European Guidelines for AP/PA chest X-rays: routinely satisfiable in a paediatric radiology division?

OBJECTIVES: Accurate collimation helps to reduce unnecessary irradiation and improves radiographic image quality, which is especially important in the radiosensitive paediatric population. For AP/PA chest radiographs in children, a minimal field size (MinFS) from "just above the lung apices" to "T12/L1" with age-dependent tolerance is suggested by the 1996 European Commission (EC) guidelines, which were examined qualitatively and quantitatively at a paediatric radiology division. METHODS: Five hundred ninety-eight unprocessed chest X-rays (45% boys, 55% girls; mean age 3.9 years, range 0-18 years) were analysed with a self-developed tool. Qualitative standards were assessed based on the EC guidelines, as well as the overexposed field size and needlessly irradiated tissue compared to the MinFS. RESULTS: While qualitative guideline recommendations were satisfied, mean overexposure of +45.1 ± 18.9% (range +10.2% to +107.9%) and tissue overexposure of +33.3 ± 13.3% were found. Only 4% (26/598) of the examined X-rays completely fulfilled the EC guidelines. CONCLUSIONS: This study presents a new chest radiography quality control tool which allows assessment of field sizes, distances, overexposures and quality parameters based on the EC guidelines. Utilising this tool, we detected inadequate field sizes, inspiration depths, and patient positioning. Furthermore, some debatable EC guideline aspects were revealed. KEY POINTS: • European Guidelines on X-ray quality recommend exposed field sizes for common examinations. • The major failing in paediatric radiographic imaging techniques is inappropriate field size. • Optimal handling of radiographic units can reduce radiation exposure to paediatric patients. • Constant quality control helps ensure optimal chest radiographic image acquisition in children.

Is Embolization an Effective Treatment for Recurrent Hemorrhage After Hip or Knee Arthroplasty?

BACKGROUND: Spontaneous recurrent hemorrhage after arthroplasty of the hip or knee is a rare condition. In patients who do not have coagulopathy, the likeliest etiology for hemarthrosis is hypertrophic vascular synovium. Treatments include arthroscopic or open synovectomy, or angiography with embolization; however, because the condition is rare, seldom reported, and debilitating, small case series characterizing the efficacy of any approach are important to allow a collective experience with this condition to emerge. QUESTIONS/PURPOSES: We attempted to (1) determine whether angiography with embolization can prevent recurrent hemarthrosis after hip or knee arthroplasty in a small series of patients with or without coagulopathy, and (2) evaluate complications associated with this intervention. METHODS: Between 2005 and 2014, seven patients presented with spontaneous, recurrent hemarthroses. One patient had polycythemia vera and factor XIII deficiency as underlying illnesses. All patients were treated with selective transarterial embolization, and all had followup at a minimum of 12 months (range, 12-102 months; median, 74 months). Other treatments during this time included hematoma removals and flap operations in one patient, and indications for transarterial embolization included recurrent hemarthrosis. The patients included six men and one woman with a median age of 72 years (range, 61-78 years). Five patients underwent one or more reoperations before transarterial embolization. A diagnostic workup for coagulopathy was performed in all patients; one patient was identified to have polycythemia ruba vera and factor XIII deficiency, however the patient still was treated with transarterial embolization because it was perceived to be the least invasive of available options. No other patients had a diagnosis of coagulopathy. Angiography showed hypervascularity in all patients and a contrast agent showed extravasation in two. Selective transarterial embolization of branches of the internal iliac artery, common femoral artery, deep femoral artery, or the popliteal artery was performed with polyvinyl alcohol particles, microspheres, and/or coils. Patients were followed clinically during 12 to 102 months (median, 74 months) to determine whether the hemorrhages recurred. RESULTS: Technical success was achieved in all patients. No procedure-related complications were reported. On followup, recurrent hemorrhage was reported in one patient who had a diagnosis of coagulopathy before the procedure. He underwent three reinterventions and five reoperations. Three months after initial embolization, a flap procedure was performed. CONCLUSIONS: In a small series of patients with a minimum followup of 1 year, we found selective transarterial embolization to be effective in patients without underlying coagulopathy in preventing recurrences of spontaneous recurrent hematoma or hemarthrosis of the hip and the knee. This condition is rare, therefore comparative trials are unlikely to be done. Because transarterial embolization is relatively low risk and generally well tolerated, we consider it to be a reasonable approach for consideration with other options such as arthroscopic or open synovectomy and revision arthroplasty. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Large, segmental, circular vascular malformation of the small intestine (in a female toddler with hematochezia): unusual presentation in a child.

BACKGROUND: Failure to thrive and hematochezia in children may be alarm signs warranting endoscopy. In contrast, vascular malformations of the small intestine are uncommon in this age group. We report on a female toddler in whom various imaging techniques revealed an unusually large segmental vascular malformation of the ileum as the cause of the child's main clinical symptoms. CASE PRESENTATION: A 19 months old girl presented with severe anemia (Hb 3 mmol/l), failure to thrive and chronic diarrhea. Diagnostics for intestinal blood loss and pathogens were negative. The child had duodenoscopy, also for histological diagnosis of celiac disease, with negative results. A dietary protocol was suggestive for inadequate iron intake and she was supplemented. After symptomless four-months the child presented again, now with mild abdominal pain and, for the first time, hematochezia. An orienting abdominal ultrasound (US) study showed a suspicious tumorous bowel condition. A subsequent detailed abdominal US supplemented by a saline enema during investigation (i.e., "hydrocolon", to improve outlining of the formation's localization) revealed a large circumferential cystiform vascular mass of the ileum causing segmental ileal obstruction.Complementing preoperative abdominal hydro-MRI, planned based on the findings of the US study, confirmed the suspected vascular malformation of the ileum and exquisitely outlined the extent, location and anatomy.The patient was successfully operated laparoscopically, the affected ileum segment with the mass was completely removed as proven by histology, and the child recovered well. CONCLUSIONS: The huge segmental vascular malformation of the distal ileum described here is an extreme rarity in young children. Although the reported child's presenting symptoms malabsorption and malnutrition could have been responsible for its severe anemia, this was obviously caused by blood losses from the ileal vascular malformation. It was due to incipient abdominal pain rather than hematochezia that abdominal US was performed and proved crucial for correctly diagnosing this rare malformation. Even in this extensive case detailed imaging work-up including adapted MRI added all information necessary for minimal invasive laparoscopic en bloc resection.

Gadolinium-free MR in coarctation-can contrast-enhanced MR angiography be replaced?

OBJECTIVE: To determine the difference in vessel measurements, signal-to-noise ratio (SNR), and voxel size between contrast-enhanced and noncontrast magnetic resonance techniques in patients with coarctation of the aorta (CoA). MATERIALS AND METHODS: In 39 patients, vessel size, SNR, and voxel size were compared in cine magnetic resonance imaging (MRI), gadolinium-free magnetic resonance angiography (Gd-free MRA), and contrast-enhanced MRA (ce-MRA). RESULTS: There was no significant difference in measurement and SNR, but there was a significant difference in voxel size (P<.001). CONCLUSIONS: Our results show that, in CoA patients, monitoring of vessel size using cine MRI and Gd-free MRA is equivalent to ce-MRA while being less invasive.

The eternal tale of dialysis access vessels and restenosis: are drug-eluting balloons the solution?

In dialysis access fistulas and grafts, percutaneous transluminal angioplasty (PTA) is frequently followed by restenosis development, which results in repeated periodical re-interventions. The technique of drug-eluting balloon (DEB) angioplasty has shown promising results in the treatment of femoropopliteal arteriosclerotic lesions. In contrast to arteriosclerotic arteries, dialysis access vessels host unfavorable hemodynamics due to the direct conduction of high-pressure fluid into a low-pressure system. Hence, the beneficial effect of DEB angioplasty may be limited in this system. However, a first prospective randomized trial on 40 patients with arteriovenous fistula or graft stenoses exhibited a significantly higher 6-month primary patency of the treated lesions after DEB angioplasty than after uncoated balloon angioplasty. Despite such a positive reference, general recommendations regarding the value of DEBs in dialysis access vessels cannot be considered as serious unless large randomized controlled trials have been performed.

Placement of hemoparin-coated stents in the iliac arteries: early experience and midterm results in 28 patients.

PURPOSE: Aim was to determine immediate results and mid-term outcome of the hemoparin-coated (HC) stainless-steel stent (camouflage coating) in the treatment of occlusive lesions of the iliac arteries. MATERIALS AND METHODS: Twenty-eight patients were prospectively treated with the use of a HC stent between January 2007 and March 2010. Clinical examination and color-doppler ultrasound were performed at 1, 3, 6 and 12 months, CT angiography (CTA) or MR angiography (MRA) at 12 months. Indication for treatment was a high-grade stenosis of the common iliac and/or external iliac artery. RESULTS: Successful placement was achieved in all patients. Significant decrease in translesional pressure gradient (>10 mm Hg) was measured in 27 patients (96%). In one patient, proximal dissection occurred without flow limitation. A minor complication (small access site hematoma) occurred in one patient (4%). Two patients (7%) were lost to follow-up. After 12 months, stent patency in CTA, MRA and ultrasound was 100%. 20 patients (77%) experienced an initial improvement of at least one clinical stage. In one patient (4%), mild intimal hyperplasia without significant stenosis was observed. In three patients (12%), proximal or distal stenosis occurred. A non-significant increase of mean ankle-brachial index (ABI) after treatment was measured (0.85 ± 0.27 vs. 0.75 ± 0.22, respectively; p=0.328). CONCLUSIONS: The use of HC stents in patients with iliac artery occlusive disease may lead to a lower rate of intimal hyperplasia and thus to increased patency rates even in heavily calcified vessels. However, large-scale prospective trials have to be performed to evaluate the long-term patency rates of the HC coated stents.

The impact of iterative reconstruction on image quality and radiation dose in thoracic and abdominal CT.

PURPOSE: To compare the image quality and radiation dose between iterative reconstruction (IR) and standard filtered back projection (FBP) in CT of the chest and abdomen. MATERIALS AND METHODS: Thoracic CT was performed in 50 patients (38 male, 12 female; mean age, 51 ± 23 yrs; range, 7-85 yrs) and abdominal CT was performed in 50 patients (36 male, 14 female; mean age, 62 ± 13 yrs; range, 20-85 yrs), using IR as well as FBP for image reconstruction. Image noise was quantitatively assessed measuring standard deviation of Hounsfield Units (HU) in defined regions of interest in subcutaneous tissue. Scan length and Computed Tomography Dose Index (CTDI) were documented. Scan length, image noise, and CTDI of both reconstruction techniques were compared by using paired tests according to the nature of variables (McNemar test or Student t test). Overall subjective image quality and subjective image noise were compared. RESULTS: There was no significant difference between the protocols in terms of mean scan length (p>0.05). Image noise was statistically significantly higher with IR, although the difference was clinically insignificant (13.3 ± 3.0 HU and 13.6 ± 3.0 HU for thoracic CT and 11.5 ± 3.1 HU and 11.7 ± 3.0 HU for abdominal CT, p<0.05). There was no significant difference in overall subjective image quality and subjective image noise. The radiation dose was significantly lower with IR. Volume-weighted CTDI decreased by 64% (6.2 ± 2.5 mGy versus 17.1 ± 9.5 mGy, p<0.001) for thoracic CT and by 58% (7.8 ± 4.6 mGy versus 18.5 ± 8.6 mGy, p<0.001) for abdominal CT. CONCLUSIONS: Our study shows that in thoracic and abdominal CT with IR, there is no clinically significant impact on image quality, yet a significant radiation dose reduction compared to FBP.

Secondary aortic dissection after endoluminal treatment of an intramural hematoma of the thoracoabdominal aorta: endovascular extension with two stent grafts and scarce distal landing.

Secondary dissection in the descending aorta after endovascular therapy may demand subsequent interventional procedures. This can set a particularly significant challenge for the endovascular specialist. When implanting an aortic prosthesis, a sufficient contact between the covered segment and the healthy vessel wall is advisable. However, our case shows that, in individual cases, it is indeed efficient to place an aortic stent graft on top of the distal end of the dissection. This is proven by a three-year follow-up CT-angiography.