwell and Dr. Clare Groves

The use of imaging techniques other than x-ray is not nearly as widespread for psoriatic arthritis as it is for rheumatoid arthritis, and there are no guidelines on their use in this disease, according to Dr. Philip G. Conaghan, professor of musculoskeletal medicine at the University of Leeds in England. “For the vast majority of clinicians, x-rays are still the first line of investigation.”

In part, the imaging approach is dictated by the subtype of psoriatic arthritis (PsA). For example, in the spondylitic subtype with axial involvement, the work-up would be similar to that for a patient with inflammatory back pain: x-rays of the sacroiliac joints, followed by MRI if necessary.

For peripheral PsA, x-rays of the hand joints would be performed first to detect erosions and evidence of new bone formation. “In the clear-cut patient, who's got a dactylitic digit, often imaging won't be required. You'll make a clinical diagnosis in those patients, especially if there's a history of psoriasis or nail pitting or other features that lead you to think this is a psoriatic arthritis,” he said.

There are considerably fewer data on MRI and ultrasound in PsA than in rheumatoid arthritis (RA), but “before there's any bone damage, there's soft tissue inflammation,” said Dr. Conaghan, cochair of the OMERACT (Outcome Measures in Rheumatology) MRI Inflammatory Arthritis Task Force. Imaging modalities like MRI and ultrasound that pick up soft tissue abnormalities earlier than x-ray may be more useful.

“What we see with PsA—being typically seronegative—is that a lot of that inflammation is more than just intra-articular synovitis, as we see in RA. You see a lot of extra-articular inflammation. So you find more tenosynovitis, more subcutaneous edema, and sometimes enthesitis,” said Dr. Conaghan, who contributed to the OMERACT rheumatoid arthritis MRI reference image atlas. “Both ultrasound and MRI have a role to play in managing this disease, depending on their availability at your center.” Both techniques are useful for identifying tenosynovitis and synovitis. Ultrasound allows physicians to pick up subcutaneous edema at lower levels than would be possible on a physical examination.

For MRI, sequences that pick up inflammation—gadolinium-enhanced or STIR sequences—are the most useful, said Dr. Conaghan. “For peripheral joint PsA, you could use patient-friendly extremity MRI. [Magnet strength] anywhere from 0.2 T up to 3 T could be used.”

Ultrasound and MRI are both sensitive to inflammation, but “the link between inflammation and joint damage has not been as strongly made for PsA as for RA,” Dr. Conaghan noted. Several groups are looking at clarifying this link. “Once that has been achieved, there will be more rationale for stamping out inflammation.” Researchers will need to do large randomized trials to see if the suppression of inflammation can slow structural disease progression, as it does in RA.

There are no guidelines for using MRI or ultrasound to diagnose and follow patients with PsA at the moment; current clinical practice relies on clinical markers. However, OMERACT is developing a scoring system for peripheral PsA. The largest challenge that the group faces is that “we just don't have a lot of MR data sets [on PsA] available for us to look at,” said Dr. Conaghan. “We welcome hearing from groups with such MRI sets.”

Several groups are working on scoring systems for enthesitis using both ultrasound and MRI. Some of this work will be updated at the European League Against Rheumatism congress this summer. Work on evaluating MRI for the assessment of PsA is also ongoing, but these large imaging datasets are at least 1-2 years down the road. The OMERACT scoring system may be ready for validation in the next year.

Another problem with developing imaging guidelines for PsA is that disease involvement may be much more sporadic. “So you have fewer joints to evaluate per person, meaning that you might need larger datasets to show change.”

Ultrasound and MRI are likely to be used in the future in the drug development process to show effectiveness of investigational drugs over time.

MRI with gadolinium contrast reveals dactylitis in the toe of this patient. Courtesy Dr. Philip Helliwell and Dr. Clare Groves

The use of imaging techniques other than x-ray is not nearly as widespread for psoriatic arthritis as it is for rheumatoid arthritis, and there are no guidelines on their use in this disease, according to Dr. Philip G. Conaghan, professor of musculoskeletal medicine at the University of Leeds in England. “For the vast majority of clinicians, x-rays are still the first line of investigation.”

In part, the imaging approach is dictated by the subtype of psoriatic arthritis (PsA). For example, in the spondylitic subtype with axial involvement, the work-up would be similar to that for a patient with inflammatory back pain: x-rays of the sacroiliac joints, followed by MRI if necessary.

For peripheral PsA, x-rays of the hand joints would be performed first to detect erosions and evidence of new bone formation. “In the clear-cut patient, who's got a dactylitic digit, often imaging won't be required. You'll make a clinical diagnosis in those patients, especially if there's a history of psoriasis or nail pitting or other features that lead you to think this is a psoriatic arthritis,” he said.

There are considerably fewer data on MRI and ultrasound in PsA than in rheumatoid arthritis (RA), but “before there's any bone damage, there's soft tissue inflammation,” said Dr. Conaghan, cochair of the OMERACT (Outcome Measures in Rheumatology) MRI Inflammatory Arthritis Task Force. Imaging modalities like MRI and ultrasound that pick up soft tissue abnormalities earlier than x-ray may be more useful.

“What we see with PsA—being typically seronegative—is that a lot of that inflammation is more than just intra-articular synovitis, as we see in RA. You see a lot of extra-articular inflammation. So you find more tenosynovitis, more subcutaneous edema, and sometimes enthesitis,” said Dr. Conaghan, who contributed to the OMERACT rheumatoid arthritis MRI reference image atlas. “Both ultrasound and MRI have a role to play in managing this disease, depending on their availability at your center.” Both techniques are useful for identifying tenosynovitis and synovitis. Ultrasound allows physicians to pick up subcutaneous edema at lower levels than would be possible on a physical examination.

For MRI, sequences that pick up inflammation—gadolinium-enhanced or STIR sequences—are the most useful, said Dr. Conaghan. “For peripheral joint PsA, you could use patient-friendly extremity MRI. [Magnet strength] anywhere from 0.2 T up to 3 T could be used.”

Ultrasound and MRI are both sensitive to inflammation, but “the link between inflammation and joint damage has not been as strongly made for PsA as for RA,” Dr. Conaghan noted. Several groups are looking at clarifying this link. “Once that has been achieved, there will be more rationale for stamping out inflammation.” Researchers will need to do large randomized trials to see if the suppression of inflammation can slow structural disease progression, as it does in RA.

There are no guidelines for using MRI or ultrasound to diagnose and follow patients with PsA at the moment; current clinical practice relies on clinical markers. However, OMERACT is developing a scoring system for peripheral PsA. The largest challenge that the group faces is that “we just don't have a lot of MR data sets [on PsA] available for us to look at,” said Dr. Conaghan. “We welcome hearing from groups with such MRI sets.”

Several groups are working on scoring systems for enthesitis using both ultrasound and MRI. Some of this work will be updated at the European League Against Rheumatism congress this summer. Work on evaluating MRI for the assessment of PsA is also ongoing, but these large imaging datasets are at least 1-2 years down the road. The OMERACT scoring system may be ready for validation in the next year.

Another problem with developing imaging guidelines for PsA is that disease involvement may be much more sporadic. “So you have fewer joints to evaluate per person, meaning that you might need larger datasets to show change.”

Ultrasound and MRI are likely to be used in the future in the drug development process to show effectiveness of investigational drugs over time.

MRI with gadolinium contrast reveals dactylitis in the toe of this patient. Courtesy Dr. Philip Helliwell and Dr. Clare Groves

To the Editor: I would like to comment on the excellent review article on barium esophagography by Drs. Allen, Baker, and Falk in your February 2009 issue. In their opening clinical vignette, they describe a 55-year-old female patient with gastroesophageal reflux disease (GERD) and slowly worsening dysphagia for solids. The patient was sent for barium esophagography, which disclosed an obstructing mucosal ring in the distal esophagus. The patient was then sent for endoscopy so that the ring could be treated with dilation. The authors present this case as an example of the type of patient who could obtain benefit from barium esophagography as the initial study. I disagree. In this patient’s case, the barium procedure accomplished nothing, but it did unnecessarily cost the patient money, time, and radiation exposure. The patient would have been better served by being sent directly for endoscopy at the start of her workup, so that her condition could be diagnosed and treated with a single procedure. In her case, this would have spared her any need for the barium procedure. I believe that patients with dysphagia and GERD are best served by initial endoscopy, since GERD is associated with esophageal strictures, dysplasia, and cancer. Barium esophagography can be reserved for those who have had a normal or nondiagnostic endoscopy. For example, a patient with dysphagia and a normal endoscopy might then be sent for esophagography to diagnose a motility disorder.

To the Editor: I would like to comment on the excellent review article on barium esophagography by Drs. Allen, Baker, and Falk in your February 2009 issue. In their opening clinical vignette, they describe a 55-year-old female patient with gastroesophageal reflux disease (GERD) and slowly worsening dysphagia for solids. The patient was sent for barium esophagography, which disclosed an obstructing mucosal ring in the distal esophagus. The patient was then sent for endoscopy so that the ring could be treated with dilation. The authors present this case as an example of the type of patient who could obtain benefit from barium esophagography as the initial study. I disagree. In this patient’s case, the barium procedure accomplished nothing, but it did unnecessarily cost the patient money, time, and radiation exposure. The patient would have been better served by being sent directly for endoscopy at the start of her workup, so that her condition could be diagnosed and treated with a single procedure. In her case, this would have spared her any need for the barium procedure. I believe that patients with dysphagia and GERD are best served by initial endoscopy, since GERD is associated with esophageal strictures, dysplasia, and cancer. Barium esophagography can be reserved for those who have had a normal or nondiagnostic endoscopy. For example, a patient with dysphagia and a normal endoscopy might then be sent for esophagography to diagnose a motility disorder.

To the Editor: I would like to comment on the excellent review article on barium esophagography by Drs. Allen, Baker, and Falk in your February 2009 issue. In their opening clinical vignette, they describe a 55-year-old female patient with gastroesophageal reflux disease (GERD) and slowly worsening dysphagia for solids. The patient was sent for barium esophagography, which disclosed an obstructing mucosal ring in the distal esophagus. The patient was then sent for endoscopy so that the ring could be treated with dilation. The authors present this case as an example of the type of patient who could obtain benefit from barium esophagography as the initial study. I disagree. In this patient’s case, the barium procedure accomplished nothing, but it did unnecessarily cost the patient money, time, and radiation exposure. The patient would have been better served by being sent directly for endoscopy at the start of her workup, so that her condition could be diagnosed and treated with a single procedure. In her case, this would have spared her any need for the barium procedure. I believe that patients with dysphagia and GERD are best served by initial endoscopy, since GERD is associated with esophageal strictures, dysplasia, and cancer. Barium esophagography can be reserved for those who have had a normal or nondiagnostic endoscopy. For example, a patient with dysphagia and a normal endoscopy might then be sent for esophagography to diagnose a motility disorder.

To eliminate any risk of skin burns, transdermal medication patches should be removed before patients undergo magnetic resonance imaging scans, the Food and Drug Administration advises.

Prompted by less than half a dozen reports of burns associated with patches that contain trace amounts of aluminum or other metals, the FDA issued a public health advisory in March. The burns, reported in nicotine patches, have been described as similar to a “serious sunburn,” Dr. Sandra Kweder, deputy director of the FDA's Office of New Drugs, said during a telebriefing.

The advisory applies to all patches, even those without metals, because not all patches carry a warning about the risk, and metal may not be visible. Clinicians should instruct patients about when to remove patches before procedures and about replacing them afterward, the advisory said.

About 60 medicated patches are on the market. Uses include smoking cessation, contraception, hormone therapy, and pain treatment.

More than 25% of them contain metal, Dr. Kweder said. Even transparent patches may contain metals.

The FDA is reviewing the labeling and composition of all transdermal medication patches, and is working with manufacturers to improve labeling, which could include some type of warning on the patch.

The advisory is available online at www.fda.gov/medwatch/safety/2009/safety09.htm#Transdermal

To eliminate any risk of skin burns, transdermal medication patches should be removed before patients undergo magnetic resonance imaging scans, the Food and Drug Administration advises.

Prompted by less than half a dozen reports of burns associated with patches that contain trace amounts of aluminum or other metals, the FDA issued a public health advisory in March. The burns, reported in nicotine patches, have been described as similar to a “serious sunburn,” Dr. Sandra Kweder, deputy director of the FDA's Office of New Drugs, said during a telebriefing.

The advisory applies to all patches, even those without metals, because not all patches carry a warning about the risk, and metal may not be visible. Clinicians should instruct patients about when to remove patches before procedures and about replacing them afterward, the advisory said.

About 60 medicated patches are on the market. Uses include smoking cessation, contraception, hormone therapy, and pain treatment.

More than 25% of them contain metal, Dr. Kweder said. Even transparent patches may contain metals.

The FDA is reviewing the labeling and composition of all transdermal medication patches, and is working with manufacturers to improve labeling, which could include some type of warning on the patch.

The advisory is available online at www.fda.gov/medwatch/safety/2009/safety09.htm#Transdermal

To eliminate any risk of skin burns, transdermal medication patches should be removed before patients undergo magnetic resonance imaging scans, the Food and Drug Administration advises.

Prompted by less than half a dozen reports of burns associated with patches that contain trace amounts of aluminum or other metals, the FDA issued a public health advisory in March. The burns, reported in nicotine patches, have been described as similar to a “serious sunburn,” Dr. Sandra Kweder, deputy director of the FDA's Office of New Drugs, said during a telebriefing.

The advisory applies to all patches, even those without metals, because not all patches carry a warning about the risk, and metal may not be visible. Clinicians should instruct patients about when to remove patches before procedures and about replacing them afterward, the advisory said.

About 60 medicated patches are on the market. Uses include smoking cessation, contraception, hormone therapy, and pain treatment.

More than 25% of them contain metal, Dr. Kweder said. Even transparent patches may contain metals.

The FDA is reviewing the labeling and composition of all transdermal medication patches, and is working with manufacturers to improve labeling, which could include some type of warning on the patch.

The advisory is available online at www.fda.gov/medwatch/safety/2009/safety09.htm#Transdermal

HOLLYWOOD, FLA. — Flat-panel detector systems have made it possible to perform angiography with a quarter of the contrast media routinely used with conventional image intensifiers.

“Flat-panel systems represent a huge evolution in angiographic technology,” Dr. Timothy W. Clark said at ISET 2009, an international symposium on endovascular therapy. “Much less contrast is needed to generate the same image quality as conventional image intensifiers, and because image production is more efficient, there is less radiation exposure to patients” and staff, said Dr. Clark, chief of vascular and interventional radiology at New York University. The reduction cuts the risk for contrast-induced nephropathy.

Flat panels offer a “dramatically wider dynamic range across all soft tissue anatomy, a larger field of view, homogeneous and distortion-free images, and improved detector efficiency,” he said. These features improve visualization, despite less contrast and a lower radiation dose. Unlike conventional image intensifiers, they do not involve an analog conversion, there is no geometric distortion, and there is no lateral dispersion of light to reduce image sharpness. Flat panels are less bulky and allow for greater freedom of movement.

With a flat-panel detector, Dr. Clark uses iodinated contrast diluted to 25%.

The degree of dilution depends on the contrast resolution of the flat-panel system.

For renal arteriograms, he said he has produced excellent images using a total contrast volume of 7 mL. For renal stenting, he uses 15 mL. For a popliteal chronic total occlusion, he uses a total volume of 25 mL, and for an iliac chronic total occlusion, he uses 32 mL of contrast.

“We use amazingly small volumes of contrast and still get high-resolution images,” said Dr. Clark, who does not have financial relationships with the companies that make flat-panel detectors.

One caveat regarding the use of diluted contrast is that the fluid must be power injected so it can displace the blood within the imaged vessels, he said.

HOLLYWOOD, FLA. — Flat-panel detector systems have made it possible to perform angiography with a quarter of the contrast media routinely used with conventional image intensifiers.

“Flat-panel systems represent a huge evolution in angiographic technology,” Dr. Timothy W. Clark said at ISET 2009, an international symposium on endovascular therapy. “Much less contrast is needed to generate the same image quality as conventional image intensifiers, and because image production is more efficient, there is less radiation exposure to patients” and staff, said Dr. Clark, chief of vascular and interventional radiology at New York University. The reduction cuts the risk for contrast-induced nephropathy.

Flat panels offer a “dramatically wider dynamic range across all soft tissue anatomy, a larger field of view, homogeneous and distortion-free images, and improved detector efficiency,” he said. These features improve visualization, despite less contrast and a lower radiation dose. Unlike conventional image intensifiers, they do not involve an analog conversion, there is no geometric distortion, and there is no lateral dispersion of light to reduce image sharpness. Flat panels are less bulky and allow for greater freedom of movement.

With a flat-panel detector, Dr. Clark uses iodinated contrast diluted to 25%.

The degree of dilution depends on the contrast resolution of the flat-panel system.

For renal arteriograms, he said he has produced excellent images using a total contrast volume of 7 mL. For renal stenting, he uses 15 mL. For a popliteal chronic total occlusion, he uses a total volume of 25 mL, and for an iliac chronic total occlusion, he uses 32 mL of contrast.

“We use amazingly small volumes of contrast and still get high-resolution images,” said Dr. Clark, who does not have financial relationships with the companies that make flat-panel detectors.

One caveat regarding the use of diluted contrast is that the fluid must be power injected so it can displace the blood within the imaged vessels, he said.

HOLLYWOOD, FLA. — Flat-panel detector systems have made it possible to perform angiography with a quarter of the contrast media routinely used with conventional image intensifiers.

“Flat-panel systems represent a huge evolution in angiographic technology,” Dr. Timothy W. Clark said at ISET 2009, an international symposium on endovascular therapy. “Much less contrast is needed to generate the same image quality as conventional image intensifiers, and because image production is more efficient, there is less radiation exposure to patients” and staff, said Dr. Clark, chief of vascular and interventional radiology at New York University. The reduction cuts the risk for contrast-induced nephropathy.

Flat panels offer a “dramatically wider dynamic range across all soft tissue anatomy, a larger field of view, homogeneous and distortion-free images, and improved detector efficiency,” he said. These features improve visualization, despite less contrast and a lower radiation dose. Unlike conventional image intensifiers, they do not involve an analog conversion, there is no geometric distortion, and there is no lateral dispersion of light to reduce image sharpness. Flat panels are less bulky and allow for greater freedom of movement.

With a flat-panel detector, Dr. Clark uses iodinated contrast diluted to 25%.

The degree of dilution depends on the contrast resolution of the flat-panel system.

For renal arteriograms, he said he has produced excellent images using a total contrast volume of 7 mL. For renal stenting, he uses 15 mL. For a popliteal chronic total occlusion, he uses a total volume of 25 mL, and for an iliac chronic total occlusion, he uses 32 mL of contrast.

“We use amazingly small volumes of contrast and still get high-resolution images,” said Dr. Clark, who does not have financial relationships with the companies that make flat-panel detectors.

One caveat regarding the use of diluted contrast is that the fluid must be power injected so it can displace the blood within the imaged vessels, he said.